Suchergebnisse

We thank the anonymous referee for the very useful comments, which contributed to improve the manuscript. AF is partially supported by the PRIN-INAF 2017 with the project Towards the SKA and CTA era: discovery, localisation, and physics of transients sources (P.I. M. Giroletti). These observations made use of the LCO network. DAH, CP, DH, and JB are supported by NSF Grant AST1911225 and NASA Grant 80NSSC19k1639. TMB was funded by the CONICYT PFCHA/DOCTORADOBECAS CHILE/201772180113. MG is supported by the Polish NCN MAESTRO grant 2014/14/A/ST9/00121. TWC acknowledges the funding provided by the Alexander von Humboldt Foundation and the EU Funding under Marie Sklodowska-Curie grant agreement No 842471, and Thomas Kruhler for reducing X-Shooter spectrum. LG was funded by the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 839090. This work has been partially supported by the Spanish grant PGC2018-095317-B-C21 within the European Funds for Regional Development (FEDER). CPG acknowledges support from EU/FP7ERC grant no. [615929]. GL was supported by a research grant (19054) from VILLUM FONDEN. MN is supported by a Royal Astronomical Society Research Fellowship. RL is supported by a Marie Sklodowska-Curie Individual Fellowship within the Horizon 2020 European Union (EU) Framework Programme for Research and Innovation (H2020-MSCA-IF-2017-794467). GT acknowledges partial support by the National Science Foundation under Award No. AST-1909796. Research by SV is supported by NSF grants AST-1813176 and AST-2008108. Some of the observations reported here were obtained at the MMT Observatory, a joint facility of the University of Arizona and the Smithsonian Institution under program 2018A-UAO-G16 (PI Terreran). Some of the data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration under program NW440 (PI Fong). The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Maunakea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain. W. M. Keck Observatory and MMT Observatory accesswas supported by Northwestern University and the Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA). Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere under ESO programmes 199.D-0143, 0100.D-0751(B), 0101.D-0199(B), 099.A-9025(A), 0100.A-9099(A)099.A-9099 and 0100.A-9099. This work makes use of observations from the LCO network. Part of the funding for GROND (both hardware as well as personnel) was generously granted from the Leibniz-Prize to Prof. G. Hasinger (DFG grant HA 1850/28-1). The Pan-STARRS1 Surveys (PS1) have been made possible through contributions of the Institute for Astronomy, the University of Hawaii, the Pan-STARRS Project Office, the Max-Planck Society and its participating institutes, the Max Planck Institute for Astronomy, Heidelberg, and the Max Planck Institute for Extraterrestrial Physics, Garching, The Johns Hopkins University, Durham University, the University of Edinburgh, Queen's University Belfast, the Harvard-Smithsonian Center for Astrophysics, the Las Cumbres Observatory Global Telescope Network Incorporated, the National Central University of Taiwan, the Space Telescope Science Institute, the National Aeronautics and Space Administration Grants No.s NNX08AR22G, NNX12AR65G, and NNX14AM74G, the National Science Foundation under Grant No. AST-1238877, the University of Maryland, Eotvos Lorand University (ELTE), the Los Alamos National Laboratory and the Gordon and Betty Moore foundation. TheATLAS surveys are funded through NASA grants NNX12AR55G. This work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, https://www.cosmos.esa.int/web/gaia/dpac/consortium).Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. This research made use of TARDIS, a community-developed software package for spectral synthesis in supernovae (Kerzendorf & Sim 2014). The development of TARDIS received support from the Google Summer of Code initiative and from ESA's Summer of Code in Space program. TARDIS makes extensive use of Astropy and PyNE. ; This article has been accepted for publication in MNRAS published by Oxford University Press on behalf of the Royal Astronomical Society ; We present and discuss the optical spectrophotometric observations of the nearby (z = 0.087) Type I superluminous supernova (SLSN I) SN 2017gci, whose peak K-corrected absolute magnitude reaches M-g = -21.5 mag. Its photometric and spectroscopic evolution includes features of both slow- and of fast-evolving SLSN I, thus favoring a continuum distribution between the two SLSN-I subclasses. In particular, similarly to other SLSNe I, the multiband light curves (LCs) of SN 2017gci show two re-brightenings at about 103 and 142 d after the maximum light. Interestingly, this broadly agrees with a broad emission feature emerging around 6520 angstrom after similar to 51 d from the maximum light, which is followed by a sharp knee in the LC. If we interpret this feature as H alpha, this could support the fact that the bumps are the signature of late interactions of the ejecta with a (hydrogen-rich) circumstellar material. Then we fitted magnetar- and CSM-interaction-powered synthetic LCs on to the bolometric one of SN 2017gci. In the magnetar case, the fit suggests a polar magnetic field B-p similar or equal to 6 x 10(14) G, an initial period of the magnetar P-initial similar or equal to 2.8 ms, an ejecta mass M-ejecta similar or equal to 9M(circle dot) and an ejecta opacity kappa similar or equal to 0.08 cm(2) g(-1). A CSM-interaction scenario would imply a CSM mass similar or equal to 5 M-circle dot and an ejecta mass similar or equal to 12M(circle dot). Finally, the nebular spectrum of phase + 187 d was modeled, deriving a mass of similar or equal to 10 M-circle dot for the ejecta. Our models suggest that either a magnetar or CSM interaction might be the power sources for SN 2017gci and that its progenitor was a massive (40 M-circle dot) star. ; PRIN-INAF 2017 ; National Science Foundation (NSF) AST1911225 AST-1813176 AST-2008108 ; CONICYT PFCHA/DOCTORADOBECAS CHILE/2017 72180113 ; Polish NCN MAESTRO 2014/14/A/ST9/00121 ; Alexander von Humboldt Foundation ; European Commission 842471 ; European Commission 839090 ; European Commission PGC2018-095317-B-C21 ; VILLUM FONDEN 19054 ; Royal Astronomical Society Research Fellowship ; Marie Sklodowska-Curie Individual Fellowship within the Horizon 2020 European Union (EU) Framework Programme for Research and Innovation H2020-MSCA-IF-2017-794467 ; National Science Foundation (NSF) AST-1909796 AST-1238877 ; University of Arizona 2018A-UAO-G16 ; Smithsonian Institution 2018A-UAO-G16 ; National Aeronautics & Space Administration (NASA) NW440 NNX08AR22G NNX12AR65G NNX14AM74G ; W.M. Keck Foundation ; Northwestern University ; Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA) ; European Organisation for Astronomical Research in the Southern Hemisphere 199.D-0143 0100.D-0751(B) 0101.D-0199(B) 099.A-9025(A) 0100.A-9099(A)099.A-9099 0100.A-9099 ; German Research Foundation (DFG) ; European Commission HA 1850/28-1 ; National Aeronautics & Space Administration (NASA) NNX12AR55G 80NSSC19k1639 ; Google Summer of Code initiative ; ESA's Summer of Code in Space program ; European Commission 615929

S.J. Prentice is supported by H2020 ERC grant no. 758638. J.J. Teffs is funded by the consolidated STFC grant no. R27610. This paper is based in part on observations collected at the European Southern Observatory (ESO) under ESO programme 1103.D-0328(J). T.W. Chen acknowledges the European Union Funding under Marie Sklodowska-Curie grant no. H2020-MSCA-IF-2018-842471. L. Galbanywas funded by the European Union'sHorizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant no. 839090. This work has been partially supported by the Spanish grant no. PGC2018-095317-B-C21 within the European Funds for Regional Development (FEDER). M. Gromadzki is supported by the Polish National Science Center (NCN) MAESTRO grant no. 2014/14/A/ST9/00121. T. M uller-Bravo was funded by the CONICYT PFCHA/DOCTORADOBECAS CHILE/2017-72180113. M. Nicholl is supported by a Royal Astronomical Society Research Fellowship. Thiswork makes use of observations obtained by the Las Cumbres Observatory global telescope network. The LCO team is supported by NSF grant nos AST-1911225 and AST-1911151. Based in part on observations made with the Liverpool Telescope operated on the island of La Palma by Liverpool John Moores University in the Spanish Observatorio del Roque de los Muchachos of the Institutode Astrofisica de Canarias with financial support from the UK Science and Technology Facilities Council. The data presented here were obtained in part with ALFOSC, which is provided by the Instituto de As-trofisica de Andalucia (IAA) under a joint agreement with the University of Copenhagen and NOTSA, with observation having been made with the Nordic Optical Telescope, operated at the Observatorio del Roque de los Muchachos, La Palma, Spain, of the Instituto de Astrofisica de Canarias. This work has made use of data from the Asteroid Terrestrial-impact Last Alert System (ATLAS) project. ATLAS is primarily funded to search for near earth asteroids through NASA grant nos NN12AR55G, 80NSSC18K0284, and 80NSSC18K1575; by-products of the NEO search include images and catalogues from the survey area. The ATLAS science products have been made possible through the contributions of the University of Hawaii Institute for Astronomy, the Queen's University Belfast, and the Space Telescope Science Institute. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile, as part of ePESSTO+(the advanced Public ESO Spectroscopic Survey for Transient Objects Survey). ePESSTO + observations were obtained under ESO programme ID 1103.D-0328 (PI: Inserra). LCO data have been obtained via OPTICON proposals (IDs: SUPA2020B-002 SUPA2020A-001 OPTICON 20A/015 and OPTICON 20B/003). The OPTICON project has received funding from the European Union's Horizon 2020 research and innovation programme under grant no. 730890. ; Stripped-envelope supernovae (SE-SNe) show a wide variety of photometric and spectroscopic properties. This is due to the different potential formation channels and the stripping mechanism that allows for a large diversity within the progenitors outer envelope compositions. Here, the photometric and spectroscopic observations of SN 2020cpg covering ∼130 d from the explosion date are presented. SN 2020cpg (z = 0.037) is a bright SE-SNe with the B-band peaking at MB = −17.75 ± 0.39 mag and a maximum pseudo-bolometric luminosity of Lmax = 6.03 ± 0.01 × 1042 erg s−1. Spectroscopically, SN2020cpg displays a weak high- and low-velocity H α feature during the photospheric phase of its evolution, suggesting that it contained a detached hydrogen envelope prior to explosion. From comparisons with spectral models, the mass of hydrogen within the outer envelope was constrained to be ∼0.1 M . From the pseudo-bolometric light curve of SN 2020cpg a 56Ni mass of MNi ∼ 0.27 ± 0.08M was determined using an Arnett-like model. The ejecta mass and kinetic energy of SN 2020cpg were determined using an alternative method that compares the light curve of SN 2020cpg and several modelled SE-SNe, resulting in an ejecta mass of Mejc ∼ 5.5 ± 2.0 M and a kinetic energy of EK ∼ 9.0 ± 3.0 × 1051 erg. The ejected mass indicates a progenitor mass of 18−25 M . The use of the comparative light curve method provides an alternative process to the commonly used Arnett-like model to determine the physical properties of SE-SNe. ; H2020 ERC 758638 ; UK Research & Innovation (UKRI) ; Science & Technology Facilities Council (STFC) R27610 ; European Southern Observatory (ESO) 1103.D-0328(J) ; European Commission H2020-MSCA-IF-2018-842471 839090 730890 PGC2018-095317-B-C21 ; Polish National Science Center (NCN) MAESTRO 2014/14/A/ST9/00121 ; CONICYT PFCHA/DOCTORADOBECAS CHILE/2017-72180113 ; Royal Astronomical Society Research Fellowship ; National Science Foundation (NSF) AST-1911225 AST-1911151 ; UK Research & Innovation (UKRI) ; Science & Technology Facilities Council (STFC) ; National Aeronautics & Space Administration (NASA) NN12AR55G 80NSSC18K0284 80NSSC18K1575 ; ESO programme 1103.D-0328

Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile, as part of ePESSTO/ePESSTO+ (the extended Public ESO Spectroscopic Survey for Transient Objects Survey). ePESSTO+ observations were obtained under ESO program ID 1103.D-0328 (PI: Inserra). EP would like to thank Stuart Sim for useful discussion on the working of TARDIS. This research made use of TARDIS, a community-developed software package for spectral synthesis in supernovae (Kerzendorf & Sim 2014; Kerzendorf et al. 2019). The development of TARDIS received support from the Google Summer of Code initiative and from the European Space Agency's (ESA) Summer of Code in Space program. TARDIS makes extensive use ofAstropy and PyNE. TWC acknowledges the funding provided by the Alexander von Humboldt Foundation and the EUFunding underMarie SklodowskaCurie grant H2020-MSCA-IF-2018-842471. TMBwas funded by the Comisi ' on Nacional de Investigaci ' on Cient ' ifica y Tecnol ' ogica (CONICYT) PFCHA/DOCTORADOBECAS CHILE/2017-72180113. MG is supported by the Polish Narodowe Centrum Nauki (NCN) MAESTRO grant 2014/14/A/ST9/00121. MN is supported by a Royal Astronomical Society Research Fellowship. ACK: LG was funded by the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 839090. This work has been partially supported by the Spanish grant PGC2018-095317-B-C21 within the European Funds for Regional Development (FEDER). GL is supported by a research grant (19054) from VILLUM FONDEN This work makes use of observations from the Las Cumbres Observatory (LCO) global telescope network. The LCO team is supported by National Science Foundation (NSF) grants AST1911225, AST-1911151, and NASA grant 80NSSC19K1639. This paper is also based on observations made with Swift (UVOT) and the Liverpool Telescope (LT). The Liverpool Telescope is operated on the island of La Palma by Liverpool John Moores University in the Spanish Observatorio del Roque de losMuchachos of the Instituto de Astrofisica de Canarias with financial support from the UK Science and Technology Facilities Council (STFC). LCO data have been obtained via Optical Infrared Co-ordination Network for Astronomy (OPTICON) proposals (IDs: SUPA2020B-002 OPTICON 20B/003 and SUPA2019B-007 OPTICON 19B-009). The OPTICON project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 730890. Thiswork hasmade use of data from the AsteroidTerrestrialimpact Last Alert System (ATLAS) project. The ATLAS project is primarily funded to search for near earth asteroids through NASA grants NN12AR55G, 80NSSC18K0284, and 80NSSC18K1575; byproducts of the Near-Earth Object (NEO) search include images and catalogs from the survey area. This work was partially funded by Kepler/K2 grant J1944/80NSSC19K0112 and HST GO-15889, and STFC grants ST/T000198/1 and ST/S006109/1. The ATLAS science products have been made possible through the contributions of the University of Hawaii Institute for Astronomy, the Queen's University Belfast, the Space Telescope Science Institute, the South African Astronomical Observatory, and The Millennium Institute of Astrophysics (MAS), Chile. This work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, https://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. Based on observations obtained at the Southern Astrophysical Research (SOAR) telescope, which is a joint project of the Minist ' erio da Ciencia, Tecnologia e Inovaces (MCTI/LNA) do Brasil, the US National Science Foundation`s NOIRLab, the University of North Carolina at Chapel Hill (UNC), and Michigan State University (MSU). This work has made use of data from the Gamma-ray Burst Optical/Near-infrared Detector (GROND) instrument at the 2.2 MPE telescope at La Silla, Chile. Part of the funding for GROND (both hardware as well as personnel) was generously granted from the Leibniz-Prize to Prof. G. Hasinger (Deutsche Forschungsgemeinschaft (DFG) grant HA 1850/28-1). GROND data were obtained under European Southern Observatory (ESO) programme ID 0103.A-9099. This research has made use of the NASA/IPAC Extragalactic Database (NED), which is funded by the National Aeronautics and Space Administration and operated by the California Institute of Technology. This research made use of Photutils, an Astropy package for detection and photometry of astronomical sources (Bradley et al. 2020). Based on data products from observations made with ESO Telescopes at the La Silla or Paranal Observatories under ESO programme ID 179.A-2010. IRAF is distributed by the National Optical Astronomy Observatories, which is operated by the Association of Universities for Research in Astronomy, Inc. (AURA) under cooperative agreement with the National Science Foundation. This research made use of NUMPY (Harris et al. 2020), MATPLOTLIB (Hunter 2007), and ASTROPY (Astropy Collaboration 2013, 2018). ; We present optical spectroscopy together with ultraviolet, optical, and near-infrared photometry of SN 2019hcc, which resides in a host galaxy at redshift 0.044, displaying a sub-solar metallicity. The supernova spectrum near peak epoch shows a 'w' shape at around 4000 Å which is usually associated with OII lines and is typical of Type I superluminous supernovae. SN 2019hcc post-peak spectra show a well-developed Hα P-Cygni profile from 19 d past maximum and its light curve, in terms of its absolute peak luminosity and evolution, resembles that of a fast-declining Hydrogen-rich supernova (SN IIL). The object does not show any unambiguous sign of interaction as there is no evidence of narrow lines in the spectra or undulations in the light curve. Our TARDIS spectral modelling of the first spectrum shows that carbon, nitrogen, and oxygen (CNO) at 19 000 K reproduce the 'w' shape and suggests that a combination of non-thermally excited CNO and metal lines at 8000K could reproduce the feature seen at 4000 Å. The Bolometric light-curve modelling reveals that SN 2019hcc could be fit with a magnetar model, showing a relatively strong magnetic field (B > 3 × 1014 G), which matches the peak luminosity and rise time without powering up the light curve to superluminous luminosities. The high-energy photons produced by the magnetar would then be responsible for the detected OII lines. As a consequence, SN 2019hcc shows that a 'w' shape profile at around 4000 Å, usually attributed to OII, is not only shown in superluminous supernovae and hence it should not be treated as the sole evidence of the belonging to such a supernova type. ; European Organisation for Astronomical Research in the Southern Hemisphere, Chile, ePESSTO/ePESSTO+ extended Public ESO Spectroscopic Survey for Transient Objects Survey). ePESSTO+ observations were obtained under ESO program) 1103.D-0328 ; Google Incorporated ; European Space Agency's (ESA) Summer of Code in Space program ; Alexander von Humboldt Foundation ; EU under Marie Sklodowska-Curie H2020-MSCA-IF-2018-842471 ; Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT) CHILE/2017-72180113 ; Polish Narodowe Centrum Nauki (NCN) MAESTRO grant 2014/14/A/ST9/00121 ; Royal Astronomical Society Research Fellowship ; SKA South Africa 839090 ; European Commission PGC2018-095317-B-C21 ; VILLUM FONDEN 19054 ; National Science Foundation (NSF) AST-1911225 AST-1911151 ; National Aeronautics & Space Administration (NASA) 80NSSC19K1639 NN12AR55G 80NSSC18K0284 80NSSC18K1575 ; UK Research & Innovation (UKRI) ; Science & Technology Facilities Council (STFC) ; European Union's Horizon 2020 research and innovation programme 730890 ; Kepler/K2 grant J1944/80NSSC19K0112 HST GO-15889 ; UK Research & Innovation (UKRI) ; Science & Technology Facilities Council (STFC) ST/T000198/1 ST/S006109/1 ; Gaia Multilateral Agreement ; GROND ; German Research Foundation (DFG) HA 1850/28-1 ; European Southern Observatory (ESO) programme 0103.A-9099 ; National Aeronautics & Space Administration (NASA) ; ESO Telescopes at the La Silla or Paranal Observatories under ESO programme 179.A-2010

MRK acknowledges support from the Australian Research Council through awards FT180100375 and DP190101258. EW and JTM acknowledge support by the Australian Research Council Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D), through project number CE170100013. SFS is grateful for the support of a CONACYT grant CB-285080 and FC-2016-01-1916, and funding from the PAPIIT-DGAPAIN100519 (UNAM) project.LGwas funded by the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 839090. LG has also been partially supported by the Spanish grant PGC2018-095317-B-C21 within the European Funds for Regional Development (FEDER) ; In this paper, we analyse the statistics of the 2D gas-phase oxygen abundance distributions of 100 nearby galaxies drawn from the Calar Alto Legacy Integral Field spectroscopy Area survey. After removing the large-scale radial metallicity gradient, we compute the two-point correlation functions of the resulting metallicity fluctuation maps. We detect correlations in the majority of our targets, which we show are significantly in excess of what is expected due to beam-smearing, and are robust against the choice of metallicity diagnostic. We show that the correlation functions are generally well-fit by the predictions of a simple model for stochastic metal injection coupled with diffusion, and from the model we show that, after accounting for the effects of both beam smearing and noise, the galaxies in our sample have characteristic correlation lengths of ∼1 kpc. Correlation lengths increase with both stellar mass and star formation rate, but show no significant variation with Hubble type, barredness, or merging state. We also find no evidence for a theoretically predicted relationship between gas velocity dispersion and correlation length, though this may be due to the small dynamic range in gas velocity dispersion across our sample. Our results suggest that measurements of 2D metallicity correlation functions can be a powerful tool for studying galaxy evolution. ; Australian Research Council Centre of Excellence CE170100013 ; H2020 Marie Skłodowska-Curie Actions 839090, PGC2018-095317-B-C21 ; Australian Research Council DP190101258, FT180100375 ; Consejo Nacional de Ciencia y Tecnología CB-285080, FC-2016-01-1916, PAPIIT-DGAPAIN100519 ; Horizon 2020 ; European Regional Development Fund

