Probing the gamma-ray emission from HESS J1834-087 using H.E.S.S. and Fermi LAT observations
Abstract
Previous observations with HESS have revealed the existence of an extended very-high-energy (VHE; E>100 GeV) gamma-ray source, HESS J1834-087, coincident with the SNR W41. The origin of the gamma-ray emission has been further investigated with HESS and the Fermi-LAT. The gamma-ray data provided by 61h (HESS) and 4 yrs (Fermi LAT) of observations cover over 5 decades in energy (1.8GeV - 30TeV). The morphology and spectrum of the TeV and GeV sources have been studied and multi-wavelength data have been used to investigate the origin of the observed emission. The TeV source can be modeled with a sum of two components: one point-like and one significantly extended (sig_TeV = 0.17{\deg}), both centered on SNR W41 and exhibiting spectra described by a power law of index 2.6. The GeV source detected with Fermi is extended (sig_GeV =0.15{\deg}) and morphologically matches the VHE emission. Its spectrum can be described by a power-law with index 2.15 and joins smoothly the one of the whole TeV source. A break appears in the spectra around 100 GeV. Two main scenarios are proposed to explain the emission: a pulsar wind nebula (PWN) or the interaction of SNR W41 with a molecular cloud. X-ray observations suggest the presence of a point-like source (pulsar candidate) near the center of the SNR and non-thermal X-ray diffuse emission which could arise from a potential PWN. The PWN scenario is supported by the match of of the TeV and GeV positions with the putative pulsar. However, the overall spectrum is reproduced by a 1-zone leptonic model only if an excess of low-energy electrons is injected by a high spin-down power pulsar. This low-energy component is not needed if the point-like TeV source is unrelated to the extended GeV and TeV sources. The interacting SNR scenario is supported by the spatial coincidence between the gamma-ray sources, the detection of OH maser lines and the hadronic modeling.
Keywords
Cite
@article{arxiv.1407.0862,
title = {Probing the gamma-ray emission from HESS J1834-087 using H.E.S.S. and Fermi LAT observations},
author = {The H. E. S. S. Collaboration and : and A. Abramowski and F. Aharonian and F. Ait Benkhali and A. G. Akhperjanian and E. Angüner and G. Anton and M. Backes and S. Balenderan and A. Balzer and A. Barnacka and Y. Becherini and J. Becker Tjus and K. Bernlöhr and E. Birsin and E. Bissaldi and J. Biteau and M. Böttcher and C. Boisson and J. Bolmont and P. Bordas and J. Brucker and F. Brun and P. Brun and T. Bulik and S. Carrigan and S. Casanova and P. M. Chadwick and R. Chalme-Calvet and R. C. G. Chaves and A. Cheesebrough and M. Chrétien and S. Colafrancesco and G. Cologna and J. Conrad and C. Couturier and Y. Cui and M. Dalton and M. K. Daniel and I. D. Davids and B. Degrange and C. Deil and P. deWilt and H. J. Dickinson and A. Djannati-Ataï and W. Domainko and L. O'C. Drury and G. Dubus and K. Dutson and J. Dyks and M. Dyrda and T. Edwards and K. Egberts and P. Eger and P. Espigat and C. Farnier and S. Fegan and F. Feinstein and M. V. Fernandes and D. Fernandez and A. Fiasson and G. Fontaine and A. Förster and M. Füßling and M. Gajdus and Y. A. Gallant and T. Garrigoux and G. Giavitto and B. Giebels and J. F. Glicenstein and M. -H. Grondin and M. Grudzińska and S. Häffner and J. Hahn and J. Harris and G. Heinzelmann and G. Henri and G. Hermann and O. Hervet and A. Hillert and J. A. Hinton and W. Hofmann and P. Hofverberg and M. Holler and D. Horns and A. Jacholkowska and C. Jahn and M. Jamrozy and M. Janiak and F. Jankowsky and I. Jung and M. A. Kastendieck and K. Katarzyński and U. Katz and S. Kaufmann and B. Khélifi and M. Kieffer and S. Klepser and D. Klochkov and W. Kluźniak and T. Kneiske and D. Kolitzus and Nu. Komin and K. Kosack and S. Krakau and F. Krayzel and P. P. Krüger and H. Laffon and G. Lamanna and J. Lefaucheur and A. Lemière and M. Lemoine-Goumard and J. -P. Lenain and T. Lohse and A. Lopatin and C. -C. Lu and V. Marandon and A. Marcowith and R. Marx and G. Maurin and N. Maxted and M. Mayer and T. J. L. McComb and J. Méhault and P. J. Meintjes and U. Menzler and M. Meyer and R. Moderski and M. Mohamed and E. Moulin and T. Murach and C. L. Naumann and M. de Naurois and J. Niemiec and S. J. Nolan and L. Oakes and H. Odaka and S. Ohm and E. de Oña Wilhelmi and B. Opitz and M. Ostrowski and I. Oya and M. Panter and R. D. Parsons and M. Paz Arribas and N. W. Pekeur and G. Pelletier and J. Perez and P. -O. Petrucci and B. Peyaud and S. Pita and H. Poon and G. Pühlhofer and M. Punch and A. Quirrenbach and S. Raab and M. Raue and I. Reichardt and A. Reimer and O. Reimer and M. Renaud and R. de los Reyes and F. Rieger and L. Rob and C. Romoli and S. Rosier-Lees and G. Rowell and B. Rudak and C. B. Rulten and V. Sahakian and D. A. Sanchez and A. Santangelo and R. Schlickeiser and F. Schüssler and A. Schulz and U. Schwanke and S. Schwarzburg and S. Schwemmer and H. Sol and G. Spengler and F. Spies and Ł. Stawarz and R. Steenkamp and C. Stegmann and F. Stinzing and K. Stycz and I. Sushch and J. -P. Tavernet and T. Tavernier and A. M. Taylor and R. Terrier and M. Tluczykont and C. Trichard and K. Valerius and C. van Eldik and B. van Soelen and G. Vasileiadis and C. Venter and A. Viana and P. Vincent and H. J. Völk and F. Volpe and M. Vorster and T. Vuillaume and S. J. Wagner and P. Wagner and R. M. Wagner and M. Ward and M. Weidinger and Q. Weitzel and R. White and A. Wierzcholska and P. Willmann and A. Wörnlein and D. Wouters and R. Yang and V. Zabalza and M. Zacharias and A. A. Zdziarski and A. Zech and H. -S. Zechlin and Fermi-LAT Collaboration and F. Acero and J. M. Casandjian and J. Cohen-Tanugi and F. Giordano and L. Guillemot and J. Lande and H. Pletsch and Y. Uchiyama},
journal= {arXiv preprint arXiv:1407.0862},
year = {2015}
}
Comments
12 pages, 8 figures, Accepted for publication in Astronomy & Astrophysics