Indirect evidence for an active radio pulsar in the quiescent state of the transient ms pulsar SAX J1808.4-3658

Abstract

Millisecond radio pulsars are neutron stars that have been spun-up by the transfer of angular momentum during the low-mass X-ray binary phase. The transition from an accretion-powered to a rotation-powered pulsar takes place on evolutionary timescales at the end of the accretion process, however it may also occur sporadically in systems undergoing transient X-ray activity. We have obtained the first optical spectrum of the low mass transient X-ray pulsar SAX J1808.4-3658 in quiescence. Similar to the black widow millisecond pulsar B1957+20, this X-ray pulsar shows a large optical modulation at the orbital period due to an irradiated companion star. Using the brightness of the companion star as a bolometer, we conclude that a very high irradiating luminosity, a factor of ~100 larger than directly observed, must be present in the system. This most likely derives from a rotation-powered neutron star that resumes activity during quiescence.

arXiv commentAccepted for publication on ApJL (3 pages +2 color figures, references added)

References in corpus (25)

• Correcting for the Effects of Interstellar Extinction
• On the Fate of Gas Accreting at a Low Rate onto a Black Hole
• Three-dimensional MHD Simulations of Radiatively Inefficient Accretion Flows
• Crustal Heating and Quiescent Emission from Transiently Accreting Neutron Stars
• The two-hour orbit of a binary millisecond X-ray pulsar
• The Neutron Stars of Soft X-Ray Transients
• Advection-Dominated Accretion and Black Hole Event Horizons
• The Thermal X-ray Spectra of Cen X-4, Aql X-1, and 4U 1608-522 in Quiescence
• The Disk-Magnetosphere Interaction in the Accretion-Powered Millisecond Pulsar SAX J1808.4-3658
• An X-ray Nebula Associated with the Millisecond Pulsar B1957+20
• Quasi-periodic X-ray brightness fluctuations in an accreting millisecond pulsar
• Aquila X-1 from outburst to quiescence: the onset of the propeller effect and signs of a turned-on rotation-powered pulsar
• A Brown Dwarf Companion for the Accreting Millisecond Pulsar SAX J1808.4-3658
• An XMM-Newton study of the 401 Hz accreting pulsar SAX J1808.4-3658 in quiescence
• High-Speed Optical Photometry of the Ultracompact X-ray Binary 4U 1626-67
• The Optical Counterpart to SAX J1808.4-3658 in Quiescence: Evidence of an Active Radio Pulsar?
• On the bolometric quiescent luminosity and luminosity swing of black hole candidate and neutron star low mass X-ray transients
• The first outburst of SAX J1808.4-3658 revisited
• The Optical Counterpart of the Accreting Millisecond Pulsar SAX J1808.4-3658 in Outburst: Constraints on the Binary Inclination
• The optical counterpart to SAX J1808.4-3658: observations in quiescence
• Constraints on the Neutron Star Magnetic Field of the two X-ray Transients SAX J1808.4-3658 and Aql X-1
• A Search for Pulsars in Quiescent Soft X-Ray Transients. I
• Halpha Flares from V404 Cyg in Quiescence
• A XMM-Newton observation during the 2000 outburst of SAX J1808.4-3658
• Coupling Between Periodic and Aperiodic Variability in SAX J1808.4-3658

Cited by in corpus (54)

