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Related papers: General Physical Properties of CGRaBS Blazars

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The long-term optical and infrared color variability of blazars has been investigated with the SMARTS monitoring data. The sample in this study consists of 49 flat spectrum radio quasars and 22 BL Lac objects. The fractional variability…

Astrophysics of Galaxies · Physics 2015-11-11 Bing-Kai Zhang , Xiao-Shan Zhou , Xiao-Yun Zhao , Ben-Zhong Dai

Blazars are a sub-category of radio-loud active galactic nuclei with relativistic jets pointing towards to the observer. They are well-known for their non-thermal variable emission, which practically extends over the whole electromagnetic…

High Energy Astrophysical Phenomena · Physics 2019-01-28 Stella Boula , Maria Petropoulou , Apostolos Mastichiadis

Estimating black hole masses of blazars is still a big challenge. Because of the contamination of jets, using the previously suggested size -- continuum luminosity relation can overestimate the broad line region (BLR) size and black hole…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Xue-Bing Wu , F. K. Liu , M. Z. Kong , R. Wang , J. L. Han

A sample of 111 Fermi blazars each with a well-established radio core luminosity, broad-line luminosity, bolometric luminosity and black hole mass has been compiled from the literatures.We present a significant correlation between radio…

High Energy Astrophysical Phenomena · Physics 2015-06-24 Xiaoling Yu , Xiong Zhang , Haojing Zhang , Dingrong Xiong , Bijun Li , Yongjuan Cha , Yongyun Chen , Xia Huang , Yuwei Wang

There is general consensus that active galactic nuclei (AGNs) derive their radiating power from a supermassive black hole (SMBH) that accretes matter. Yet, their precise powering mechanisms and the resulting growth of the SMBH are poorly…

Astrophysics of Galaxies · Physics 2025-05-21 Jose Maria Sanchez Zaballa , Eugenio Bottacini , Andrea Tramacere

Blazars are a sub-population of quasars whose jets are nearly aligned with the line-of-sight, which tend to exhibit multi-wavelength variability on a variety of timescales. Quasi-periodic variability on year-like timescales has been…

High Energy Astrophysical Phenomena · Physics 2018-09-05 A. Miguel Holgado , Alberto Sesana , Angela Sandrinelli , Stefano Covino , Aldo Treves , Xin Liu , Paul Ricker

Since late 2007, we have been monitoring a large sample of known and likely gamma-ray-loud blazars at 15 GHz twice per week with the Owens Valley Radio Observatory (OVRO) 40 m Telescope. Our initial sample included the 1158 sources above…

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

Jet launching in radio loud (RL) quasars is one of the fundamental problems in astrophysics. Exploring the differences in the inner accretion disk properties between RL and radio quiet (RQ) quasars might yield helpful clues to this puzzle.…

High Energy Astrophysical Phenomena · Physics 2018-12-27 Zhen-Yi Cai , Yu-Han Sun , Jun-Xian Wang , Fei-Fan Zhu , Wei-Min Gu , Feng Yuan

The exact location of the $\gamma$-ray emitting region in blazar jets has long been a matter of debate. However, the location has important implications about the emission processes, geometric and physical parameters of the jet, as well as…

High Energy Astrophysical Phenomena · Physics 2025-05-21 Maitreya Kundu , Arit Bala , Saugata Barat , Ritaban Chatterjee

The $Fermi$ blazar observations show a strong correlation between $\gamma$-ray luminosities and spectral indices. BL Lac objects are less luminous with harder spectra than flat-spectrum radio quasars (FSRQs). Interestingly FSRQs are evident…

High Energy Astrophysical Phenomena · Physics 2019-04-24 Tushar Mondal , Banibrata Mukhopadhyay

We present a new assessment of the contribution of Blazars to the extragalactic background radiation across the e.m. spectrum. Our calculations rely on deep Blazar radio counts that we derived combining several multifrequency surveys. The…

Astrophysics · Physics 2009-11-13 P. Giommi , S. Colafrancesco , E. Cavazzuti , M. Perri , C. Pittori

Blazars are highly variable active galactic nuclei which emit radiation at all wavelengths from radio to gamma-rays. Polarized radiation from blazars is one key piece of evidence for synchrotron radiation at low energies and it also varies…

The flat spectrum radio quasar PKS 1510-089 is one of the most active blazars across the entire electromagnetic spectrum, displaying periods of flaring activity. This study explores its spectral variability over a decade. By employing the…

High Energy Astrophysical Phenomena · Physics 2024-12-25 Alfredo Amador-Portes , Vahram Chavushyan , Víctor M. Patiño-Álvarez , José Ramón-Valdés

We study the quasi-simultaneous near-IR, optical, UV, and X-ray photometry of eleven gamma-ray selected blazars for which redshift estimates larger than 1.2 have been recently provided. Four of these objects turn out to be high-power…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 P. Padovani , P. Giommi , A. Rau

We have recently proposed a new simplified scenario where blazars are classified as flat-spectrum radio quasars (FSRQs) or BL Lacs according to the prescriptions of unified schemes, and to a varying combination of Doppler boosted radiation…

High Energy Astrophysical Phenomena · Physics 2015-06-15 P. Giommi , P. Padovani , G. Polenta

We present the preliminary results from two new surveys of blazars that have direct implications on the GLAST detection of extragalactic sources from two different perspectives: microwave selection and a combined deep X-ray/radio selection.…

We present the results of a long-term periodicity search in a sample of $\gamma$-ray blazars within a multiwavelength context. These blazars have been selected from the Steward Observatory sample as part of its optical monitoring program…

High Energy Astrophysical Phenomena · Physics 2022-11-16 J. Otero-Santos , P. Peñil , J. A. Acosta-Pulido , J. Becerra González , C. M. Raiteri , M. I. Carnerero , M. Villata

A study of the statistics of cosmological black-hole jet sources is applied to EGRET blazar data, and predictions are made for GLAST. Black-hole jet sources are modeled as collimated relativistic plasma outflows with radiation beamed along…

Astrophysics · Physics 2008-11-26 Charles D. Dermer

This work studies the relationship between accretion-disk size and quasar properties, using a sample of 95 quasars from the SDSS-RM project with measured lags between the $g$ and $i$ photometric bands. Our sample includes disk lags that are…