K.A.P., M.W.-V., and L.G. were supported in part by the US National Science Foundation under grant AST-1311862. K.A. P. additionally acknowledges support from PITT PACC. K.A. P. was also supported in part by the Berkeley Center for Cosmological Physics and the Director, Office of Science, Office of High Energy Physics of the U.S. Department of Energy under contract No. DE-AC02-05CH11231 and U.S. Department of Energy Office of Science under contract No. DE-AC02-76SF00515. L.G. was additionally funded in part by the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No. 839090. We thank the referee, whose comments have improved this paper, and Saurabh Jha, Kyle Boone, and Ravi Gupta for useful conversations. This research has made use of the NASA/IPAC Extragalactic Database (NED), which is funded by the National Aeronautics and Space Administration and operated by the California Institute of Technology. Funding for the Sloan Digital Sky Survey IV has been provided by the Alfred P. Sloan Foundation, the U.S. Department of Energy Office of Science, and the Participating Institutions. SDSS-IV acknowledges support and resources from the Center for High-Performance Computing at the University of Utah. The SDSS website is www.sdss.org. SDSS-IV is managed by the Astrophysical Research Consortium for the Participating Institutions of the SDSS Collaboration, including the Brazilian Participation Group, the Carnegie Institution for Science, Carnegie Mellon University, the Chilean Participation Group, the French Participation Group, Harvard-Smithsonian Center for Astrophysics, Instituto de Astrofisica de Canarias, Johns Hopkins University, Kavli Institute for the Physics and Mathematics of the Universe (IPMU)/University of Tokyo, Lawrence Berkeley National Laboratory, Leibniz Institut fur Astrophysik Potsdam (AIP), Max-Planck-Institut fur Astronomie (MPIA Heidelberg), Max-Planck-Institut fur Astrophysik (MPA Garching), Max-Planck-Institut fur Extraterrestrische Physik (MPE), National Astronomical Observatories of China, New Mexico State University, New York University, University of Notre Dame, Observatario Nacional/MCTI, The Ohio State University, Pennsylvania State University, Shanghai Astronomical Observatory, United Kingdom Participation Group, Universidad Nacional Autonoma de Mexico, University of Arizona, University of Colorado Boulder, University of Oxford, University of Portsmouth, University of Utah, University of Virginia, University of Washington, University of Wisconsin, Vanderbilt University, and Yale University. This research uses services or data provided by the Astro Data Lab at NSF's National Optical-Infrared Astronomy Research Laboratory. NOIRLab is operated by the Association of Universities for Research in Astronomy (AURA), Inc., under a cooperative agreement with the National Science Foundation. The Legacy Surveys consist of three individual and complementary projects: the Dark Energy Camera Legacy Survey (DECaLS; Proposal ID #2014B-0404; PIs: David Schlegel and Arjun Dey), the Beijing-Arizona Sky Survey (BASS; NOAO Prop. ID #2015A-0801; PIs: Zhou Xu and Xiaohui Fan), and the Mayall z-band Legacy Survey (MzLS; Prop. ID #2016A-0453; PI: Arjun Dey). DECaLS, BASS, and MzLS together include data obtained, respectively, at the Blanco telescope, Cerro Tololo Inter-American Observatory, NSF's NOIRLab; the Bok telescope, Steward Observatory, University of Arizona; and the Mayall telescope, Kitt Peak National Observatory, NOIRLab. The Legacy Surveys project is honored to be permitted to conduct astronomical research on Iolkam Du'ag (Kitt Peak), a mountain with particular significance to the Tohono O'odham Nation. This project used data obtained with the Dark Energy Camera (DECam), which was constructed by the Dark Energy Survey (DES) collaboration. Funding for the DES Projects has been provided by the U.S. Department of Energy, the U.S. National Science Foundation, the Ministry of Science and Education of Spain, the Science and Technology Facilities Council of the United Kingdom, the Higher Education Funding Council for England, the National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign, the Kavli Institute of Cosmological Physics at the University of Chicago, Center for Cosmology and Astro-Particle Physics at The Ohio State University, the Mitchell Institute for Fundamental Physics and Astronomy at Texas A&M University, Financiadora de Estudos e Projetos, Fundacao Carlos Chagas Filho de Amparo, Financiadora de Estudos e Projetos, Fundacao Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro, Conselho Nacional de Desenvolvimento Cientifico e Tecnologico and the Ministerio da Ciencia, Tecnologia e Inovacao, the Deutsche Forschungsgemeinschaft and the Collaborating Institutions in the Dark Energy Survey. The Collaborating Institutions are Argonne National Laboratory, the University of California at Santa Cruz, the University of Cambridge, Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas-Madrid, the University of Chicago, University College London, the DES-Brazil Consortium, the University of Edinburgh, the Eidgenossische Technische Hochschule (ETH) Zurich, Fermi National Accelerator Laboratory, the University of Illinois at UrbanaChampaign, the Institut de Ciencies de l'Espai (IEEC/CSIC), the Institut de Fisica d'Altes Energies, Lawrence Berkeley National Laboratory, the Ludwig Maximilians Universitat Munchen and the associated Excellence Cluster Universe, the University of Michigan, NSF's NOIRLab, the University of Nottingham, The Ohio State University, the University of Pennsylvania, the University of Portsmouth, SLAC National Accelerator Laboratory, Stanford University, the University of Sussex, and Texas A&M University. The Legacy Survey team makes use of data products from the Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE), which is a project of the Jet Propulsion Laboratory/California Institute of Technology. NEOWISE is funded by the National Aeronautics and Space Administration. The Legacy Surveys imaging of the DESI footprint is supported by the Director, Office of Science, Office of High Energy Physics of the U.S. Department of Energy under contract No. DE-AC02-05CH1123; by the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility under the same contract; and by the U.S. National Science Foundation, Division of Astronomical Sciences under contract No. AST-0950945 to NOAO. This publication makes use of data products from the Two Micron All Sky Survey, which is a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technology, funded by the National Aeronautics and Space Administration and the National Science Foundation. This research has made use of the NASA/IPAC Infrared Science Archive, which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. Some of the data presented in this paper were obtained from the Mikulski Archive for Space Telescopes (MAST). STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. Support for MAST for non-HST data is provided by the NASA Office of Space Science via grant NNX09AF08G and by other grants and contracts. ; We analyze 143 Type Ia supernovae (SNe Ia) observed in H band (1.6-1.8 mu m) and find that SNe Ia are intrinsically brighter in H band with increasing host galaxy stellar mass. We find that SNe Ia in galaxies more massive than 10(10)(.4)(3) M-circle dot are 0.13 +/- 0.04 mag brighter in H than SNe Ia in less massive galaxies. The same set of SNe Ia observed at optical wavelengths, after width-color-luminosity corrections, exhibit a 0.10 +/- 0.03 mag offset in the Hubble residuals. We observe an outlier population (vertical bar Delta H-max vertical bar > 0.5 mag) in the H band and show that removing the outlier population moves the mass threshold to 10(10.65) M-circle dot and reduces the step in H band to 0.08 +/- 0.04 mag, but the equivalent optical mass step is increased to 0.13 +/- 0.04 mag. We conclude that the outliers do not drive the brightness-host-mass correlation. Less massive galaxies preferentially host more higher-stretch SNe Ia, which are intrinsically brighter and bluer. It is only after correction for width-luminosity and color- luminosity relationships that SNe Ia have brighter optical Hubble residuals in more massive galaxies. Thus, finding that SNe Ia are intrinsically brighter in H in more massive galaxies is an opposite correlation to the intrinsic (prewidth-luminosity correction) optical brightness. If dust and the treatment of intrinsic color variation were the main driver of the host galaxy mass correlation, we would not expect a correlation of brighter H-band SNe Ia in more massive galaxies. ; National Science Foundation (NSF) AST-1311862 ; PITT PACC ; Berkeley Center for Cosmological Physics ; United States Department of Energy (DOE) DE-AC02-05CH11231 DE-AC02-05CH1123 DE-AC02-76SF00515 ; European Commission 839090 ; National Aeronautics & Space Administration (NASA) ; Alfred P. Sloan Foundation ; United States Department of Energy (DOE) ; Participating Institutions ; Center for High-Performance Computing at the University of Utah ; SDSS Collaboration, including the Brazilian Participation Group ; Carnegie Institution for Science, Carnegie Mellon University ; Chilean Participation Group ; French Participation Group ; Smithsonian Institution ; Harvard-Smithsonian Center for Astrophysics ; Instituto de Astrofisica de Canarias ; Johns Hopkins University ; Kavli Institute for the Physics and Mathematics of the Universe (IPMU)/University of Tokyo ; United States Department of Energy (DOE) ; Leibniz Institut fur Astrophysik Potsdam (AIP) ; Max-Planck-Institut fur Astronomie (MPIA Heidelberg) Max-Planck-Institut fur Astrophysik (MPA Garching) Max-Planck-Institut fur Extraterrestrische Physik (MPE) ; National Astronomical Observatories of China ; New Mexico State University ; New York University ; University of Notre Dame ; Observatario Nacional/MCTI ; Ohio State University ; Pennsylvania State University ; Shanghai Astronomical Observatory ; United Kingdom Participation Group ; Universidad Nacional Autonoma de Mexico ; University of Arizona ; University of Colorado Boulder ; University of Oxford ; University of Portsmouth ; University of Utah ; University of Virginia ; University of Washington ; University of Wisconsin ; Vanderbilt University ; Yale University ; United States Department of Energy (DOE) ; National Science Foundation (NSF) ; Spanish Government ; UK Research & Innovation (UKRI) ; Science & Technology Facilities Council (STFC) ; UK Research & Innovation (UKRI) ; Higher Education Funding Council for England ; National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign ; Kavli Institute of Cosmological Physics at the University of Chicago ; Ohio State University ; Mitchell Institute for Fundamental Physics and Astronomy at Texas AM University ; Financiadora de Inovacao e Pesquisa (Finep) ; Fundacao Carlos Chagas Filho de Amparo Fundacao Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio De Janeiro (FAPERJ) ; Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPQ) ; Spanish Government ; German Research Foundation (DFG) ; Collaborating Institutions in the Dark Energy Survey ; National Energy Research Scientific Computing Center ; United States Department of Energy (DOE) ; National Science Foundation (NSF) NSF - Directorate for Mathematical & Physical Sciences (MPS) AST-0950945 ; Association of Universities for Research in Astronomy, Inc., under NASA NAS5-26555 National Aeronautics & Space Administration (NASA) NNX09AF08G

