X-Ray Observations of XTE J1550-564 During the Decay of the 2000 Outburst - I. Chandra and RXTE Energy Spectra

Abstract

We report on the evolution of the X-ray energy spectrum for the black hole candidate (BHC) X-ray transient XTE J1550-564 during the decay of the 2000 outburst. The Rossi X-ray Timing Explorer (RXTE) and Chandra observations span nearly five orders of magnitude in luminosity. The RXTE spectra are dominated by a power-law component and a comparatively weak soft component was also detected for the first two observations. The source made a transition to the canonical hard state near a luminosity of 9E36 erg/s over several observations as evidenced by a drop in the flux of the soft component in the RXTE energy band and a hardening of the power-law component to a photon index near 1.6. The power-law did not exhibit this behavior for the previous XTE J1550-564 outburst. For some observations, we detect a high energy cutoff and find that the cutoff is more significant and at lower energy during the transition than in the hard state. The cutoff in the hard state is at higher energy than has been seen for most previous accreting BHCs. The Chandra spectrum provides evidence for spectral evolution after the hard state transition. It is well, but not uniquely, described by a power-law with a photon index of 2.30^{+0.41}_{-0.48} (90% confidence) and interstellar absorption. Advection-dominated accretion flow models predict gradual spectral softening as the luminosity drops, but our observations do not allow us to determine if the spectral evolution is gradual or sudden. The lowest luminosity we measure for XTE J1550-564 with Chandra is 5E32 erg/s (0.5-7 keV, for a distance of 4 kpc). Although this is probably not the true quiescent luminosity, it represents a useful upper limit on this quantity.

10 pages, accepted by ApJ, revisions include an additional conclusion, additions and clarifications to the discussion and some changes in the details of the RXTE spectral analysis

References in corpus (7)

• New Evidence for Black Hole Event Horizons from Chandra
• X-ray states and radio emission in the black hole candidate XTE J1550-564
• The Quiescent X-Ray Spectrum of the Neutron Star in Cen X-4 Observed with Chandra/ACIS-S
• Multiwavelength Observations of the Black Hole Candidate XTE J1550-564 during the 2000 Outburst
• Mapping the inner accretion disk of the galactic black hole J1550-564 through its rise to outburst
• X-Ray Observations of XTE J1550-564 During the Decay of the 2000 Outburst - II. Timing
• A BeppoSAX view of transient black hole candidates in quiescence

Cited by in corpus (60)

