相关论文: Accretion and nuclear activity in Virgo early-type…

New radio continuum observations of galaxies in the Virgo cluster region at 4.85, 8.6, and 10.55 GHz are presented. These observations are combined with existing measurements at 1.4 and 0.325 GHz. The sample includes 81 galaxies were…

(Abridged) We propose a new method to estimate the Bondi (hot gas) accretion rates, \dot M_B, onto the supermassive black holes (SMBHs) at the centres of elliptical galaxies. It can be applied even if the Bondi radius is not well-resolved…

We study the early growth of massive seed black holes (BHs) via accretion in protogalactic nuclei where the stellar bulge component is assembled, performing axisymmetric two-dimensional radiation hydrodynamical simulations. We find that…

M32 hosts a 2.5x10^6 solar mass central black hole, but signs of nuclear activity in this galaxy have long eluded detection. We report the first conclusive detection of the nucleus of M32 in X-rays, based on high-resolution, sensitive…

We present a clustering analysis of X-ray selected AGN by compiling X-ray samples from the literature and re-estimating the dark matter (DM) halo masses of AGN in a uniform manner. We find that moderate luminosity AGN (Lx(2-10…

We present 6 cm Very Large Array observations of the Greene & Ho (2004) sample of 19 low-mass active galaxies with high accretion rates. This is one of the only studies of a uniform sample of narrow-line Seyfert 1 (NLS1) galaxies with such…

Chandra X-ray observations of the giant elliptical galaxy M87 resolve the thermal state of the hot interstellar medium into the accretion (Bondi) radius of its central 3 10^9 Msun black hole. We measure the X-ray gas temperature and density…

Non-blazar radio-galaxies emitting in the very-high-energy (VHE; >100 GeV) regime offer a unique perspective for probing particle acceleration and emission processes in black hole (BH) accretion-jet systems. The misaligned nature of these…

We have selected a sample of X-ray emitting active galactic nuclei (AGNs) in low-mass host galaxies (5e9-2e10 Msun) out to z~1. By comparing to AGNs in more massive hosts, we have found that the AGN spatial number density and the fraction…

We examine the 1.4GHz radio luminosities of galaxies arising from star formation and active galactic nuclei (AGN) within the state-of-the-art cosmological hydrodynamic simulation Simba. Simba grows black holes via gravitational torque…

Recent measurements, of the velocities of stars near the center of the Milky Way have provided the strongest evidence for the presence of a supermassive black hole in a galaxy, but the observational uncertainties poorly constrain many of…

High-resolution simulations of supermassive black holes in isolated galaxies have suggested the importance of short (~10 Myr) episodes of rapid accretion caused by interactions between the black hole and massive dense clouds within the…

Six low-luminosity active galactic nuclei have been imaged at multiple frequencies from 1.7--43 GHz (2.3--15 GHz for three of the galaxies) using the Very Long Baseline Array. In spite of dynamic ranges of about 100 in several frequency…

The globular cluster M15 has recently been found to host a possible central black hole with a mass of ~2000 solar masses. A deep, high-resolution Chandra image failed to detect the "nucleus" of the cluster in X-rays. The upper limit on the…

Only a small fraction of local galaxies harbor an accreting black hole, classified as an active galactic nucleus (AGN). However, many stellar systems are plausibly expected to host black holes, from globular clusters to nuclear star…

The spectral energy distributions of galactic black holes in the low/hard state and of low-luminosity AGN possess many common features, the most prominent being: compact, flat (or inverted) spectrum radio cores with high brightness…

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…

Under the assumption that jets in active galactic nuclei are powered by accretion and the spin of the central supermassive black hole, we are able to reproduce the radio luminosity functions of high- and low-excitation galaxies.…

If a black hole formed in a core-collapse supernova is accreting material from the base of the envelope, the accretion luminosity could be observable in the supernova light curve. Here we continue the study of matter fall back onto a black…

An attempt is made to reconcile the large wind-loss rates of stars in the Galactic Centre (GC) with the predicted low accretion rate for Sgr A*, the putative blackhole at the heart of the Milky Way. It is found that, independent of the…