Multiwavelength Observations of the VHE Blazar 1ES 2344+514
Abstract
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 >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 hours live-time. A strong VHE {\gamma}-ray flare on 2007 December 7 is measured at F(>300 GeV) = (6.76 \pm 0.62) \times 10-11 ph 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 \pm 0.09) \times 10-11 ph 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 {\Gamma} = 2.78 \pm 0.09stat \pm 0.15syst. 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 ~7 during the campaign. On 2007 December 8 the highest ever observed X-ray flux from 1ES 2344+514 was measured by Swift XRT at a flux of F(2-10 keV) = (6.28 \pm 0.31) \times 10-11 erg cm-2 s-1. Evidence for a correlation between the X-ray flux and VHE {\gamma}-ray flux on nightly time-scales is indicated with a Pearson correlation coefficient of r = 0.60 \pm 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.
Keywords
Cite
@article{arxiv.1106.4594,
title = {Multiwavelength Observations of the VHE Blazar 1ES 2344+514},
author = {V. A. Acciari and E. Aliu and T. Arlen and T. Aune and M. Beilicke and W. Benbow and D. Boltuch and V. Bugaev and A. Cannon and L. Ciupik and P. Cogan and P. Colin and R. Dickherber and A. Falcone and S. J. Fegan and J. P. Finley and P. Fortin and L. F. Fortson and A. Furniss and D. Gall and G. H. Gillanders and J. Grube and R. Guenette and G. Gyuk and D. Hanna and J. Holder and D. Horan and C. M. Hui and T. B. Humensky and A. Imran and P. Kaaret and N. Karlsson and M. Kertzman and D. Kieda and J. Kildea and A. Konopelko and H. Krawczynski and F. Krennrich and M. J. Lang and S. LeBohec and G. Maier and P. Moriarty and R. Mukherjee and R. A. Ong and A. N. Otte and D. Pandel and J. S. Perkins and A. Pichel and M. Pohl and J. Quinn and K. Ragan and P. T. Reynolds and H. J. Rose and M. Schroedter and G. H. Sembroski and A. W. Smith and D. Steele and S. P. Swordy and M. Theiling and J. A. Toner and A. Varlotta and V. V. Vassiliev and S. Vincent and R. Wagner and S. P. Wakely and J. E. Ward and T. C. Weekes and A. Weinstein and T. Weisgarber and D. A. Williams and S. Wissel and M. Wood and B. Zitzer},
journal= {arXiv preprint arXiv:1106.4594},
year = {2015}
}
Comments
13 pages, 7 figures, accepted by ApJ