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The first three months of sky-survey operation with the Fermi Gamma Ray Space Telescope (Fermi) Large Area Telescope (LAT) reveals 132 bright sources at |b|>10 deg with test statistic greater than 100 (corresponding to about 10 sigma). Two…

High Energy Astrophysical Phenomena · Physics 2009-09-30 A. A. Abdo

We present the method and first results of a survey for high-redshift (z>3) radio-loud quasars, which is based on optical identifications of 2902 flat-spectrum radio sources with S(5GHz)>= 25mJy. The radio sample was defined over a 1600 sq…

Astrophysics · Physics 2009-10-30 I. M. Hook , R. H. Becker , R. G. McMahon , R. L. White

In the recently published 3FGL catalogue, the Fermi/LAT collaboration reports the detection of $\gamma$-ray emission from 3034 sources obtained after four years of observations. The nature of 1010 of those sources is unknown, whereas 2023…

High Energy Astrophysical Phenomena · Physics 2017-06-21 J. Lefaucheur , S. Pita

We study the $\gamma$-ray and broadband spectral energy distribution (SED) properties of a complete sample of 104 bright, radio-selected low-synchrotron peaked (LSP) blazars. Most of the sources have already been detected in the…

High Energy Astrophysical Phenomena · Physics 2018-08-08 B. Arsioli , G. Polenta

Blazars are currently separated into BL Lacertae objects (BL Lacs) and flat spectrum radio quasars (FSRQ) based on the strength of their emission lines. This is done rather arbitrarily by defining a diagonal line in the Ca H&K break value…

Astrophysics · Physics 2009-11-10 H. Landt , P. Padovani , E. S. Perlman , P. Giommi

The first Fermi-LAT High-energy source catalog (1FHL), containing gamma-ray sources detected above 10 GeV, is an ideal sample to characterize the physical properties of the most extreme gamma-ray sources. We investigate the pc scale…

High Energy Astrophysical Phenomena · Physics 2016-10-19 R. Lico , M. Giroletti , M. Orienti , F. D'Ammando

The exact location of the gamma-ray emitting region in blazars is still controversial. In order to attack this problem we present first results of a cross-correlation analysis between radio (11 cm to 0.8 mm wavelength, F-GAMMA program) and…

We present the results of a multi-frequency, time-averaged analysis of blazars included in the Candidate Gamma-ray Blazar Survey catalog. Our sample consists of 324 $\gamma$-ray detected ($\gamma$-ray loud) and 191 non $\gamma$-ray detected…

High Energy Astrophysical Phenomena · Physics 2017-12-20 Vaidehi S. Paliya , L. Marcotulli , M. Ajello , M. Joshi , S. Sahayanathan , A. R. Rao , D. Hartmann

Blazars are powerful, variable emitters from radio to gamma-ray wavelengths. Even though the general picture of synchrotron emission at low energies and inverse Compton at the high energy end is well established, many important aspects of…

High Energy Astrophysical Phenomena · Physics 2019-08-15 W. Max-Moerbeck , J. L. Richards , V. Pavlidou , T. J. Pearson , A. C. S. Readhead , T. Hovatta , O. G. King , R. Reeves

We collect data from the radio to the gamma-ray range for three complete samples of blazars: the Slew Survey and the 1Jy samples of BL Lacs and the 2Jy sample of Flat Spectrum Radio-Loud Quasars (FSRQs). The fraction of objects detected in…

Astrophysics · Physics 2009-10-30 G. Fossati , L. Maraschi , A. Celotti , A. Comastri , G. Ghisellini

Blazars are radio-loud active galactic nuclei well known for their non thermal emission spanning a wide range of frequencies. The Roma-BZCAT is, to date, the most comprehensive list of these sources. We performed the cross-match of several…

High Energy Astrophysical Phenomena · Physics 2015-05-04 A. Maselli , F. Massaro , R. D'Abrusco , G. Cusumano , V. La Parola , A. Segreto , G. Tosti

We collect the 2LAC and MOJAVE quasi-simultaneous data to investigate the radio-gamma connection of blazars. The cross sample contains 166 sources. The statistic analysis based on this sample confirms positive correlations between these two…

High Energy Astrophysical Phenomena · Physics 2014-09-03 Fan Xu-Liang , Bai Jin-Ming , Liu Hong-Tao , Chen Liang , Liao Neng-Hui

We present the results of nine years of the blazar observing programme at the RATAN-600 radio telescope (2005-2014). The data were obtained at six frequency bands (1.1, 2.3, 4.8, 7.7, 11.2, 21.7 GHz) for 290 blazars, mostly BL Lacs. In…

Astrophysics of Galaxies · Physics 2017-07-26 M. Mingaliev , Yu. Sotnikova , T. Mufakharov , E. Nieppola , M. Tornikoski , J. Tammi , A. Lahteenmaki , R. Udovitskiy , A. Erkenov

Blazars are the brightest and most abundant persistent sources in the extragalactic gamma-ray sky. Due to their significance, they are often observed across various energy bands to explore potential correlations between emissions at…

High Energy Astrophysical Phenomena · Physics 2024-01-22 P. Giommi , N. Sahakyan , D. Israyelyan , M. Manvelyan

Blazars, including BL Lacs and FSRQs, are the most luminous extragalactic {\gamma}-ray sources. They account for about 56% of the sources listed in the recent Fermi-LAT catalog (4FGL-DR4). The optical and UV spectra of BL Lacs are nearly…

A large sample of known and likely gamma-ray blazars has been monitored twice per week since late 2007 at 15 GHz with the Owens Valley Radio Observatory (OVRO) 40-meter Telescope. The sample contains about 1700 sources, including the…

High Energy Astrophysical Phenomena · Physics 2012-05-03 W. Max-Moerbeck , J. L. Richards , V. Pavlidou , T. Hovatta , O. G. King , T. J. Pearson , A. C. S. Readhead , R. Reeves , M. C. Shepherd

This work investigates the multi-wavelength properties of 165 4FGL blazars from the Fermi-LAT fourth source catalogue, looking for with counterparts in the Australian SKA Pathfinder (ASKAP) First Large Absorption Survey in HI (FLASH)…

(Abridged) We carried out an extensive search to identify the counterparts of all the sources listed in the WMAP 3-yr catalogue using literature and archival data. Our work led to the identification of 309 WMAP sources, 98% of which are…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 P. Giommi , S. Colafrancesco , P. Padovani , D. Gasparrini , E. Cavazzuti , S. Cutini

High-redshift ($z >3$) $\gamma$-ray blazars are rare, but they are crucial for our understanding of jet evolution, $\gamma$-ray production and propagation, and the growth of supermassive black holes in the early universe. A new analysis of…

High Energy Astrophysical Phenomena · Physics 2024-06-07 Hai Lei , Ying-Kang Zhang , Xiong Jiang , Sebastian Kiehlmann , Anthony C. S. Readhead , Liang Chen , Neng-Hui Liao , Tao An

Nearly one-third of the gamma-ray sources detected by Fermi are still unidentified, despite significant recent progress in this effort. On the other hand, all the gamma-ray extragalactic sources associated in the second Fermi-LAT catalog…

High Energy Astrophysical Phenomena · Physics 2019-08-19 F. Massaro , R. D'Abrusco , A. Paggi , N. Masetti , M. Giroletti , G. Tosti , Howard A. Smith , S. Funk