Acknowledgements. We thank the anonymous referee for useful comments. We thank Marco Fiaschi for carrying out some of the Asiago observations. EK is supported by the Turku Collegium of Science, Medicine and Technology. EK also acknowledge support from the Science and Technology Facilities Council (STFC; ST/P000312/1). ECK acknowledges support from the G.R.E.A.T. research environment and support from The Wenner-Gren Foundations. MF is supported by a Royal Society – Science Foundation Ireland University Research Fellowship. EC, LT, AP, and MT are partially supported by the PRIN-INAF 2017 with the project "Towards the SKA and CTA era: discovery, localization, and physics of transient objects". HK was funded by the Academy of Finland projects 324504 and 328898. TWC acknowledges the EU Funding under Marie Skłodowska-Curie grant agreement No. 842471. LG was funded by the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 839090. This work has been partially supported by the Spanish grant PGC2018-095317-B-C21 within the European Funds for Regional Development (FEDER). MG is supported by the Polish NCN MAESTRO grant 2014/14/A/ST9/00121. KM acknowledges support from EU H2020 ERC grant no. 758638. TMB was funded by the CONICYT PFCHA / DOCTORADOBECAS CHILE/2017-72180113. MN is supported by a Royal Astronomical Society Research Fellowship. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere under ESO programmes 67.D-0438, 60.A-9475, 199.D-0143, and 1103.D-0328. Some of the observations reported in this paper were obtained with the Southern African Large Telescope (SALT) under programme 2018-1-DDT-003 (PI: Kankare). Polish participation in SALT is funded by grant No. MNiSW DIR/WK/2016/07. Based on observations made with the Nordic Optical Telescope, operated by the Nordic Optical Telescope Scientific Association at the Observatorio del Roque de los Muchachos, La Palma, Spain, of the Instituto de Astrofisica de Canarias. The data presented here were obtained in part with ALFOSC, which is provided by the Instituto de Astrofisica de Andalucia (IAA) under a joint agreement with the University of Copenhagen and NOTSA. This work is partly based on the NUTS2 programme carried out at the NOT. NUTS2 is funded in part by the Instrument Center for Danish Astrophysics (IDA). The Liverpool Telescope is operated on the island of La Palma by Liverpool John Moores University in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias with financial support from the UK Science and Technology Facilities Council. This paper is also based on observations collected at the Copernico 1.82 m and Schmidt 67/92 Telescopes operated by INAF – Osservatorio Astronomico di Padova at Asiago, Italy. Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the National Research Council (Canada), CONICYT (Chile), Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina), and Ministério da Ciência, Tecnologia e Inovação (Brazil). Observations were carried out under programme GS-2017A-C-1. This project used data obtained with the Dark Energy Camera (DECam), which was constructed by the Dark Energy Survey (DES) collaboration. Funding for the DES Projects has been provided by the DOE and NSF (USA), MISE (Spain), STFC (UK), HEFCE (UK), NCSA (UIUC), KICP (U. Chicago), CCAPP (Ohio State), MIFPA (Texas A&M University), CNPQ, FAPERJ, FINEP (Brazil), MINECO (Spain), DFG (Germany) and the collaborating institutions in the Dark Energy Survey, which are Argonne Lab, UC Santa Cruz, University of Cambridge, CIEMAT-Madrid, University of Chicago, University College London, DES-Brazil Consortium, University of Edinburgh, ETH Zürich, Fermilab, University of Illinois, ICE (IEEC-CSIC), IFAE Barcelona, Lawrence Berkeley Lab, LMU München and the associated Excellence Cluster Universe, University of Michigan, NOAO, University of Nottingham, Ohio State University, OzDES Membership Consortium, University of Pennsylvania, University of Portsmouth, SLAC National Lab, Stanford University, University of Sussex, and Texas A&M University. Based on observations obtained with the Samuel Oschin 48-inch Telescope at the Palomar Observatory as part of the Zwicky Transient Facility project. ZTF is supported by the National Science Foundation under Grant No. AST-1440341 and a collaboration including Caltech, IPAC, the Weizmann Institute for Science, the Oskar Klein Center at Stockholm University, the University of Maryland, the University of Washington, Deutsches Elektronen-Synchrotron and Humboldt University, Los Alamos National Laboratories, the TANGO Consortium of Taiwan, the University of Wisconsin at Milwaukee, and Lawrence Berkeley National Laboratories. Operations are conducted by COO, IPAC, and UW. Based on observations at Cerro Tololo Inter-American Observatory, National Optical Astronomy Observatory (NOAO Prop. ID 2017A-0260; and PI: Soares-Santos), which is operated by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation. The Pan-STARRS1 Surveys (PS1) and the PS1 public science archive have been made possible through contributions by the Institute for Astronomy, the University of Hawaii, the Pan-STARRS Project Office, the Max-Planck Society and its participating institutes, the Max Planck Institute for Astronomy, Heidelberg and the Max Planck Institute for Extraterrestrial Physics, Garching, The Johns Hopkins University, Durham University, the University of Edinburgh, the Queen's University Belfast, the Harvard-Smithsonian Center for Astrophysics, the Las Cumbres Observatory Global Telescope Network Incorporated, the National Central University of Taiwan, the Space Telescope Science Institute, the National Aeronautics and Space Administration under Grant No. NNX08AR22G issued through the Planetary Science Division of the NASA Science Mission Directorate, the National Science Foundation Grant No. AST-1238877, the University of Maryland, Eotvos Lorand University (ELTE), the Los Alamos National Laboratory, and the Gordon and Betty Moore Foundation. Some of the data presented in this paper were obtained from the Mikulski Archive for Space Telescopes (MAST). STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. This work is based in part on archival data obtained with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. This research has made use of NED which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. We have made use of the Weizmann Interactive Supernova Data Repository (Yaron & Gal-Yam 2012, https://wiserep.weizmann.ac.il). ; 1 iraf is distributed by the National Optical Astronomy Observatories, which are operated by the Association of Universities for Research in Astronomy, Inc., under cooperative agreement with the National Science Foundation. ; The fraction of core-collapse supernovae (CCSNe) occurring in the central regions of galaxies is not well constrained at present. This is partly because large-scale transient surveys operate at optical wavelengths, making it challenging to detect transient sources that occur in regions susceptible to high extinction factors. Here we present the discovery and follow-up observations of two CCSNe that occurred in the luminous infrared galaxy (LIRG) NGC 3256. The first, SN 2018ec, was discovered using the ESO HAWK-I/GRAAL adaptive optics seeing enhancer, and was classified as a Type Ic with a host galaxy extinction of AV = 2.1−0.1+0.3 mag. The second, AT 2018cux, was discovered during the course of follow-up observations of SN 2018ec, and is consistent with a subluminous Type IIP classification with an AV = 2.1 ± 0.4 mag of host extinction. A third CCSN, PSN J10275082−4354034 in NGC 3256, was previously reported in 2014, and we recovered the source in late-time archival Hubble Space Telescope imaging. Based on template light curve fitting, we favour a Type IIn classification for it with modest host galaxy extinction of AV = 0.3−0.3+0.4 mag. We also extend our study with follow-up data of the recent Type IIb SN 2019lqo and Type Ib SN 2020fkb that occurred in the LIRG system Arp 299 with host extinctions of AV = 2.1−0.3+0.1 and AV = 0.4−0.2+0.1 mag, respectively. Motivated by the above, we inspected, for the first time, a sample of 29 CCSNe located within a projected distance of 2.5 kpc from the host galaxy nuclei in a sample of 16 LIRGs. We find, if star formation within these galaxies is modelled assuming a global starburst episode and normal IMF, that there is evidence of a correlation between the starburst age and the CCSN subtype. We infer that the two subgroups of 14 H-poor (Type IIb/Ib/Ic/Ibn) and 15 H-rich (Type II/IIn) CCSNe have different underlying progenitor age distributions, with the H-poor progenitors being younger at 3σ significance. However, we note that the currently available sample sizes of CCSNe and host LIRGs are small, and the statistical comparisons between subgroups do not take into account possible systematic or model errors related to the estimated starburst ages. ; DOCTORADOBECAS CHILE/2017-72180113 ; Deutsches Elektronen-Synchrotron and Humboldt University ; EU H2020 ERC 758638 ; IFAE Barcelona ; IPAC ; Instituto de Astrofisica de Canarias ; KICP ; MIFPA ; Marie Skłodowska-Curie 839090,PGC2018-095317-B-C21 ; Max Planck Institute for Astronomy ; Max Planck Institute for Extraterrestrial Physics ; NOAO ; National Central University of Taiwan ; National Optical Astronomy Observatories ; Science Foundation Ireland University ; Turku Collegium of Science, Medicine and Technology ; Weizmann Institute for Science ; National Science Foundation NSF ; U.S. Department of Energy USDOE ; National Aeronautics and Space Administration AST-1238877,NNX08AR22G NASA ; Gordon and Betty Moore Foundation NAS5-26555 GBMF ; Merck Institute for Science Education MISE ; University of Illinois at Urbana-Champaign UIUC ; Stanford University SU ; Argonne National Laboratory ANL ; Lawrence Berkeley National Laboratory 2017A-0260 LBNL ; University of Wisconsin-Milwaukee ; Ohio State University OSU ; California Institute of Technology CIT ; University of Chicago ; University of Michigan U-M ; University of Washington UW ; Johns Hopkins University JHU ; Texas A and M University TAMU ; University of Maryland UMD ; University of Hawai'i UH ; Los Alamos National Laboratory LANL ; University of Portsmouth ; Smithsonian Astrophysical Observatory SAO ; National Centre for Supercomputing Applications NCSA ; Horizon 2020 Framework Programme H2020 ; SLAC National Accelerator Laboratory SLAC ; National Research Council NRC ; Space Telescope Science Institute STScI ; Center for Cosmology and Astroparticle Physics, Ohio State University CCAPP ; Wenner-Gren Stiftelserna ; Science and Technology Facilities Council ST/P000312/1 STFC ; Royal Society ; Royal Astronomical Society MNiSW DIR/WK/2016/07 RAS ; University College London UCL ; European Commission 842471 EC ; University of Nottingham ; University of Sussex AST-1440341 ; University of Edinburgh ED ; Queen's University Belfast QUB ; Durham University ; Deutsche Forschungsgemeinschaft DFG ; Suomen Akatemia 324504,328898 ; Comisión Nacional de Investigación Científica y Tecnológica CONICYT ; Ministerio de Ciencia, Tecnología e Innovación Productiva MINCyT ; Ministerio de Economía y Competitividad MINECO ; Ministério da Ciência, Tecnologia e Inovação MCTI ; Liverpool John Moores University LJMU ; Max-Planck-Gesellschaft MPG ; Narodowe Centrum Nauki 2014/14/A/ST9/00121 NCN ; Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro FAPERJ ; Financiadora de Estudos e Projetos FINEP ; European Regional Development Fund ERDF ; Eötvös Loránd Tudományegyetem ELTE

