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

Multiwavelength observations of the high-frequency-peaked blazar 1ES2344+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 >100GeV) γ-ray, X-ray, and UV energies. Observations with VERITAS in...

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Autores principales: 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.
Formato: JOUR
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_0004637X_v738_n2_p_Acciari
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
Descripción
Sumario:Multiwavelength observations of the high-frequency-peaked blazar 1ES2344+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 >100GeV) γ-ray, X-ray, and UV energies. Observations with VERITAS in VHE γ-rays yield a strong detection of 20σ with 633 excess events in a total exposure of 18.1 hr live time. A strong VHE γ-ray flare on 2007 December 7 is measured at F(>300GeV) = (6.76 0.62) × 10 -11 photonscm -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(>300GeV) = (1.06 0.09) × 10 -11 photonscm -2 s -1 (7.6% of the Crab Nebula flux). The differential photon spectrum between 390GeV and 8.3TeV for the time-averaged observations excluding 2007 December 7 is well described by a power law with a photon index of Γ = 2.78 0.09 stat 0.15 syst . On the flaring night of 2007 December 7 the measured VHE γ-ray photon index was Γ = 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 2-10keV flux ranged by a factor of 7 during the campaign. On 2007 December 8 the highest ever observed X-ray flux from 1ES2344+514 was measured by Swift X-ray Telescope at a flux of F(2-10keV) = (6.28 0.31) × 10 -11 ergcm -2 s -1 . Evidence for a correlation between the X-ray flux and VHE γ-ray flux on nightly timescales is indicated with a Pearson correlation coefficient of r = 0.60 0.11. Contemporaneous spectral energy distributions (SEDs) of 1ES2344+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 1ES2344+514 from non-contemporaneous observations. © 2011. The American Astronomical Society. All rights reserved.

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