Related papers: Inside the Bondi radius of M87
The hypothesized supermassive black hole in the nucleus of M31 (which we shall hereafter call M31*) has many features in common with Sgr A* at the Galactic Center, yet they differ in several significant and important ways. Though M31* is…
The interplay between supermassive black holes (SMBHs) and their environments is believed to command an essential role in galaxy evolution. The majority of these SMBHs are in the radiative inefficient accretion phase where this interplay…
It has long been recognised that the main obstacle to accretion of gas onto supermassive black holes (SMBHs) is large specific angular momentum. It is feared that the gas settles in a large scale disc, and that accretion would then proceed…
M87, the active galaxy at the center of the Virgo cluster, is ideal for studying the interaction of a supermassive black hole (SMBH) with a hot, gas-rich environment. A deep Chandra observation of M87 exhibits an approximately circular…
Most supermassive black holes (SMBHs) are accreting at very low levels and are difficult to distinguish from the galaxy centers where they reside. Our own Galaxy's SMBH provides a uniquely instructive exception, and we present a close-up…
We analyse the environment of the supermassive black hole (SMBH) in the centre of a massive elliptical galaxy NGC 1275 in the Perseus cluster, hosting the radio source 3C 84. We focus on the young radio lobe observed inside the estimated…
Supermassive black hole (SMBH) masses can be measured using molecular gas kinematics. Here we present high angular resolution ($0.12$ arcsec or $\approx11$ pc) Atacama Large Millimeter/submillimeter Array observations of the $^{12}$CO(2-1)…
Over the past decades, there has been significant progress in our understanding of accreting supermassive black holes (SMBHs) that drive active galactic nuclei (AGNs), both from observational and theoretical perspectives. As an iconic…
We have analysed the soft X-ray emission from the nuclear source of the nearby spiral galaxy M81, using the available data collected with ROSAT, ASCA, BeppoSAX and Chandra. The source flux is highly variable, showing (sometimes dramatic: a…
Chaotic cold accretion (CCA) profoundly differs from classic black hole accretion models. Using 3D high-resolution simulations, we probe the impact of rotation on the hot and cold accretion flow in a typical massive galaxy. In the hot mode,…
We consider the spike mass density profile in a dark halo by self-consistently solving the relativistic Bondi accretion of dark matter onto a non-spining black hole of mass $M$. We assume that the dominant component of the dark matter in…
The radio emission from supermassive black holes in nearby early-type galaxies can be used to test possible explanations for their low luminosities. We calculate the expected contribution from thermal synchrotron emission from hot accretion…
Compact objects are expected to exist in the accretion disks of supermassive black holes (SMBHs) in active galactic nuclei (AGNs), and in the presence of such a dense environment ($\sim 10^{14}\,{\rm cm^{-3}}$), they will form a new kind of…
Some ultraluminous X-ray sources in nearby galaxies show soft components resembling thermal disc emission. Calculations based on blackbody emission then indicate that the accreting black holes at the centres of these discs have masses of…
We study the growth of black holes (BHs) in galaxies using three-dimensional smoothed particle hydrodynamic simulations with new implementations of the momentum mechanical feedback, and restriction of accreted elements to those that are…
We present a new code for performing general-relativistic radiation-hydrodynamics simulations of accretion flows onto black holes. The radiation field is treated in the optically-thick approximation, with the opacity contributed by Thomson…
We present gas and total mass profiles for 13 low-redshift, relaxed clusters spanning a temperature range 0.7-9 keV, derived from all available Chandra data of sufficient quality. In all clusters, gas temperature profiles are measured to…
We present the results of a new global radiation transport code coupled to a general relativistic magneto-hydrodynamic simulation of an accreting, non-rotating black hole. For the first time, we are able to explain from first principles in…
We investigate the properties of accretion flows onto a black hole (BH) with a mass of $M_{\rm BH}$ embedded in an initially uniform gas cloud with a density of $n_{\infty}$ in order to study rapid growth of BHs in the early Universe. In…
Merging supermassive black hole-black hole (BHBH) binaries produced in galaxy mergers are promising sources of detectable gravitational waves. If such a merger takes place in a gaseous environment, there is a possibility of a simultaneous…