VERITAS observations of the BL Lac object TXS 0506+056
Abstract
On 2017 September 22, the IceCube Neutrino Observatory reported the detection of the high-energy neutrino event \icnu, of potential astrophysical origin. It was soon determined that the neutrino direction was consistent with the location of the gamma-ray blazar \txs~(3FGL J0509.4+0541), which was in an elevated gamma-ray emission state as measured by the \emph{Fermi} satellite. VERITAS observations of the neutrino/blazar region started on 2017 September 23 in response to the neutrino alert and continued through 2018 February 6. While no significant very-high-energy (VHE; E 100 GeV) emission was observed from the blazar by VERITAS in the two-week period immediately following the IceCube alert, TXS 0506+056 was detected by VERITAS with a significance of 5.8 standard deviations () in the full 35-hour data set. The average photon flux of the source during this period was , or 1.6\% of the Crab Nebula flux, above an energy threshold of 110 GeV, with a soft spectral index of .
Keywords
Cite
@article{arxiv.1807.04607,
title = {VERITAS observations of the BL Lac object TXS 0506+056},
author = {A. U. Abeysekara and A. Archer and W. Benbow and R. Bird and A. Brill and R. Brose and J. H. Buckley and J. L. Christiansen and A. J. Chromey and M. K. Daniel and A. Falcone and Q. Feng and J. P. Finley and L. Fortson and A. Furniss and G. H. Gillanders and O. Gueta and D. Hanna and O. Hervet and J. Holder and G. Hughes and T. B. Humensky and C. A. Johnson and P. Kaaret and P. Kar and N. Kelley-Hoskins and M. Kertzman and D. Kieda and M. Krause and F. Krennrich and M. J. Lang and P. Moriarty and R. Mukherjee and S. O'Brien and R. A. Ong and A. N. Otte and N. Park and A. Petrashyk and M. Pohl and E. Pueschel and J. Quinn and K. Ragan and P. T. Reynolds and G. T. Richards and E. Roache and C. Rulten and I. Sadeh and M. Santander and S. S. Scott and G. H. Sembroski and K. Shahinyan and J. Tyler and S. P. Wakely and A. Weinstein and R. M. Wells and P. Wilcox and A. Wilhelm and D. A. Williams and T. J Williamson and B. Zitzer},
journal= {arXiv preprint arXiv:1807.04607},
year = {2018}
}