Discovery and follow-up studies of the extended, off-plane, VHE gamma-ray source HESS J1507-622

Abstract

Context: The detection of gamma-rays in the very-high-energy (VHE) range (100 GeV-100 TeV) offers the possibility of studying the parent population of ultrarelativistic particles found in astrophysical sources, so it is useful for understanding the underlying astrophysical processes in nonthermal sources. Aim: The discovery of the VHE gamma-ray source HESS J1507-622 is reported and possibilities regarding its nature are investigated. Methods: The H.E.S.S. array of imaging atmospheric Cherenkov telescopes (IACTs) has a high sensitivity compared with previous instruments (~1% of the Crab flux in 25 hours observation time for a 5 sigma point-source detection) and has a large field of view (~5 deg in diameter). HESS J1507-622 was discovered within the ongoing H.E.S.S. survey of the inner Galaxy, and the source was also studied by means of dedicated multiwavelength observations. Results: A Galactic gamma-ray source, HESS J1507-622, located ~3.5 deg from the Galactic plane was detected with a statistical significance > 9 sigma. Its energy spectrum is well fitted by a power law with spectral index Γ= 2.24 +/- 0.16_{stat} +/- 0.20_{sys} and a flux above 1 TeV of (1.5 +/- 0.4_{stat} +/- 0.3_{sys}) X 10^{-12} cm^{-2} s^{-1}. Possible interpretations (considering both hadronic and leptonic models) of the VHE gamma-ray emission are discussed in the absence of an obvious counterpart.

Accepted for publication in A&A

References in corpus (9)

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Cited by in corpus (18)

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• Search for extended sources in the Galactic Plane using 6 years of Fermi-Large Area Telescope Pass 8 data above 10 GeV
• Surveys with the Cherenkov Telescope Array
• Sub-PeV Neutrinos from TeV Unidentified Sources in the Galaxy
• Time-dependent Modeling of Pulsar Wind Nebulae
• Understanding hadronic gamma-ray emission from supernova remnants
• Search for Galactic PeV Gamma Rays with the IceCube Neutrino Observatory
• Gamma-rays from pulsar wind nebulae in starburst galaxies
• Search for PeV Gamma-Ray Emission from the Southern Hemisphere with 5 Years of Data from the IceCube Observatory
• Discovery of an extended source of gamma-ray emission in the Southern Hemisphere
• Exploring the potential X-ray counterpart of the puzzling TeV gamma-ray source HESS J1507-622 with new Suzaku observations
• Exploring the nature of the unidentified VHE gamma-ray source HESS J1507-622
• XMM-Newton and Chandra X-ray follow-up observations of the VHE gamma-ray source HESS J1507-622
• A new method of reconstructing very-high-energy gamma-ray spectra: the Template Background Spectrum
• Ancient Pulsar Wind Nebulae as a natural explanation for unidentified gamma-ray sources