Suchergebnisse

Armstrong, P., et al. ; SN 2017jgh is a type IIb supernova discovered by Pan-STARRS during the C16/C17 campaigns of the Kepler/K2 mission. Here, we present the Kepler/K2 and ground based observations of SN 2017jgh, which captured the shock cooling of the progenitor shock breakout with an unprecedented cadence. This event presents a unique opportunity to investigate the progenitors of stripped envelope supernovae. By fitting analytical models to the SN 2017jgh light curve, we find that the progenitor of SN 2017jgh was likely a yellow supergiant with an envelope radius of ∼ 50-290R⊙, and an envelope mass of ∼ 0-1.7M⊙. SN 2017jgh likely had a shock velocity of ∼7500-10 300 km s-1. Additionally, we use the light curve of SN 2017jgh to investigate how early observations of the rise contribute to constraints on progenitor models. Fitting just the ground based observations, we find an envelope radius of ∼ 50-330R⊙, an envelope mass of ∼ 0.3-1.7M⊙ and a shock velocity of ∼9000-15 000 km s-1. Without the rise, the explosion time cannot be well constrained that leads to a systematic offset in the velocity parameter and larger uncertainties in the mass and radius. Therefore, it is likely that progenitor property estimates through these models may have larger systematic uncertainties than previously calculated. ; BET and his group were supported by the Australian Research Council Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D), through project number CE170100013. The UCSC transient team is supported in part by NASA/K2 grants 80NSSC18K0303 and 80NSSC19K0113, the Gordon & Betty Moore Foundation, the Heising-Simons Foundation, and by a fellowship from the David and Lucile Packard Foundation to RJF. DOJ acknowledges support provided by NASA Hubble Fellowship grant HST-HF2-51462.001, which is awarded by the Space Telescope Science Institute, operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555. IA 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 programme (grant agreement number 852097), from the Israel Science Foundation (grant number 2752/19), from the United States - Israel Binational Science Foundation (BSF), and from the Israeli Council for Higher Education Alon Fellowship. MRD acknowledges support from the NSERC through grant RGPIN-2019-06186, the Canada Research Chairs Program, the Canadian Institute for Advanced Research (CIFAR), and the Dunlap Institute at the University of Toronto. DAC acknowledges support from the National Science Foundation Graduate Research Fellowship under Grant DGE1339067. This project has been supported by the LP2018-7 Lendület grant of the Hungarian Academy of Sciences. LG acknowledges financial support from the Spanish Ministry of Science, Innovation and Universities (MICIU) under the 2019 Ramón y Cajal program RYC2019-027683 and from the Spanish MICIU project PID2020-115253GA-I00. BJS is supported by NASA grant 80NSSC19K1717 and NSF grants AST-1920392 and AST-1911074. Support for TWSH was provided by NASA through the NASA Hubble Fellowship grant HST-HF2-51458.001-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. Research by SV is supported by NSF grants AST-1813176 and AST-2008108. LK acknowledges the financial support of the Hungarian National Research, Development and Innovation Office grant NKFIH PD-134784. LK and ZsB are supported by the Jànos Bolyai Research Scholarship of the Hungarian Academy of Sciences. The Konkoly team has been supported by the project 'Transient Astrophysical Objects' GINOP 2.3.2-15-2016-00033 of the National Research, Development and Innovation Office (NKFIH), Hungary, funded by the European Union. SWJ acknowledges support from US National Science Foundation award AST-1615455. This research has made use of the SVO Filter Profile Service (http://svo2.cab.inta-csic.es/theory/fps/) supported from the Spanish MINECO through grant AYA2017-84089. The LCO team is supported by NASA grant 80NSSC19K0119 and NSF grants AST-1911225 and AST-1911151.

There is considerable potential to decarbonise household energy consumption through the electrification of heating systems which can absorb excess renewable power and mitigate power network constraints through intelligent control. However, current standards discourage low carbon electricity sources through outdated assumptions; predicated upon a traditional electricity network which had higher emissions. Consequently, the implementation of product Energy labelling across Europe is biased against electric space and water heating systems in favour of gas. This paper examines the impact of this bias through a case study of the European Union's product labelling directive for domestic hot water systems. Laboratory testing of a market leading electric water tank and an A rated instantaneous gas boiler has demonstrated efficiencies of 87.4% and 72.9% respectively. In spite of this, the labelling directive assigns a C rating to the tank. This is due to a conversion coefficient (CC)within the directive's calculation based on an average electricity generation efficiency of 40% without a similar coefficient for gas. This paper advocates the removal of the CC factor from the directive to normalise the comparison, thus promoting a technology uniquely suited towards absorbing intermittent renewable energy sources with negligible costs.

OBJECTIVE--To formulate consensus based guidelines for antenatal care in a health district. DESIGN--Prospective formulation of draft guidelines by a working group of consultant obstetricians and general practitioners with an obstetric interest, canvassing opinions of all GPs in the district by questionnaire, and revision and final circulation of the guidelines. SETTING--One health district. SUBJECTS--All 160 GPs in the district and members of the working party. MAIN MEASURES--Questionnaire responses to specific proposals within the draft guidelines for managing anaemia, antepartum haemorrhage, and hypertension. RESULTS--136 GPs responded (response rate 85%); responders and nonresponders did not differ in age, sex, or presence on obstetric list. Overall they favoured more conservative management than suggested in the guidelines. For example, only 38% (44/116) prescribed iron routinely and 34% (38/113) referred to hospital for haemoglobin concentration of < or = 10 g/l; 10% referred women unnecessarily for oedema unassociated with proteinuria; and 20% managed active bleeding progressing to old brown staining as an urgent admission. The guidelines were revised according to the relative weight of the views obtained. CONCLUSION--Establishing guidelines is mainly a political process. Canvassed views influenced guidelines most when internal disagreement existed within the working party. IMPLICATIONS AND ACTION--Regular revising of the guidelines is planned, which, in conjunction with repeating the questionnaire to monitor changing practice, will allow a long term district wide clinical review.