First detection of VHE gamma-rays from SN 1006 by H.E.S.S

TL;DR

This paper reports the first detection of very high energy gamma-rays from SN 1006 using H.E.S.S., confirming particle acceleration in supernova remnants and providing insights into emission mechanisms.

Contribution

First VHE gamma-ray detection of SN 1006 with H.E.S.S., demonstrating particle acceleration and emission processes in this supernova remnant.

Findings

Detected VHE gamma-rays from SN 1006

Gamma-ray spectrum is compatible with a power-law

Flux is about 1% of Crab Nebula flux

Abstract

Recent theoretical predictions of the lowest very high energy (VHE) luminosity of SN 1006 are only a factor 5 below the previously published H.E.S.S. upper limit, thus motivating further in-depth observations of this source. Deep observations at VHE energies (above 100 GeV) were carried out with the High Energy Stereoscopic System (H.E.S.S.) of Cherenkov Telescopes from 2003 to 2008. More than 100 hours of data have been collected and subjected to an improved analysis procedure. Observations resulted in the detection of VHE gamma-rays from SN 1006. The measured gamma-ray spectrum is compatible with a power-law, the flux is of the order of 1% of that detected from the Crab Nebula, and is thus consistent with the previously established H.E.S.S. upper limit. The source exhibits a bipolar morphology, which is strongly correlated with non-thermal X-rays. Because the thickness of the VHE-shell is compatible with emission from a thin rim, particle acceleration in shock waves is likely to be the origin of the gamma-ray signal. The measured flux level can be accounted for by inverse Compton emission, but a mixed scenario that includes leptonic and hadronic components and takes into account the ambient matter density inferred from observations also leads to a satisfactory description of the multi-wavelength spectrum.