Hyper-runaway and hypervelocity white dwarf candidates in Gaia Data Release 3: Possible remnants from Ia/Iax supernova explosions or dynamical encounters

Andrei P. Igoshev*, Hagai Perets, Na'ama Hallakoun

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

Type Ia and other peculiar supernovae (SNe) are thought to originate from the thermonuclear explosions of white dwarfs (WDs). Some of the proposed channels involve the ejection of a partly exploded WD (e.g. Iax SN remnant) or the companion of an exploding WD at extremely high velocities (>400 km s-1). Characterization of such hyper-runaway/hypervelocity (HVS) WDs might therefore shed light on the physics and origins of SNe. Here we analyse the Gaia DR3 data to search for HVS WDs candidates and peculiar sub-main-sequence (sub-MS) objects. We retrieve the previously identified HVSs and find 46 new HVS candidates. Among these we identify two new unbound WDs and two new unbound sub-MS candidates. The remaining stars are hyper-runaway WDs and hyper-runaway sub-MS stars. The numbers and properties of the HVS WD and sub-MS candidates suggest that extreme velocity ejections (>1000 km s-1) can accompany at most a small fraction of type Ia SNe, disfavouring a significant contribution of the D6-scenario to the origin of Ia SNe. The rate of HVS ejections following the hybrid WD reverse-detonation channel could be consistent with the identified HVSs. The numbers of lower-velocity HVS WDs could be consistent with type Iax SNe origin and/or contribution from dynamical encounters. We also searched for HVS WDs related to known SN remnants but identified only one such candidate.

Original languageEnglish
Pages (from-to)6223-6237
Number of pages15
JournalMonthly Notices of the Royal Astronomical Society
Volume518
Issue number4
DOIs
StatePublished - 1 Feb 2023
Externally publishedYes

Keywords

  • methods: statistical
  • subdwarfs
  • supernovae: general
  • white dwarfs

Fingerprint

Dive into the research topics of 'Hyper-runaway and hypervelocity white dwarf candidates in Gaia Data Release 3: Possible remnants from Ia/Iax supernova explosions or dynamical encounters'. Together they form a unique fingerprint.

Cite this