We are grateful to Viktoriya Morozova, Anthony L. Piro, Lars Bildsten, Bill Paxton, J. J. Eldridge, Eva Laplace, Sergei I. Blinnikov, Ken'ichi Nomoto, Masaomi Tanaka, and Nozomu Tominaga for their comments and discussions. D.H., D.A.H., G.H., C.M., and J.B. were supported by NSF grants AST-1313484 and AST-1911225, as well as by NASA grant 80NSSC19kf1639. D.H. is thankful for support and hospitality by the National Astronomical Observatory of Japan where many discussions of this work took place. J.A.G. is supported by the NSF GRFP under grant number 1650114. I.A. is a CIFAR Azrieli Global Scholar in the Gravity and the Extreme Universe Program and acknowledges support from that program, from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (grant agreement number 852097), from the Israel Science Foundation (grant numbers 2108/18 and 2752/19), from the United States - Israel Binational Science Foundation (BSF), and from the Israeli Council for Higher Education Alon Fellowship. C.P.G acknowledges support from EU/FP7- ERC grant number 615929. Research by S.V. is supported by NSF grant AST{1813176. Q.F. acknowledges support from the JSPS Kakenhi grant (20J23342). K. Maeda acknowledges support by JSPS KAKENHI grants JP20H00174, JP20H04737, JP18H04585, JP18H05223, and JP17H02864. G.F. acknowledges the support from CONICET through grant PIP-2015-2017- 11220150100746CO and from ANPCyT through grant PICT-2017-3133. M.D.S. acknowledges support from a project grant (8021-00170B) from the Independent Research Fund Denmark and a generous grant (28021) from the VILLUM FONDEN. M.G. is supported by the Polish NCN MAESTRO grant 2014/14/A/ST9/00121. K. Maguire is funded by the EU H2020 ERC grant number 758638. T.M.B. was funded by the CONICYT PFCHA/DOCTORADOBECAS CHILE/2017- 72180113. This paper made use of data from the Las Cumbres Observatory global network of telescopes through the Supernova Key Project and Global Supernova Project. This paper includes data gathered with the 6.5 meter Magellan Telescopes located at Las Campanas Observatory, Chile. The CSP-I was supported by the NSF under grants AST-0306969, AST-0607438 and AST-1008343. This research has made use of the NASA/IPAC Extragalactic Database (NED), which is funded by NASA and operated by the California Institute of Technology, as well as IRAF, which is distributed by NOAO (operated by AURA, Inc.), under cooperative agreement with NSF. The authors wish to recognize and acknowledge the very signi cant cultural role and reverence that the summit of Haleakal a has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from the mountain. Funding for SDSS-III has been provided by the Alfred P. Sloan Foundation, the Participating Institutions, the National Science Foundation, and the U.S. Department of Energy O ce of Science. The SDSS-III website is http://www.sdss3.org/. SDSS-III is managed by the Astrophysical Research Consortium for the Participating Institutions of the SDSS-III Collaboration, including the University of Arizona, the Brazilian Participation Group, Brookhaven National Laboratory, Carnegie Mellon University, University of Florida, the French Participation Group, the German Participation Group, Harvard University, the Instituto de Astro sica de Canarias, the Michigan State/Notre Dame/JINA Participation Group, Johns Hopkins University, Lawrence Berkeley National Laboratory, Max Planck Institute for Astrophysics, Max Planck Institute for Extraterrestrial Physics, New Mexico State University, New York University, Ohio State University, Pennsylvania State University, University of Portsmouth, Princeton University, the Spanish Participation Group, University of Tokyo, University of Utah, Vanderbilt University, University of Virginia, University of Washington, and Yale University. ; The diversity of Type II supernovae (SNe II) is thought to be driven mainly by differences in their progenitor's hydrogen-rich (H-rich) envelope mass, with SNe IIP having long plateaus (~100 days) and the most massive H-rich envelopes. However, it is an ongoing mystery why SNe II with short plateaus (tens of days) are rarely seen. Here, we present optical/near-infrared photometric and spectroscopic observations of luminous Type II short-plateau SNe 2006Y, 2006ai, and 2016egz. Their plateaus of about 50–70 days and luminous optical peaks (lesssim−18.4 mag) indicate significant pre-explosion mass loss resulting in partially stripped H-rich envelopes and early circumstellar material (CSM) interaction. We compute a large grid of MESA+STELLA single-star progenitor and light-curve models with various progenitor zero-age main-sequence (ZAMS) masses, mass-loss efficiencies, explosion energies, 56Ni masses, and CSM densities. Our model grid shows a continuous population of SNe IIP–IIL–IIb-like light-curve morphology in descending order of H-rich envelope mass. With large 56Ni masses (gsim0.05 M⊙), short-plateau SNe II lie in a confined parameter space as a transitional class between SNe IIL and IIb. For SNe 2006Y, 2006ai, and 2016egz, our findings suggest high-mass red supergiant (RSG) progenitors (MZAMS sime 18–22 M⊙) with small H-rich envelope masses (${M}_{{{\rm{H}}}_{\mathrm{env}}}\simeq 1.7\,{M}_{\odot }$) that have experienced enhanced mass loss ($\dot{M}\simeq {10}^{-2}\,{M}_{\odot }\,{\mathrm{yr}}^{-1}$) for the last few decades before the explosion. If high-mass RSGs result in rare short-plateau SNe II, then these events might ease some of the apparent underrepresentation of higher-luminosity RSGs in observed SN II progenitor samples.

We thank the anonymous referee for their many suggestions that improved this paper. We thank Miguel Perez-Torres for helpful discussions. MN is supported by a Royal Astronomical Society Research Fellowship. TW is funded in part by European Research Council grant 320360 and by European Commission grant 730980. PGJ and GC acknowledge support from European Research Council Consolidator Grant 647208. GL and PC are supported by a research grant (19054) from Villum Fonden. MG is supported by the Polish NCN MAESTRO Grant 2014/14/A/ST9/00121. NI is partially supported by Polish NCN DAINA Grant 2017/27/L/ST9/03221. IA is a CIFAR Azrieli Global Scholar in the Gravity and the Extreme Universe Program and acknowledges support from that program, from the Israel Science Foundation (grant numbers 2108/18 and 2752/19), from the United States-Israel Binational Science Foundation (BSF), and from the Israeli Council forHigher Education Alon Fellowship. JB, DH, and CP were supported by NASA Grant 80NSSC18K0577. TWCacknowledges the EU Funding underMarie Sklodowska-Curie grant agreement No. 842471. LG was funded by the European Union's Horizon 2020 Framework Programme under theMarie Sklodowska-Curie grant agreement No. 839090. Thiswork has been partially supported by the Spanish grant PGC2018-095317-B-C21 within the European Funds for Regional Development (FEDER). SGGacknowledges support by FCT under Projects CRISP PTDC/FIS-AST-31546 and UIDB/00099/2020. IM is a recipient of the Australian Research Council Future Fellowship FT190100574. TMBwas funded by the CONICYT PFCHA/DOCTORADOBECAS CHILE/2017-72180113. KDA acknowledges support provided by NASA through the NASA Hubble Fellowship grant HST-HF2-51403.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555. This work is based on data collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile, under ESO programmes 1103.D-0328 and 0104.B-0709 and as part of ePESSTO+(the advanced Public ESO Spectroscopic Survey for Transient Objects Survey), observations from the Las Cumbres Observatory network, the 6.5 meterMagellan Telescopes located at Las Campanas Observatory, Chile, the MMT Observatory, a joint facility of the University of Arizona and the Smithsonian Institution and the WilliamHerschel Telescope (programme W19B/P7). Swift data were supplied by the UK Swift Science Data Centre at the University of Leicester. The Liverpool Telescope andWilliam Herschel Telescope are operated on the island of La Palma by Liverpool John Moores University in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias with financial support from the UK Science and Technology Facilities Council. ; At 66 Mpc, AT2019qiz is the closest optical tidal disruption event (TDE) to date, with a luminosity intermediate between the bulk of the population and the faint-and-fast event iPTF16fnl. Its proximity allowed a very early detection and triggering of multiwavelength and spectroscopic follow-up well before maximum light. The velocity dispersion of the host galaxy and fits to the TDE light curve indicate a black hole mass ≈106M , disrupting a star of ≈1M . By analysing our comprehensive UV, optical, and X-ray data, we show that the early optical emission is dominated by an outflow, with a luminosity evolution L ∝ t2, consistent with a photosphere expanding at constant velocity ( 2000 km s−1), and a line-forming region producing initially blueshifted H and He II profiles with v = 3000–10 000 km s−1. The fastest optical ejecta approach the velocity inferred from radio detections (modelled in a forthcoming companion paper from K. D. Alexander et al.), thus the same outflow may be responsible for both the fast optical rise and the radio emission – the first time this connection has been observed in a TDE. The light-curve rise begins 29 ± 2 d before maximum light, peaking when the photosphere reaches the radius where optical photons can escape. The photosphere then undergoes a sudden transition, first cooling at constant radius then contracting at constant temperature. At the same time, the blueshifts disappear from the spectrum and Bowen fluorescence lines (N III) become prominent, implying a source of far-UV photons, while the X-ray light curve peaks at ≈1041 erg s−1. Assuming that these X-rays are from prompt accretion, the size and mass of the outflow are consistent with the reprocessing layer needed to explain the large optical to X-ray ratio in this and other optical TDEs, possibly favouring accretion-powered over collision-powered outflow models. ; Royal Astronomical Society Research Fellowship ; European Research Council (ERC) 320360 647208 ; European Commission European Commission Joint Research Centre 730980 ; Villum Fonden 19054 ; Polish NCN MAESTRO Grant 2014/14/A/ST9/00121 ; Polish NCN DAINA Grant 2017/27/L/ST9/03221 ; Israel Science Foundation 2108/18 2752/19 ; US-Israel Binational Science Foundation ; Israeli Council forHigher Education Alon Fellowship ; National Aeronautics & Space Administration (NASA) 80NSSC18K0577 NAS5-26555 ; European Union (EU) 842471 839090 ; European Union (EU) PGC2018-095317-B-C21 ; Portuguese Foundation for Science and Technology CRISP PTDC/FIS-AST-31546 UIDB/00099/2020 ; Australian Research Council FT190100574 ; CONICYT PFCHA/DOCTORADOBECAS CHILE 2017-72180113 ; NASA through the NASA Hubble Fellowship grant - Space Telescope Science Institute HST-HF2-51403.001-A ; European Organisation for Astronomical Research in the Southern Hemisphere, Chile, under ESO programmes 1103.D-0328 0104.B-0709 ; WilliamHerschel Telescope W19B/P7 ; Science & Technology Facilities Council (STFC)

