An ultra-massive fast-spinning white dwarf in a peculiar binary system

Abstract

White dwarfs typically have masses in a narrow range centered at about 0.6 solar masses (Msun). Only a few ultra-massive white dwarfs (M>1.2 Msun) are known. Those in binary systems are of particular interest because a small amount of accreted mass could drive them above the Chandrasekhar limit, beyond which they become gravitationally unstable. Using data from the XMM-Newton satellite, we show that the X-ray pulsator RX J0648.0-4418 is a white dwarf with mass > 1.2 Msun, based only on dynamical measurements. This ultra-massive white dwarf in a post-common envelope binary with a hot subdwarf can reach the Chandrasekhar limit, and possibly explode as a Type Ia supernova, when its helium-rich companion will transfer mass at an increased rate through Roche lobe overflow.

Science article and Supporting Online Material are available at http://www.sciencemag.org/ Submitted 13 May 2009; accepted 23 July 2009

References in corpus (10)

• The European Photon Imaging Camera on XMM-Newton: The MOS Cameras
• A Radio Pulsar/X-ray Binary Link
• Are There Magnetars in High Mass X-ray Binaries? The Case of SuperGiant Fast X-Ray Transients
• The age and colors of massive white dwarf stars
• A Massive White Dwarf Companion to the Eccentric Binary Pulsar System PSR B2303+46
• Mass-radius relations for massive white dwarf stars
• The discovery of 13s X-ray pulsations from the hydrogen depleted subdwarf O6 star binary HD49798
• Analysis of a Very Massive DA White Dwarf via the Trigonometric Parallax and Spectroscopic Methods
• On the empirical evidence for the existence of ultra-massive white dwarfs
• FUSE Observation of the Ultramassive White Dwarf PG1658+441

Cited by in corpus (74)

