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Very high energy γ -ray emission from RBS 0970

Brown, Anthony M.

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In this Letter I report the Fermi Large Area Telescope (LAT) detection of very high energy (VHE; E > 100 GeV) γ -ray emission from the BL Lac object RBS 0970. 5.3 years of LAT observations revealed the presence of three VHE photon events within 0. ◦1 of RBS 0970, with a subsequent unbinned likelihood analysis finding RBS 0970 to be a source of VHE photons at the 6.5σ level of confidence. The ≥1 GeV flux, binned in monthly periods, did not indicate any flux brightening of RBS 0970 accompanying the emission of the VHE photons. However, a likelihood analysis of the 0.1−100 GeV flux, binned in 28 d periods centred on detection of the VHE photons, revealed that the emission of the lowest energy VHE photons coincided with a hardening of the γ -ray spectrum. Interestingly, the same analysis did not find any significant γ -ray emission from RBS 0970 during the emission of the highest energy VHE event. The discovery of RBS 0970 as a VHE emitter, combined with the spectral variability, suggest RBS 0970 to be a good candidate for follow-up observations with ground-based γ -ray observatories.


Brown, A. M. (2014). Very high energy γ -ray emission from RBS 0970. Monthly Notices of the Royal Astronomical Society: Letters, 442(1), L56-L60.

Journal Article Type Article
Acceptance Date Apr 13, 2014
Publication Date Jul 1, 2014
Deposit Date Apr 10, 2015
Publicly Available Date Apr 10, 2015
Journal Monthly Notices of the Royal Astronomical Society: Letters
Electronic ISSN 1745-3933
Publisher Oxford University Press
Peer Reviewed Peer Reviewed
Volume 442
Issue 1
Pages L56-L60
Keywords Radiation mechanisms, Non-thermal galaxies, Active BL Lacertae object, Individual: RBS 0970 galaxies, Jets gamma rays, Galaxies


Published Journal Article (431 Kb)

Copyright Statement
This article has been published in Monthly Notices of the Royal Astronomical Society © 2014 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.

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