Suchergebnisse

We present DES16C3cje, a low-luminosity, long-lived type II supernova (SN II) at redshift 0.0618, detected by the Dark Energy Survey (DES). DES16C3cje is a unique SN. The spectra are characterized by extremely narrow photospheric lines corresponding to very low expansion velocities of . 1500 km s−1 , and the light curve shows an initial peak that fades after 50 days before slowly rebrightening over a further 100 days to reach an absolute brightness of M푟 ∼ −15.5 mag. The decline rate of the late-time light curve is then slower than that expected from the powering by radioactive decay of 56Co, but is comparable to that expected from accretion power. Comparing the bolometric light curve with hydrodynamical models, we find that DES16C3cje can be explained by either i) a low explosion energy (0.11 foe) and relatively large 56Ni production of 0.075 M from a ∼ 15 M red supergiant progenitor typical of other SNe II, or ii) a relatively compact ∼ 40 M star, explosion energy of 1 foe, and 0.08 M of 56Ni. Both scenarios require additional energy input to explain the late-time light curve, which is consistent with fallback accretion at a rate of ∼ 0.5 × 10−8 M s−1. ; EU/FP7-ERC grant 615929 ; European Union (EU) 839090 ; Alexander von Humboldt Foundation ; Science Foundation Ireland ; Polish NCN MAESTRO 2014/14/A/ST9/00121 ; Royal Astronomical Society Research Fellowship ; European Organisation for Astronomical Research in the Southern Hemisphere, Chile 299.D-5040(A) 299.D-5040(B) 0100.D-0461(A) 194.C-0207(I) ; PESSTO, (the Public ESO Spectroscopic Survey for Transient Objects Survey) ESO program 197.D1075 199.D-0143 ; Programme NOAO GS-2016B-Q-9 ; United States Department of Energy (DOE) ; National Science Foundation (NSF) ; 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 ; Kavli Institute of Cosmological Physics at the University of Chicago ; 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) ; Collaborating Institutions in the Dark Energy Survey ; United States Department of Energy (DOE) University of Chicago ; University of California at Santa Cruz ; University of Cambridge ; Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas-Madrid ; University of Chicago ; University College London ; DES-Brazil Consortium ; University of Edinburgh ; 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 Universitat 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 United States Department of Energy (DOE) ; Stanford University ; University of Sussex ; Texas AM University ; OzDES Membership Consortium ; German Research Foundation (DFG) HA 1850/28-1 ; European Union (EU) PGC2018-095317-B-C21 ; National Science Foundation (NSF) AST-1138766 AST-1536171 ; MINECO AYA2015-71825 ESP2015-66861 FPA2015-68048 SEV-2016-0588 SEV2016-0597 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) 240672 291329 306478 ; National Council for Scientific and Technological Development (CNPq) 465376/2014-2 ; National Energy Research Scientific Computing Center (NERSC), a U.S. Department of Energy Office of Science User Facility DE-AC02-05CH11231 ; United States Department of Energy (DOE) DE-AC02-07CH11359

Gutiérrez, C. P., et al. ; We present the photometric and spectroscopic evolution of supernova (SN) 2019cad during the first ∼100 d from explosion. Based on the light-curve morphology, we find that SN 2019cad resembles the double-peaked Type Ib/c SN 2005bf and the Type Ic PTF11mnb. Unlike those two objects, SN 2019cad also shows the initial peak in the redder bands. Inspection of the g-band light curve indicates the initial peak is reached in ∼8 d, while the r-band peak occurred ∼15 d post-explosion. A second and more prominent peak is reached in all bands at ∼45 d past explosion, followed by a fast decline from ∼60 d. During the first 30 d, the spectra of SN 2019cad show the typical features of a Type Ic SN, however, after 40 d, a blue continuum with prominent lines of Si ii λ6355 and C ii λ6580 is observed again. Comparing the bolometric light curve to hydrodynamical models, we find that SN 2019cad is consistent with a pre-SN mass of 11 M?, and an explosion energy of 3.5 × 1051 erg. The light-curve morphology can be reproduced either by a double-peaked 56Ni distribution with an external component of 0.041 M?, and an internal component of 0.3 M? or a double-peaked 56Ni distribution plus magnetar model (P ∼11 ms and B ∼26 × 1014 G). If SN 