Galactic Ultracompact X-ray Binaries: Disk Stability and Evolution

Abstract

We study the mass transfer rates and disk stability conditions of ultracompact X-ray binaries (UCXBs) using empirical time-averaged X-ray luminosities from Paper I (Cartwright et al. 2013) and compiled information from the literature. The majority of UCXBs are consistent with evolutionary tracks for white dwarf donors. Three UCXBs with orbital periods longer than 40 minutes have mass transfer rates above 10^{-10} Msun/year, inconsistent with white dwarf donor tracks. We show that if helium star donors can retain their initial high entropy, they can explain the observed mass transfer rates of these UCXBs. Several UCXBs show persistent luminosities apparently below the disk instability limit for irradiated He accretion disks. We point out that a predominantly C and/or O disk (as observed in the optical spectra of several) lowers the disk instability limit, explaining this disagreement. The orbital period and low time-averaged mass transfer rate of 2S 0918-549 provide evidence that the donor star is a low-entropy C/O white dwarf, consistent with optical spectra. We combine existing information to constrain the masses of the donors in 4U 1916-053 (0.064+-0.010 Msun) and 4U 1626-67 (<0.036 Msun for a 1.4 Msun neutron star). We show that 4U 1626-67 is indeed persistent, and not undergoing a transient outburst, leaving He star models as the best explanation for the donor.

arXiv comment13 pages, 7 figures, ApJ in press

References in corpus (93)

