English
Related papers

Related papers: Progress in understanding Blazars from BeppoSAX ob…

200 papers

We present BeppoSAX LECS, MECS, and PDS spectra of eleven X-ray selected BL Lacertae objects. Combining these sources with the ones presented elsewhere we have a sample of 21 BL Lacs from the Einstein Medium Sensitivity and Einstein Slew…

Astrophysics · Physics 2009-11-07 V. Beckmann , A. Wolter , A. Celotti , L. Costamante , G. Ghisellini , T. Maccacaro , G. Tagliaferri

We summarize the results of BeppoSAX ToO observation of blazars that were known to be in a high state from observations carried out in the optical or X-ray or TeV bands.In some of the observed sources, two spectral components were detected,…

Astrophysics · Physics 2007-05-23 Gianpiero Tagliaferri , Gabriele Ghisellini , Marcello Ravasio

We report the BeppoSAX observations of 6 Flat Spectrum Radio Quasars. Three of them have a clear detection up to 100 keV with the PDS instrument. For 4 objects the X-ray spectrum is satisfactorily fitted by a power-law continuum with…

The phenomenology of gamma-ray bright blazars can be accounted for by a sequence in the source power and intensity of the diffuse radiation field surrounding the relativistic jet. Correspondingly, the equilibrium particle distribution peaks…

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

Multiwavelength observations of blazars such as Mrk 421 and Mrk 501 show that they exhibit strong short time variabilities in flare-like phenomena. Based on the homogeneous synchrotron self-Compton (SSC) model and assuming that time…

Astrophysics · Physics 2009-10-31 H. Li , M. Kusunose

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

As a special contribution to the proceedings of the BeppoSAX workshop dedicated to blazar astrophysics we present a catalog of 157 X-ray spectra and the broad-band Spectral Energy Distribution (SED) of 84 blazars observed by BeppoSAX during…

We study the quasi-simultaneous Spectral Energy Distributions (SED) of 48 LBAS blazars, collected within three months of the Fermi LAT Bright AGN Sample (LBAS) data taking period, combining Fermi and Swift data with radio NIR-Optical and…

High Energy Astrophysical Phenomena · Physics 2009-12-21 S. Raino' , E. Cavazzuti , S. Colafrancesco , P. Giommi , A. Tramacere , the Fermi-LAT Collaboration

The spectral energy distribution and variability of several blazars (Mkn 501, 1 ES 2344+51.4, PKS 2155-30.4, 1 ES 1218+30.4, 3C 454.3) along the blazar sequence is investigated using a selfconsistent and timedependent lepto-hadronic hybrid…

High Energy Astrophysical Phenomena · Physics 2011-09-12 Matthias Weidinger , Felix Spanier

The results of the first ever contemporaneous multi-wavelength observation campaign on the BL Lac object PKS2155-304 involving Swift, NuSTAR, Fermi-LAT and H.E.S.S. are reported. The use of these instruments allows us to cover a broad…

High Energy Astrophysical Phenomena · Physics 2020-07-08 H. E. S. S. , Fermi , NuSTAR collaborations

I describe a general framework that could allow to understand the broad band spectra of blazars and lead to a unified picture of the emission from relativistic jets, in BL Lac objects as well as in flat spectrum, radio loud Quasars. The…

Astrophysics · Physics 2009-10-30 L. Maraschi

Blazars are characterized by large amplitude and fast variability, indicating that the electron distribution is rapidly changing, often on time scales shorter than the light crossing time. The emitting region is sufficiently compact to let…

Astrophysics · Physics 2009-10-31 Marco Chiaberge , Gabriele Ghisellini

We present new BeppoSAX LECS and MECS observations, covering the energy range 0.1 - 10 keV (observer's frame), of four BL Lacertae objects selected from the 1 Jy sample. All sources display a flat (alpha_x ~ 0.7) X-ray spectrum, which we…

Astrophysics · Physics 2009-11-10 P. Padovani , L. Costamante , P. Giommi , G. Ghisellini , A. Celotti , A. Wolter

Blazars are characterized by large amplitude and fast variability, indicating that the electron distribution is rapidly changing, often on time scales shorter than the light crossing time. We study the time dependent behavior of the…

Astrophysics · Physics 2007-05-23 Marco Chiaberge , Gabriele Ghisellini

We report on two BeppoSAX observations of BL Lac (2200+420) performed respectively in June and December 1999, as part of a ToO program to monitor blazars in high states of activity. During both runs the source has been detected up to 100…

Blazars exhibit flux and spectral variations of largest amplitude at the highest frequencies. Therefore, monitoring their variability at X- and gamma-rays is the most effective tool to peer into the mighty powerhouse of these sources. High…

Astrophysics · Physics 2007-05-23 Elena Pian

We present the results of a spectral and temporal study of the complete set of BeppoSAX NFI (11) and WFC (71) observations of the BL Lac object Mkn 501. The WFC 2-28 keV data, reported here for the first time, were collected over a period…

Astrophysics · Physics 2009-11-10 E. Massaro , M. Perri , P. Giommi , R. Nesci , F. Verrecchia

We analyse a group of radio sources, a subset of the 200 mJy sample, all of which have core-jet radio structures measured with VLBI and have flat spectra stretching from the radio to the millimetre/sub-millimetre band. Thus the objects have…

Astrophysics · Physics 2009-11-10 S. Anton , I. W. A. Browne

The overall spectra (SED) of blazars, from radio to gamma-ray energies, seem to obey well defined trends, with a continuity of properties between blazars of different classes. To quantify this statement we can either investigate their…

Astrophysics · Physics 2007-05-23 Gabriele Ghisellini

We use the distributions of spectral indices of a large homogenous sample of Fermi-detected blazars to re-investigate the relationship between flat spectrum radio quasars (FSRQs) and subclasses of BL Lac objects (BL Lacs). We compute the…

High Energy Astrophysical Phenomena · Physics 2020-07-20 E. U. Iyida , F. C. Odo , A. E. Chukwude , A. A. Ubachukwu
‹ Prev 1 2 3 10 Next ›