Maqola

Three Hypervelocity White Dwarfs in Gaia DR2: Evidence for Dynamically Driven Double-degenerate Double-detonation Type Ia Supernovae

Ken J. ShenDepartment of Astronomy and Theoretical Astrophysics Center, University of California, Berkeley, CA 94720, USA; [email protected]Douglas BoubertInstitute of Astronomy, University of Cambridge, Madingley Rise, Cambridge, CB3 0HA, UKBoris T. GänsickeDepartment of Physics, University of Warwick, Coventry CV4 7AL, UKSaurabh W. JhaDepartment of Physics and Astronomy, Rutgers, the State University of New Jersey, 136 Frelinghuysen Road, Piscataway, NJ 08854, USAJennifer E. AndrewsSteward Observatory, University of Arizona, 933 N. Cherry Avenue, Tucson, AZ 85721, USALaura ChomiukDepartment of Physics and Astronomy, Michigan State University, East Lansing, MI 48824, USARyan J. FoleyDepartment of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064, USAMorgan FraserSchool of Physics, O’Brien Centre for Science North, University College Dublin, Belfield, Dublin 4, IrelandMariusz GromadzkiWarsaw University Astronomical Observatory, Al. Ujazdowskie 4, PL-00-478 Warszawa, PolandJames GuillochonHarvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USAMarissa M. KotzeSouth African Astronomical Observatory, P.O. Box 9, Observatory, 7935, South AfricaKate MaguireAstrophysics Research Centre, School of Mathematics and Physics, Queen’s University Belfast, Belfast BT7 1NN, UKMatthew R. SiebertDepartment of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064, USANathan SmithSteward Observatory, University of Arizona, 933 N. Cherry Avenue, Tucson, AZ 85721, USAJay StraderDepartment of Physics and Astronomy, Michigan State University, East Lansing, MI 48824, USACarles BadenesDepartment of Physics and Astronomy and Pittsburgh Particle Physics, Astrophysics and Cosmology Center (PITT PACC), University of Pittsburgh, 3941 O’Hara Street, Pittsburgh, PA 15260, USAWolfgang KerzendorfEuropean Southern Observatory, Karl-Schwarzschild-Strasse 2, D-85748 Garching bei München, GermanyDetlev KoesterInstitut für Theoretische Physik und Astrophysik, Universität Kiel, D-24098 Kiel, GermanyMarkus KromerHeidelberger Institut für Theoretische Studien, Schloss-Wolfsbrunnenweg 35, D-69118 Heidelberg, GermanyBroxton MilesDepartment of Physics, North Carolina State University, Raleigh, NC 27695, USARüdiger PakmorHeidelberger Institut für Theoretische Studien, Schloss-Wolfsbrunnenweg 35, D-69118 Heidelberg, GermanyJosiah SchwabDepartment of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064, USAOdette TolozaDepartment of Physics, University of Warwick, Coventry CV4 7AL, UKSilvia ToonenAnton Pannekoek Institute for Astronomy, University of Amsterdam, 1090 GE Amsterdam, The NetherlandsDean M. TownsleyDepartment of Physics and Astronomy, University of Alabama, Tuscaloosa, AL, USABrian J. WilliamsSpace Telescope Science Institute, Baltimore, MD 21218, USA

2018en

ABI

Annotatsiya

Abstract Double detonations in double white dwarf (WD) binaries undergoing unstable mass transfer have emerged in recent years as one of the most promising Type Ia supernova (SN Ia) progenitor scenarios. One potential outcome of this “dynamically driven double-degenerate double-detonation” (D 6 ) scenario is that the companion WD survives the explosion and is flung away with a velocity equal to its >1000 km s −1 pre-SN orbital velocity. We perform a search for these hypervelocity runaway WDs using Gaia 's second data release. In this paper, we discuss seven candidates followed up with ground-based instruments. Three sources are likely to be some of the fastest known stars in the Milky Way, with total Galactocentric velocities between 1000 and 3000 km s −1 , and are consistent with having previously been companion WDs in pre-SN Ia systems. However, although the radial velocity of one of the stars is >1000 km s −1 , the radial velocities of the other two stars are puzzlingly consistent with 0. The combined five-parameter astrometric solutions from Gaia and radial velocities from follow-up spectra yield tentative 6D confirmation of the D 6 scenario. The past position of one of these stars places it within a faint, old SN remnant, further strengthening the interpretation of these candidates as hypervelocity runaways from binary systems that underwent SNe Ia.

Hali tarjima qilinmagan

Identifikatorlar

DOI: 10.3847/1538-4357/aad55b

Iqtiboslar va manbalar

3 ta iqtibos0 ta foydalanilgan manba

Koʻrsatkichlar — AkademScholar