• Modules for Experiments in Stellar Astrophysics (MESA)
• Common Envelope Evolution: Where we stand and how we can move forward
• The disc instability model of dwarf-novae and low-mass X-ray binary transients
• Thermonuclear (type-I) X-ray bursts observed by the Rossi X-ray Timing Explorer
• Evolutionary Binary Sequences for Low- and Intermediate-Mass X-ray Binaries
• The Neutron Star Mass-Radius Relation and the Equation of State of Dense Matter
• Photospheric radius expansion X-ray bursts as standard candles
• Magnetic Fields of Accreting X-Ray Pulsars with the Rossi X-Ray Timing Explorer
• X-ray irradiation in low mass binary systems
• Formation and evolution of compact binaries in globular clusters: II. Binaries with neutron stars
• Evidence for a Massive Neutron Star from a Radial-Velocity Study of the Companion to the Black Widow Pulsar PSR B1957+20
• Superhumps in Cataclysmic Binaries. XXV. q_crit, epsilon(q), and Mass-Radius
• Discovery of a Second Millisecond Accreting Pulsar: XTE J1751-305
• Transformation of a Star into a Planet in a Millisecond Pulsar Binary
• Six new candidate ultracompact X-ray binaries
• Discovery of a High-Latitude Accreting Millisecond Pulsar in an Ultracompact Binary
• White Dwarf Donors in Ultracompact Binaries: The Stellar Structure of Finite Entropy Objects
• Further Constraints on Thermal Quiescent X-ray Emission from SAX J1808.4-3658
• In-Orbit Performance of MAXI Gas Slit Camera (GSC) on ISS
• On the possibility of a helium white dwarf donor in the presumed ultracompact binary 2S 0918-549
• The Symbiotic Neutron Star Binary GX 1+4/V2116 Ophiuchi
• The chemical composition of donors in AM CVn stars and ultra-compact X-ray binaries: observational tests of their formation
• Models of Type I X-Ray Bursts in 4U 1820-30
• Orbital Variability in the Eclipsing Pulsar Binary PSR B1957+20
• Formation of Short-Period Binary Pulsars in Globular Clusters
• Optical spectra of the carbon-oxygen accretion discs in the ultra-compact X-ray binaries 4U 0614+09, 4U 1543-624 and 2S 0918-549
• Ultracompact X-Ray Binaries with Neon-Rich Degenerate Donors
• High-Speed Optical Photometry of the Ultracompact X-ray Binary 4U 1626-67
• Stability of helium accretion discs in ultracompact binaries
• Binary and Long-Term (Triple?) Modulations of 4U 1820$-$30 in NGC 6624
• Circumbinary disks and cataclysmic variable evolution
• Optical spectroscopy of (candidate) ultra-compact X-ray binaries: constraints on the composition of the donor stars
• Double-Peaked X-Ray Lines from the Oxygen/Neon-Rich Accretion Disk in 4U1626-67
• Spin-Down of Radio Millisecond Pulsars at Genesis
• Ultra-compact (X-ray) binaries
• Formation of black-hole X-ray binaries in globular clusters
• The evolution of ultracompact X-ray binaries
• The Thermal Evolution of the Donors in AM CVn Binaries
• Discovery of a Second Transient Low-Mass X-ray Binary in the Globular Cluster NGC 6440
• INTEGRAL spectroscopy of the accreting millisecond pulsar XTE J1807-294 in outburst
• What ignites on the neutron star of 4U 0614+091?
• Ultracompact Binaries as Bright X-Ray Sources in Elliptical Galaxies
• Common envelope: on the mass and the fate of the remnant
• Theoretical Considerations on the Properties of Accreting Millisecond Pulsars
• On the formation of neon-enriched donor stars in ultracompact X-ray binaries
• Ultracompact X-ray Binaries in Globular Clusters: Variability of the Optical Counterpart of X1832-330 in NGC 6652
• An ultracompact X-ray binary in the globular cluster M15 (NGC7078)
• Formation of Ultracompact X-ray Binaries in Dense Star Clusters
• Accelerated Orbital Expansion And Secular Spin Down of the Accreting Millisecond Pulsar SAX J1808.4-3658
• Creating ultra-compact binaries in globular clusters through stable mass transfer
• Discovery of a 205.89 Hz accreting-millisecond X-ray pulsar in the globular cluster NGC 6440
• New Torque Reversal and Spin-Up of 4u 1626- 67 Observed by Fermi/GBM and Swift/BAT
• Galactic Populations of Ultracompact Binaries
• BeppoSAX study of the broad-band properties of luminous globular cluster X-ray sources
• Detection of negative superhumps in a LMXRB -- an end to the long debate on the nature of V1405 Aql (X1916-053)
• Population synthesis of ultracompact X-ray binaries in the Galactic Bulge
• Optical Observations of SAX J1808.4-3658 During Quiescence
• X-Ray Spectroscopy of the Low-Mass X-ray Binaries 2S 0918-549 and 4U1543-624: Evidence for Neon-Rich Degenerate Donors
• The Orbital Period of the Ultracompact Low-Mass X-Ray Binary 4U 1543--624
• Eclipse Timings of the Transient Low Mass X-ray Binary EXO0748-676. IV. The Rossi X-Ray Timing Explorer Eclipses
• Timing of the 2008 Outburst of SAX J1808.4-3658 with XMM-Newton: A Stable Orbital Period Derivative over Ten Years
• On the nature of two low M-dot X-ray bursters: 1RXS J170854.4-321857 and 1RXS J171824.2-402934
• Timing Analysis of the Light Curve of the Dipping-Bursting X-ray Binary X1916-053
• Time-resolved optical photometry of the ultra-compact binary 4U0614+091
• Hot White Dwarf Donors in Ultracompact X-Ray Binaries
• An ultracompact X-ray binary in the globular cluster NGC 1851
• Radius-expansion burst spectra from 4U 1728-34: an ultracompact binary?
• Hydrogen-Poor Disks in Compact X-Ray Binaries
• VLT spectroscopy and non-LTE modeling of the C/O-dominated accretion disks in two ultracompact X-ray binaries
• Measuring the spin up of the Accreting Millisecond Pulsar XTE J1751-305
• High-resolution X-ray spectroscopy of the ultracompact LMXB pulsar 4U 1626-67
• XMM-Newton Spectroscopy of the Accretion-Driven Millisecond X-ray Pulsar XTE J1751-305 in Outburst
• Superhumps: Confronting Theory with Observation
• X-ray Spectroscopy of Candidate Ultracompact X-ray Binaries
• Adiabatic Mass Loss and the Outcome of the Common Envelope Phase of Binary Evolution
• Formation of the planet around the millisecond pulsar J1719-1438
• The Likely Orbital Period of the Ultracompact Low-Mass X-Ray Binary 2S 0918-549
• A relativistically broadened O VIII Lyalpha line in the ultra-compact X-ray binary 4U 0614+091
• Long-term luminosity behavior of 14 ultracompact X-ray binaries
• X-ray Spectroscopy of the Accreting Millisecond Pulsar XTE J0929-314 in Outburst
• Parameterization studies of the properties of the X-ray dips for Low Mass X-ray binary X1916-053
• Spectral and temporal changes associated with flux enhancement in 4U 1626-67
• Discovery of a broad O VIII Ly alpha line in the ultra-compact X-ray binary 4U 1543-624
• Very long-term X-ray variations in LMXBs: solar cycle-like variations in the donor?
• The UV Spectrum of the Ultra-compact X-ray Binary- 4U 1627-673
• Galactic Ultracompact X-ray Binaries: Empirical Luminosities
• Angular Momentum Loss Mechanisms in Cataclysmic Variables below the Period Gap
• Dynamical Ne K Edge and Line Variations in the X-Ray Spectrum of the Ultra-compact Binary 4U 0614+091
• Accretion-powered Millisecond Pulsar Outbursts
• The Connection Between Low-Mass X-ray Binaries and (Millisecond) Pulsars: A Binary Evolution Perspective
• Time-resolved X-Shooter spectra and RXTE light curves of the ultra-compact X-ray binary candidate 4U 0614+091
• Millihertz Quasi-periodic Optical Oscillations in 4U 0614+091
• Fast Optical and X-ray Variability in the UCXB 4U0614+09

