Complete RXTE Spectral Observations of the Black Hole X-ray Nova XTE J1550–564

By G. Sobczak, J. E. McClintock, Ronald A. Remillard, W. Cui, A. Levine, E. Morgan, J. Orosz, C. Bailyn. 2000

135 citations recorded by the source corpus.

We report on the X-ray spectral behavior of XTE J1550-564 during its 1998-1999 outburst. XTE J1550-564 is an exceptionally bright X-ray nova and is also the third Galactic black hole candidate known to exhibit quasi-periodic X-ray oscillations above 50 Hz. Our study is based on 209 pointed observations using the PCA and HEXTE instruments on board the Rossi X-Ray Timing Explorer (RXTE) spanning 250 days and covering the entire double-peaked eruption that occurred from 1998 September until 1999 May. The spectra are fitted to a model including multicolor blackbody disk and power-law components. The spectra from the first half of the outburst are dominated by the power-law component, whereas the spectra from the second half are dominated by the disk component. The source is observed in the very high and high/soft outburst states of black hole X-ray novae. During the very high state, when the power-law component dominated the spectrum, the inner disk radius is observed to vary by more than an order of magnitude; the radius decreased by a factor of 16 in one day during a 6.8 crab flare. If the larger of these observed radii is taken to be the last stable orbit, then the smaller observed radius would imply that the inner edge of the disk is inside the event horizon! However, we conclude that the apparent variations of the inner disk radius observed during periods of increased power-law emission are probably caused by the failure of the multicolor disk/power-law model; the actual physical radius of the inner disk may remain fairly constant. This interpretation is supported by the fact that the observed inner disk radius remains approximately constant over 120 days in the high state, when the power-law component is weak, even though the disk flux and total flux vary by an order of magnitude. The mass of the black hole inferred by equating the approximately constant inner disk radius observed in the high/soft state with the last stable orbit for a Schwarzschild black hole is MBH = 7.4 M☉(D/6 kpc)(cos i)-1/2.

Subfields: Astronomy and Astrophysics, Biomedical Engineering

View Paper: https://www.semanticscholar.org/paper/3d36ce6f548212279f80d89358b70cac9b0b5fa8

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Citations in the corpus

A physical model for the continuum variability and QPO in accreting black holes (2011, methodology): “We use RXTE data from the 1998 outburst of XTE J1550-564 (Remillard et al 2002; Sobczak et al 2000; Rao et al 2010; Wilson & Done 2001).”
A Unified Model for Black Hole X-Ray Binary Jets? (2004, background): “In the following we investigate radio and X-ray light curves of four blackhole binaries – GRS 1915+105, GX 339-4, XTE J1859+226 and XTE J1550-564 – undergoing state transitions in order to investigate this point.”
WATCHDOG: A COMPREHENSIVE ALL-SKY DATABASE OF GALACTIC BLACK HOLE X-RAY BINARIES (2015, background): “…McClintock et al. (2001b), [146] Brocksopp et al. (2010b),[147] Frontera et al. (2001), [148] Brocksopp et al. (2010b), [149] Zurita et al. (2006), [150] Sobczak et al. (2000), [151] Remillard et al. (2002), [152] Kubota & Makishima (2004), [153] Rodriguez et al. (2004), [154] Kalemci et al.…”
Multitemperature Blackbody Spectrum of a Thin Accretion Disk around a Kerr Black Hole: Model Computations and Comparison with Observations (2004, background): “Park et al. (2004) studied the 2002 outburst of U1543; Sobczak et al. (2000) analyzed the outburst of J1550 in 1998–1999; and Sobczak et al. (1999) analyzed J1655’s 1996– 1997 outburst.”
The Spin of the Near-Extreme Kerr Black Hole GRS 1915+105 (2006, methodology): “It is well known that fits to PCA spectra of the Crab Nebula reveal residuals as large as 1%, and we therefore added the customary systematic error of 1% to all PCU energy channels using the tool grppha (e.g., Sobczak et al. 2000).”
X-Ray Properties of Black-Hole Binaries (2006, background): “Thirdly, a number of different QPO types were commonly observed over a wide range of luminosities (e.g., Morgan et al. 1997; Sobczak et al. 2000a; Homan et al. 2001).”
Do X-ray binary spectral state transition luminosities vary? (2003, methodology): “The measurement of the X-ray flux comes from Sobczak et al. (2000), with the assumption that the state transition occurred at the luminosity measured in observation number 205.”
X-Ray Spectroscopic Evidence for Intermediate-Mass Black Holes: Cool Accretion Disks in Two Ultraluminous X-Ray Sources (2002, background): “These temperatures differ from those derived from the spectra of stellar-mass black holes in bright states; in such spectrakT ’ 1 keV is typical (e.g., Sobczak et al. 2000) but temperatures can reach to nearly 2 keV in extreme cases.”
AN IMPROVED DYNAMICAL MODEL FOR THE MICROQUASAR XTE J1550−564 (2011, background): “Within a few weeks thereafter, it reached an intensity of ∼2.5 Crab and maintained that level for a few months before it slipped below the threshold of RXTE (a few mCrab) in mid-1999 (Sobczak et al. 2000).”
Measuring the spins of accreting black holes (2011, background): “Then, just as quickly, the source intensity declined to its pre-outburst level (Sobczak et al 2000).”
The spin of the black hole microquasar XTE J1550−564 via the continuum-fitting and Fe-line methods (2010, background): “The flux in the dominant power-law component rose by the same factor and then just as quickly its intensity declined (Sobczak et al. 2000; McClintock et al. 2009).”
Dynamical Evidence for a Black Hole in the Microquasar XTE J1550–564 (2001, background): “The spectral analysis of Sobczak et al. (2000) for the intense flare of 1998 September 19 implies an unabsorbed flux of 3:7 10 7 ergs cm 2 s 1 over the range of 1–20 keV, with the spectrum dominated by the power-law component.”
Characterizing the Quasi-periodic Oscillation Behavior of the X-Ray Nova XTE J1550–564 (2002, methodology): “…observations during the 1998-1999 outburst, the X-ray power spectra of XTE J1550[564 exhibit quasiperiodic oscillations (QPOs) at both high frequencies (HFQPOs; D100È285 Hz; Remillard et al. 1999a ; Homan et al. 2001) and low frequencies (LFQPOs; 0.08È18 Hz; Cui et al. 1999 ; Sobczak et al. 2000a).”
Evidence for Harmonic Relationships in the High-Frequency Quasi-periodic Oscillations of XTE J1550–564 and GRO J1655–40 (2002, methodology): “The typical flux uncertainties (see Table 3 of Sobczak et al. 2000b) are in the range 0:2 0:3ð Þ 10 8 ergs cm 2 s 1, which is smaller than the symbol size in Figure 5.”
Correlated X-Ray Spectral and Timing Behavior of the Black Hole Candidate XTE J1550–564: A New Interpretation of Black Hole States (2000, methodology): “It should be noted that the values for the temperature are read from the CD; values obtained from spectral fits yield a maximum temperature of ∼1.1 keV (instead of 1.05 keV), see Sobczak et al. (2000c).”
The evolution of the timing properties of the black-hole transient GX 339-4 during its 2002/2003 outburst (2005, unknown): “XTE J1550– 564 also showed the more common QPO-type associated with a flat-top noise component (see Cui et al. 1999 and Sobczak et al. 2000).”