This work was supported by the Science and Technology Facilities Council (grant number ST/P006760/1) through the DISCnet Centre forDoctoral Training. M.Sullivan and M.Smith acknowledge support from EU/FP7-ERC grant 615929, and PW acknowledges support from STFC grant ST/R000506/1. LG was funded by the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 839090. This work has been partially supported by the Spanish grant PGC2018-095317-B-C21 within the European Funds for Regional Development (FEDER). Funding for the DES Projects has been provided by the U.S. Department of Energy, the U.S. National Science Foundation, the Ministry of Science and Education of Spain, the Science and Technology Facilities Council of the United Kingdom, the Higher Education Funding Council for England, the National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign, the Kavli Institute of Cosmological Physics at the University of Chicago, the Center for Cosmology and Astro-Particle Physics at the Ohio StateUniversity, the Mitchell Institute for Fundamental Physics and Astronomy at Texas A&M University, Financiadora de Estudos e Projetos, Fundacao Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro, Conselho Nacional de Desenvolvimento Cientifico e Tecnologico and the Ministerio da Ciencia, Tecnologia e Inovacao, the Deutsche Forschungsgemeinschaft and the Collaborating Institutions in the Dark Energy Survey. The Collaborating Institutions are Argonne National Laboratory, the University of California at Santa Cruz, the University of Cambridge, Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas-Madrid, the University of Chicago, University College London, the DES-Brazil Consortium, the University of Edinburgh, the Eidgen ossische Technische Hochschule (ETH) Z urich, Fermi National Accelerator Laboratory, theUniversity of Illinois at Urbana Champaign, the Institut de Ciencies de l'Espai (IEEC/CSIC), the Institut de Fisica d'Altes Energies, Lawrence Berkeley National Laboratory, the Ludwig-Maximilians Universit at M unchen and the associated Excellence Cluster Universe, the University of Michigan, the National Optical Astronomy Observatory, the University of Nottingham, The Ohio State University, the University of Pennsylvania, the University of Portsmouth, SLAC National Accelerator Laboratory, Stanford University, the University of Sussex, Texas A&M University, and the OzDES Membership Consortium. The DES data management system is supported by the National Science Foundation under grant numbers AST-1138766 and AST-1536171. The DES participants from Spanish institutions are partially supported by MINECO under grants AYA2015-71825, ESP2015-66861, FPA2015-68048, SEV-2016-0588, SEV-2016-0597, and MDM-2015-0509, some of which include ERDF funds from the European Union. IFAE is partially funded by the CERCA program of the Generalitat de Catalunya. Research leading to these results has received funding from the European Research Council under the European Union's Seventh Framework Program (FP7/2007-2013) including ERC grant agreements 240672, 291329, and 306478. We acknowledge support from the Brazilian Instituto Nacional de Ciencia e Tecnologia (INCT) e-Universe (CNPq grant 465376/2014-2). ; This manuscript has been authored by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the US Department of Energy, Office of Science, Office of High Energy Physics. ; The data underlying this paper are available in the DES3YR data release, available at https://www.darkenergysurvey.org/des-year-3- supernova-cosmology-results/, and in the online supplementary material. ; Supplementary data are available at MNRAS online. Table 1. Seeing-optimized image stack parameters. ; Analyses of Type Ia supernovae (SNe Ia) have found puzzling correlations between their standardized luminosities and host galaxy properties: SNe Ia in high-mass, passive hosts appear brighter than those in lower mass, star-forming hosts. We examine the host galaxies of SNe Ia in the Dark Energy Survey 3-yr spectroscopically confirmed cosmological sample, obtaining photometry in a series of 'local' apertures centred on the SN, and for the global host galaxy. We study the differences in these host galaxy properties, such as stellar mass and rest-frame U - R colours, and their correlations with SN Ia parameters including Hubble residuals. We find all Hubble residual steps to be >3 sigma in significance, both for splitting at the traditional environmental property sample median and for the step of maximum significance. For stellar mass, we find a maximal local step of 0.098 +/- 0.018mag; similar to 0.03mag greater than the largest global stellar mass step in our sample (0.070 +/- 0.017mag). When splitting at the sample median, differences between local and global U - R steps are small, both similar to 0.08mag, but are more significant than the global stellar mass step (0.057 +/- 0.017mag). We split the data into sub-samples based on SN Ia light-curve parameters: stretch (x(1)) and colour (c), finding that redder objects (c > 0) have larger Hubble residual steps, for both stellar mass and U - R, for both local and global measurements, of similar to 0.14mag. Additionally, the bluer (star-forming) local environments host a more homogeneous SN Ia sample, with local U - R rms scatter as low as 0.084 +/- 0.017mag for blue (c < 0) SNe Ia in locally blue U - R environments. ; Science and Technology Facilities Council through the DISCnet Centre forDoctoral Training ST/P006760/1 ; EU/FP7-ERC grant 615929 ; UK Research & Innovation (UKRI) Science & Technology Facilities Council (STFC) ST/R000506/1 ; European Commission 839090 ; Spanish grant within the European Funds for Regional Development (FEDER) PGC2018-095317-B-C21 ; United States Department of Energy (DOE) ; National Science Foundation (NSF) ; Spanish Government ; UK Research & Innovation (UKRI) Science & Technology Facilities Council (STFC) ; Higher Education Funding Council for England ; National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign ; Ohio State University ; Mitchell Institute for Fundamental Physics and Astronomy at Texas AM University ; Ciencia Tecnologia e Inovacao (FINEP) ; Fundacao Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro ; National Council for Scientific and Technological Development (CNPq) ; Ministerio da Ciencia, Tecnologia e Inovacao ; German Research Foundation (DFG) ; University of California at Santa Cruz ; University of Cambridge ; Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas-Madrid ; ETH Zurich ; United States Department of Energy (DOE) University of Chicago ; University of Illinois at Urbana Champaign ; Institut de Ciencies de l'Espai (IEEC/CSIC) ; Institut de Fisica d'Altes Energies ; United States Department of Energy (DOE) ; Ludwig-Maximilians Universit at Munchen and the associated Excellence Cluster Universe ; University of Michigan System ; National Science Foundation (NSF) NSF - Directorate for Mathematical & Physical Sciences (MPS) ; University of Nottingham ; Ohio State University ; University of Pennsylvania ; University of Portsmouth ; Stanford University ; University of Sussex ; Texas AM University ; OzDES Membership Consortium ; National Science Foundation (NSF) AST-1138766 AST-1536171 ; MINECO AYA2015-71825 ESP2015-66861 FPA2015-68048 SEV-2016-0588 SEV-2016-0597 MDM-2015-0509 ; ERDF funds from the European Union ; CERCA program of the Generalitat de Catalunya ; European Research Council under the European Union's Seventh Framework Program (FP7/2007-2013) ; European Research Council (ERC) European Commission 240672 291329 306478 ; National Council for Scientific and Technological Development (CNPq) 465376/2014-2 ; Kavli Institute of Cosmological Physics at the University of Chicago ; University College London ; DES-Brazil Consortium ; University of Edinburgh

Research by D.J.S. is supported by NSF grants AST-1821967, AST-1821987, AST-1813708, AST-1813466, and AST-1908972, as well as by the Heising-Simons Foundation under grant #20201864. The CSP-II has been supported by National Science Foundation (NSF) grants AST-1008343, AST-1613426, AST-1613455, and AST-1613472, as well as by the Danish Agency for Science and Technology and Innovation through a Sapere Aude Level 2 grant. E.Y.H. and J.L. also acknowledge the support of the Florida Space Grant Consortium. This work was partially performed at the Aspen Center for Physics, which is supported by NSF grant PHY-1607611. Research by S.V. is supported by NSF grants AST1813176 and AST-2008108. L.G. was funded by the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No. 839090. This work has been partially supported by the Spanish grant PGC2018-095317-B-C21 within the European Funds for Regional Development (FEDER). M.S. is supported by generous grants from Villum FONDEN (13261, 28021) and by a project grant (8021-00170B) from the Independent Research Fund Denmark. A.V.F. is grateful for financial assistance from the TABASGO Foundation, the Christopher R. Redlich Fund, and the Miller Institute for Basic Research in Science (U.C. Berkeley). Based on observations obtained at the international Gemini Observatory (GN-2015A-Q-8, GS-2015A-Q-5), a program of NSF's NOIRLab, which is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation. on behalf of the Gemini Observatory partnership: the National Science Foundation (United States), National Research Council (Canada), Agencia Nacional de Investigacion y Desarrollo (Chile), Ministerio de Ciencia, Tecnologia e Innovacion (Argentina), Ministerio da Ciencia, Tecnologia, Inovacoes e Comunicacoes (Brazil), and Korea Astronomy and Space Science Institute (Republic of Korea). This paper includes data gathered with the Nordic Optical Telescope (PI Stritzinger) at the Observatorio del Roque de los Muchachos, La Palma, Spain. This work is based in part on observations from the Deep Imaging Multi-Object Spectrograph at the Keck II telescope. We are grateful to the staff at the Keck Observatory for their assistance, and we extend special thanks to those of Hawaiian ancestry on whose sacred mountain we are privileged to be guests. The W. M. Keck Observatory is operated as a scientific partnership among the California Institute of Technology, the University of California, and NASA; it was made possible by the generous financial support of the W. M. Keck Foundation. We thank S. Bradley Cenko for assistance with the Keck spectral reductions, as well as Patrick Kelly, WeiKang Zheng, and John Mauerhan for their assistance with the observations. D.J.S. is a visiting Astronomer at the Infrared Telescope Facility, which is operated by the University of Hawaii under contract 80HQTR19D0030 with the National Aeronautics and Space Administration. Based on data products from observations made with ESO Telescopes at the La Silla Paranal Observatory under programmes 188.D-3003 and 191.D-0935: PESSTO (the Public ESO Spectroscopic Survey for Transient Objects). ; Unburned carbon is potentially a powerful probe of Type Ia supernova (SN) explosion mechanisms. We present comprehensive optical and near-infrared (NIR) data on the "transitional" Type Ia SN 2015bp. An early NIR spectrum (t=−9.9 days with respect to B-band maximum) displays a striking C I λ1.0693μm line at 11.9×103~km s−1, distinct from the prominent Mg II λ1.0927μm feature, which weakens toward maximum light. SN 2015bp also displays a clear C II λ6580A notch early (t=−10.9 days) at 13.2×103~km s−1, consistent with our NIR carbon detection. At MB=−18.46, SN 2015bp is less luminous than a normal SN Ia and, along with iPTF13ebh, is the second member of the transitional subclass to display prominent early-time NIR carbon absorption. We find it unlikely that the C I feature is misidentified He I λ1.0830μm because this feature grows weaker toward maximum light, while the helium line produced in some double-detonation models grows stronger at these times. Intrigued by these strong NIR carbon detections, but lacking NIR data for other SNe Ia, we investigated the incidence of optical carbon in the sample of nine transitional SNe Ia with early-time data (t≲−4 days). We find that four display C II λ6580A, while two others show tentative detections, in line with the SN Ia population as a whole. We conclude that at least ∼50% of transitional SNe Ia in our sample do not come from sub-Chandrasekhar mass explosions due to the clear presence of carbon in their NIR and optical spectra. ; National Science Foundation (NSF) AST-1821967 AST-1821987 AST-1813708 AST-1813466 AST-1908972 PHY-1607611 AST1813176 AST-2008108 ; Heising-Simons Foundation 20201864 ; National Science Foundation (NSF) AST-1008343 AST-1613426 AST-1613455 AST-1613472 ; Danish Agency for Science and Technology and Innovation ; Florida Space Grant Consortium ; European Commission 839090 ; Spanish grant within the European Funds for Regional Development (FEDER) PGC2018-095317-B-C21 ; Villum Foundation 13261 28021 ; Independent Research Fund Denmark 8021-00170B ; TABASGO Foundation ; Christopher R. Redlich Fund ; Miller Institute for Basic Research in Science (U.C. Berkeley) ; International Gemini Observatory GN-2015A-Q-8 GS-2015A-Q-5 ; W.M. Keck Foundation ; University of Hawaii 80HQTR19D0030 ; National Aeronautics & Space Administration (NASA) ; ESO Telescopes at the La Silla Paranal Observatory 188.D-3003 191.D-0935: PESSTO

