A1 Refereed original research article in a scientific journal
MAGIC reveals a complex morphology within the unidentified gamma-ray source HESS J1857+026
Authors: J. Aleksic, S. Ansoldi, L. A. Antonelli, P. Antoranz, A. Babic, P. Bangale, U. Barres de Almeida, J. A. Barrio, J. Becerra González, W. Bednarek, E. Bernardini, A. Biland, O. Blanch, S. Bonnefoy, G. Bonnoli, F. Borracci, T. Bretz, E. Carmona, A. Carosi, D. Carreto Fidalgo, P. Colin, E. Colombo, J. L. Contreras, J. Cortina, S. Covino, P. Da Vela, F. Dazzi, A. De Angelis, G. De Caneva, B. De Lotto, C. Delgado Mendez, M. Doert, A. Domínguez, D. Dominis Prester, D. Dorner, M. Doro, S. Einecke, D. Eisenacher, D. Elsaesser, E. Farina, D. Ferenc, M. V. Fonseca, L. Font, K. Frantzen, C. Fruck, R. J. García López, M. Garczarczyk, D. Garrido Terrats, M. Gaug, N. Godinovi´c, A. González Muñoz, S. R. Gozzini, D. Hadasch, M. Hayashida, J. Herrera, A. Herrero, D. Hildebrand, J. Hose, D. Hrupec, W. Idec, V. Kadenius, H. Kellermann, S. Klepser, K. Kodani, Y. Konno, J. Krause, H. Kubo, J. Kushida, A. La Barbera, D. Lelas, N. Lewandowska, E. Lindfors, S. Lombardi, M. López, R. López-Coto, A. López-Oramas, E. Lorenz, I. Lozano, M. Makariev, K. Mallot, G. Maneva, N. Mankuzhiyil, K. Mannheim, L. Maraschi, B. Marcote, M. Mariotti, M. Martínez, D. Mazin, U. Menzel, M. Meucci, J. M. Miranda, R. Mirzoyan, A. Moralejo, P. Munar-Adrover, D. Nakajima, A. Niedzwiecki, K. Nilsson, K. Nishijima, K. Noda, N. Nowak, E. de Oña Wilhelmi, R. Orito, A. Overkemping, S. Paiano, M. Palatiello, D. Paneque, R. Paoletti, J. M. Paredes, X. Paredes-Fortuny, S. Partini, M. Persic, F. Prada, P. G. Prada Moroni, E. Prandini, S. Preziuso, I. Puljak, R. Reinthal, W. Rhode, M. Ribó, J. Rico, J. Rodriguez Garcia, S. Rügamer, A. Saggion, T. Saito, K. Saito, K. Satalecka, V. Scalzotto, V. Scapin, C. Schultz, T. Schweizer, S. N. Shore, A. Sillanpää, J. Sitarek, I. Snidaric, D. Sobczynska, F. Spanier, V. Stamatescu?, A. Stamerra, T. Steinbring, J. Storz, M. Strzys, S. Sun, T. Suri´c, L. Takalo, H. Takami, F. Tavecchio, P. Temnikov, T. Terzi´c, D. Tescaro, M. Teshima, J. Thaele, O. Tibolla, D. F. Torres, T. Toyama, A. Treves, M. Uellenbeck, P. Vogler, R. M. Wagner, F. Zandanel, R. Zanin
Publisher: EDP SCIENCES S A
Publication year: 2014
Journal: Astronomy and Astrophysics
Journal name in source: ASTRONOMY & ASTROPHYSICS
Journal acronym: ASTRON ASTROPHYS
Article number: A96
Volume: 571
Number of pages: 8
ISSN: 0004-6361
DOI: https://doi.org/10.1051/0004-6361/201423517
Results. We detected very-high-energy gamma-ray emission from HESS J1857+026 with a significance of 12 sigma above 150 GeV. The differential energy spectrum between 100 GeV and 13 TeV is described well by a power law function dN/dE = N-0(E/1TeV)(-Gamma) with N-0 = (5.37 +/- 0.44(stat) +/- 1.5(sys)) X 10(-12) (TeV-1 cm(-2) s(-1)) and Gamma = 2.16 +/- 0.07(stat) +/- 0.15(sys), which bridges the gap between the GeV emission measured by Fermi-LAT and the multi-TeV emission measured by H.E.S.S.. In addition, we present a detailed analysis of the energy-dependent morphology of this region. We couple these results with archival multiwavelength data and outline evidence in favor of a two-source scenario, whereby one source is associated with a PWN, while the other could be linked with a molecular cloud complex containing an HII region and a possible gas cavity.
