Very high energy γ-ray observations of Mrk 501 using the TACTIC imaging γ-ray telescope during 2005 06Show others and affiliations
2008 (English)In: Journal of Physics G: Nuclear and Particle Physics, ISSN 0954-3899, E-ISSN 1361-6471, Vol. 35, no 6, article id 065202Article in journal (Refereed) Published
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Text
Abstract [en]
In this paper we report on the Markarian 501 results obtained during our TeV γ-ray observations from 11 March to 12 May 2005 and 28 February to 7 May 2006 for 112.5 h with the TACTIC γ-ray telescope. During 2005 observations for 45.7 h, the source was found to be in a low state and we have placed an upper limit of 4.62 × 10−12 photons cm−2 s−1 at 3σ level on the integrated TeV γ-ray flux above 1 TeV from the source direction. However, during 2006 observations for 66.8 h, detailed data analysis revealed the presence of a TeV γ-ray signal from the source with a statistical significance of 7.5σ above Eγ≥ 1 TeV. The time-averaged differential energy spectrum of the source in the energy range 1–11 TeV is found to match well with the power-law function of the form (dΦ/dE = f0E−Γ) with f0 = (1.66 ± 0.52) × 10−11 cm−2 s−1 TeV−1 and Γ = 2.80 ± 0.27.
Place, publisher, year, edition, pages
2008. Vol. 35, no 6, article id 065202
National Category
Astronomy, Astrophysics and Cosmology
Research subject
Natural Science, Physics
Identifiers
URN: urn:nbn:se:lnu:diva-51570DOI: 10.1088/0954-3899/35/6/065202OAI: oai:DiVA.org:lnu-51570DiVA, id: diva2:915333
2016-03-292016-03-292017-11-30Bibliographically approved