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arXiv · 1310.6498

Long term observations of B2 1215+30 with VERITAS

VERITAS collaboration·E. Aliu·S. Archambault·T. Arlen·T. Aune·M. Beilicke·W. Benbow·R. Bird·A. Bouvier·J. H. Buckley·V. Bugaev·A. Cesarini·L. Ciupik·M. P. Connolly·W. Cui·J. Dumm·M. Errando·A. Falcone·S. Federici·Q. Feng·J. P. Finley·P. Fortin·L. Fortson·A. Furniss·N. Galante·L. Gérard·G. H. Gillanders·S. Griffin·J. Grube·G. Gyuk·D. Hanna·J. Holder·G. Hughes·T. B. Humensky·P. Kaaret·M. Kertzman·Y. Khassen·D. Kieda·H. Krawczynski·F. Krennrich·M. J. Lang·A. S Madhavan·G. Maier·P. Majumdar·S. McArthur·A. McCann·P. Moriarty·R. Mukherjee·D. Nieto·A. O'Faoláin de Bhróithe·R. A. Ong·M. Orr·A. N. Otte·N. Park·J. S. Perkins·M. Pohl·A. Popkow·H. Prokoph·J. Quinn·K. Ragan·L. C. Reyes·P. T. Reynolds·G. T. Richards·E. Roache·D. B. Saxon·G. H. Sembroski·C. Skole·A. W. Smith·M. Soares-Furtado·D. Staszak·I. Telezhinsky·G. Tešić·M. Theiling·A. Varlotta·V. V. Vassiliev·S. Vincent·S. P. Wakely·T. C. Weekes·A. Weinstein·R. Welsing·D. A. Williams·B. Zitzer·M. Böttcher·M. Fumagalli·J. Jadhav
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Abstract

We report on VERITAS observations of the BL Lac object B2 1215+30 between 2008 and 2012. During this period, the source was detected at very high energies (VHE; E > 100 GeV) by VERITAS with a significance of $8.9\sigma$ and showed clear variability on time scales larger than months. In 2011, the source was found to be in a relatively bright state and a power-law fit to the differential photon spectrum yields a spectral index of $3.6 \pm 0.4_{\mathrm{stat}} \pm 0.3_{\mathrm{syst}}$ with an integral flux above 200 GeV of $(8.0 \pm 0.9_{\mathrm{stat}} \pm 3.2_{\mathrm{syst}}) \times 10^{-12}\, \mathrm{cm}^{-2} \mathrm{s}^{-1}$. No short term variability could be detected during the bright state in 2011. Multi-wavelength data were obtained contemporaneous with the VERITAS observations in 2011 and cover optical (Super-LOTIS, MDM, Swift-UVOT), X-ray (Swift-XRT), and gamma-ray (Fermi-LAT) frequencies. These were used to construct the spectral energy distribution (SED) of B2 1215+30. A one-zone leptonic model is used to model the blazar emission and the results are compared to those of MAGIC from early 2011 and other VERITAS-detected blazars. The SED can be well reproduced with model parameters typical for VHE-detected BL Lacs.

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VERITAS collaboration, E. Aliu, S. Archambault, T. Arlen, T. Aune, M. Beilicke, W. Benbow, R. Bird, A. Bouvier, J. H. Buckley, V. Bugaev, A. Cesarini, L. Ciupik, M. P. Connolly, W. Cui, J. Dumm, M. Errando, A. Falcone, S. Federici, Q. Feng, J. P. Finley, P. Fortin, L. Fortson, A. Furniss, N. Galante, L. Gérard, G. H. Gillanders, S. Griffin, J. Grube, G. Gyuk, D. Hanna, J. Holder, G. Hughes, T. B. Humensky, P. Kaaret, M. Kertzman, Y. Khassen, D. Kieda, H. Krawczynski, F. Krennrich, M. J. Lang, A. S Madhavan, G. Maier, P. Majumdar, S. McArthur, A. McCann, P. Moriarty, R. Mukherjee, D. Nieto, A. O'Faoláin de Bhróithe, R. A. Ong, M. Orr, A. N. Otte, N. Park, J. S. Perkins, M. Pohl, A. Popkow, H. Prokoph, J. Quinn, K. Ragan, L. C. Reyes, P. T. Reynolds, G. T. Richards, E. Roache, D. B. Saxon, G. H. Sembroski, C. Skole, A. W. Smith, M. Soares-Furtado, D. Staszak, I. Telezhinsky, G. Tešić, M. Theiling, A. Varlotta, V. V. Vassiliev, S. Vincent, S. P. Wakely, T. C. Weekes, A. Weinstein, R. Welsing, D. A. Williams, B. Zitzer, M. Böttcher, M. Fumagalli, J. Jadhav. 2013-10-24. Long term observations of B2 1215+30 with VERITAS. https://doi.org/10.1088/0004-637x/779/2/92

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