• Hot subluminous stars
• Progenitors of type Ia supernovae
• Spectral models for binary products: Unifying Subdwarfs and Wolf-Rayet stars as a sequence of stripped-envelope stars
• Mass-accreting white dwarfs and type Ia supernovae
• Hot subdwarf binaries from the MUCHFUSS project - Analysis of 12 new systems and a study of the short-period binary population
• The MUCHFUSS project - Searching for hot subdwarf binaries with massive unseen companions: Survey, target selection and atmospheric parameters
• SGRs and AXPs as rotation powered massive white dwarfs
• Hot subdwarf stars in close-up view I. Rotational properties of subdwarf B stars in close binary systems and nature of their unseen companions
• Nickel-Rich Outflows Produced by the Accretion-Induced Collapse of White Dwarfs: Lightcurves and Spectra
• White Dwarf Pulsars as Possible Cosmic Ray Electron-Positron Factories
• The first ultracompact Roche lobe-filling hot subdwarf binary
• Upgraded Giant Metrewave Radio Telescope timing of NGC 1851A: a possible millisecond pulsar-neutron star system
• Evolution Of Post-Impact Remnant Helium Stars In Type Ia Supernova Remnants Within The Single-Degenerate Scenario
• Effects of strong magnetic fields and rotation on white dwarf structure
• The formation of neutron star systems through accretion-induced collapse in white-dwarf binaries
• A stripped helium star in the potential black hole binary LB-1
• The rates of Type Ia Supernovae. II. Diversity of events at low and high redshift
• X-ray and optical observations of the unique binary system HD49798/RXJ0648.0-4418
• The double-degenerate model for the progenitors of type Ia supernovae
• A selection of hot subluminous stars in the GALEX survey I. Correlation with the Guide Star Catalog
• The helium star donor channel for the progenitors of type Ia supernovae with different metallicities
• Massive unseen companions to hot faint underluminous stars from SDSS (MUCHFUSS) - Analysis of seven close subdwarf B binaries
• The hybrid CONe WD + He star scenario for the progenitors of type Ia supernovae
• Helium star evolutionary channel to super-Chandrasekhar mass type Ia supernovae
• Detection of a white dwarf companion to the white dwarf SDSSJ125733.63+542850.5
• An Isolated White Dwarf with 317-Second Rotation and Magnetic Emission
• Magnetic Dipole Moment of SGRs and AXPs Described as Massive and Magnetic White Dwarfs
• CTCV J2056-3014: An X-ray-faint Intermediate Polar Harboring An Extremely Fast-spinning White Dwarf
• Stars stripped in binaries -- the living gravitational wave sources
• Discovery of spin-up in the X-ray pulsar companion of the hot subdwarf HD 49798
• The Chandra ACIS Timing Survey Project: glimpsing a sample of faint X-ray pulsators
• Super-Eddington wind scenario for the progenitors of type Ia supernovae: Accreting He-rich matter onto white dwarfs
• A likely candidate of type Ia supernova progenitors: the X-ray pulsating companion of the hot subdwarf HD 49798
• He-Accreting WDs: AM CVn stars with WD Donors
• Evolving ONe WD+He star systems to intermediate-mass binary pulsars
• The single-degenerate model for the progenitors of accretion-induced collapse events
• X-ray emission from the luminous O-type subdwarf HD 49798 and its compact companion
• Criteria for Dynamical Timescale Mass Transfer of Metal-poor Intermediate-mass Stars
• NICER monitoring of supersoft X-ray sources
• Gravitational waves from fast-spinning white dwarfs
• Discovery of a compact companion to the hot subdwarf star BD+37 442
• The double degenerate system NLTT 11748
• A young contracting white dwarf in the peculiar binary HD 49798/RX J0648.0--4418?
• AR Scorpii and possible gravitational wave radiation from pulsar white dwarfs
• HD 49798: Its History of Binary Interaction and Future Evolution
• White dwarfs in an ungravity-inspired model
• New X-ray observations of the hot subdwarf binary HD49798 / RXJ0648.0-4418
• Search for X-ray emission from subdwarf B stars with compact companion candidates
• Three new X-ray emitting sdO stars discovered with Chandra
• X-rays from Hot Subdwarfs
• Off-centre carbon burning in He-accreting carbon-oxygen white dwarfs
• The nature of the high Galactic latitude O-star HD93521: new results from X-ray and optical spectroscopy
• Hot subdwarf wind models with accurate abundances I. Hydrogen dominated stars HD 49798 and BD+18${}^{\circ }$2647
• Is the X-ray pulsating companion of HD 49798 a possible type Ia supernova progenitor?
• Gravitational waves from SGRs and AXPs as fast-spinning white dwarfs
• A spectroscopic and kinematic survey of fast hot subdwarfs
• Constraints on the winds of hot subdwarf stars from X-ray observations of two sdB binaries with compact companions: CD -30 11223 and PG 1232-136
• Effects of the core-collapse supernova ejecta impact on a rapidly rotating massive companion star
• Follow-up observations of X-ray emitting hot subdwarf star: the He-rich sdO BD +37° 1977
• Mass limits of the extremely fast-spinning white dwarf CTCV J2056-3014
• The first massive compact companion in a wide orbit around a hot subdwarf star
• Hot subdwarfs - Small stars marking important events in stellar evolution
• Similarities of SGRs with low magnetic field and white dwarf pulsars
• The lack of X-ray pulsations in the extreme helium star BD+37${}^{\circ }$442 and its possible stellar wind X-ray emission
• Prospects for the Observation of Continuous Gravitational Waves from Deformed Fast-spinning White Dwarfs
• Formation of millisecond pulsar-helium star binaries
• Timing the X-ray pulsating companion of the hot-subdwarf HD 49798 with NICER
• On the X-ray pulsar HD 49798: a contracting white dwarf with debris disk?
• X-ray observation of the Roche-lobe filling white dwarf plus hot subdwarf system ZTF J213056.71+442046.5
• Gravitational Wave Emission by Accretion of Matter and Magnetic Deformation in Fast Rotating White Dwarfs
• The Stripped-Star Ultraviolet Magellanic Cloud Survey (SUMS): The UV Photometric Catalog and Stripped Star Candidate Selection
• The progenitor of a type Ia supernova with a short delay time?
• X-ray emission from hot subdwarfs with compact companions
• A search for coherent radio emission from RX J0648.0-4418