2019cad were to suffer from significant host reddening (which cannot be ruled out), the 56Ni model would require extreme values, while the magnetar model would still be feasible. ; CPG and MS acknowledge support from EU/FP7-ERC grant No. (615929). MO acknowledges support from UNRN PI2018 40B696 grant. GP acknowledges support by ANID - Millennium Science Initiative - ICN12_009. NER acknowledges support from MIUR, PRIN 2017 (grant 20179ZF5KS). MF is supported by a Royal Society - Science Foundation Ireland University Research Fellowship. SM acknowledges support from the Magnus Ehrnrooth foundation. AR acknowledges support from ANID BECAS/DOCTORADO NACIONAL 21202412. TMR acknowledges the financial support of the Jenny and Antti Wihuri foundation and the Vilho, Yrjö and Kalle Väisälä Foundation of the Finnish academy of Science and Letters. MS is supported by generous grants from VILLUM FONDEN (13261, 28021) and by a project grant (8021-00170B) from the Independent Research Fund Denmark. LG was funded by the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 839090. JB, DH, DAH, and CP were supported by NSF grant AST-1911225. TMB was funded by the CONICYT PFCHA/DOCTORADOBECAS CHILE/2017-72180113. This work has been partially supported by the Spanish grant PGC2018-095317-B-C21 within the European Funds for Regional Development (FEDER).

We present DES16C3cje, a low-luminosity, long-lived type II supernova (SN II) at redshift 0.0618, detected by the Dark Energy Survey (DES). DES16C3cje is a unique SN. The spectra are characterized by extremely narrow photospheric lines corresponding to very low expansion velocities of1500 km s, and the light curve shows an initial peak that fades after 50 d before slowly rebrightening over a further 100 d to reach an absolute brightness of M ∼-15.5 mag. The decline rate of the late-time light curve is then slower than that expected from the powering by radioactive decay of Co, but is comparable to that expected from accretion power. Comparing the bolometric light curve with hydrodynamical models, we find that DES16C3cje can be explained by either (i) a low explosion energy (0.11 foe) and relatively large Ni production of 0.075 M from an ∼15 M red supergiant progenitor typical of other SNe II, or (ii) a relatively compact ∼40 M star, explosion energy of 1 foe, and 0.08 M of Ni. Both scenarios require additional energy input to explain the late-time light curve, which is consistent with fallback accretion at a rate of ∼0.5 × 10 M s. ; 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 Ciênciae Tecnologia (INCT) e-Universe (CNPq grant 465376/2014-2). Some of the data presented here were 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 Inovac¸ão (Brazil). Gemini observations were obtained under programme NOAO GS-2016B-Q-9. CPG and MS acknowledge support from EU/FP7-ERC grant No. [615929]. LG was funded by the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 839090. TWC acknowledgments the funding provided by the Alexander von Humboldt Foundation. MF is supported by a Royal Society–Science Foundation Ireland University Research Fellowship. MG is supported by the Polish NCN MAESTRO grant 2014/14/A/ST9/00121. MN is supported by a Royal Astronomical Society Research Fellowship. 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¸ão Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro, Conselho Nacional de Desenvolvimento Científico e Tecnológico and the Ministério da Ciência, Tecnologia e Inovac¸ão, the Deutsche Forschungsgemeinschaft and the Collaborating Institutions in the Dark Energy Survey. This work has been partially supported by the Spanish grant PGC2018-095317-B-C21 within the European Funds for Regional Development (FEDER). 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). 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. This manuscript has been authored by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy, Office of Science, Office of High Energy Physics. The United States Government retains and the publisher, by accepting the article 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 manuscript, or allow others to do so, for United States Government purposes. This research used resources of the National Energy Research Scientific Computing Center (NERSC), a U.S. Department of Energy Office of Science User Facility operated under Contract No. DE-AC02-05CH11231.

