Related papers: Eccentricity of HLX-1
The black hole candidate X-ray transient XTE J1817-330 was observed by the Swift satellite over 160 days of its 2006 outburst with the XRT and UVOT instruments. At the start of the observations, the XRT spectra show that the 0.6-10 keV…
The black hole X-ray binary source 4U 1543--47 experienced a super-Eddington outburst in 2021, reaching a peak flux of up to $\sim1.96\times10^{-7}\rm erg\ \rm cm^{-2}\ \rm s^{-1}$ ($\sim 8.2$ Crab) in the 2--10\,keV band. Soon after the…
The faintest ultraluminous X-ray sources (ULXs), those with 0.3-10 keV luminosities 1 < L_X/10^39 < 3 erg s^-1, tend to have X-ray spectra that are disk-like but broader than expected for thin accretion disks. These `broadened disk' spectra…
Super-Eddington accretion discs with 3 and 15 dot M_E around black holes with mass 10 M_sun are examined by two-dimensional radiation hydrodynamical calculations extending from the inner disc edge to 5*10^4 r_g and lasting up to \sim 10^6…
We use global three dimensional radiation magneto-hydrodynamical simulations to study accretion disks onto a $5\times 10^8M_{\odot}$ black hole with accretion rates varying from $\sim 250L_{Edd}/c^2$ to $1500 L_{Edd}/c^2$. We form the disks…
We propose that Kozai's phenomenon is responsible for the long-term evolution of stellar orbits near a supermassive black hole. We pursue the idea that this process may be driven by a fossil accretion disc in the centre of our Galaxy,…
We obtained multi-epoch Very Large Telescope (VLT) optical spectroscopic data in 2011 and 2012 on the ultraluminous X-ray source (ULX) NGC 5408 X-1. We confirm that the HeII\lambda4686 line has a broad component with an average FWHM of…
We present time-resolved optical spectroscopy of the counterpart to the high-inclination black hole low-mass X-ray binary Swift J1357.2-0933 in quiescence. Absorption features from the mass donor star were not detected. Instead the spectra…
In this paper we present a combined analysis of data obtained with the Hubble Space Telescope (HST), Very Large Telescope (VLT), and Swift X-ray telescope (XRT) of the intermediate mass black hole ESO 243-49 HLX-1 that were taken 2 months…
The luminous accreting pulsar SMC X-1 is an appropriate target to explore the accretion dynamics. SMC X-1 shows unique quasi-periodic flux variability of 40-65$\,$days known as superorbital modulation. To constrain the accretion structure…
An otherwise dormant supermassive black hole (SMBH) in a galactic nucleus flares up when it tidally disrupts a star passing by. Most of the tidal disruption events (TDEs) and candidates discovered in the optical/UV have broad optical…
X-ray dipping in the black hole binary Cygnus X-1, the Galactic jet source GRO J1655-40 and in low mass X-ray binaries is discussed. It is shown that spectral analysis strongly constrains emission models. Measurement of dip ingress/egress…
Recent observations of Sgr A* give strong constraints for possible models of the physical nature of Sgr A* and suggest the presence of a massive black~hole with M<2 10^6 M_sun surrounded by an accretion disk which we estimate to radiate at…
We present Very Large Telescope optical spectra of the black hole candidate X-ray binary MAXI J1836-194 at the onset of its 2011 outburst. Although the spectrum was taken at the beginning of the outburst and contains a significant…
We study the spectral evolution of the black hole candidate EXO 1846$-$031 during its 2019 outburst, in the 1--150 keV band,with the {\it {Hard X-ray Modulation Telescope}}. The continuum spectrum is well modelled with an absorbed…
Most black hole binaries show large changes in X-ray luminosity caused primarily by variations in mass accretion rate. An important question for understanding black hole accretion and jet production is whether the inner edge of the…
HLX-1, currently the best intermediate-mass black hole candidate, has undergone seven violent outbursts, each with a peak X-ray luminosity of $L_{\mathrm{peak},\mathrm{X}}\sim 10^{42}\ \rm{erg\ s^{-1}}$. Interestingly, the properties of the…
We studied the thermal stability of non-self-gravitating turbulent $\alpha$-discs around supermassive black holes (SMBHs) to test a new type of high-amplitude galactic nucleus flares. By calculating the disc structures, we computed the…
Aims. ESO 243-49 HLX-1, otherwise known as HLX-1, is an intermediate mass black hole (IMBH) candidate located 8" (3.7 Kpc) from the centre of the edge-on S0 galaxy ESO 243-49. How the black hole came to be associated with this galaxy, and…
Outflows are inevitably driven from the disk if the vertical component of the black hole (BH) gravity cannot resist the radiation force. We derive the mass loss rate in the outflows by solving a dynamical equation for the vertical gas…