X-ray observation of the Roche-lobe filling white dwarf plus hot subdwarf system ZTF J213056.71+442046.5
arXiv:2204.09127 · doi:10.3847/1538-4357/ac686e
Abstract
ZTF J213056.71+442046.5 is the prototype of a small class of recently discovered compact binaries composed of a white dwarf and a hot subdwarf that fills its Roche-lobe. Its orbital period of only 39 min is the shortest known for the objects in this class. Evidence for a high orbital inclination (i=86 deg) and for the presence of an accretion disk has been inferred from a detailed modeling of its optical photometric and spectroscopic data. We report the results of an XMM-Newton observation carried out on 2021 January 7. ZTF J213056.71+442046.5 was clearly detected by the Optical Monitor, which showed a periodic variability in the UV band (200-400 nm), with a light curve similar to that seen at longer wavelengths. Despite accretion on the white dwarf at an estimated rate of the order of 10^{-9} M_sun/yr, no X-rays were detected with the EPIC instrument, with a limit of ~10^{30} erg/s on the 0.2-12 keV luminosity. We discuss possible explanations for the lack of a strong X-ray emission from this system.
Accepted for publication on The Astrophysical Journal
References in corpus (17)
- The Gaia mission
- The Zwicky Transient Facility: System Overview, Performance, and First Results
- Estimating distances from parallaxes. V: Geometric and photogeometric distances to 1.47 billion stars in Gaia Early Data Release 3
- HI4PI: A full-sky HI survey based on EBHIS and GASS
- The Second-Generation Guide Star Catalog: Description and Properties
- The hot subdwarf B + white dwarf binary KPD 1930+2752 - a Supernova Type Ia progenitor candidate
- Hot subdwarf binaries from the MUCHFUSS project - Analysis of 12 new systems and a study of the short-period binary population
- An ultra-massive fast-spinning white dwarf in a peculiar binary system
- Evolution of Low-Mass Helium Stars in Semidetached Binaries
- The first ultracompact Roche lobe-filling hot subdwarf binary
- A hot subdwarf-white dwarf super-Chandrasekhar candidate supernova Ia progenitor
- A new class of Roche lobe-filling hot subdwarf binaries
- PTF1 J082340.04+081936.5: A hot subdwarf B star with a low mass white dwarf companion in an 87 minute orbit
- Discovery of a double detonation thermonuclear supernova progenitor
- Phases of Mass Transfer from Hot Subdwarfs to White Dwarf Companions and Their Photometric Properties
- The OmegaWhite survey for short-period variable stars - V. Discovery of an ultracompact hot subdwarf binary with a compact companion in a 44 minute orbit
- Constraints on the winds of hot subdwarf stars from X-ray observations of two sdB binaries with compact companions: CD -30 11223 and PG 1232-136