We present observations of the unusually luminous Type II supernova (SN) 2016gsd. With a peak absolute magnitude of V = -19.95 ± 0.08, this object is one of the brightest Type II SNe, and lies in the gap of magnitudes between the majority of Type II SNe and the superluminous SNe. Its light curve shows little evidence of the expected drop from the optically thick phase to the radioactively powered tail. The velocities derived from the absorption in H α are also unusually high with the blue edge tracing the fastest moving gas initially at 20 000 km s-1, and then declining approximately linearly to 15 000 km s-1 over ∼100 d. The dwarf host galaxy of the SN indicates a low-metallicity progenitor which may also contribute to the weakness of the metal lines in its spectra. We examine SN 2016gsd with reference to similarly luminous, linear Type II SNe such as SNe 1979C and 1998S, and discuss the interpretation of its observational characteristics. We compare the observations with a model produced by the jekyll code and find that a massive star with a depleted and inflated hydrogen envelope struggles to reproduce the high luminosity and extreme linearity of SN 2016gsd. Instead, we suggest that the influence of interaction between the SN ejecta and circumstellar material can explain the majority of the observed properties of the SN. The high velocities and strong H α absorption present throughout the evolution of the SN may imply a circumstellar medium configured in an asymmetric geometry. ; MF acknowledges the support of a Royal Society – Science Foundation Ireland University Research Fellowship. The JEKYLL simulations were performed on resources provided by the Swedish National Infrastructure for Computing (SNIC) at Parallelldatorcentrum (PDC). PL acknowledges support from the Swedish Research Council. MS is supported by a generous grant (13261) from Villum Fonden and a project grant (8021-00170B) from the Independent Research Fund Denmark (IRFD). NUTS2 is funded in part by the Instrument Center for Danish Astronomy (IDA). This work is based (in part) on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile as part of PESSTO (the Public ESO Spectroscopic Survey for Transient Objects) ESO program 188.D−3003, 191.D−0935, more ESO acknowledgements. 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. The SCUSS is funded by the Main Direction Program of Knowledge Innovation of Chinese Academy of Sciences (No. KJCX2−EW−T06). It is also an international cooperative project between National Astronomical Observatories, Chinese Academy of Sciences, and Steward Observatory, University of Arizona, USA. Technical support and observational assistance from the Bok telescope are provided by Steward Observatory. The project is managed by the National Astronomical Observatory of China and Shanghai Astronomical Observatory. Data resources are supported by Chinese Astronomical Data Center (CAsDC). SD and PC acknowledge Project 11573003 supported by NSFC. This research uses data obtained through the Telescope Access Program (TAP), which has been funded by the National Astronomical Observatories of China, the Chinese Academy of Sciences, and the Special Fund for Astronomy from the Ministry of Finance. SJS acknowledges STFC grant ST/P000312/1. This work has made use of data from the Asteroid Terrestial-impact Last Alert System (ATLAS) Project. ATLAS is primarily funded to search for near earth asteroids through NASA grants NN12AR55G, 80NSSC18K0284, and 80NSSC18K1575; byproducts 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 Univeristy Belfast, the Space Telescope Science Institute, and the South African Astronomical Observatory. OR acknowledges support by projects IC120009 'Millennium Institute of Astrophysics (MAS)' of the Iniciativa Científica Milenio del Ministerio de Economía, Fomento y Turismo de Chile and CONICYT PAI/INDUSTRIA 79090016. JH acknowledges financial support from the Finnish Cultural Foundation. Some data were taken with the Las Cumbres Observatory Network. GH and DAH are supported by NSF grant AST-1313484. GH thanks the LSSTC Data Science Fellowship Program, which is funded by LSSTC, NSF Cybertraining Grant #1829740, the Brinson Foundation, and the Moore Foundation; his participation in the program has benefited this work. 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 also makes use of observations collected at the European Southern Observatory under ESO programme 0103.D-0338(A). CPG acknowledges support from EU/FP7-ERC grant no. [615929].

