HESS J1741-302: a hidden accelerator in the Galactic planeShow others and affiliations
Number of Authors: 2522018 (English)In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 612, article id A13Article in journal (Refereed) Published
Abstract [en]
The H.E.S.S. Collaboration has discovered a new very high energy (VHE, E > 0.1 TeV) gamma-ray source, HESS J1741-302, located in the Galactic plane. Despite several attempts to constrain its nature, no plausible counterpart has been found so far at X-ray and MeV/GeV gamma-ray energies, and the source remains unidentified. An analysis of 145-h of observations of HESS J1741-302 at VHEs has revealed a steady and relatively weak TeV source (similar to 1% of the Crab Nebula flux), with a spectral index of Gamma = 2.3 +/- 0.2(stat) +/- 0.2(sys), extending to energies up to 10 TeV without any clear signature of a cut-off. In a hadronic scenario, such a spectrum implies an object with particle acceleration up to energies of several hundred TeV. Contrary to most H.E.S.S. unidentified sources, the angular size of HESS J1741-302 is compatible with the H.E.S.S. point spread function at VHEs, with an extension constrained to be below 0.068 degrees at a 99% confidence level. The gamma-ray emission detected by H.E.S.S. can be explained both within a hadronic scenario, due to collisions of protons with energies of hundreds of TeV with dense molecular clouds, and in a leptonic scenario, as a relic pulsar wind nebula, possibly powered by the middle-aged (20 kyr) pulsar PSR B1737-30. A binary scenario, related to the compact radio source 1LC 358.266+0.038 found to be spatially coincident with the best fit position of HESS J1741-302, is also envisaged.
Place, publisher, year, edition, pages
2018. Vol. 612, article id A13
Keywords [en]
gamma rays: ISM, gamma rays: general, cosmic rays, ISM: clouds
National Category
Physical Sciences
Identifiers
URN: urn:nbn:se:su:diva-155937DOI: 10.1051/0004-6361/201730581ISI: 000429404700013Scopus ID: 2-s2.0-85045528109OAI: oai:DiVA.org:su-155937DiVA, id: diva2:1215565
2018-06-082018-06-082022-10-24Bibliographically approved