Unveiling the origin of HESS J1809-193
Abstract
Aims: The main goal of this paper is to provide new insights on the origin of the observable flux of γ rays from HESS J1809-193 using new high-quality observations in the radio domain.
Methods: We used the Expanded Very Large Array (now known as the Karl G. Jansky Very large Array, JVLA) to produce a deep full-synthesis imaging at 1.4 GHz of the vicinity of PSR J1809-1917. These data were used in conjunction with 12CO observations from the James Clerk Maxwell Telescope in the transition line J = 3-2 and atomic hydrogen data from the Southern Galactic Plane Survey to investigate the properties of the interstellar medium in the direction of the source HESS J1809-193.
Results: The new radio continuum image, obtained with a synthesized beam of 8'' × 4'' and a sensitivity of 0.17 mJy beam-1, reveals with unprecedented detail all the intensity structures in the field. No radio counterpart to the observed X-ray emission supposed to be a pulsar wind nebula powered by PSR J1809-1917 is seen in the new JVLA image. We discovered a system of molecular clouds on the edge of the supernova remnant (SNR) G11.0-0.0 shock front, which is positionally coincident with the brightest part of the TeV source HESS J1809-193. We determine, on the basis of kinematic and morphological evidences, a physical link of the SNR with the clouds for which we estimated a total (molecular plus atomic) mass of ~3 × 103M⊙ and a total proton density in the range 2-3 × 103 cm-3.
Conclusions: We propose as the most likely origin of the very high-energy γ-ray radiation from HESS J1809-193 a hadronic mechanism through collisions of ions accelerated at the SNR G11.0-0.0 shock with the molecular matter in the vicinity of the remnant.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- March 2016
- DOI:
- 10.1051/0004-6361/201527578
- arXiv:
- arXiv:1601.04962
- Bibcode:
- 2016A&A...587A..71C
- Keywords:
-
- ISM: supernova remnants;
- ISM: clouds;
- radio continuum: ISM;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 7 pages, 5 figures, Accepted to be published in the Astronomy and Astrophysics Main Journal