H. Abdalla, R. Adam, Felix A. Aharonian, F. Ait Benkhali, Ekrem Oǧuzhan Angüner, C. Arcaro, C. Armand, T. Armstrong, H. Ashkar, M. Backes, V. Baghmanyan, V. Barbosa Martins, A. Barnacka, M. Barnard, Y. Becherini, D. Berge, K. Bernlohr, B. Bi, M. Bottcher, C. Boisson, J. Bolmont, M. de Bony de Lavergne, Pol Bordas, M. Breuhaus, F. Brun, P. Brun, M. Bryan, M. Buchele, T. Bulik, T. Bylund, S. Caroff, A. Carosi, Sabrina Casanova, T. Chand, S. Chandra, A. Chen, G. Cotter, M. Curylo, J. Damascene Mbarubucyeye, I. D. Davids, J. Davies, C. Deil, J. Devin, P. deWilt, L. Dirson, A. Djannati-Atai, A. Dmytriiev, A. Donath, V. Doroshenko, C. Duffy, J. Dyks, Kathrin Egberts, F. Eichhorn, S. Einecke, G. Emery, J. -P. Ernenwein, K. Feijen, S. Fegan, A. Fiasson, G. Fichet de Clairfontaine, G. Fontaine, S. Funk, Matthias Fussling, S. Gabici, Y. A. Gallant, G. Giavitto, L. Giunti, D. Glawion, J. F. Glicenstein, D. Gottschall, M. -H. Grondin, J. Hahn, M. Haupt, G. Hermann, J. A. Hinton, W. Hofmann, Clemens Hoischen, T. L. Holch, M. Holler, M. Horbe, D. Horns, D. Huber, M. Jamrozy, D. Jankowsky, F. Jankowsky, A. Jardin-Blicq, V. Joshi, I. Jung-Richardt, E. Kasai, M. A. Kastendieck, K. