Related papers: Breaking the Blazar Sequence: A New View of Radio …
In this proceeding we explore a pathway to radio-loudness under the hypothesis that retrograde accretion onto giant spinning black holes leads to the launch of powerful jets, as seen in radio loud QSOs and recently in LAT/Fermi and…
We present the completed results of a high resolution radio imaging survey of all (~200) low-luminosity active galactic nuclei (LLAGNs) and AGNs in the Palomar Spectroscopic Sample. The high incidences of pc-scale radio nuclei, with…
The Fermi and Swift satellites, together with ground based Cherenkov telescopes, has greatly improved our knowledge of blazars, namely Flat Spectrum Radio Quasars and BL Lac objects, since all but the most powerful emit most of their…
The majority of nearby radio-loud AGN are found in massive, old elliptical galaxies with weak emission lines. At high redshifts,however, most known radio AGN have strong emission lines. In this paper, we examine a subset of radio AGN with…
The radio-X-ray slope in the fundamental plane of radio-loud active galactic nuclei (AGNs) is found to be steeper compared with that of radio-quiet AGNs in previous works. In this work, we reinvestigate the fundamental plane in radio-loud…
We study hadronic models of broad-band emission of jets in radio-loud active galactic nuclei, and their implications for the accretion in those sources. We show that the models that account for broad-band spectra of blazars emitting in the…
Radio-loud AGN are characterized by relativistic jets originating near the central supermassive black hole and forming large-scale radio sources at parsec to kiloparsec to Megaparsec distances. The jets are energetically significant, in…
We address the very large diversity of the jet production efficiency in active galactic nuclei (AGNs) by using data on low redshift AGNs selected from the Swift/BAT catalog and having black hole (BH) masses larger than…
The nuclei of most normal galaxies contain supermassive black holes, which can accrete gas through a disk and become active. These Active Galactic Nuclei, AGN, can form jets which are observed on scales from AU to Mpc and from meter…
In order to further test our hypothesis that jets and disk around compact accreting objects are symbiotic features we investigate the newly discovered superluminal galactic radio jets GRS 1915+105 and GRO J1655-40 and the two famous…
Non-blazar Active Galactic Nuclei (AGN) have emerged as a new gamma-ray emitting source class on the extragalactic sky and started to deepen our understanding of the physical processes and the nature of AGN in general. The detection of…
We explore the evolution in power of black holes of all masses, and their associated jets, within the scheme of an accretion rate-dependent state transition. Below a critical value of the accretion rate all systems are assumed to undergo a…
The jet in active galactic nuclei (AGN) is a key ingredient in understanding the co-evolution of galaxies and their central supermassive black holes (SMBHs). Unfortunately, the mechanism of jet launching and collimation is still elusive.…
We investigate the relation between black hole mass, M_bh, and jet power, Q_jet, for a sample of BL Lacs and radio quasars. We find that BL Lacs are separated from radio quasars by the FR I/II dividing line in M_bh-Q_jet plane, which…
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…
Most of the electromagnetic output of blazars (BL Lac objects and Flat Spectrum Radio Quasars) comes out in the gamma-ray band, making the Large Area Telescope [0.1-100 GeV] onboard the Fermi satellite and the Cherenkov telescopes crucial…
We collect a large sample with a reliable redshift detected by the Fermi satellite after 10 years of data (4FGL-DR2), including blazars, $\gamma$-ray Narrow-line Seyfert 1 galaxies ($\gamma$NLS1s), and radio galaxies. The spectral energy…
The classical diagrams of radio loudness and jet power as a function of mass and accretion rate of the central spacetime singularity in active galactic nuclei are reanalyzed by including the data of the recently discovered powerful…
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…
Seyfert galaxies and quasars were first discovered through optical and radio techniques, but in recent years high-energy emission, that can penetrate central gas and dust, has become essentially the defining characteristic of an AGN. AGNs…