Multiwavelength observations of the very high energy blazar 1es 2344+514

Acciari, V. A.
Aliu, E.
Arlen, T.
Aune, T.
Beilicke, M.
Benbow, W.
Boltuch, D.
Bugaev, V.
Cannon, A.
Ciupik, L.
... show 10 more
Acciari, V. A. Aliu, E.; Arlen, T.; Aune, T.; Beilicke, M.; Benbow, W.; Boltuch, D.; Bugaev, V.; Cannon, A.; Ciupik, L.; Cogan, P.; Colin, P.; Dickherber, R.; Falcone, A.; Fegan, S. J.; Finley, J. P.; Fortin, P.; Fortson, L. F.; Furniss, A.; Gall, D.; Gillanders, G. H.; Grube, J.; Guenette, R.; Gyuk, G.; Hanna, D.; Holder, J.; Horan, D.; Hui, C. M.; Humensky, T. B.; Imran, A.; Kaaret, P.; Karlsson, N.; Kertzman, M.; Kieda, D.; Kildea, J.; Konopelko, A.; Krawczynski, H.; Krennrich, F.; Lang, M. J.; LeBohec, S.; Maier, G.; Moriarty, P.; Mukherjee, R.; Ong, R. A.; Otte, A. N.; Pandel, D.; Perkins, J. S.; Pichel, A.; Pohl, M.; Quinn, J.; Ragan, K.; Reynolds, P. T.; Rose, H. J.; Schroedter, M.; Sembroski, G. H.; Smith, A. W.; Steele, D.; Swordy, S. P.; Theiling, M.; Toner, J. A.; Varlotta, A.; Vassiliev, V. V.; Vincent, S.; Wagner, R.; Wakely, S. P.; Ward, J. E.; Weekes, T. C.; Weinstein, A.; Weisgarber, T.; Williams, D. A.; Wissel, S.; Wood, M.; Zitzer, B. (2011). Multiwavelength observations of the very high energy blazar 1es 2344+514. The Astrophysical Journal 738 (2),
Multiwavelength observations of the high-frequency-peaked blazar 1ES 2344+514 were performed from 2007 October to 2008 January. The campaign represents the first contemporaneous data on the object at very high energy (VHE, E > 100 GeV) gamma-ray, X-ray, and UV energies. Observations with VERITAS in VHE gamma-rays yield a strong detection of 20s with 633 excess events in a total exposure of 18.1 hr live time. A strong VHE gamma-ray flare on 2007 December 7 is measured at F(> 300 GeV) = (6.76 +/- 0.62) x 10(-11) photons cm(-2) s(-1), corresponding to 48% of the Crab Nebula flux. Excluding this flaring episode, nightly variability at lower fluxes is observed with a time-averaged mean of F(> 300 GeV) = (1.06 +/- 0.09) x 10(-11) photons cm(-2) s(-1) (7.6% of the Crab Nebula flux). The differential photon spectrum between 390 GeV and 8.3 TeV for the time-averaged observations excluding 2007 December 7 is well described by a power law with a photon index of G = 2.78 +/- 0.09(stat) +/- 0.15(syst). On the flaring night of 2007 December 7 the measured VHE gamma-ray photon index was Gamma = 2.43 +/- 0.22(stat) +/- 0.15(syst). Over the full period of VERITAS observations contemporaneous X-ray and UV data were taken with Swift and RXTE. The measured 2-10 keV flux ranged by a factor of similar to 7 during the campaign. On 2007 December 8 the highest ever observed X-ray flux from 1ES 2344+514 was measured by Swift X-ray Telescope at a flux of F(2-10 keV) = (6.28 +/- 0.31) x 10(-11) erg cm(-2) s(-1). Evidence for a correlation between the X-ray flux and VHE. -ray flux on nightly timescales is indicated with a Pearson correlation coefficient of r = 0.60 +/- 0.11. Contemporaneous spectral energy distributions (SEDs) of 1ES 2344+514 are presented for two distinct flux states. A one-zone synchrotron self-Compton (SSC) model describes both SEDs using parameters consistent with previous SSC modeling of 1ES 2344+514 from non-contemporaneous observations.
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