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Related papers: Jet and accretion power in the most powerful Fermi…

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We present the results of studying the accretion disk vs jet power for a large fraction of all the blazars detected by the Fermi Gamma-Ray Space Telescope. The disk power is inferred from the emission line luminosities obtained from…

High Energy Astrophysical Phenomena · Physics 2022-09-27 Garima Rajguru , Ritaban Chatterjee

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…

High Energy Astrophysical Phenomena · Physics 2015-06-23 G. Ghisellini , F. Tavecchio

We studied all blazars of known redshift detected by the Fermi satellite during its first three months survey. For the majority of them, pointed Swift observations ensures a good multiwavelength coverage, enabling us to to reliably…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 G. Ghisellini , F. Tavecchio , L. Foschini , G. Ghirlanda , L. Maraschi , A. Celotti

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…

High Energy Astrophysical Phenomena · Physics 2015-06-17 G. Ghisellini

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…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 G. Ghisellini

The Fermi, Swift and INTEGRAL satellites, together with ground based (especially Cherenkov) telescopes made possible a great progress in our understanding of relativistic jets. We can now start to attack the difficult questions of jet…

High Energy Astrophysical Phenomena · Physics 2011-12-16 G. Ghisellini

The new high energy data coming mainly from the Fermi and Swift satellites and from the ground based Cerenkov telescopes are making possible to study not only the energetics of blazar jets, but also their connection to the associated…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Gabriele Ghisellini

With the release of the first year Fermi catalogue, the number of blazars detected above 100 MeV lying at high redshift has been largely increased. There are 28 blazars at z>2 in the "clean" sample. All of them are Flat Spectrum Radio…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 G. Ghisellini , G. Tagliaferri , L. Foschini , G. Ghirlanda , F. Tavecchio , R. Della Ceca , F. Haardt , M. Volonteri , N. Gehrels

We study the general physical properties of Fermi blazars using the Fermi fourth source catalog data (4FGL-DR2). The quasi-simultaneous multiwavelength data of Fermi blazar are fitted by using the one-zone leptonic model to obtain some…

High Energy Astrophysical Phenomena · Physics 2023-07-03 Yongyun Chen , Qiusheng Gu , Junhui Fan , Xiaoling Yu , Xiaogu Zhong , Hongyu Liu , Nan Ding , Dingrong Xiong , Xiaotong Guo

We have analyzed a large sample of clean blazars detected by Fermi Large Area Telescope (LAT). Using literature and calculation, we obtained intrinsic $\gamma$-ray luminosity excluding beaming effect, black hole mass, broad-line luminosity…

High Energy Astrophysical Phenomena · Physics 2015-06-19 Dingrong Xiong , Xiong Zhang

The LAT instrument, onboard the Fermi satellite, in its first three months of operation detected more than 100 blazars at more than the 10 sigma level. This is already a great improvement with respect to its predecessor, the instrument…

Cosmology and Nongalactic Astrophysics · Physics 2009-12-18 G. Ghisellini

The power carried by the jet of blazars is large, compared to the luminosity produced by their accretion disk, and is probably in the form of kinetic energy of a normal electron-proton plasma. The Poynting flux is modest, as suggested by…

Astrophysics · Physics 2008-07-18 G. Ghisellini

We study a sample of 30 high-redshift blazars ($z>2.5$) by means of spectra and the radiation mechanism with Fermi Large Area Telescope $\gamma$-ray observations spanning 15 years. Three models -- the power law, power law with an…

High Energy Astrophysical Phenomena · Physics 2025-01-27 Fan Wu , Benzhong Dai

We study the relation between the mass accretion rate, the jet power, and the black hole mass of blazars. To this aim, we make use of the Sloan Digital Sky Survey (SDSS) and the 11 months catalog of blazars detected at energies larger than…

High Energy Astrophysical Phenomena · Physics 2012-05-18 T. Sbarrato , G. Ghisellini , L. Maraschi , M. Colpi

We observed 5 gamma-ray loud blazars at redshift greater than 2 with the X-Ray Telescope (XRT) and the UltraViolet and Optical Telescope (UVOT) onboard the Swift satellite, and the Gamma-Ray burst Optical Near-Infrared Detector (GROND)…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 G. Ghisellini , M. Nardini , G. Tagliaferri , J. Greiner , P. Schady , A. Rau , L. Foschini , F. Tavecchio , G. Ghirlanda , T. Sbarrato

Jet origination is one of the most important questions of AGN, yet it stays obscure. In this work, we made use of information of emission lines, spectral energy distributions (SEDs), \textit{Fermi}-LAT $\gamma$-ray emission, construct a…

High Energy Astrophysical Phenomena · Physics 2022-02-02 Hubing Xiao , Zhihao OuYang , Lixia Zhang , Liping Fu , Shaohua Zhang , Xiangtao Zeng , Junhui Fan

We have not identified for sure what is the mechanism launching, accelerating and collimating relativistic jets. The two most likely possibilities are the gravitational energy of the accreting matter or the rotational energy of a spinning…

High Energy Astrophysical Phenomena · Physics 2018-09-21 Gabriele Ghisellini

We discuss the relation between the power carried by relativistic jets and the nuclear power provided by accretion, for a group of blazars including FSRQs and BL Lac objects. They are characterized by good quality broad band X-ray data…

Astrophysics · Physics 2009-11-07 Laura Maraschi , Fabrizio Tavecchio

We observed with the NuSTAR satellite 3 blazars at z>2, detected in gamma-rays by Fermi/LAT and in the soft X-rays, but not yet observed above 10 keV. The flux and slope of their X-ray continuum, together with Fermi/LAT data allows us to…

High Energy Astrophysical Phenomena · Physics 2019-07-10 G. Ghisellini , M. L. Perri , G. Costamante , G. Tagliaferri , T. Sbarrato , S. Campitiello , G. Madejski , F. Tavecchio , G. Ghirlanda

The Fermi Gamma-Ray Space Telescope observations of blazars show a strong correlation between the spectral index of their gamma-ray spectra and their synchrotron peak frequency $\nu_{\rm{pk}}^{\rm{syn}}$; additionally, the rate of Compton…

High Energy Astrophysical Phenomena · Physics 2018-10-17 Stella Boula , Demosthenes Kazanas , Apostolos Mastichiadis
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