A survey for radio emission from white dwarfs in the VLA Sky Survey

Pelisoli, Ingrid; Chomiuk, Laura; Strader, Jay; Marsh, T. R.; Aydi, Elias; Dage, Kristen C.; Kyer, Rebecca; Molina, Isabella; Panurach, Teresa; Urquhart, Ryan; Maccarone, Thomas J.; Rich, R. Michael; Rodriguez, Antonio C.; Breedt, E.; Brown, A. J.; Dhillon, V. S.; Dyer, M. J.; Gaensicke, Boris T.; Garbutt, J. A.; Green, M. J.; Kennedy, M. R.; Kerry, P.; Littlefair, S. P.; Munday, James; Parsons, S. G.
Referencia bibliográfica

Monthly Notices of the Royal Astronomical Society

Fecha de publicación:
6
2024
Número de autores
25
Número de autores del IAC
1
Número de citas
2
Número de citas referidas
2
Descripción
Radio emission has been detected from tens of white dwarfs, in particular in accreting systems. Additionally, radio emission has been predicted as a possible outcome of a planetary system around a white dwarf. We searched for 3 GHz radio continuum emission in 846 000 candidate white dwarfs previously identified in Gaia using the Very Large Array Sky Survey (VLASS) Epoch 1 Quick Look Catalogue. We identified 13 candidate white dwarfs with a counterpart in VLASS within 2 arcsec. Five of those were found not to be white dwarfs in follow-up or archival spectroscopy, whereas seven others were found to be chance alignments with a background source in higher resolution optical or radio images. The remaining source, WDJ204259.71+152108.06, is found to be a white dwarf and M-dwarf binary with an orbital period of 4.1 d and long-term stochastic optical variability, as well as luminous radio and X-ray emission. For this binary, we find no direct evidence of a background contaminant, and a chance alignment probability of only ≈2 per cent. However, other evidence points to the possibility of an unfortunate chance alignment with a background radio and X-ray emitting quasar, including an unusually poor Gaia DR3 astrometric solution for this source. With at most one possible radio emitting white dwarf found, we conclude that strong (≳1-3 mJy) radio emission from white dwarfs in the 3 GHz band is virtually non-existent outside of interacting binaries.