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Related papers: Multi wavelength study of 4C+28.07

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The narrow-line Seyfert 1 galaxy SBS 0846+513 was first detected by the Large Area Telescope (LAT) on-board Fermi in 2011 June-July when it underwent a period of flaring activity. Since then, as Fermi continues to accumulate data on this…

In this paper, we present light curves for 3C 279 over a time period of six years; from 2008 to 2014. Our multiwavelength data comprise 1 mm to gamma-rays, with additional optical polarimetry. Based on the behaviour of the gamma-ray light…

We report on observations of BL Lacertae during the first 18 months of Fermi-LAT science operations and present results from a 48-day multifrequency coordinated campaign from 2008 August 19 to 2008 October 7. The radio to gamma-ray behavior…

High Energy Astrophysical Phenomena · Physics 2015-05-27 A. A. Abdo

S5 0716+714 is a typical BL Lacertae object. In this paper we present the analysis and results of long term simultaneous observations in the radio, near-infrared, optical, X-ray and $\gamma$-ray bands, together with our own photometric…

High Energy Astrophysical Phenomena · Physics 2015-06-18 N. H. Liao , J. M. Bai , H. T. Liu , S. S. Weng , Liang Chen , F. Li

Fast Radio Bursts (FRBs) are a mysterious flash phenomenon detected in radio wavelengths with a duration of only a few milliseconds, and they may also have prompt gamma-ray flashes. Here we carry out a blind search for msec-duration…

High Energy Astrophysical Phenomena · Physics 2019-06-07 Shotaro Yamasaki , Tomonori Totani , Norita Kawanaka

We present a multi-wavelength study of the Flat Spectrum Radio Quasar PKS 1222+216, analyzing its long-term variability of radio data obtained in 2013-2020 from the iMOGABA, MOJAVE, and VLBA-BU-BLAZAR programs, along with $\gamma$-ray data…

High Energy Astrophysical Phenomena · Physics 2026-03-12 Yeji Jo , Sang-Sung Lee

Total intensity variability light curves offer a unique insight into the ongoing debate about the launching mechanism of jets. For this work, we utilise the availability of radio and $\gamma$-ray light curves over a few decades of the radio…

We present a multiwavelength study of the unidentified Fermi gamma-ray source 0FGL J1830.3+0617, which exhibits variability above 200 MeV on timescales of days to weeks. Within the Fermi 95% confidence error contour lies B1827+0617, a radio…

High Energy Astrophysical Phenomena · Physics 2009-08-12 N. Mirabal , J. P. Halpern

Fermi has provided the largest sample of {\gamma}-ray selected blazars to date. In this work we use a complete sample of FSRQs detected during the first year of operation to determine the luminosity function (LF) and its evolution with…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 M. Ajello , M. S. Shaw , R. W. Romani , C. D. Dermer , L. Costamante , O. G. King , W. Max-Moerbeck , A. Readhead , A. Reimer , J. L. Richards , M. Stevenson

We present a multi-wavelength temporal analysis of the blazar 3C 454.3 during the high $\gamma$-ray active period from May-December, 2014. Except for X-rays, the period is well sampled at near-infrared (NIR)-optical by the \emph{SMARTS}…

High Energy Astrophysical Phenomena · Physics 2017-01-04 Pankaj Kushwaha , Alok C. Gupta , Ranjeev Misra , K. P. Singh

In 2006 the stand-alone MAGIC-I telescope discovered very high energy gamma-ray emission from 3C279. Additional observations were triggered when the source entered an exceptionally bright optical state in January 2007 and the Fermi space…

High Energy Astrophysical Phenomena · Physics 2019-08-16 K. Berger , J. Becerra González , G. Bonnoli , L. Maraschi , F. Tavecchio , A. Domínguez , E. Lindfors , A. Stamerra

Blazars are the most active extragalactic gamma-ray sources. They show sporadic bursts of activity, lasting from hours to months. In this work we present a 10-year analysis of a sample of bright sources detected by Fermi-LAT (100 MeV - 300…

High Energy Astrophysical Phenomena · Physics 2021-09-29 J. R. Sacahui , A. V. Penacchioni , A. Marinelli , A. Sharma , M. Castro , J. M. Osorio , M. A. Morales

PKS 0438$-$436 at a redshift of $z=2.856$ has been previously recognized as possessing perhaps the most luminous known synchrotron jet. Little is known about this source since the maximum elevation above the horizon is low for the Very…

High Energy Astrophysical Phenomena · Physics 2019-01-09 Brian Punsly , Andrea Tramacere , Preeti Kharb , Paola Marziani

We present multiwavelength spectral analyses of two Fermi-LAT blazars, OJ 287 and 3C 279, that are part of the Boston University multiwaveband polarization program. The data have been compiled from observations with Fermi, RXTE, the VLBA,…

High Energy Astrophysical Phenomena · Physics 2011-11-07 Manasvita Joshi , Alan Marscher , Svetlana Jorstad , Markus Boettcher , Ivan Agudo , Valeri Larionov , Margo Aller , Mark Gurwell , Anne Lahteenmaki

We report on the extreme behaviour of the high redshift blazar GB B1428+4217 at z=4.72. A continued programme of radio measurements has revealed an exceptional flare in the lightcurve, with the 15.2 GHz flux density rising by a factor ~3…

Astrophysics · Physics 2009-09-17 M. A. Worsley , A. C. Fabian , G. G. Pooley , C. J. Chandler

We carried a detailed temporal and spectral study of the BL\,Lac by using the long-term \emph{Fermi}-LAT and \emph{Swift}-XRT/UVOT observations, during the period MJD\,59000-59943. The daily-binned $\gamma$-ray light curve displays a…

High Energy Astrophysical Phenomena · Physics 2023-11-16 Zahir Shah

The GeV observations by Fermi-LAT give us the opportunity to characterize the high-energy emission (100 MeV - 300 GeV) variability properties of the BL Lac object S5 0716+714. In this study, we performed flux and spectral analysis of more…

High Energy Astrophysical Phenomena · Physics 2015-06-15 B. Rani , T. P. Krichbaum , B. Lott , L. Fuhrmann , J. A. Zensus

In spring 2005 the blazar 3C 454.3 was observed in an unprecedented bright state from the near-IR to the hard X-ray frequencies. A mm outburst peaked in June-July 2005, and it was followed by a flux increase at high radio frequencies. In…

Astrophysics · Physics 2020-05-06 M. Villata , C. M. Raiteri , M. F. Aller

Aims. The high energy spectrum of 3C 273 is usually understood in terms of inverse-Compton emission in a relativistic leptonic jet. This model predicts variability patterns and delays that could be tested with simultaneous observations from…

High Energy Astrophysical Phenomena · Physics 2015-04-22 V. Esposito , R. Walter , P. Jean , A. Tramacere , M. Türler , A. Lähteenmäki , M. Tornikoski

CTA 102 is a $\gamma$-ray bright blazar that exhibited multiple flares in observations by the Large Area Telescope on board the Fermi Gamma-Ray Space Telescope during the period of 2016-2018. We present results from the analysis of…