• A universal radio/X-ray correlation in low/hard state black hole binaries
• WATCHDOG: A Comprehensive All-Sky Database of Galactic Black Hole X-ray Binaries
• The distances to Galactic low-mass X-ray binaries: consequences for black hole luminosities and kicks
• Dynamical Evidence for a Black Hole in the Microquasar XTE J1550-564
• Evidence for Harmonic Relationships in the High Frequency QPOs of XTE J1550-564 and GRO J1655-40
• On the Origin of Radio Emission in the X-ray States of XTE J1650-500 during the 2001-2002 Outburst
• The Spin of the Black Hole Microquasar XTE J1550-564 via the Continuum-Fitting and Fe-Line Methods
• The X-ray Spectral Evolution of Galactic Black Hole X-ray Binaries Toward Quiescence
• Correlation between the photon index and X-ray luminosity of black hole X-ray binaries and active galactic nuclei: observations and interpretation
• The X-ray Spectra of Black Hole X-ray Novae in Quiescence as Measured by Chandra
• Jet spectral breaks in black hole X-ray binaries
• The Analogous Structure of Accretion Flows in Supermassive and Stellar Mass Black Holes: New Insights from Faded Changing-Look Quasars
• The infrared/X-ray correlation of GX 339-4: Probing hard X-ray emission in accreting black holes
• The gas-to-extinction ratio and the gas distribution in the Galaxy
• Multi-wavelength observations of the Galactic black hole transient 4U1543-47 during outburst decay: state transitions and jet contribution
• Evidence for a compact jet dominating the broadband spectrum of the black hole accretor XTE J1550-564
• Spectral evolution of the microquasar XTE J1550-564 over its entire 2000 outburst
• On the origin of black hole X-ray emission in quiescence: Chandra observations of XTE J1550-564 and H 1743-322
• Spectral and Fourier analyses of X-ray QPO in accreting black holes
• A peculiar spectral state transition of 4U1705--44: when an Atoll looks like a Z
• The X-ray/gamma-ray spectrum of XTE J1550--564 in the very high state
• The 2002 Outburst of the Black-Hole X-ray Binary 4U 1543-47: Optical and Infrared Light Curves
• Detection of Low-Hard State Spectral and Timing Signatures from the Black Hole X-Ray Transient XTE J1650-500 at Low X-Ray Luminosities
• X-Ray Observations of the Black Hole Transient 4U 1630-47 During Two Years of X-Ray Activity
• The 2015 Decay of the Black Hole X-ray Binary V404 Cygni: Robust Disk-Jet Coupling and a Sharp Transition into Quiescence
• Modeling the hard states of XTE J1550--564 during its 2000 outburst
• X-Ray Jet Emission from the Black Hole X-Ray Binary XTE J1550-564 with Chandra in 2000
• The Galactic black hole transient H1743-322 during outburst decay: connections between timing noise, state transitions and radio emission
• A close look at the state transitions of Galactic black hole transients during outburst decay
• An X-ray Timing Study of XTE J1550--564: Evolution of the Low Frequency QPO for the Complete 2000 Outburst
• GRO J1655-40: Early Stages of the 2005 Outburst
• Hard X-ray emission of the microquasar GRO J1655-40 during the rise of its 2005 outburst
• Spectral differences between the jets in `radio loud' and `radio quiet' hard state black hole binaries
• Parallel tracks in infrared versus X-ray emission in black hole X-ray transient outbursts: a hysteresis effect?
• A Low/Hard State Outburst of XTE J1550-564
• The X-ray properties of the black hole transient MAXI J1659-152 in quiescence
• Understanding X-ray Irradiation in Low-Mass X-ray Binaries directly from their Light-Curves
• X-Ray Flares and Oscillations from the Black Hole Candidate X-Ray Transient XTE J1650-500 at Low Luminosity
• Hard X-ray emission of the microquasar GX 339-4 in the low/hard state
• Accretion Disk Spectra of the Brightest Ultra-luminous X-ray Source in M82
• Radio and X-ray observations during the outburst decay of the Black Hole Candidate XTE J1908+094
• Exploring Accretion and Disk-Jet Connections in the LLAGN M81*
• The photon-index - time-lag correlation in black-hole X-ray binaries
• A tool to separate optical/infrared disc and jet emission in X-ray transient outbursts: the colour-magnitude diagrams of XTE J1550-564
• Colours of black holes: infrared flares from the hot accretion disc in XTE J1550-564
• Fast variability as a probe of the smallest regions around accreting black holes
• Chandra and RXTE Spectroscopy of the Galactic Microquasar XTE J1550-564 in Outburst
• X-Ray Observations of XTE J1550-564 During the Decay of the 2000 Outburst - II. Timing
• Radio Variability from a Quiescent Stellar Mass Black Hole Jet
• Observations of the Disk/Jet Coupling of MAXI J1820+070 During its Descent to Quiescence
• The MAVERIC survey: A hidden pulsar and a black hole candidate in ATCA radio imaging of the globular cluster NGC 6397
• Studying the accretion geometry of EXO 2030+375 at luminosities close to the propeller regime
• GRS 1739-278 observed at very low luminosity with XMM-Newton and NuSTAR
• NIR and optical observations of the failed outbursts of black hole binary XTE J1550-564
• The X-ray Properties of Million Solar Mass Black Holes
• A Lack of Radio Emission from Neutron Star Low Mass X-ray Binaries
• Broadband X-ray spectrum of XTE J1550-564 during 2003 outburst
• Alignment and precession of a black hole misaligned with its accretion disc: Application to Low Mass X-ray Binaries
• A Study of the Variation of Geometry of Accretion Flows of Compact Objects through Timing and Spectral Analysis of Their Outbursts
• A model for 3:2 HFQPO pairs in black hole binaries based on cosmic battery