We present observations of the unusually luminous Type II supernova (SN) 2016gsd. With a peak absolute magnitude of V = -19.95 +/- 0.08, this object is one of the brightest Type II SNe, and lies in the gap of magnitudes between the majority of Type II SNe and the superluminous SNe. Its light curve shows little evidence of the expected drop from the optically thick phase to the radioactively powered tail. The velocities derived from the absorption in( )H alpha are also unusually high with the blue edge tracing the fastest moving gas initially at 20 000 km s(-1), and then declining approximately linearly to 15000 km s(-1) over similar to 100 d. The dwarf host galaxy of the SN indicates a low-metallicity progenitor which may also contribute to the weakness of the metal lines in its spectra. We examine SN 2016gsd with reference to similarly luminous, linear Type II SNe such as SNe 1979C and 1998S, and discuss the interpretation of its observational characteristics. We compare the observations with a model produced by the JEKYLL code and find that a massive star with a depleted and inflated hydrogen envelope struggles to reproduce the high luminosity and extreme linearity of SN 2016gsd. Instead, we suggest that the influence of interaction between the SN ejecta and circumstellar material can explain the majority of the observed properties of the SN. The high velocities and strong H alpha absorption present throughout the evolution of the SN may imply a circumstellar medium configured in an asymmetric geometry. ; Jenny and AnttiWihuri Foundation Vilho, Yrjo and Kalle Vaisala Fund of the Finnish academy of Science and Letters UCD seed funding scheme SF1518 Science Foundation Ireland Swedish Research Council Villum Fonden 13261 Independent Research Fund Denmark (IRFD) 802100170B Instrument Center for Danish Astronomy (IDA) European Organisation for Astronomical Research in the Southern Hemisphere, Chile as part of PESSTO (the Public ESO Spectroscopic Survey for Transient Objects) ESO program 188.D-3003 191.D-0935 National Aeronautics & Space Administration (NASA) NNX08AR22G National Science Foundation (NSF) AST-1238877 Chinese Academy of Sciences KJCX2-EW-T06 Chinese Astronomical Data Center (CAsDC) National Natural Science Foundation of China 11573003 National Astronomical Observatories of China Chinese Academy of Sciences Special Fund for Astronomy from the Ministry of Finance Science & Technology Facilities Council (STFC) ST/P000312/1 National Aeronautics & Space Administration (NASA) NN12AR55G 80NSSC18K0284 80NSSC18K1575 Iniciativa Cientifica Milenio del Ministerio de Economia, Fomento y Turismo de Chile IC120009 CONICYT PAI/INDUSTRIA 79090016 Finnish Cultural Foundation National Science Foundation (NSF) AST-1313484 LSSTC Data Science Fellowship Program - LSSTC NSF Cybertraining Grant 1829740 Brinson Foundation Gordon and Betty Moore Foundation European Union (EU) 839090 European Southern Observatory under ESO programme 0103.D0338(A) EU/FP7-ERC grant 615929

The division between stripped-envelope supernovae (SE-SNe) and superluminous supernovae (SLSNe) is not well-defined in either photometric or spectroscopic space. While a sharp luminosity threshold has been suggested, there remains an increasing number of transitional objects that reach this threshold without the spectroscopic signatures common to SLSNe. In this work, we present data and analysis on four SNe transitional between SE-SNe and SLSNe; the He-poor SNe 2019dwa and 2019cri, and the He-rich SNe 2019hge and 2019unb. Each object displays long-lived and variable photometric evolution with luminosities around the SLSN threshold of Mr < -19.8 mag. Spectroscopically however, these objects are similar to SE-SNe, with line velocities lower than either SE-SNe and SLSNe, and thus represent an interesting case of rare transitional events. ; KM, MRM, and SJP are supported by H2020 ERC grant no. 758638. LG acknowledges financial support from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement no. 839090, and from the Spanish Ministry of Science, Innovation and Universities (MICIU) under the 2019 Ramón y Cajal programme RYC2019-027683. TMB was funded by the CONICYT PFCHA / DOCTORADOBECAS CHILE/2017-72180113. MG is supported by the EU Horizon 2020 research and innovation programme under grant agreement no. 101004719. SGG acknowledges support by FCT under Project CRISP PTDC/FIS-AST-31546/2017. MN is supported by a Royal Astronomical Society Research Fellowship and H2020 ERC grant no. 948381. T-WC acknowledges the EU Funding under Marie Skłodowska-Curie grant H2020-MSCA-IF-2018-842471. The LT 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.