Related papers: Basic properties of Fermi blazars and the "blazar …
We perform magnetohydrodynamic simulations in full general relativity of disk accretion onto nonspinning black hole binaries with mass ratio 36:29. We survey different disk models which differ in their scale height, total size and magnetic…
Relativistic plasma jets are observed in many accreting black holes. According to theory, coiled magnetic fields close to the black hole accelerate and collimate the plasma, leading to a jet being launched. Isolating emission from this…
It is currently not known if repeating fast radio bursts (FRBs) are fundamentally different from those that have not been seen to repeat. One striking difference between repeaters and apparent non-repeaters in the CHIME sample is that the…
A hyperaccretion disk around a stellar-mass black hole is a plausible model for the central engine that powers gamma-ray bursts (GRBs). We estimate the luminosity of a jet driven by magnetohydrodynamic processes such as the Blandford-Znajek…
We report on optical spectroscopy of 165 Flat Spectrum Radio Quasars (FSRQs) in the Fermi 1LAC sample, which have helped allow a nearly complete study of this population. Fermi FSRQ show significant evidence for non-thermal emission even in…
We investigate the physical properties of \textit{Fermi} TeV BL Lac objects jets by modeling the quasi-simultaneous spectral energy distribution of 29 \textit{Fermi} TeV BL Lacs in the frame of a one-zone leptonic synchrotron self-Compton…
We studied the relation of accretion-jet power and disk luminosity, especially the jet efficiencies and disk radiative efficiencies for different accretion disks as well as black hole (BH) spin, in order to explore the origin of radio…
Blazars are sources whose jet is pointing to us. Since their jets are relativistic, the flux is greatly amplified in the direction of motion, making blazars the most powerful persistent objects in the Universe. This is true at all…
In this presentation, we report the results of intraday variability in the optical (BVRI bands) and hard X-ray band (3-79 keV) in a number of blazars. In the optical microvariability studies of the blazars S5 0716+714 and BL Lac, we…
Hard X-ray observations are crucial to study the non-thermal jet emission from high-redshift, powerful blazars. We observed two bright z>2 flat spectrum radio quasars (FSRQs) in hard X-rays to explore the details of their relativistic jets…
Blazars are classically divided into the BL Lac (BLL) and Flat-Spectrum Radio Quasar (FSRQ) subclasses, corresponding to radiatively inefficient and efficient accretion regimes, respectively, largely based on the equivalent width (EW) of…
We estimate the masses of massive black holes in BL Lac objects from their host galaxy luminosity. The power of jets and central optical ionizing luminosity for a sample of BL Lac objects are derived from their extended radio emission and…
It has been suggested that the prompt emission in gamma-ray bursts consists of several components giving rise to the observed spectral shape. Here we examine a sample of the 8 brightest, single pulsed {\it Fermi} bursts whose spectra are…
Through the modelling of the Spectral Energy Distribution of blazars we can infer the physical parameters required to originate the flux we see. Then we can estimate the power of blazar jets in the form of matter and fields. These estimates…
We study the radio galaxies with known redshift detected by the Fermi satellite after 10 years of data (4FGL-DR2). We use a one-zone leptonic model to fit the quasi-simultaneous multiwavelength data of these radio galaxies and study the…
Fast radio bursts (FRBs) are millisecond-duration intense radio flares occurring at cosmological distances. Many models have been proposed to explain these topical astronomical events, but none has so far been confirmed. Here we show that a…
Using Chandra X-ray observations of 9 nearby, X-ray luminous ellipticals with good optical velocity dispersion measurements, we show that a tight correlation exists between the Bondi accretion rates calculated from the X-ray data and…
Under the hypothesis of gravitational redshift induced by the central supermassive black hole, and based on line widths and shifts of redward shifted H$\beta$ and H$\alpha$ broad emission lines for more than 8000 SDSS DR7 AGNs, we measure…
We fit the spectral energy distributions (SEDs) of a GeV-TeV FSRQ sample with the leptonic model. Their gamma_min of the relativistic electron distributions, which significantly affect the estimates of the jet properties, are constrained,…
Fast radio bursts (FRBs) offer unique probes of diverse cosmological phenomena due to their characteristic properties, including short duration timescale and high dispersion measure. This study investigates two distinct theoretical…