Motivated by the identification of the blazar TXS 0506+056 as the first promising high-energy neutrino counterpart candidate, we search for additional neutrino blazar candidates among the Fermi-Large Area Telescope detected blazars. We investigate the multiwavelength behavior from radio to GeV gamma-rays of blazars found to be in spatial coincidence with single high-energy neutrinos and lower-energy neutrino flare candidates. In addition, we compare the average gamma-ray emission of the potential neutrino-emitting sources to the entire sample of gamma-ray blazars. We find that neutrino-emitting blazar candidates are statistically compatible with hypotheses of both a linear correlation and no correlation between neutrino and gamma-ray energy flux. ; Initiative and Networking Fund of the Helmholtz Association National Science Foundation (NSF) AST-1908952 AST-1920392 AST1911074 AST-1515927 AST-1908570 AST0808050 AST-1109911 AST-0908816 European Research Council under the European Union's Horizon 2020 research and innovation program 771282 Comisión Nacional de Investigación Cientifica y Tecnológica (CONICYT) Basal AFB-170002 Academy of Finland 317383 320085 United States Department of Energy (DOE) DE-AC02-76SF00515 Gordon and Betty Moore Foundation GBMF5490 Mt. Cuba Astronomical Foundation Ohio State University Chinese Academy of Sciences South America Center for Astronomy (CAS-SACA) Villum Foundation George Skestos National Aeronautics & Space Administration (NASA) NNX08AW31G NNX11A043G NNX14AQ89G National Aeronautics & Space Administration (NASA) NNG05GF22G National Science Foundation (NSF) AST-0909182 AST-1313422
The Type Ia supernova (SN Ia) LSQ14fmg exhibits exaggerated properties that may help to reveal the origin of the "super-Chandrasekhar" (or 03fg-like) group. The optical spectrum is typical of a 03fg-like SN Ia, but the light curves are unlike those of any SNe Ia observed. The light curves of LSQ14fmg rise extremely slowly. At -23 rest-frame days relative toB-band maximum, LSQ14fmg is already brighter thanJandHbands, far more luminous than any 03fg-like SNe Ia with near-infrared observations. At 1 month past maximum, the optical light curves decline rapidly. The early, slow rise and flat color evolution are interpreted to result from an additional excess flux from a power source other than the radioactive decay of the synthesized Ni-56. The excess flux matches the interaction with a typical superwind of an asymptotic giant branch (AGB) star in density structure, mass-loss rate, and duration. The rapid decline starting at around 1 month pastB-band maximum may be an indication of rapid cooling by active carbon monoxide (CO) formation, which requires a low-temperature and high-density environment. These peculiarities point to an AGB progenitor near the end of its evolution and the core degenerate scenario as the likely explosion mechanism for LSQ14fmg. ; National Science Foundation (NSF) AST-1008343 AST-1613426 AST-1613455 AST-1613472 AST-1008962 AST-1907570 AST1920392 AST-1911074 AST-1515927 AST1908570 AST-0908816 Danish Agency for Science and Technology and Innovation through a Sapere Aude Level 2 grant European Union's Horizon 2020 research and innovation program under Marie Sklodowska-Curie grant 839090 European Union (EU) PGC2018-095317-B-C21 DiRAC Institute in the Department of Astronomy at the University of Washington George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy Mitchell Foundation Academy of Finland 324504 328898 National Aeronautics & Space Administration (NASA) 80NSSC19K1717 Gordon and Betty Moore Foundation GBMF5490 Mt. Cuba Astronomical Foundation Ohio State University Chinese Academy of Sciences South America Center for Astronomy (CASSACA) Villum Foundation Independent Research Fund Denmark (IRFD) 8021-00170B VILLUM FONDEN 13261 28021 ESO Telescopes at the Paranal Observatory 099. D-0022(A)
Context. With an estimated diameter in the 320–350 km range, (704) Interamnia is the fifth largest main belt asteroid and one of the few bodies that fills the gap in size between the four largest bodies with D > 400 km (Ceres, Vesta, Pallas and Hygiea) and the numerous smaller bodies with diameter ≤200 km. However, despite its large size, little is known about the shape and spin state of Interamnia and, therefore, about its bulk composition and past collisional evolution. Aims. We aimed to test at what size and mass the shape of a small body departs from a nearly ellipsoidal equilibrium shape (as observed in the case of the four largest asteroids) to an irregular shape as routinely observed in the case of smaller (D ≤ 200 km) bodies. Methods. We observed Interamnia as part of our ESO VLT/SPHERE large program (ID: 199.C-0074) at thirteen different epochs. In addition, several new optical lightcurves were recorded. These data, along with stellar occultation data from the literature, were fed to the All-Data Asteroid Modeling algorithm to reconstruct the 3D-shape model of Interamnia and to determine its spin state. Results. Interamnia's