BATSE monitoring of BLAZARS

Dean, A. J.; Malizia, A.; Westmore, M. J.; Gurriaran, R.; Lei, F.; Bassani, L.; Stephen, J. B.
April 2000
AIP Conference Proceedings;2000, Vol. 510 Issue 1, p342
Academic Journal
Since the time coverage of BATSE is nearly complete over 8 years, this instrument offers a unique opportunity to monitor highly variable sources such as blazars in a relatively unexplored energy band (20–100 keV). Here we present some examples of this capability which is particularly useful during period of flaring activity. Four years of monitoring of the QSO 71.07 in the hard X-ray band is presented which indicates enhanced hard X-ray emission during an optical flare. BATSE also allowed the extraction of spectra during bright states. These data indicate that the spectrum steepens when the source is brighter. Results are also presented for the BL Lacs MKN501 and PKS 2005-489 during high energy flares, first detected by other instruments. The potential of using BATSE to study sources over long periods of time and to follow the emission before and after flares is clearly demonstrated. © 2000 American Institute of Physics.


Related Articles

  • On the Blazar Contribution to the Cosmic X-ray Background: Implications for the Compton Thick Population. Draper, Aden R.; Ballantyne, David R. // AIP Conference Proceedings;7/15/2010, Vol. 1248 Issue 1, p421 

    We investigate the contribution of blazars to the cosmic X-ray background (CXB). The radio blazar luminosity function is found by beaming the luminosity function of radio loud active galactic nuclei (AGN). Average blazar spectral energy distributions are created to convert radio luminosity to...

  • A low density of the extragalactic background light revealed by the H.E.S.S. spectra of the BL Lac objects 1ES 1101-232 and H 2356-309. Costamante, Luigi // Astrophysics & Space Science;May2007, Vol. 309 Issue 1-4, p487 

    The study of the TeV emission from extragalactic sources is hindered by the uncertainties on the diffuse Extragalactic Background Light (EBL). The recent H.E.S.S. results on the blazars 1ES 1101-232 and H 2356-309 represent a breakthrough on this issue. Their unexpectedly hard spectra allow an...

  • Hard MeV-GeV spectra of blazars. Katarzyński, K. // Astronomy & Astrophysics / Astronomie et Astrophysique;Jan2012, Vol. 537, p1 

    Aims. Very high energy (VHE) gamma-ray emission from a distant source (z >≳ 0.2) can be efficiently absorbed by means of the electron-positron pair creation process. Analyses of the unabsorbed spectra imply that the intrinsic TeV emission of some blazars is hard, with spectral indices of...

  • The Optical Microvariability and Spectral Changes of the BL Lacertae Object S5 0716+714. Poon, H.; Fan, J.; Fu, J. // Journal of Astrophysics & Astronomy;Mar-Jun2011, Vol. 32 Issue 1/2, p97 

    The BL Lac object S5 0716+714 was monitored in the optical band during October 2008, December 2008 and February 2009. We achieved a best temporal resolution of about 5 min in the BVRI bands. The source was active during the whole monitoring campaign. It showed microvariability in 13 days out of...

  • Optical Spectra Evolution of BL Lac Objects. Bi, X.; Wang, B.; Ni, Z.; Cai, Q.; Tian, J. // Journal of Astrophysics & Astronomy;Mar-Jun2011, Vol. 32 Issue 1/2, p109 

    Many quasi-simultaneous optical observations of nine BL Lac objects are obtained from literature. We study the relationship between the optical spectral index and the luminosity of BL Lac objects, and are tempted to exploit spectral evolution in the optical frequency ranges. Our results show...

  • Spectral Variability of FSRQs. Gu, Minfeng; Ai, Y. // Journal of Astrophysics & Astronomy;Mar-Jun2011, Vol. 32 Issue 1/2, p87 

    The optical variability of 29 flat spectrum radio quasars in SDSS Stripe 82 region are investigated by using DR7 released multi-epoch data. All FSRQs show variations with overall amplitude ranging from 0.24 mag to 3.46 mag in different sources. About half of FSRQs show a bluer-when-brighter...

  • Photopolarimetry of 3C 66A in 2003. Efimov, Yu. S.; Primak, N. V. // Astrophysics;Jan2006, Vol. 49 Issue 1, p36 

    The BL Lac-type object 3C 66A was observed at the Crimean Astrophysical Observatory during the international project OJ-94. Observations were made over 10 nights from February through December 2003 at the Cassegrain focus of the 125-cm AZT-11 telescope with a photopolarimeter capable of...

  • Color variability of BL Lac in 2002-2008. Hagen-Thorn, V.; Blinov, D.; Hagen-Thorn, E. // Astronomy Reports;Nov2011, Vol. 55 Issue 11, p1000 

    An analysis of multicolor photometric observations of BL Lac performed at the Astronomical Institute of Saint Petersburg State University was carried out to determine the color characteristics of the variable sources responsible for the activity of this object. The existence of two variable...

  • Monitoring of Bright Blazars with MAGIC in the 2007/2008 Season. Satalecka, Konstancja; Ching-Cheng Hsu; Bernardini, Elisa; Bonnoli, Giacomo; Galante, Nicola; Goebel, Florian; Lindfors, Elina; Majumdar, Pratik; Stamerra, Antonio; Wagner, Robert // AIP Conference Proceedings;4/8/2009, Vol. 1112 Issue 1, p223 

    Because of the short duty-cycles and observation-time constraints, studies of bright TeV (E>100 GeV) blazars are mostly restricted to flaring episodes or rather short (days to few weeks) multiwavelength campaigns. At the same time, long-term studies of these objects are essential to gain a more...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics