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.
Documento: | Artículo |
Título: | Multiwavelength observations of the very high energy blazar 1ES 2344+514 |
Autor: | 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. |
Filiación: | Fred Lawrence Whipple Observatory, Harvard-Smithsonian Center for Astrophysics, Amado, AZ 85645, United States Department of Physics and Astronomy, Bartol Research Institute, University of Delaware, Newark, DE 19716, United States Department of Physics and Astronomy, University of California, Los Angeles, CA 90095, United States Santa Cruz Institute for Particle Physics, Department of Physics, University of California, Santa Cruz, CA 95064, United States Department of Physics, Washington University, St. Louis, MO 63130, United States School of Physics, University College Dublin, Belfield, Dublin 4, Ireland Astronomy Department, Adler Planetarium and Astronomy Museum, Chicago, IL 60605, United States Physics Department, McGill University, Montreal, QC H3A 2T8, Canada Physics Department, University of Utah, Salt Lake City, UT 84112, United States Department of Astronomy and Astrophysics, 525 Davey Lab, Pennsylvania State University, University Park, PA 16802, United States Department of Physics, Purdue University, West Lafayette, IN 47907, United States Department of Physics and Astronomy, Barnard College, Columbia University, NY 10027, United States School of Physics, National University of Ireland, Galway, Ireland Laboratoire Leprince-Ringuet, Ecole Polytechnique, CNRS/IN2P3, F-91128 Palaiseau, France Enrico Fermi Institute, University of Chicago, Chicago, IL 60637, United States Department of Physics and Astronomy, Iowa State University, Ames, IA 50011, United States Department of Physics and Astronomy, University of Iowa, Van Allen Hall, Iowa City, IA 52242, United States Department of Physics and Astronomy, DePauw University, Greencastle, IN 46135-0037, United States Department of Physics, Pittsburg State University, 1701 South Broadway, Pittsburg, KS 66762, United States Department of Life and Physical Sciences, Galway-Mayo Institute of Technology, Dublin Road, Galway, Ireland Instituto de Astronomia y Fisica Del Espacio, Casilla de Correo 67 - Sucursal 28, Ciudad Autnoma de Buenos Aires (C1428ZAA), Argentina Department of Applied Physics and Instrumentation, Cork Institute of Technology, Bishopstown, Cork, Ireland School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, United Kingdom Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439, United States |
Año: | 2011 |
Volumen: | 738 |
Número: | 2 |
DOI: | http://dx.doi.org/10.1088/0004-637X/738/2/169 |
Título revista: | Astrophysical Journal |
Título revista abreviado: | Astrophys. J. |
ISSN: | 0004637X |
Registro: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_0004637X_v738_n2_p_Acciari |