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Related papers: Flat-Spectrum Radio Quasars from SDSS DR3 Quasar C…

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Blazars' non-thermal emission shows rapid variability across all wavelengths, so spectral energy distributions (SEDs) built from quasi-simultaneous data are crucial for revealing the jets physical properties. In this work, we construct…

High Energy Astrophysical Phenomena · Physics 2026-05-22 Yi Zhong , Zhujian Wan , Rui Xue , Hubing Xiao , Dingrong Xiong , Ze-Rui Wang

We compiled the radio, optical, and X-ray data of blazars from the Sloan Digital Sky Survey (SDSS) database, and presented the distribution of luminosities and broad band spectral indices. The distribution of luminosities shows that the…

High Energy Astrophysical Phenomena · Physics 2015-03-20 Huaizhen Li , Luoen Chen , Yunguo Jiang , Tingfeng Yi

We study the synchrotron component of the spectral energy distribution (SED) on the sample of 877 blazars using the ASDC SED Builder Tool with available broadband data from the literature. Our sample includes 423 flat-spectrum radio sources…

Astrophysics of Galaxies · Physics 2016-03-30 M. Mingaliev , Yu. Sotnikova , T. Mufakharov , A. Erkenov , R. Udovitskiy

We estimate the intrinsic luminosities and synchrotron peak frequency using the derived Doppler factor for a sample of 170 BL Lac objects, of which the synchrotron peak frequency are derived by fitting the SED constructed with the collected…

Astrophysics · Physics 2009-11-13 Zhongzu Wu , Minfeng Gu , D. R. Jiang

We present a method of constraining the properties of the $\gamma$-ray emitting region in flat spectrum radio quasars (FSRQs) in the one-zone proton synchrotron model, where the $\gamma$-rays are produced by synchrotron radiation of…

High Energy Astrophysical Phenomena · Physics 2015-08-06 Maria Petropoulou , Stavros Dimitrakoudis

We present multiwaveband observations of a well selected sample of 28 quasars and two radio galaxies with flat radio spectra and strong millimeter wave emission (referred to here as FSRQ's). The observations include multifrequency VLBI…

Our knowledge of the blazar surface densities and luminosity functions, which are fundamental parameters, relies still on samples at relatively high flux limits. As a result, our understanding of this rare class of active galactic nuclei is…

Astrophysics · Physics 2011-02-11 P. Padovani , P. Giommi , H. Landt , E. S. Perlman

We have utilized the largest sample of $\gamma$-ray selected Fermi flat-spectrum radio quasars (FSRQs) ever used (519 sources) to construct the luminosity function and its evolution through the cosmic history. In addition to spanning large…

High Energy Astrophysical Phenomena · Physics 2025-12-02 Garima Rajguru , Lea Marcotulli , Marco Ajello , Mattia Di Mauro , Meg Urry

Flat Spectrum Radio Quasars (FSRQs) and BL Lac objects detected in the first three months of the Fermi survey neatly separate in the gamma-ray spectral index vs gamma-ray luminosity plane. BL Lac objects are less luminous and have harder…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 G. Ghisellini , L. Maraschi , F. Tavecchio

Our understanding of the unification of jetted AGN has evolved greatly as jet samples have increased in size. Here, based on the largest-ever sample of over 2000 well-sampled jet spectral energy distributions, we examine the synchrotron…

Astrophysics of Galaxies · Physics 2021-05-12 Mary Keenan , Eileen T. Meyer , Markos Georganopoulos , Karthik Reddy , Omar J. French

We present the results from the Suzaku X-ray observations of five flat-spectrum radio quasars (FSRQs), namely PKS0208-512, Q0827+243, PKS1127-145, PKS1510-089 and 3C 454.3. All these sources were additionally monitored simultaneously or…

High Energy Astrophysical Phenomena · Physics 2015-05-18 LAT Collaboration , A. A. Abdo , F. Tavecchio , M. Sikora , P. Schady , P. Roming , M. M. Chester , L. Maraschi

Several independent lines of evidence now point to a correlation between black hole mass, M_bh, and radio-luminosity. In this paper we discuss the correlation for quasars from the FIRST Bright Quasar Survey (FBQS), using black hole mass…

Astrophysics · Physics 2009-11-06 M. Lacy , S. A. Laurent-Muehleisen , S. E. Ridgway , R. H. Becker , R. L. White

While there are a lot of investigations on the optical variability of flat-spectrum radio quasars (FSRQs), not much work has been done on the optical variability of steep-spectrum radio quasars (SSRQs). We investigate the optical…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Minfeng Gu , Y. L. Ai

The optical radiation emitted by blazars contains contributions from synchrotron radiation by relativistic electrons in the jets, as well as thermal radiation emitted mainly by the Accretion Disk (AD), the Broad Line Region (BLR) and the…

In this Letter, the properties of the extended radio emission form SDSS DR7 quasars with $0.4<z<0.8$ is studied. This low redshift sample is useful since any corresponding FIRST radio observations are sensitive enough to detect extended…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Brian Punsly , Shaohua Zhang

We present simultaneous optical and X-ray data from Swift for a sample of FSRQs selected from the EMSS survey. We present also a complete analysis of Swift and INTEGRAL data on 4 blazars recently discussed as possibly challenging the trends…

Astrophysics · Physics 2009-11-13 L. Maraschi , L. Foschini , G. Ghisellini , F. Tavecchio , R. M. Sambruna

Active galactic nuclei (AGNs) can power relativistic jets, which are called blazars when pointed close to our line of sight. Depending on the presence or absence of emission lines in their optical spectra, blazars are categorized into flat…

High Energy Astrophysical Phenomena · Physics 2024-04-23 Garima Rajguru , L. Marcotulli , M. Ajello , A. Tramacere

It has been inferred from large unbiased samples that $10\%$-$15\%$ of all quasars are radio-loud (RL). Using the quasar catalog from the Sloan Digital Sky Survey, we show that the radio-loud fraction (RLF) for high broad line (HBL)…

Astrophysics of Galaxies · Physics 2022-08-31 A. Chakraborty , A. Bhattacharjee , M. S. Brotherton , R. Chatterjee , S. Chatterjee , M. Gilbert

Context. The steep-spectrum radio quasars (SSRQs) are powerful radio sources, with thermal emission from accretion disk and jet nonthermal emission likely both contributing in the Ultraviolet (UV)/optical luminosity, however the former may…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Minfeng Gu , Shuang-Liang Li

We present a temporal and spectral analysis of the gamma-ray flux from nine of the brightest flat spectrum radio quasars (FSRQs) detected with the Fermi Large Area Telescope (LAT) during its first eight years of operation, with the aim of…

High Energy Astrophysical Phenomena · Physics 2020-11-20 Atreya Acharyya , Paula M. Chadwick , Anthony M. Brown