Related papers: A Black Hole Nova Obscured by an Inner Disk Torus
The most luminous X-ray sources in nearby elliptical galaxies are likely black hole low-mass X-ray binaries (BHLMXBs). In the Milky Way, such systems are always transient, and with the exception of GRS1915+105 have burst durations on the…
We discuss new observations of X-ray novae which provide strong evidence that black holes have event horizons. Optical observations of 13 X-ray novae indicate that these binary stars contain collapsed objects too heavy to be stable neutron…
Outbursts of the black hole (BH) X-ray binaries are dramatic events occurring in our Galaxy approximately once a year. They are detected by the X-ray telescopes and often monitored at longer wavelengths. We analyse the X-ray and…
We present a detailed spectral analysis of Swift and NuSTAR observations of the very faint X-ray transient and black hole system Swift J1357.2-0933 during an early low hard state of its 2017 outburst. Swift J1357.2-0933 was observed at…
The relative phasing of the X-ray eclipse ephemeris and optical radial velocity (RV) curve for the X-ray binary IC10 X-1 suggests the He[$\lambda$4686] emission-line originates in a shadowed sector of the stellar wind that avoids ionization…
Understanding how black holes accrete and supply feedback to their environment is one of the outstanding challenges of modern astrophysics. Swift J1910.2-0546 is a candidate black hole low-mass X-ray binary that was discovered in 2012 when…
We explore possible systematic errors in the mass measurements of stellar mass black holes. We find that significant errors can arise from the assumption of zero or constant emission from the accretion flow, which is commonly used when…
Stellar-mass black holes (BHs) represent the natural end states of massive stars. It is estimated that $10^8$ stellar-mass BHs are present in the Milky Way galaxy, a significant fraction of which are expected to be isolated. Despite their…
Only a few of the dozen or so stellar-mass black holes have been observed away from the plane of the Galaxy$^1$. Those few could have been ejected from the plane as a result of a ``kick'' received during a supernova explosion, or they could…
We discuss the observational consequences of black hole spin in X-ray binaries within the framework of the standard thin accretion disk model. When compared to theoretical flux distribution from the surface of a thin disk surrounding a Kerr…
Recent discoveries of massive black holes (MBHs) in dwarf galaxies suggest that they may have a more common presence than once thought. Systematic searches are revealing more candidates, but this process could be accelerated by predictions…
Stellar-mass black holes (BHs) are predicted to be embedded in the disks of active galactic nuclei (AGN) due to gravitational drag and in-situ star formation. However, clear evidence for AGN disk-embedded BHs is currently lacking. Here, as…
We report on the results of optical, near-infrared (NIR) and mid-infrared observations of the black hole X-ray binary candidate (BHB) MAXI J1535-571 during its 2017/2018 outburst. During the first part of the outburst (MJD 58004-58012), the…
We present high-time resolution optical spectroscopy and imaging of the black hole transient Swift J1357.2-0933 during its 2017 outburst. The light curves show recurrent dips resembling those discovered during the 2011 outburst. The dip…
Supermassive black holes (SMBHs) at the centers of active galaxies are fed by accretion disks that radiate from the infrared or optical to the X-ray bands. Several types of objects can orbit SMBHs, including massive stars, neutron stars,…
Black hole (BH) spins in low-mass X-ray binaries (LMXBs) cover a range of values that can be explained by accretion after BH birth. In contrast, the three BH spin measurements in high-mass X-ray binaries (HMXBs) show only values near the…
When a star is tidally disrupted by a supermassive black hole (SMBH), the streams of liberated gas form an accretion disk after their return to pericenter. We demonstrate that Lense-Thirring precession in the spacetime around a rotating…
Microlensing is one of the most promising tools for discovering stellar-mass black holes (BHs) in the Milky Way because it allows us to probe dark or faint celestial compact objects. While the existence of stellar-mass BHs has been…
In the past three decades, many stars orbiting about the supermassive black hole (SMBH) at the Galactic Centre (Sgr A*) were identified. Their orbital nature can give stringent constraints for the mass of the SMBH. In particular, the star…
By comparing the orbital period distributions of black hole and neutron star low mass X-ray binaries (LMXBs) in the Ritter-Kolb catalogue we show that there is statistical evidence for a dearth of black hole systems at short orbital periods…