Related papers: Jet-accretion system in the nearby mJy Radio Galax…
Low-luminosity active galactic nuclei (LLAGNs) represent the bulk of the AGN population in the present-day universe and they trace the low-level accreting supermassive black holes. In order to probe the accretion and jet physical properties…
Here we discuss the jet production efficiency in a sample of 17 young radio galaxies with measured redshifts, kinematic ages, and nuclear X-ray fluxes, for which the observed luminosities of compact jets/lobes and accretion disks correspond…
We present simultaneous, sub-arcsecond (<=50pc) resolution 5 GHz, 8.4 GHz, and 15 GHz VLA observations of a well-defined sample of sixteen low-luminosity active galactic nuclei (LLAGNs). The radio emission in most of these nuclei does not…
There is a resurgence of interest in black holes sparked by the LIGO-VIRGO detection of stellar black hole mergers and recent astronomical investigations of jets and accretion disks which probe the spacetime geometry of black holes with…
We present the largest visually selected sample of extended ($>$60 arcsec) radio-loud active galactic nuclei (RLAGN) to date, based on the LOw-Frequency Array Two-Metre Sky Survey second data release (LoTSS DR2). From the broader LoTSS DR2…
We explore an accretion model for low luminosity AGN (LLAGN) that attributes the low radiative output to a low mass accretion rate rather than a low radiative efficiency. In this model, electrons are assumed to drain energy from the ions as…
Over recent years there has been mounting evidence that accreting supermassive black holes in active galactic nuclei (AGN) and stellar mass black holes have similar observational signatures: thermal emission from the accretion disk, X-ray…
We present the results of hard-X-ray observations of four broad-line radio galaxies (BLRGs) with the Rossi X-Ray Timing Explorer (RXTE). The original motivation behind the observations was to search for systematic differences between the…
Radiatively inefficient accretion flows (RIAFs) are believed to power supermassive black holes (SMBH) in the underluminous cores of galaxies. Such black holes are typically accompanied by flat-spectrum radio cores indicating the presence of…
We compare accretion and black hole spin as potential energy sources for outbursts from AGN in brightest cluster galaxies (BCGs). Based on our adopted spin model, we find that the distribution of AGN power estimated from X-ray cavities is…
FR0 galaxies constitute the most abundant jet population in the local Universe. With their compact jet structure, they are broadband photon emitters and have been proposed as multi-messenger sources. Recently, these sources have been…
We study the broad emission line blazars detected in the gamma-ray band by the Large Area Telescope onboard the Fermi satellite and with the optical spectrum studied by Shaw et al. (2012, 2013). The observed broad line strength provides a…
The overall classification of X-ray jets has clung to that prevalent in the radio: FRI vs. FRII (including quasars). Indeed, the common perception is that X-ray emission from FRI's is synchrotron emission whereas that from FRII's may be…
Radio relic sources in galaxy clusters are often described as the remnants of powerful radio galaxies. Here we develop a model for the evolution of such relics after the jets cease to supply energy to the lobes. This includes the treatment…
We investigate the extraction of the rotational energy of a black hole under different accreting environment. When the accretion rate is moderate, the accretion disk consists of an outer thin disk and an inner advection-dominated accretion…
Recent advances in general relativistic magnetohydrodynamic modeling of jets offer unprecedented insights into the inner workings of accreting black holes that power the jets in active galactic nuclei (AGN) and other accretion systems. I…
We present an analysis of deep mid- to far-infrared (MFIR) Spitzer photometric observations of the southern 2Jy sample of powerful radio sources (0.05 < z < 0.7), conducting a statistical investigation of the links between radio jet, AGN,…
We present the results of the analysis of a sample of 17 low-luminosity (L_x < 1e42 erg/s), radio loud AGNs in massive galaxies. The sample is extracted from the SDSS database and it spans uniformly a wide range in optical [OIII] emission…
Black hole X-ray binaries display significant stochastic variability on short time-scales (0.01-100 seconds), with a complex pattern of lags in correlated variability seen in different energy bands. This behaviour is generally interpreted…
Black hole accretion and jet production are areas of intensive study in astrophysics. Recent work has found a relation between radio luminosity, X-ray luminosity, and black hole mass. With the assumption that radio and X-ray luminosity are…