Multiwavelength observations of markarian 421 in 2005-2006

D. Horan, V. A. Acciari, S. M. Bradbury, J. H. Buckley, V. Bugaev, K. L. Byrum, A. Cannon, O. Celik, A. Cesarini, Y. C.K. Chow, L. Ciupik, P. Cogan, A. D. Falcone, S. J. Fegan, J. P. Finley, P. Fortin, L. F. Fortson, D. Gall, G. H. Gillanders, J. GrubeG. Gyuk, D. Hanna, E. Hays, M. Kertzman, J. Kildea, A. Konopelko, H. Krawczynski, F. Krennrich, M. J. Lang, K. Lee, P. Moriarty, T. Nagai, J. Niemiec, R. A. Ong, J. S. Perkins, M. Pohl, J. Quinn, P. T. Reynolds, H. J. Rose, G. H. Sembroski, A. W. Smith, D. Steele, S. P. Swordy, J. A. Toner, V. V. Vassiliev, S. P. Wakely, T. C. Weekes, R. J. White, D. A. Williams, M. D. Wood

Research output: Contribution to journalArticlepeer-review

48 Scopus citations

Abstract

Since 2005 September, the Whipple 10 m Gamma-ray Telescope has been operated primarily as a blazar monitor. The five northern hemisphere blazars that have already been detected at the Whipple Observatory, Markarian 421 (Mrk 421), H1426+428, Mrk 501, 1ES 1959+650, and 1ES 2344+514, are monitored routinely each night that they are visible. We report on the Mrk 421 observations taken from 2005 November to 2006 June in the gamma-ray, X-ray, optical, and radio bands. During this time, Mrk 421 was found to be variable at all wavelengths probed. Both the variability and the correlations among different energy regimes are studied in detail here. A tentative correlation, with large spread, was measured between the X-ray and gamma-ray bands, while no clear correlation was evident among the other energy bands. In addition to this, the well-sampled spectral energy distribution of Mrk 421 (1101+384) is presented for three different activity levels. The observations of the other blazar targets will be reported separately.

Original languageEnglish (US)
Pages (from-to)596-618
Number of pages23
JournalAstrophysical Journal
Volume695
Issue number1
DOIs
StatePublished - Apr 10 2009

Bibliographical note

Funding Information:
The authors thank EmmetRoache, JoeMelnick,KevinHarris, Edward Little, and all of the staff at the WhippleObservatory for their support. We also thank the anonymous referee for providing us with constructive suggestions, which were implemented to improve this paper. This research was supported in part by the US Department of Energy, the National Science Foundation, the Smithsonian Institution, Science Foundation Ireland, by PPARC in the UK, and by NSERC in Canada. The ASM quicklook results were provided by the ASM/RXTE teams at MIT and at the RXTE SOF and GOF at NASA's GSFC. The UMRAO team acknowledges the support of the NSF (AST 0607523) and the support of the University of Michigan. Y.Y.K. is a Research Fellow of the Alexander von Humboldt Foundation. RATAN- 600 observations are partly supported by the Russian Foundation for Basic Research (projects 01-02-16812, 05-02-17377, 08-02-00545). The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. This research has made use of the MOJAVE (Lister & Homan 2005) and 2 cm survey (Kellermann et al. 2004) programs database. The Mets?hovi team acknowledges support from the Academy of Finland. Acquisition and analysis of Swift data was supported at PSU through NASA grant NNX08AC38G, as part of the Swift Cycle 3 GI program.

Funding Information:
IRAF is distributed by the National Optical Astronomy Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under cooperative agreement with the National Science Foundation. http://iraf.noao.edu/

Funding Information:
The authors thank Emmet Roache, Joe Melnick, Kevin Harris, Edward Little, and all of the staff at the Whipple Observatory for their support. We also thank the anonymous referee for providing us with constructive suggestions, which were implemented to improve this paper. This research was supported in part by the US Department of Energy, the National Science Foundation, the Smithsonian Institution, Science Foundation Ireland, by PPARC in the UK, and by NSERC in Canada. The ASM quicklook results were provided by the ASM/RXTE teams at MIT and at the RXTE SOF and GOF at NASA’s GSFC. The UMRAO team acknowledges the support of the NSF (AST 0607523) and the support of the University of Michigan. Y.Y.K. is a Research Fellow of the Alexander von Humboldt Foundation. RATAN-600 observations are partly supported by the Russian Foundation for Basic Research (projects 01-02-16812, 05-02-17377, 08-02-00545). The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. This research has made use of the MOJAVE (Lister & Homan 2005) and 2 cm survey (Kellermann et al. 2004) programs database. The Metsähovi team acknowledges support from the Academy of Finland. Acquisition and analysis of Swift data was supported at PSU through NASA grant NNX08AC38G, as part of the Swift Cycle 3 GI program.

Publisher Copyright:
© 2009. The American Astronomical Society. All rights reserved. Printed in the U.S.A.

Keywords

  • BL Lacertae objects: individual (Markarian 421)
  • Gamma rays: observations
  • X-rays: individual (Markarian 421)

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