相关论文: MAXI~J1348--630: Estimating the black hole mass an…

We present the results of X-ray variability and spectral analysis of a sample of 15 new candidates for active galactic nuclei with relatively low-mass black holes (BHs). They are selected from the Second XMM-Newton Serendipitous Source…

We present a discovery of the correlation between the X-ray spectral (photon) index and mass accretion rate observed in AGN NGC 4051. We analyzed spectral transition episodes observed in NGC 4051 using XMM/Newton, Suzaku and RXTE. We…

Based on broadband timing analysis of Insight-HXMT and NICER data from the 2019 outburst of the black hole X-ray binary (BHXRB) MAXI J1348-630, we report the detection of the coexistence and competitive interplay between type-C and type-B…

We present Swift broadband observations of the recently discovered black hole candidate, X-ray transient, XTE J1752-223, obtained over the period of outburst from October 2009 to June 2010. From Swift-UVOT data we confirm the presence of an…

MAXI J1820+070 (optical counterpart ASASSN-18ey) is a black hole candidate discovered through its recent very bright outburst. The low extinction column and long duration at high flux allow detailed measurements of the accretion process to…

We have compared the 2001 XMM-Newton spectra of the stellar mass black hole binary XTE J1650-500 and the active galaxy MGC-6-30-15, focusing on the broad, excess emission features at ~4--7 keV displayed by both sources. Such features are…

In this paper, we investigate the black hole (BH) spin contribution to jet power, especially for the magnetic arrested disk (MAD), where only inner accretion disk luminosity is closely coupled with the spin-jet power, and try to explain the…

Black hole X-ray binaries (BHXRBs) play a crucial role in understanding the accretion of matter onto a black hole. Here, we focus on exploring the transient BHXRB \source~discovered by Swift/BAT and MAXI/GSC during its January 2019…

We report on six Chandra and one HST/WFC3 observation of CXO J122518.6+144545, discovered by Jonker et al. (2010) as a candidate hyperluminous X-ray source (HLX), X-ray bright supernova or recoiling supermassive black hole at $L_X = 2.2…

The supermassive black holes ($M_{\rm BH} \sim 10^{6}$$-$$10^{10}~M_\odot$) that power luminous active galactic nuclei (AGNs), i.e., quasars, generally show a correlation between thermal disk emission in the ultraviolet (UV) and coronal…

We present the timing analysis results of MAXI J1803$-$298, a black hole candidate, during its 2021 outburst using data obtained from the \textit{Insight-}HXMT and \textit{NICER} telescopes. Our analysis reveals that the source undergoes a…

Recently we discovered an unprecedented supermassive black hole binary (SMBHB) candidate in the nearby Seyfert galaxy SDSS J1430+2303, which is predicted to merge within three years. X-ray spectroscopy may bring unique kinematic evidence…

We report on our attempt to understand the outbursting profile of Galactic Black Hole (GBH) sources, keeping in mind the evolution of temporal and spectral features during the outburst. We present results of evolution of Quasi-periodic…

Black hole accretion disks appear to produce invariably plasma outflows that result in blue-shifted absorption features in their spectra. The X-ray absorption-line properties of these outflows are quite diverse, ranging in velocity from…

In a recent work we demonstrated that a novel X-ray scaling method, originally introduced for Galactic black holes (GBHs), can be reliably extended to estimate the mass of supermassive black holes accreting at a moderate to high level. Here…

XTE J1118+480 is a well established black hole candidate with a mass estimate in the range from 7 to 10 solar masses. With BeppoSAX we observed the source 4 times, from April to December 2000. Results of the firs t observation were already…

We present the results of a weekly monitoring of the new black hole candidate X-ray binary MAXI J1631-472 carried out with the MeerKAT radio interferometer, the Neil Gehrels Swift Observatory, and the Monitor of All-sky X-ray Image (MAXI)…

We present results from quasi-simultaneous multiwavelength observations of the Galactic black hole X-ray transient MAXI J1820$+$070 during the decay of the 2018 outburst and its entire subsequent mini-outburst in March 2019. We fit the…

The recurring transient outbursts in low-mass X-ray binaries (LMXBs) provide us with strong test-beds for constraining the poorly understood accretion process. While impossible to image directly, phase-resolved spectroscopy can provide a…

We re-investigated the `spectro-temporal' behaviour of the source XTE J1859+226 in X-rays during its outburst phase in 1999, by analysing the RXTE PCA/HEXTE data in 2 - 150 keV spectral band. Detailed analysis shows that although the…