• A state change in the low-mass X-ray binary XSS J12270-4859
• Global optical/infrared - X-ray correlations in X-ray binaries: quantifying disc and jet contributions
• A state change in the missing link binary pulsar system PSR J1023+0038
• The long-term evolution of the spin, pulse shape, and orbit of the accretion-powered millisecond pulsar SAX J1808.4-3658
• Improved Mass and Radius Constraints for Quiescent Neutron Stars in Omega Cen and NGC 6397
• A Chandra X-ray Observation of the Binary Millisecond Pulsar PSR J1023+0038
• Optical spectroscopy and photometry of SAX J1808.4-3658 in outburst
• X-ray Variability and Evidence for Pulsations from the Unique Radio Pulsar/X-ray Binary Transition Object FIRST J102347.6+003841
• Constraints on Thermal X-ray Radiation from SAX J1808.4-3658 and Implications for Neutron Star Neutrino Emission
• Orbital Evolution of an Accreting Millisecond Pulsar: Witnessing the Banquet of a Hidden Black Widow?
• An X-ray Variable Millisecond Pulsar in the Globular Cluster 47 Tucanae: Closing the Link to Low Mass X-ray Binaries
• A decade of timing an accretion-powered millisecond pulsar: The continuing spin down and orbital evolution of SAX J1808.4-3658
• Evidence for a jet contribution to the optical/infrared light of neutron star X-ray binaries
• Accreting Millisecond X-Ray Pulsars
• Transitional millisecond pulsars
• Disk-jet coupling in low-luminosity accreting neutron stars
• A Chandra X-ray Observatory Study of PSR J1740--5340 and Candidate Millisecond Pulsars in the Globular Cluster NGC 6397
• Neutron Star Radius Measurement with the Quiescent Low-Mass X-ray Binary U24 in NGC 6397
• Engulfing a radio pulsar: the case of PSR J1023+0038
• Chandra X-ray Observations of 12 Millisecond Pulsars in the Globular Cluster M28
• The light curve of the companion to PSR B1957+20
• A Hard X-Ray Power-Law Spectral Cutoff in Centaurus X-4
• Spin frequency distributions of binary millisecond pulsars
• Optical Observations of SAX J1808.4-3658 During Quiescence
• The Reflares and Outburst Evolution in the Accreting Millisecond Pulsar SAX J1808.4-3658: a Disk Truncated Near Co-rotation?
• Multiband Studies of the Optical Periodic Modulation in the X-Ray Binary SAX~J1808.4-3658 during Its Quiescence and 2008 Outburst
• On the timing properties of SAX J1808.4-3658 during its 2015 outburst
• Disks Surviving the Radiation Pressure of Radio Pulsars
• Accreting pulsars: mixing-up accretion phases in transitional systems
• Observations of the 599 Hz Accreting X-ray Pulsar IGR J00291+5934 during the 2004 Outburst and in Quiescence
• Radio pulse search and X-Ray monitoring of SAX J1808.4-3658: What Causes its Orbital Evolution?
• Pulsar Wind Nebulae and the Non-thermal X-Ray Emission of Millisecond Pulsars
• Linking burst-only X-ray binary sources to faint X-ray transients
• The optical counterparts of Accreting Millisecond X-Ray Pulsars during quiescence
• An anti-correlation between X-ray luminosity and H-alpha equivalent width in X-ray binaries
• Radio Timing and Optical Photometry of the Black Widow System PSR J1953+1846A in the Globular Cluster M71
• The optical counterpart of IGR J00291+5934 in quiescence
• System mass constraints for the accreting millisecond pulsar XTE J1814-338 using Bowen fluorescence
• The long-term evolution of the X-ray pulsar XTE J1814-338: a receding jet contribution to the quiescent optical emission?
• Timing analysis of the 2022 outburst of the accreting millisecond X-ray pulsar SAX J1808.4$-$3658: hints of an orbital shrinking
• Detecting gravitational waves from accreting neutron stars
• Discovery of a candidate quiescent low-mass X-ray binary in the globular cluster NGC 6553
• A transient I band excess in the optical spectrum of the accreting millisecond pulsar SAX J1808.4-3658
• The Quiescent Optical and Infrared Counterpart to EXO 0748-676 = UY Vol
• An Accurate Determination of the Optical Periodic Modulation in the X-Ray Binary SAX J1808.4-3658
• The Slow Orbital Evolution of the Accreting Millisecond Pulsar IGR J0029+5934
• A misfired outburst in the neutron star X-ray binary Centaurus X-4
• On the peculiar long-term orbital evolution of the eclipsing accreting millisecond X-ray pulsar SWIFT J1749.4-2807
• The near-IR counterpart of IGR J17480-2446 in Terzan 5
• Astrophysics in 2005
• Search for gamma-ray emission from four accreting millisecond pulsars with Fermi/LAT
• Electromagnetic spin down of a transient accreting millisecond pulsar during quiescence
• The puzzling case of the accreting millisecond X-ray pulsar IGR J00291+5934: flaring optical emission during quiescence
• Deciphering Accretion-Driven Starquakes in Recycled Millisecond Pulsars using Gravitational Waves