volume-equivalent diameter of 332 ± 6 km implies a bulk density of ρ = 1.98 ± 0.68 g cm−3, which suggests that Interamnia – like Ceres and Hygiea – contains a high fraction of water ice, consistent with the paucity of apparent craters. Our observations reveal a shape that can be well approximated by an ellipsoid, and that is compatible with a fluid hydrostatic equilibrium at the 2σ level. Conclusions. The rather regular shape of Interamnia implies that the size and mass limit, under which the shapes of minor bodies with a high amount of water ice in the subsurface become irregular, has to be searched among smaller (D ≤ 300 km) less massive (m ≤ 3 × 1019 kg) bodies. ; This work has been supported by the Czech Science Foundation through grant 18-09470S (J.H., J.D.) and by the Charles University Research program No. UNCE/SCI/023. This research was supported by INTER-EXCELLENCE grant LTAUSA18093 from the Czech Ministry of Education, Youth, and Sports (J.H. and O.P.). The research of O.P. is additionally supported by Horizon 2020 ERC Starting Grant "Cat-In-hAT" (grant agreement #803158) and award PRIMUS/SCI/17 from Charles University. P.V., A.D., and B.C. were Aeronautics and Space Administration under Grant No. 80NSSC18K0849 issued through the Planetary Astronomy Program. This work was supported by the National Science Centre, Poland, through grant no. 2014/13/D/ST9/01818 (A.M.). The research leading to these results has received funding from the European Union's Horizon 2020 Research and Innovation Programme, under Grant Agreement no 687378 (SBNAF). This project has been supported by the GINOP-2.3.2-15-2016-00003 and NKFIH K125015 grants of the Hungarian National Research, Development and Innovation Office (NKFIH) and by the Lendület grant LP2012-31 of the Hungarian Academy of Sciences. TRAPPIST-North is a project funded by the University of Liège, in collaboration with Cadi Ayyad University of Marrakech (Morocco). TRAPPIST-South is a project funded by the Belgian FNRS under grant FRFC 2.5.594.09. F.E.J. is a FNRS Senior Research Associate. ASAS-SN thanks the Las Cumbres Observatory and its staff for its continuing support of the ASAS-SN project. ASAS-SN is supported by the Gordon and Betty Moore Foundation through grant GBMF5490 to the Ohio State University and NSF grant AST-1515927. Development of ASAS-SN has been supported by NSF grant AST-0908816, the Mt. Cuba Astronomical Foundation, the Center for Cosmology and AstroParticle Physics at the Ohio State University, the Chinese Academy of Sciences South America Center for Astronomy (CASSACA), the Villum Foundation, and George Skestos.
We present geometric and dynamical modeling of the broad line region (BLR) for the multi-wavelength reverberation mapping campaign focused on NGC 5548 in 2014. The data set includes photometric and spectroscopic monitoring in the optical and ultraviolet, covering the H beta, Civ, and Ly alpha broad emission lines. We find an extended disk-like H beta BLR with a mixture of near-circular and outflowing gas trajectories, while the Civand Ly alpha BLRs are much less extended and resemble shell-like structures. There is clear radial structure in the BLR, with Civand Ly alpha emission arising at smaller radii than the H beta emission. Using the three lines, we make three independent black hole mass measurements, all of which are consistent. Combining these results gives a joint inference of log(10) (M-BH/M-circle dot) = 7.64(-0.18)(+0.21). We examine the effect of using the V band instead of the UV continuum light curve on the results and find a size difference that is consistent with the measured UV-optical time lag, but the other structural and kinematic parameters remain unchanged, suggesting that theVband is a suitable proxy for the ionizing continuum when exploring the BLR structure and kinematics. Finally, we compare the H beta results to similar models of data obtained in 2008 when the active galactic nucleus was at a lower luminosity state. We find that the size of the emitting region increased during this time period, but the geometry and black hole mass remained unchanged, which confirms that the BLR kinematics suitably gauge the gravitational field of the central black hole. ; National Aeronautics & Space Administration (NASA) AST-1908952 AST-1814440 Space Telescope Science Institute National Science Foundation (NSF) AST-1211916 Packard Foundation through a Packard Fellowship AST-1412315 AST-1907208 Space Telescope Science Institute 17-ATP17-0141 19-ATP19-0188 NRF grant HST-AR-15018 HST-AR-14556 Korean Government 2020R1A2C3011091 Independent Research Fund Denmark DFF 8021-00130 NASA ADAP grant 80NSSC19K1016 National Science Foundation (NSF) Eberly Research Fellowship from The Pennsylvania State University Eberly College of Science AST-1909297 Center for Exoplanets Pennsylvania State University Eberly College of Science Pennsylvania Space Grant Consortium TABASGO Foundation Christopher R. Redlich Fund Miller Institute for Basic Research in Science (U.C. Berkeley)