This paper has gone through internal review by the DES collaboration. It has Fermilab preprint number 19-115-AE and DES publication number 13387. We acknowledge support from EU/FP7- ERC grant 615929. RCN would like to acknowledge support from STFC grant ST/N000688/1 and the Faculty of Technology at the University of Portsmouth. LG was funded by the European Union's Horizon 2020 Framework Programme under the Marie Skłodowska- Curie grant agreement no. 839090. This work has been partially supported by the Spanish grant PGC2018-095317-B-C21 within the European Funds for Regional Development (FEDER). Funding for the DES Projects has been provided by the U.S. Department of Energy, the U.S. National Science Foundation, the Ministry of Science and Education of Spain, the Science and Technology Facilities Council of the United Kingdom, the Higher Education Funding Council for England, the National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign, the Kavli Institute of Cosmological Physics at the University of Chicago, the Center for Cosmology and Astro-Particle Physics at the Ohio State University, the Mitchell Institute for Fundamental Physics and Astronomy at Texas A&M University, Financiadora de Estudos e Projetos, Fundac¸ ˜ao Carlos Chagas Filho de Amparo `a Pesquisa do Estado do Rio de Janeiro, Conselho Nacional de Desenvolvimento Cient´ıfico e Tecnol´ogico and the Minist´erio da Ciˆencia, Tecnologia e Inovac¸ ˜ao, the Deutsche Forschungsgemeinschaft, and the Collaborating Institutions in the Dark Energy Survey. The Collaborating Institutions are Argonne National Laboratory, the University of California at Santa Cruz, the University of Cambridge, Centro de Investigaciones Energ´eticas, Medioambientales y Tecnol ´ogicas-Madrid, the University of Chicago, University College London, the DES-Brazil Consortium, the University of Edinburgh, the Eidgen¨ossische Technische Hochschule (ETH) Z¨urich, Fermi NationalAccelerator Laboratory, theUniversity of Illinois atUrbana- Champaign, the Institut de Ci`encies de l'Espai (IEEC/CSIC), the Institut de F´ısica d'Altes Energies, Lawrence Berkeley National Laboratory, the Ludwig-Maximilians Universit¨at M¨unchen and the associated Excellence Cluster Universe, the University of Michigan, the National Optical Astronomy Observatory, the University of Nottingham, The Ohio State University, the University of Pennsylvania, the University of Portsmouth, SLAC National Accelerator Laboratory, Stanford University, the University of Sussex, Texas A&M University, and the OzDES Membership Consortium. Based in part on observations at Cerro Tololo Inter-American Observatory, National Optical Astronomy Observatory, which is operated by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation. The DES data management system is supported by the National Science Foundation under grant numbers AST-1138766 and AST-1536171. The DES participants from Spanish institutions are partially supported by MINECO under grants AYA2015- 71825, ESP2015-66861, FPA2015-68048, SEV-2016-0588, SEV- 2016-0597, and MDM-2015-0509, some of which include ERDF funds from the European Union. IFAE is partially funded by the CERCA program of the Generalitat de Catalunya. Research leading to these results has received funding from the European Research Council under the European Union Seventh Framework Programme (FP7/2007-2013) including ERC grant agreements 240672, 291329, and 306478.We acknowledge support from the Australian Research Council Centre of Excellence for All-skyAstrophysics (CAASTRO), through project number CE110001020, and the Brazilian Instituto Nacional de Ciˆencia e Tecnologia (INCT) e-Universe (CNPq grant 465376/2014-2). This paper has been authored by Fermi Research Alliance, LLC under Contract No.DE-AC02-07CH11359 with theU.S.Department of Energy, Office of Science, Office of High Energy Physics. The United States Government retains and the publisher, by accepting the paper for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this paper, or allow others to do so, for United States Government purposes. ; We present the first Hubble diagram of superluminous supernovae (SLSNe) out to a redshift of two, together with constraints on the matter density, M, and the dark energy equation-of-state parameter, w(≡p/ρ). We build a sample of 20 cosmologically useful SLSNe I based on light curve and spectroscopy quality cuts. We confirm the robustness of the peak–decline SLSN I standardization relation with a larger data set and improved fitting techniques than previous works. We then solve the SLSN model based on the above standardization via minimization of the χ2 computed from a covariance matrix that includes statistical and systematic uncertainties. For a spatially flat cold dark matter ( CDM) cosmological model, we find M = 0.38+0.24 −0.19, with an rms of 0.27 mag for the residuals of the distance moduli. For a w0waCDM cosmological model, the addition of SLSNe I to a 'baseline' measurement consisting of Planck temperature together with Type Ia supernovae, results in a small improvement in the constraints of w0 and wa of 4 per cent.We present simulations of future surveys with 868 and 492 SLSNe I (depending on the configuration used) and show that such a sample can deliver cosmological constraints in a flat CDM model with the same precision (considering only statistical uncertainties) as current surveys that use Type Ia supernovae, while providing a factor of 2–3 improvement in the precision of the constraints on the time variation of dark energy, w0 and wa. This paper represents the proof of concept for superluminous supernova cosmology, and demonstrates they can provide an independent test of cosmology in the high-redshift (z > 1) universe. ; EU/FP7-ERC grant 615929 ; STFC grant ST/N000688/1 ; Faculty of Technology at the University of Portsmouth ; European Union's Horizon 2020 Framework Programme under the Marie Skłodowska- Curie grant agreement no. 839090 ; Spanish grant PGC2018-095317-B-C21 within the European Funds for Regional Development (FEDER) ; U.S. Department of Energy ; U.S. National Science Foundation ; Ministry of Science and Education of Spain ; Science and Technology Facilities Council of the United Kingdom ; Higher Education Funding Council for England ; National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign, ; Kavli Institute of Cosmological Physics at the University of Chicago ; Center for Cosmology and Astro-Particle Physics at the Ohio State University ; Mitchell Institute for Fundamental Physics and Astronomy at Texas A&M University ; Financiadora de Estudos e Projetos, Fundacão Carlos Chagas Filho de Amparo `a Pesquisa do Estado do Rio de Janeiro, Conselho Nacional de Desenvolvimento Científico e Tecnológico and the Ministério da Ciencia, Tecnologia e Inovacão ; Deutsche Forschungsgemeinschaft ; Collaborating Institutions in the Dark Energy Survey. ; National Science Foundation under grant numbers AST-1138766 and AST-1536171. ; T MINECO under grants AYA2015- 71825, ESP2015-66861, FPA2015-68048, SEV-2016-0588, SEV- 2016-0597, and MDM-2015-0509, some of which include ERDF funds from the European Union. ; CERCA program of the Generalitat de Catalunya. ; European Research Council under the European Union Seventh Framework Programme (FP7/2007-2013) including ERC grant agreements 240672, 291329, and 306478. ; Australian Research Council Centre of Excellence for All-skyAstrophysics (CAASTRO), through project number CE110001020 ; Brazilian Instituto Nacional de Ciˆencia e Tecnologia (INCT) e-Universe (CNPq grant 465376/2014-2) ; Fermi Research Alliance, LLC under Contract No.DE-AC02-07CH11359 with theU.S.Department of Energy, Office of Science, Office of High Energy Physics

This work was supported by the Science and Technology Facilities Council [grant number ST/P006760/1] through the DISCnet Centre for Doctoral Training. MS acknowledges support from EU/FP7-ERC grant 615929. LG was funded by the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 839090. This work has been partially supported by the Spanish grant PGC2018-095317-B-C21 within the European Funds for Regional Development (FEDER). Funding for the DES Projects has been provided by the US Department of Energy, the US '0:funding-source 3:href="http://dx.doi.org/10.13039/100000001"' National Science Foundation'/0:funding-source', the Ministry of Science and Education of Spain, the Science and Technology Facilities Council of the United Kingdom, the Higher Education Funding Council for England, the National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign, the Kavli Institute of Cosmological Physics at the University of Chicago, the Center for Cosmology and Astro-Particle Physics at the Ohio State University, the Mitchell Institute for Fundamental Physics and Astronomy at Texas A&M University, Financiadora de Estudos e Projetos, Fundacao Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro, Conselho Nacional de Desenvolvimento Cientifico e Tecnologico, and the Ministerio da Ciencia, Tecnologia e Inovacao, the Deutsche Forschungsgemeinschaft, and the Collaborating Institutions in the Dark Energy Survey. The Collaborating Institutions are Argonne National Laboratory, the University of California at Santa Cruz, the University of Cambridge, Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas-Madrid, the University of Chicago, University College London, the DES-Brazil Consortium, the University of Edinburgh, the Eidgenossische Technische Hochschule (ETH) Zurich, Fermi National Accelerator Laboratory, the University of Illinois at Urbana-Champaign, the Institut de Ciencies de l'Espai (IEEC/CSIC), the Institut de Fisica d'Altes Energies, Lawrence Berkeley National Laboratory, the Ludwig-Maximilians Universitat Munchen and the associated Excellence Cluster Universe, the University of Michigan, the National Optical Astronomy Observatory, the University of Nottingham, The Ohio State University, the University of Pennsylvania, the University of Portsmouth, SLAC National Accelerator Laboratory, Stanford University, the University of Sussex, Texas A&M University, and the OzDES Membership Consortium. This paper is based in part on observations at Cerro Tololo Inter-American Observatory, National Optical Astronomy Observatory, which is operated by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation. The DES data management system is supported by the National Science Foundation under Grant Numbers AST-1138766 and AST-1536171. The DES participants from Spanish institutions are partially supported by MINECO under grants AYA2015-71825, ESP2015-66861, FPA2015-68048, SEV-2016-0588, SEV-2016-0597, and MDM-2015-0509, some of which include ERDF funds from the European Union. IFAE is partially funded by the CERCA program of the Generalitat de Catalunya. Research leading to these results has received funding from the European Research Council under the European Union's Seventh Framework Program (FP7/2007-2013) including ERC grant agreements 240672, 291329, and 306478. We acknowledge support from the Brazilian Instituto Nacional de Ciencia e Tecnologia (INCT) e-Universe (CNPq grant 465376/2014-2). This paper has been authored by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the US Department of Energy, Office of Science, Office of High Energy Physics. This paper is based in part on data acquired at the Anglo-Australian Telescope, under program A/2013B/012. We acknowledge the traditional owners of the land on which the AAT stands, the Gamilaraay people, and pay our respects to elders past and present. This paper has been authored by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the US Department of Energy, Office of Science, Office of High Energy Physics. The United States Government retains and the publisher, by accepting this paper for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this paper, or allow others to do so, for United States Government purposes. This research has made use of the NASA/IPAC Extragalactic Database (NED), which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. ; We present DES14X2fna, a high-luminosity, fast-declining Type IIb supernova (SN IIb) at redshift z = 0.0453, detected by the Dark Energy Survey (DES). DES14X2fna is an unusual member of its class, with a light curve showing a broad, luminous peak reaching Mr −19.3mag 20 d after explosion. This object does not show a linear decline tail in the light curve until 60 d after explosion, after which it declines very rapidly (4.30 ± 0.10 mag 100 d−1 in the r band). By fitting semi-analytic models to the photometry of DES14X2fna, we find that its light curve cannot be explained by a standard 56Ni decay model as this is unable to fit the peak and fast tail decline observed. Inclusion of either interaction with surrounding circumstellar material or a rapidly-rotating neutron star (magnetar) significantly increases the quality of the model fit. We also investigate the possibility for an object similar to DES14X2fna to act as a contaminant in photometric samples of SNe Ia for cosmology, finding that a similar simulated object is misclassified by a recurrent neural network (RNN)-based photometric classifier as an SN Ia in ∼1.1–2.4 per cent of cases in DES, depending on the probability threshold used for a positive classification. ; Science and Technology Facilities Council through the DISCnet Centre for Doctoral Training ; EU/FP7-ERC grant 615929 ; European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant 839090 ; Spanish grant within the European Funds for Regional Development (FEDER) PGC2018-095317-B-C21 ; United States Department of Energy (DOE) ; National Science Foundation (NSF) ; Spanish Government ; UK Research & Innovation (UKRI) ; Science & Technology Facilities Council (STFC) ; UK Research & Innovation (UKRI) ; Higher Education Funding Council for England ; National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign ; Kavli Institute of Cosmological Physics at the University of Chicago ; Mitchell Institute for Fundamental Physics and Astronomy at Texas AM University ; Financiadora de Inovacao e Pesquisa (Finep) ; Fundacao Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio De Janeiro (FAPERJ) ; Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPQ) ; Ministerio da Ciencia, Tecnologia e Inovacao ; German Research Foundation (DFG) ; Collaborating Institutions in the Dark Energy Survey ; National Science Foundation (NSF) AST-1138766 AST-1536171 ; MINECO AYA2015-71825 ESP2015-66861 FPA2015-68048 SEV-2016-0588 SEV-2016-0597 MDM-2015-0509 ; European Commission ; CERCA program of the Generalitat de Catalunya ; European Research Council (ERC) FP7/2007-2013 ; European Research Council (ERC) European Commission 240672 291329 306478 ; Brazilian Instituto Nacional de Ciencia e Tecnologia (INCT) e-Universe (CNPq grant) 465376/2014-2 ; Fermi Research Alliance, LLC DE-AC02-07CH11359 ; Anglo-Australian Telescope A/2013B/012 ; National Aeronautics & Space Administration (NASA)

