TeV and multi-wavelength observations of Mrk421 in 2006-2008

V. A. Acciari, E. Aliu, T. Arlen, T. Aune, M. Beilicke, W. Benbow, D. Boltuch, S. M. Bradbury, J. H. Buckley, V. Bugaev, K. Byrum, A. Cannon, A. Cesarini, L. Ciupik, W. Cui, R. Dickherber, C. Duke, A. Falcone, J. P. Finley, G. FinneganL. Fortson, A. Furniss, N. Galante, D. Gall, G. H. Gillanders, S. Godambe, J. Grube, R. Guenette, G. Gyuk, D. Hanna, J. Holder, C. M. Hui, T. B. Humensky, A. Imran, P. Kaaret, N. Karlsson, M. Kertzman, D. Kieda, A. Konopelko, H. Krawczynski, F. Krennrich, M. J. Lang, G. Maier, S. McArthur, M. McCutcheon, P. Moriarty, R. A. Ong, A. N. Otte, M. Ouellette, D. Pandel

Research output: Contribution to journalArticle

84 Scopus citations

Abstract

We report on TeV γ-ray observations of the blazar Mrk421 (redshift of 0.031) with the VERITAS observatory and the Whipple 10 m Cherenkov telescope. The excellent sensitivity of VERITAS allowed us to sample the TeV γ-ray fluxes and energy spectra with unprecedented accuracy where Mrk421 was detected in each of the pointings. A total of 47.3 hr of VERITAS and 96 hr of Whipple 10 m data were acquired between 2006 January and 2008 June. We present the results of a study of the TeV γ-ray energy spectra as a function of time and for different flux levels. On 2008 May 2 and 3, bright TeV γ-ray flares were detected with fluxes reaching the level of 10 Crab. The TeV γ-ray data were complemented with radio, optical, and X-ray observations, with flux variability found in all bands except for the radio wave band. The combination of the Rossi X-ray Timing Explorer and Swift X-ray data reveal spectral hardening with increasing flux levels, often correlated with an increase of the source activity in TeV γ-rays. Contemporaneous spectral energy distributions were generated for 18 nights, each of which are reasonably described by a one-zone synchrotron self-Compton model.

Original languageEnglish (US)
Article number25
JournalAstrophysical Journal
Volume738
Issue number1
DOIs
StatePublished - Sep 1 2011

Keywords

  • BL Lacertae objects: individual (Mrk 421)
  • X-rays: galaxies
  • galaxies: jets
  • galaxies: nuclei
  • gamma rays: galaxies

Fingerprint Dive into the research topics of 'TeV and multi-wavelength observations of Mrk421 in 2006-2008'. Together they form a unique fingerprint.

  • Cite this

    Acciari, V. A., Aliu, E., Arlen, T., Aune, T., Beilicke, M., Benbow, W., Boltuch, D., Bradbury, S. M., Buckley, J. H., Bugaev, V., Byrum, K., Cannon, A., Cesarini, A., Ciupik, L., Cui, W., Dickherber, R., Duke, C., Falcone, A., Finley, J. P., ... Pandel, D. (2011). TeV and multi-wavelength observations of Mrk421 in 2006-2008. Astrophysical Journal, 738(1), [25]. https://doi.org/10.1088/0004-637X/738/1/25