Roberto Raddi, M. A. Hollands, D. Koester, J. J. Hermes, B. T. Gansicke, Ulrich Heber, Ken J. Shen, D. M. Townsley, Anna Francesca Pala, J. S. Reding, O. F. Toloza, Ingrid Domingos Pelisoli, Stephan Geier, Nicola Pietro Gentile Fusillo, Ullisse Munari, J. Strader
- We report the discovery of three stars that, along with the prototype LP 40-365, form a distinct class of chemically peculiar runaway stars that are the survivors of thermonuclear explosions. Spectroscopy of the four confirmed LP 40-365 stars finds ONe-dominated atmospheres enriched with remarkably similar amounts of nuclear ashes of partial O- and Si-burning. Kinematic evidence is consistent with ejection from a binary supernova progenitor; at least two stars have rest-frame velocities indicating they are unbound to the Galaxy. With masses and radii ranging between 0.20 and 0.28M(circle dot) and between 0.16 and 0.60 R-circle dot, respectively, we speculate these inflated white dwarfs are the partly burnt remnants of either peculiar Type Iax or electron-capture supernovae. Adopting supernova rates from the literature, we estimate that similar to 20 LP 40-365 stars brighter than 19 mag should be detectable within 2 kpc from the Sun at the end of the Gaia mission. We suggest that as they cool, these stars will evolve in theirWe report the discovery of three stars that, along with the prototype LP 40-365, form a distinct class of chemically peculiar runaway stars that are the survivors of thermonuclear explosions. Spectroscopy of the four confirmed LP 40-365 stars finds ONe-dominated atmospheres enriched with remarkably similar amounts of nuclear ashes of partial O- and Si-burning. Kinematic evidence is consistent with ejection from a binary supernova progenitor; at least two stars have rest-frame velocities indicating they are unbound to the Galaxy. With masses and radii ranging between 0.20 and 0.28M(circle dot) and between 0.16 and 0.60 R-circle dot, respectively, we speculate these inflated white dwarfs are the partly burnt remnants of either peculiar Type Iax or electron-capture supernovae. Adopting supernova rates from the literature, we estimate that similar to 20 LP 40-365 stars brighter than 19 mag should be detectable within 2 kpc from the Sun at the end of the Gaia mission. We suggest that as they cool, these stars will evolve in their spectroscopic appearance, and eventually become peculiar O-rich white dwarfs. Finally, we stress that the discovery of new LP 40-365 stars will be useful to further constrain their evolution, supplying key boundary conditions to the modelling of explosion mechanisms, supernova rates, and nucleosynthetic yields of peculiar thermonuclear explosions.…
MetadatenAuthor details: | Roberto RaddiORCiD, M. A. Hollands, D. Koester, J. J. Hermes, B. T. Gansicke, Ulrich HeberORCiDGND, Ken J. ShenORCiDGND, D. M. Townsley, Anna Francesca PalaORCiD, J. S. Reding, O. F. Toloza, Ingrid Domingos PelisoliORCiD, Stephan GeierORCiDGND, Nicola Pietro Gentile Fusillo, Ullisse MunariORCiD, J. Strader |
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DOI: | https://doi.org/10.1093/mnras/stz1618 |
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ISSN: | 0035-8711 |
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ISSN: | 1365-2966 |
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Title of parent work (English): | Monthly notices of the Royal Astronomical Society |
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Publisher: | Oxford Univ. Press |
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Place of publishing: | Oxford |
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Publication type: | Article |
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Language: | English |
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Date of first publication: | 2019/06/21 |
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Publication year: | 2019 |
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Release date: | 2020/11/02 |
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Tag: | Galaxy: kinematics and dynamics; stars: individual: LP 40-365; subdwarfs; supernovae: general; white dwarfs |
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Volume: | 489 |
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Issue: | 2 |
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Number of pages: | 20 |
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First page: | 1489 |
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Last Page: | 1508 |
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Funding institution: | German Science Foundation (DFG)German Research Foundation (DFG) [HE1356/71-1, IR190/1-1]; NASA - Space Telescope Science InstituteSpace Telescope Science InstituteNational Aeronautics & Space Administration (NASA) [HST-HF2-51357.001-A]; NASANational Aeronautics & Space Administration (NASA) [NAS5-26555, NAS 5-26555]; DFGGerman Research Foundation (DFG) [GE 2056-12-1]; Packard FoundationThe David & Lucile Horizon 2020 research and innovation programmeEuropean Research Council (FP/20072013)/ERC [320964]; UK STFC grant [ST/P000495]; Alfred P. Sloan FoundationAlfred P. Sloan Foundation; U.S. Department of Energy Office of ScienceUnited States Department of Energy (DOE); Center for High Performance Computing at the University of Utah; [15431]; [093.D-0431]; [097.D-1029]; [0101.C-0646]; [W/2017A/25]; [W/2017A/30]; [SW2017a12] |
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Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Physik und Astronomie |
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DDC classification: | 5 Naturwissenschaften und Mathematik / 52 Astronomie / 520 Astronomie und zugeordnete Wissenschaften |
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Peer review: | Referiert |
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Publishing method: | Open Access |
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| Open Access / Bronze Open-Access |
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