MULTIWAVELENGTH OBSERVATIONS OF THE VERY HIGH ENERGY BLAZAR 1ES 2344+514
Abstract
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 20{sigma} 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{sup -11} photons cm{sup -2} s{sup -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{sup -11} photons cm{sup -2} s{sup -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 {Gamma} = 2.78 {+-} 0.09{sub stat} {+-} 0.15{sub syst}. On the flaring night of 2007 December 7 the measured VHE {gamma}-ray photon index was {Gamma} = 2.43 {+-} 0.22{sub stat} {+-} 0.15{sub syst}. Over the fullmore »
- Authors:
-
- Fred Lawrence Whipple Observatory, Harvard-Smithsonian Center for Astrophysics, Amado, AZ 85645 (United States)
- Department of Physics and Astronomy and the 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 and 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)
- Publication Date:
- OSTI Identifier:
- 21584860
- Resource Type:
- Journal Article
- Journal Name:
- Astrophysical Journal
- Additional Journal Information:
- Journal Volume: 738; Journal Issue: 2; Other Information: DOI: 10.1088/0004-637X/738/2/169; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BL LACERTAE OBJECTS; CRAB NEBULA; ENERGY SPECTRA; GAMMA RADIATION; PHOTONS; SIMULATION; X RADIATION; BOSONS; COSMIC RADIO SOURCES; ELECTROMAGNETIC RADIATION; ELEMENTARY PARTICLES; IONIZING RADIATIONS; MASSLESS PARTICLES; NEBULAE; RADIATIONS; SPECTRA; SUPERNOVA REMNANTS
Citation Formats
Acciari, V A, Benbow, W, Aliu, E, Boltuch, D, Arlen, T, Fegan, S J, Aune, T, Furniss, A, Beilicke, M, Bugaev, V, Dickherber, R, Cannon, A, Ciupik, L, Fortson, L F, Cogan, P, Colin, P, Falcone, A, Finley, J P, Gall, D, and Fortin, P. MULTIWAVELENGTH OBSERVATIONS OF THE VERY HIGH ENERGY BLAZAR 1ES 2344+514. United States: N. p., 2011.
Web. doi:10.1088/0004-637X/738/2/169; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA).
Acciari, V A, Benbow, W, Aliu, E, Boltuch, D, Arlen, T, Fegan, S J, Aune, T, Furniss, A, Beilicke, M, Bugaev, V, Dickherber, R, Cannon, A, Ciupik, L, Fortson, L F, Cogan, P, Colin, P, Falcone, A, Finley, J P, Gall, D, & Fortin, P. MULTIWAVELENGTH OBSERVATIONS OF THE VERY HIGH ENERGY BLAZAR 1ES 2344+514. United States. https://doi.org/10.1088/0004-637X/738/2/169; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)
Acciari, V A, Benbow, W, Aliu, E, Boltuch, D, Arlen, T, Fegan, S J, Aune, T, Furniss, A, Beilicke, M, Bugaev, V, Dickherber, R, Cannon, A, Ciupik, L, Fortson, L F, Cogan, P, Colin, P, Falcone, A, Finley, J P, Gall, D, and Fortin, P. 2011.
"MULTIWAVELENGTH OBSERVATIONS OF THE VERY HIGH ENERGY BLAZAR 1ES 2344+514". United States. https://doi.org/10.1088/0004-637X/738/2/169; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA).
@article{osti_21584860,
title = {MULTIWAVELENGTH OBSERVATIONS OF THE VERY HIGH ENERGY BLAZAR 1ES 2344+514},
author = {Acciari, V A and Benbow, W and Aliu, E and Boltuch, D and Arlen, T and Fegan, S J and Aune, T and Furniss, A and Beilicke, M and Bugaev, V and Dickherber, R and Cannon, A and Ciupik, L and Fortson, L F and Cogan, P and Colin, P and Falcone, A and Finley, J P and Gall, D and Fortin, P},
abstractNote = {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 20{sigma} 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{sup -11} photons cm{sup -2} s{sup -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{sup -11} photons cm{sup -2} s{sup -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 {Gamma} = 2.78 {+-} 0.09{sub stat} {+-} 0.15{sub syst}. On the flaring night of 2007 December 7 the measured VHE {gamma}-ray photon index was {Gamma} = 2.43 {+-} 0.22{sub stat} {+-} 0.15{sub 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 {approx}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{sup -11} erg cm{sup -2} s{sup -1}. Evidence for a correlation between the X-ray flux and VHE {gamma}-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.},
doi = {10.1088/0004-637X/738/2/169; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)},
url = {https://www.osti.gov/biblio/21584860},
journal = {Astrophysical Journal},
issn = {0004-637X},
number = 2,
volume = 738,
place = {United States},
year = {Sat Sep 10 00:00:00 EDT 2011},
month = {Sat Sep 10 00:00:00 EDT 2011}
}