First detection of a VHE gamma-ray spectral maximum from a cosmic source: HESS discovery of the Vela X nebula

van Eldik C (2006)


Publication Status: Published

Publication Type: Journal article, Original article

Publication year: 2006

Journal

Publisher: EDP Sciences

Book Volume: 448

Journal Issue: 2

DOI: 10.1051/0004-6361:200600014

Abstract

The Vela supernova remnant (SNR) is a complex region containing a number of sources of non-thermal radiation. The inner section of this SNR, within 2 degrees of the pulsar PSR B0833-45, has been observed by the HESS γ-ray atmospheric Cherenkov detector in 2004 and 2005. A strong signal is seen from an extended region to the south of the pulsar, within an integration region of radius 0.8° around the position (α = 0835 00, δ = -45°36′ J2000.0). The excess coincides with a region of hard X-ray emission seen by the ROSAT and ASCA satellites. The observed energy spectrum of the source between 550 GeV and 65 TeV is well fit by a power law function with photon index Γ = 1.45 ± 0.09 ± 0.2 and an exponential cutoff at an energy of 13.8 ± 2.3 ± 4.1 TeV. The integral flux above 1 TeV is (1.28 ± 0.17 ± 0.38) × 10 cm s. This result is the first clear measurement of a peak in the spectral energy distribution from a VHE γ-ray source, likely related to inverse Compton emission. A fit of an Inverse Compton model to the HESS spectral energy distribution gives a total energy in non-thermal electrons of ∼2 × 10 erg between 5 TeV and 100 TeV, assuming a distance of 290 parsec to the pulsar. The best fit electron power law index is 2.0, with a spectral break at 67 TeV. © ESO 2006.

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How to cite

APA:

van Eldik, C. (2006). First detection of a VHE gamma-ray spectral maximum from a cosmic source: HESS discovery of the Vela X nebula. Astronomy & Astrophysics, 448(2). https://doi.org/10.1051/0004-6361:200600014

MLA:

van Eldik, Christopher. "First detection of a VHE gamma-ray spectral maximum from a cosmic source: HESS discovery of the Vela X nebula." Astronomy & Astrophysics 448.2 (2006).

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