English
Related papers

Related papers: The TANAMI Multiwavelength Program: Dynamic SEDs o…

200 papers

We compile from literature the broadband SEDs of twelve TeV blazars observed simultaneously or quasi-simultaneously with Fermi/LAT and other instruments. Two SEDs are available for each of the objects and the state is identified as a low or…

High Energy Astrophysical Phenomena · Physics 2015-06-04 Jin Zhang , Shuang-Nan Zhang , En-Wei Liang

Context:The HAGAR Telescope Array at Hanle, Ladakh has been regularly monitoring the nearby blazar Mkn 421 for the past 7yrs. Aims: Blazars show flux variability in all timescales across the electromagnetic spectrum. While there is abundant…

Blazars are jet-dominated extragalactic objects characterized by the emission of strongly variable non-thermal radiation across the entire electromagnetic spectrum. Therefore, the study of blazars (and in general of radio loud AGN) through…

High Energy Astrophysical Phenomena · Physics 2019-08-15 C. Monte , S. Raino , F. Gargano , S. Cutini , D. Gasparrini , J. Leon Tavares , G. Polenta

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

We present an optical to X-ray spectral analysis of four 'hypervariable' AGN (HVAs) discovered by comparing Pan-STARRS data to that from SDSS over a 10 year baseline (Lawrence et al 2016). There is some evidence that these objects are X-ray…

Using high-resolution radio imaging with VLBI techniques, the TANAMI program has been observing the parsec-scale radio jets of southern (declination south of -30{\deg}) gamma-ray bright AGN simultaneously with Fermi/LAT monitoring of their…

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…

TANAMI is a multiwavelength program monitoring active galactic nuclei (AGN) south of -30deg declination including high-resolution Very Long Baseline Interferometry (VLBI) imaging, radio, optical/UV, X-ray and gamma-ray studies. We have…

We perform a multi-band statistical analysis of core-dominated superluminal active galactic nuclei (AGN) detected with Fermi Large Area Telescope (LAT). The detection rate of $\gamma$-ray jets is found to be high for optically bright AGN.…

Cosmology and Nongalactic Astrophysics · Physics 2010-06-14 T. G. Arshakian , J. León-Tavares , J. Torrealba , V. H. Chavushyan

We report the results of our long-term multiwavelength spectral energy distribution (SED) study on the flat spectrum radio quasar 3C 279 during the $\sim14$ years (2008--2022) of {\sl Fermi}-LAT (Large Area Telescope) observing period. The…

We collect a large sample with a reliable redshift detected by the Fermi satellite after 10 years of data (4FGL-DR2), including blazars, $\gamma$-ray Narrow-line Seyfert 1 galaxies ($\gamma$NLS1s), and radio galaxies. The spectral energy…

High Energy Astrophysical Phenomena · Physics 2023-02-23 Chen Yongyun , Gu Qiusheng , Fan Junhui , Yu Xiaoling , Ding Nan , Xiong Dingrong , Guo Xiaotong

Blazars are the most luminous and variable AGNs, and thus excellent probes of accretion and emission processes close to the central engine. We focus on PKS 1510-089 ($z=0.36$), one of the brightest gamma-ray sources in the Fermi LAT…

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

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

The gamma-ray blazar PKS 0208-512 has shown strong periods of flaring, at all frequencies from radio to gamma-ray. This has led to its inclusion in the TANAMI project, which tracks the jets of southern AGN using VLBI as well as supporting…

High Energy Astrophysical Phenomena · Physics 2012-06-28 J. M. Blanchard , J. E. J. Lovell , J. Dickey , R. Ojha , M. Kadler , R. Nesci , P. G. Edwards , J. Stevens , M. Dutka , C. Muller , T. Pursimo

The parsec-scale radio properties of 232 active galactic nuclei (AGNs), most of which are blazars, detected by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope have been observed contemporaneously by the Very Long…

High Energy Astrophysical Phenomena · Physics 2015-06-11 J. D. Linford , G. B. Taylor , F. K. Schinzel

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 a multi-wavelength study of four high redshift blazars, S5 0014+81 ($z=3.37$), CGRaBS J0225+1846 ($z=2.69$), BZQ J1430+4205 ($z=4.72$), and 3FGL J1656.2$-$3303 ($z=2.40$), using the quasi-simultaneous data from {\it Swift}, {\it…

High Energy Astrophysical Phenomena · Physics 2016-07-06 Vaidehi S. Paliya , M. L. Parker , A. C. Fabian , C. S. Stalin

We combined multi-wavelength data for blazars from the Roma-BZCAT catalog and analyzed hundreds of X-ray spectra. We present the fluxes and Spectral Energy Distributions (SEDs), in 12 frequency bands from radio to $\gamma$-rays, for a final…

Astrophysics of Galaxies · Physics 2016-06-17 Peiyuan Mao , C. Megan Urry , Francesco Massaro , Alessandro Paggi , Joe Cauteruccio , Soren R. Künzel

A study of blazar PKS 1424-418 was carried out using multi waveband data collected by Fermi-LAT, Swift-XRT, Swift-UVOT and SMARTS telescopes between MJD 56000 to MJD 56600 (14 Mar 2012 to 4 Nov 2013). Two flaring episodes were identified by…

High Energy Astrophysical Phenomena · Physics 2021-01-18 Jayant Abhir , Jophin Joseph , Sonal R Patel , Debanjan Bose