We present multiwavelength observations of two gap transients that were followed by the Carnegie Supernova Project-II. The observations are supplemented with data obtained by a number of different programs. Here in the first of two papers, we focus on the intermediate-luminosity red transient (ILRT) designated SNhunt120, while in a companion paper we examine the luminous red novae AT 2014ej. Our data set for SNhunt120 consists of an early optical discovery, estimated to be within three days after outburst, the subsequent optical and near-infrared broadband followup extending over a period of about two months, two visual and two near-infrared wavelength spectra, and Spitzer Space Telescope observations extending from early (+28 d) to late (+1155 d) phases. SNhunt120 resembles other ILRTs such as NGC 300-2008-OT and SN 2008S, and like these other ILRTs, SNhunt120 exhibits prevalent midinfrared emission at both early and late phases. From the comparison of SNhunt120 and other ILRTs to electron-capture supernova simulations, we find that the current models underestimate the explosion kinetic energy and thereby produce synthetic light curves that overestimate the luminosity. Finally, examination of pre-outburst Hubble Space Telescope images yields no progenitor detection. ; USA's NSF AST-0306969 AST-0607438 AST-1008343 AST-1613426 AST-1613455 AST-1613472 ; Danish Agency for Science and Technology and Innovation ; Independent Research Fund Denmark (IRFD) 8021-00170B ; VILLUM FONDEN 13261 ; Science Foundation Ireland ; European Union (EU) 754513 ; Aarhus University Research Foundation ; National Science Foundation (NSF) AST1613455 ; Texas A&M University Mitchell/Heep/Munnerlyn Chair in Observational Astronomy ; European Union (EU) 839090 ; European Union (EU) PGC2018-095317-B-C21 ; Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT) CONICYT FONDECYT 1191038 ; Ministry of Economy, Development, and Tourism's Millennium Science Initiative IC120009 ; Catania University 55722062134

Despite vast improvements in the measurement of the cosmological parameters, the nature of dark energy and an accurate value of the Hubble constant (H0) in the Hubble–Lemaˆıtre law remain unknown. To break the current impasse, it is necessary to develop as many independent techniques as possible, such as the use of Type II supernovae (SNe II). The goal of this paper is to demonstrate the utility of SNe II for deriving accurate extragalactic distances, which will be an asset for the next generation of telescopes where more-distant SNe II will be discovered. More specifically, we present a sample from the Dark Energy Survey Supernova Program (DES-SN) consisting of 15 SNe II with photometric and spectroscopic information spanning a redshift range up to 0.35. Combining our DES SNe with publicly available samples, and using the standard candle method (SCM), we construct the largest available Hubble diagram with SNe II in the Hubble flow (70 SNe II) and find an observed dispersion of 0.27 mag. We demonstrate that adding a colour term to the SN II standardization does not reduce the scatter in the Hubble diagram. Although SNe II are viable as distance indicators, this work points out important issues for improving their utility as independent extragalactic beacons: find new correlations, define a more standard subclass of SNe II, construct new SN II templates, and dedicate more observing time to high-redshift SNe II. Finally, for the first time, we perform simulations to estimate the redshift-dependent distance-modulus bias due to selection effects. ; National Science Foundation (NSF) AST-1211916 ; TABASGO Foundation, Gary and Cynthia Bengier ; Christopher R. Redlich Fund ; Sylvia and Jim Katzman Foundation ; Miller Institute for Basic Research in Science (UC Berkeley) - European Union 839090 ; Spanish grant PGC2018-095317-B-C21 ; European Union (EU) ; EU/FP7-ERC grant 615929 ; National Science Foundation (NSF) ; Hyper Suprime-Cam (HSC) collaboration includes the astronomical communities of Japan ; Hyper Suprime-Cam (HSC) collaboration includes the astronomical communities of Japan ; Princeton University ; Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU) ; University of Tokyo ; High Energy Accelerator Research Organization (KEK) ; FIRST programme from the Japanese Cabinet Office ; Ministry of Education, Culture, Sports, Science and Technology, Japan (MEXT) ; Ministry of Education, Culture, Sports, Science and Technology, Japan (MEXT) Japan Society for the Promotion of Science ; Japan Science & Technology Agency (JST) ; Toray Industries, Inc. ; Institute for Astronomy (the University of Hawaii) ; Max Planck Society Foundation CELLEX ; National Central University of Taiwan ; Space Telescope Science Institute ; National Aeronautics & Space Administration (NASA) NNX08AR22G ; National Science Foundation (NSF) AST-1238877 ; University of Maryland ; Eotvos Lorand University (ELTE) ; National Aeronautics & Space Administration (NASA) ; W.M. Keck Foundation ; National Research Council of Canada ; Centre National de la Recherche Scientifique (CNRS) ; Science & Technology Facilities Council (STFC) ; National Research Council ; Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT) ; Australian Research Council ; National Council for Scientific and Technological Development (CNPq) ; Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) GN-2005A-Q11 GN-2005B-Q-7 GN-2006A-Q-7 GS-2005A-Q-11 GS-2005BQ-6 GS-2008B-Q-56 ; United States Department of Energy (DOE) ; Spanish Government ; Science & Technology Facilities Council (STFC) ; Higher Education Funding Council for England ; National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign ; Ohio State University ; Mitchell Institute for Fundamental Physics and Astronomy at Texas AM University ; Ciencia Tecnologia e Inovacao (FINEP) ; Fundacao Carlos Chagas Filho de Amparo ; Conselho Nacional de Desenvolvimento Cient'tronomy at Texas AM University ; German Research Foundation (DFG) ; University of Portsmouth ; OzDES Membership Consortium ; National Science Foundation (NSF) AST-1138766 AST-1536171 AYA2015-71825 ESP2015-66861 FPA2015-68048 SEV2016-0588 SEV-2016-0597 ; European Union (EU) ; European Union - CERCA programme of the Generalitat de Catalunya ; European Research Council (ERC) ; European Research Council (ERC) 240672 291329 306478 ; National Council for Scientific and Technological Development (CNPq) 465376/2014-2 ; United States Department of Energy (DOE) DE-AC02-05CH11231

We thanks CONACYT FC-2016-01-1916 and CB-285080 projects and PAPIIT IN100519 project for support on this study. LG was funded by the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 839090. EADLthanks all Stellar Population Synthesis and Chemical Evolution group of the Instituto de Astronomia-UNAM for the help through the by-eye morphological classification. ; We study the presence of optically-selected active galactic nuclei (AGNs) within a sample of 867 galaxies extracted from the extended Calar-Alto Legacy Integral Field spectroscopy Area (eCALIFA) spanning all morphological classes. We identify 10 Type-I and 24 Type-II AGNs, amounting to ∼4 per cent of our sample, similar to the fraction reported by previous explorations in the same redshift range. We compare the integrated properties of the ionized and molecular gas, and stellar population of AGN hosts and their non-active counterparts, combining them with morphological information. The AGN hosts are found in transitory parts (i.e. green-valley) in almost all analysed properties which present bimodal distributions (i.e. a region where reside star-forming galaxies and another with quiescent/retired ones). Regarding morphology, we find AGN hosts among the most massive galaxies, with enhanced central stellar-mass surface density in comparison to the average population at each morphological type. Moreover, their distribution peaks at the Sab-Sb classes and none are found among very late-type galaxies (>Scd). Finally, we inspect how the AGN could act in their hosts regarding the quenching of star-formation. The main role of the AGN in the quenching process appears to be the removal (or heating) of molecular gas, rather than an additional suppression of the already observed decrease of the star-formation efficiency from late-to-early type galaxies. ; Consejo Nacional de Ciencia y Tecnologia (CONACyT) FC-2016-01-1916 CB-285080 ; European Commission 839090 ; Programa de Apoyo a Proyectos de Investigacion e Innovacion Tecnologica (PAPIIT) IN100519