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Title: VERITAS Observations of the BL Lac Object TXS 0506+056

Journal Article · · The Astrophysical Journal. Letters (Online)
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On 2017 September 22, the IceCube Neutrino Observatory reported the detection of the high-energy neutrino event IC 170922A, of potential astrophysical origin. It was soon determined that the neutrino direction was consistent with the location of the gamma-ray blazar TXS 0506+056 (3FGL J0509.4+0541), which was in an elevated gamma-ray emission state as measured by the Fermi satellite. Very Energetic Radiation Imaging Telescope Array System (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 (σ) in the full 35 hr data set. The average photon flux of the source during this period was (8.9 ± 1.6) × 10–12 cm–2 s–1, or 1.6% of the Crab Nebula flux, above an energy threshold of 110 GeV, with a soft spectral index of 4.8 ± 1.3.

Research Organization:
Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC)
Sponsoring Organization:
USDOE Office of Science (SC)
Contributing Organization:
The VERITAS Collaboration
OSTI ID:
1544096
Journal Information:
The Astrophysical Journal. Letters (Online), Vol. 861, Issue 2; ISSN 2041-8213
Publisher:
Institute of Physics (IOP)Copyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 20 works
Citation information provided by
Web of Science

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Cited By (10)

High-energy neutrino flux from individual blazar flares journal September 2019
TXS 0506+056, the first cosmic neutrino source, is not a BL Lac journal January 2019
Modelling the coincident observation of a high-energy neutrino and a bright blazar flare text January 2019
Probing the Emission Mechanism and Magnetic Field of Neutrino Blazars with Multiwavelength Polarization Signatures journal May 2019
Investigation of Two Fermi -LAT Gamma-Ray Blazars Coincident with High-energy Neutrinos Detected by IceCube journal July 2019
Cascading Constraints from Neutrino-emitting Blazars: The Case of TXS 0506+056 journal August 2019
Investigation of Two Fermi -LAT Gamma-Ray Blazars Coincident with High-energy Neutrinos Detected by IceCube text January 2019
Modelling the coincident observation of a high-energy neutrino and a bright blazar flare journal November 2018
Probing the Emission Mechanism and Magnetic Field of Neutrino Blazars with Multi-Wavelength Polarization Signatures text January 2019
High energy neutrino flux from individual blazar flares text January 2019