相关论文: Black-hole binaries: life begins at 40 keV
We report on X-ray observations of the black-hole candidate GX 339-4 during its 2006/2007 outburst. The hardness-intensity diagram of all RXTE/PCA data combined shows a q-shaped track similar to that observed in previous outbursts. The…
On 2004 August 15, we observed a fast (shorter than 10 hours) state transition in the bright black-hole transient GX 339-4 simultaneously with RossiXTE and INTEGRAL. This transition was evident both in timing and spectral properties.…
We have analysed X-ray outbursts from several Galactic black hole (GBH) transients, as seen by the ASM on board RXTE. We have used the best estimates of distance and black hole mass to find their luminosity (scaled to the Eddington limit),…
Black hole X-ray binaries show signs of non-thermal emission in the optical/near-infrared range. We analyze the optical/near-infrared SMARTS data on GX339$-$4 over the 2002--2011 period. Using the soft state data, we estimate the…
We report the results of observations with the Rossi X-ray Timing Explorer of the black-hole candidate GX 339-4 during the state transition of 1998. We find that both the X-ray spectrum and the characteristic of the time variability after…
We present the analysis of the high energy emission of the Galactic black hole binary GX 339-4 in a low/hard state at the beginning of its 2004 outburst. The data from 273 ks of INTEGRAL observations, spread over 4 weeks, are analyzed,…
We report on INTEGRAL observations of the bright black-hole transient GX 339-4 performed during the period August-September 2004. Our data cover three different spectral states, namely Hard/Intermediate State, Soft/Intermediate State and…
During the outbursts of black hole X-ray binaries (BHXRBs), their accretion flows transition through several states. The source luminosity rises in the hard state, dominated by non-thermal emission, before transitioning to the…
A black hole spectrum is known to change from the hard state to the soft state when the energy spectral index $\alpha$ ($F_E \propto E^{-\alpha}$) in, say, 2-20 keV range changes from $\alpha \sim 0.5$ to $\sim 1.5$. However, this…
We report on X-ray and soft gamma-ray observations of the black-hole candidate GX 339-4 during its 2007 outburst, performed with the RXTE and INTEGRAL satellites. The hardness-intensity diagram of all RXTE/PCA data combined shows a q-shaped…
We investigate systematically four outbursts of black hole system GX 339-4 observed by the Rossi X-ray Timing Explorer (RXTE) in both spectral and timing domains and find that these outbursts have some common properties although they…
We present an analysis of the relativistic reflection spectra of GX 339-4 during the hard-to-soft transition of its 2021 outburst observed by Insight-HXMT. The strong relativistic reflection signatures in the data suggest a high black hole…
Understanding the dynamics behind black hole state transitions and the changes they reflect in outbursts has become long-standing problem. The X-ray reflection spectrum describes the interaction between the hard X-ray source (the power-law…
We report multiwavelength observations of the black hole transient GX 339-4 during its outburst decay in 2011 using the data from RXTE, Swift and SMARTS. Based on the X-ray spectral, temporal, and the optical/infrared (OIR) properties, the…
The brightest Ultra-Luminous X-ray source (ULX), ESO 243-49 HLX-1, with a 0.2 - 10 keV X-ray luminosity of up to 10^42 erg s^-1, provides the strongest evidence to date for the existence of intermediate mass black holes. Although small…
We present the optical/infra-red lightcurve (O/IR) of the black hole X-ray binary GX 339-4 collected at the SMARTS 1.3m telescope from 2002 to 2010. During this time the source has undergone numerous state transitions including hard-to-soft…
We carried out spectroscopic observations of the candidate black-hole binary GX339-4 during its low-hard and high-soft X-ray states, in 1997 and 1998 respectively. We have found that the spectrum is dominated by emission lines of neutral…
We characterized the evolution of spectral and temporal properties of several Galactic black hole transients observed between 1996-2001 using the data from well sampled PCA observations close to the transition to the low/hard state. We…
We present a study of the spectral properties during state transition of GX 339-4. Data are taken from the 2010 outburst of GX 339-4, which is densely covered by Rossi X-ray Timing Explorer, providing an excellent coverage of the state…
We report on INTEGRAL observations performed during the 2004 outburst of the bright black hole transient GX 339-4. We analysed IBIS and JEM-X public data starting on 9th August and lasting about one month. During this period GX 339-4 showed…