Cited by in corpus (54)

• The Evolution of Compact Binary Star Systems
• Deep radio imaging of 47 Tuc identifies the peculiar X-ray source X9 as a new black hole candidate
• Accretion disc atmospheres and winds in low-mass X-ray binaries
• Black holes and fundamental fields in Numerical Relativity: initial data construction and evolution of bound states
• Disentangling Coalescing Neutron Star-White Dwarf Binaries for LISA
• The demographics of neutron star - white dwarf mergers: rates, delay-time distributions and progenitors
• Observatory science with eXTP
• Low Mass X-ray Binaries: The Effects of the Magnetic Braking Prescription
• Formation of millisecond pulsars with helium white dwarfs, ultra-compact X-ray binaries and gravitational wave sources
• Detectability of ultra-compact X-ray binaries as LISA sources
• The nature of very faint X-ray binaries; hints from light curves
• Thermal evolution and quiescent emission of transiently accreting neutron stars
• Ultra-compact X-ray binaries with He star companions
• Novel modelling of ultra-compact X-ray binary evolution - stable mass transfer from white dwarfs to neutron stars
• Evolution of intermediate-mass X-ray binaries driven by magnetic braking of Ap/Bp stars: I. ultracompact X-ray binaries
• UltraCompCAT: a comprehensive Catalogue of Ultra-Compact and Short Orbital Period X-ray Binaries
• Multi-messenger-Athena Synergy White Paper
• Reversing the verdict: Cataclysmic variables could be the dominant progenitors of AM CVn binaries after all
• Ultra-compact X-ray binaries as dual-line gravitational-wave sources
• Population synthesis of classical low-mass X-ray binaries in the Galactic Bulge
• The Galactic LMXB Population and the Galactic Centre Region
• Magnetic braking with MESA evolutionary models in the single star and LMXB regimes
• Effects of Irradiation on the Evolution of Ultra-compact X-ray Binaries
• Formation and Evolution of Ultraluminous X-ray Pulsar Binaries to Pulsar-Neutron Star and Pulsar-White Dwarf Systems
• HST spectrum and timing of the ultra-compact X-ray binary candidate 47 Tuc X9
• The chemical composition of the accretion disk and donor star in Ultra Compact X-ray Binaries: A comprehensive X-ray analysis
• Formation of black widows through ultra-compact X-ray binaries with He star companions
• Galactic Ultracompact X-ray Binaries: Empirical Luminosities
• Evolution of Low-Mass X-ray Binaries: the Effect of Donor Evaporation
• Discovery of a thermonuclear Type I X-ray burst in infrared: new limits on the orbital period of 4U 1728-34
• Thermonuclear explosions on neutron stars reveal the speed of their jets
• A Redshifted Inner Disk Atmosphere and Transient Absorbers in the Ultra-Compact Neutron Star X-ray Binary 4U 1916-053
• Formation and Evolution of Accreting Compact Objects
• Evidence of a non-conservative mass transfer in the ultra-compact X-ray source XB 1916-053
• Broadband X-ray emission and the reality of the broad iron line from the Neutron Star - White Dwarf X-ray binary 4U 1820-30
• Does Nature allow formation of ultra-compact black hole X-ray binaries via accretion-induced collapse of neutron stars?
• Constraining Progenitors of Observed LMXBs Using CARB Magnetic Braking
• Slow Decline and Rise of the Broad [OIII] Emission Line in Globular Cluster Black Hole Candidate RZ2109
• Compact Objects in close orbits as Gravitational Wave Sources: Formation Scenarios and Properties
• Evolving ONe WD+He WD systems to ultra-compact X-ray binaries
• PSR J1953+1844 probably being the descendant of an Ultra-compact X-ray binary
• Binary Evolution: Roche Lobe Overflow and Blue Stragglers
• On the ultra-compact nature of the neutron star system 1RXS J170854.4-321857: insights from X-ray spectroscopy
• Astrophysics with the Laser Interferometer Space Antenna
• A Spectroscopic Angle on Central Engine Size Scales in Accreting Neutron Stars
• Tracking the Enigmatic Globular Cluster Ultracompact X-ray Binary X1850--087: Extreme Radio Variability in the Hard State
• Evolution of binaries with compact objects in globular clusters
• A tentative 114-minute orbital period challenges the ultra-compact nature of the X-ray binary 4U 1812-12
• Optical spectroscopy of 4U 1812-12: an ultra-compact X-ray binary seen through an H II region
• The first extragalactic ultra-compact X-ray binary : a candidate black hole-white dwarf system
• Ultra-compact X-ray Binaries: A Review
• Algorithms and radiation dynamics for the vicinity of black holes I. Methods and codes
• Chandra/LETGS Studies of the Collisional Plasma in 4U 1626-67
• Detectability of continuous gravitational waves from planetary-mass companions orbiting compact stars