Related papers: Evidence for the evolutionary sequence of blazars:…
Broad Absorption Line (BAL) QSOs have been suggested to be youthful super-accretors based on their powerful radiatively driven absorbing outflows and often reddened continua. To test this hypothesis, we observed near IR spectra of the…
(Abridged) Using an empirical relation between the broad line region size and optical continuum luminosity, we estimated the black hole mass and accretion rate for 135 AGNs with double-peaked broad emission lines in two samples. With black…
Neutron stars inspiralling into a stellar envelope can accrete at rates vastly exceeding the Eddington limit if the flow develops pressures high enough to allow neutrinos to radiate the released gravitational energy. It has been suggested…
Primordial black holes (PBH) accretion in the late Universe can lead to significant mass growth. A larger mass further accelerates the accretion radiation output for PBHs with initial masses greater than one solar mass, potentially leading…
The relation between accretion disc (thermal emission) and jet (non-thermal emission) in blazars is still a mystery as, typically, the beamed jet emission swamps the disc even in the ultraviolet band where disc emission peaks. In this paper…
Observationally, two main spectral states, i.e., the low/hard state and the high/soft state, are identified in black hole X-ray binaries (BH-XRBs). Meanwhile, the transitions between the two states are often observed. In this paper, we…
The collapse of baryons into extremely massive stars with masses exceeding 10^4 M_Sun in a small fraction of protogalaxies at z > 10 is a promising candidate for the origin of supermassive black holes, some of which grow to a billion solar…
We present evidence for the presence of a transition in the accretion properties of radio-loud sources. For a sample of radio galaxies and radio-loud quasars, selected based on their extended radio properties, the accretion rate is…
The determination of the central black hole mass is crucial to the understanding of AGN physics. In this paper we briefly review some methods that are currently used to estimate the black hole mass of AGNs. Particularly we demonstrate the…
A strong hard X-ray luminosity from a blazar flags the presence of a very powerful jet. If the jet power is in turn related to the mass accretion rate, the most luminous hard X-ray blazars should pinpoint the largest accretion rates, and…
It has been thought that narrow-line Seyfert 1 galaxies are likely to be in the early stages of the evolution of active galaxies. To test this suggestion, the ratios of the central massive black hole (MBH) mass to the bulge mass ($M_{\rm…
We present the results of a multi-frequency, time-averaged analysis of blazars included in the Candidate Gamma-ray Blazar Survey catalog. Our sample consists of 324 $\gamma$-ray detected ($\gamma$-ray loud) and 191 non $\gamma$-ray detected…
The growth of supermassive black holes (BHs) located at the centers of their host galaxies comes mainly from accretion of gas, but how to fuel them remains an outstanding unsolved problem in quasar evolution. This issue can be elucidated by…
The physical origin of optical changing-look AGNs (CLAGNs), characterized by the appearance or disappearance of broad emission lines, is thought to be mainly driven by the variation of the black-hole (BH) accretion rate. In this work, we…
We present a new calibration of the broad-line region (BLR) size-luminosity-velocity relation using a sample of 157 AGNs with reliable Hbeta time-delay (\lag) measurements from Wang & Woo 2024. By incorporating the Eddington ratio as a…
Galactic field black hole (BH) low-mass X-ray binaries (LMXBs) are believed to form in situ via the evolution of isolated binaries. In the standard formation channel, these systems survived a common envelope phase, after which the remaining…
Accretion disks surrounding stellar mass black holes (BHs) have been suggested as potential locations for the nucleosynthesis of light elements, which are our primary observational discriminant of multiple stellar populations within…
We present the results of high signal-to-noise ratio VLT spectropolarimetry of a representative sample of 25 bright type 1 AGN at z<0.37, of which nine are radio-loud. The sample covers uniformly the 5100 A optical luminosity at…
The SEDs of 18 GeV FSRQs are collected and compiled from literature, in which both the jet emission and the accretion disk radiation can be observed, in order to investigate the correlations among their jet power (P_jet), accretion disk…
The cosmological evolution of primordial black holes (PBHs) is considered. A comprehensive view of the accretion and evaporation histories of PBHs across the entire cosmic history is presented, with focus on the critical mass holes. The…