Gaia Data Release 2 Catalogue of Extremely-low Mass White Dwarf Candidates

Abstract

Extremely-low mass white dwarf stars (ELMs) are M < 0.3 MSun helium-core white dwarfs born either as a result of a common-envelope phase or after a stable Roche-lobe overflow episode in a multiple system. The Universe is not old enough for ELMs to have formed through single-star evolution channels. As remnants of binary evolution, ELMs can shed light onto the poorly understood phase of common-envelope evolution and provide constraints to the physics of mass accretion. Most known ELMs will merge in less than a Hubble time, providing an important contribution to the signal to be detected by upcoming space-based gravitational wave detectors. There are currently less than 150 known ELMs; most were selected by colour, focusing on hot objects, in a magnitude-limited survey of the Northern hemisphere only. Recent theoretical models have predicted a much larger spacial density for ELMs than estimated observationally based on this limited sample. In order to perform meaningful comparisons with theoretical models and test their predictions, a larger well-defined sample is required. In this work, we present a catalogue of ELM candidates selected from the second data release of Gaia (DR2). We have used predictions from theoretical models and analysed the properties of the known sample to map the space spanned by ELMs in the Gaia Hertzsprung-Russell diagram. Defining a set of colour cuts and quality flags, we have obtained a final sample of 5762 ELM candidates down to Teff ~ 5000K.

14 pages, 12 figures. Accepted for publication in MNRAS

References in corpus (13)

• A Massive Pulsar in a Compact Relativistic Binary
• The ELM Survey. I. A Complete Sample of Extremely Low Mass White Dwarfs
• A Survey for Spectroscopic Binaries Among Very Low-Mass Stars
• On type Ia supernovae and the formation of single low-mass white dwarfs
• The masses of PSR J1911-5958A and its white dwarf companion
• The Future is Now: the Formation of Single Low Mass White Dwarfs in the Solar Neighborhood
• Project overview and update on WEAVE: the next generation wide-field spectroscopy facility for the William Herschel Telescope
• PSR J1738+0333: The First Millisecond Pulsar + Pulsating White Dwarf Binary
• Lessons from the curious case of the `fastest' star in Gaia DR2
• Pulsating low-mass white dwarfs in the frame of new evolutionary sequences: I. Adiabatic properties
• The sdA problem I: Physical Properties
• Pulsating low-mass white dwarfs in the frame of new evolutionary sequences: V. Asteroseismology of ELMV white dwarf stars
• HS 2231+2441: an HW Vir system composed by a low-mass white dwarf and a brown dwarf

Cited by in corpus (23)

• The ELM Survey. VIII. 98 Double White Dwarf Binaries
• The Canada-France Imaging Survey: Reconstructing the Milky Way Star Formation History from its White Dwarf Population
• A stripped helium star in the potential black hole binary LB-1
• White dwarf-main sequence binaries from Gaia EDR3: the unresolved 100pc volume-limited sample
• Discovery of 74 new bright ZZ Ceti stars in the first three years of TESS
• Gaia pulsars and where to find them
• The ELM Survey. IX. A Complete Sample of Low Mass White Dwarf Binaries in the SDSS Footprint
• White dwarf and subdwarf stars in the Sloan Digital Sky Survey Data Release 16
• The ELM Survey South. I. An Effective Search for Extremely Low Mass White Dwarfs
• A Systematic Search for Short-period Close White Dwarf Binary Candidates Based on Gaia EDR3 Catalog and Zwicky Transient Facility Data
• Extremely low-mass white dwarf stars observed in Gaia DR2 and LAMOST DR8
• Minute-cadence Observations of the LAMOST Fields with the TMTS: I. Methodology of Detecting Short-period Variables and Results from the first-year Survey
• Clean catalogues of blue horizontal-branch stars using Gaia EDR3
• Convection and rotation boosted prescription of magnetic braking: application to the formation of extremely low-mass white dwarfs
• Quantum ion thermodynamics in liquid interiors of white dwarfs
• UOCS. XIV. Uncovering extremely low mass white dwarfs and blue lurkers in NGC 752
• Uncovering the chemical structure of the pulsating low-mass white dwarf SDSS J115219.99+024814.4
• The closest extremely low-mass white dwarf to the Sun
• Detection of a new sample of Galactic White Dwarfs in the direction of the Small Magellanic Cloud
• A Catalog of 531 White Dwarf Candidates in the Local Galactic Halo from Gaia Data Release 2
• Searching for Low-mass Population III Stars Disguised as White Dwarfs
• Searching for new variable white dwarfs: The discovery of the three new pulsating and three new binary systems
• A new instability domain of CNO-flashing low-mass He-core stars on their early white-dwarf cooling branches