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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2011
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Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_0004637X_v738_n2_p_Acciari http://hdl.handle.net/20.500.12110/paper_0004637X_v738_n2_p_Acciari |
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paper:paper_0004637X_v738_n2_p_Acciari2023-06-08T14:29:02Z 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 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. 2011 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_0004637X_v738_n2_p_Acciari http://hdl.handle.net/20.500.12110/paper_0004637X_v738_n2_p_Acciari |
institution |
Universidad de Buenos Aires |
institution_str |
I-28 |
repository_str |
R-134 |
collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
description |
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. |
title |
Multiwavelength observations of the very high energy blazar 1ES 2344+514 |
spellingShingle |
Multiwavelength observations of the very high energy blazar 1ES 2344+514 |
title_short |
Multiwavelength observations of the very high energy blazar 1ES 2344+514 |
title_full |
Multiwavelength observations of the very high energy blazar 1ES 2344+514 |
title_fullStr |
Multiwavelength observations of the very high energy blazar 1ES 2344+514 |
title_full_unstemmed |
Multiwavelength observations of the very high energy blazar 1ES 2344+514 |
title_sort |
multiwavelength observations of the very high energy blazar 1es 2344+514 |
publishDate |
2011 |
url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_0004637X_v738_n2_p_Acciari http://hdl.handle.net/20.500.12110/paper_0004637X_v738_n2_p_Acciari |
_version_ |
1768545353372532736 |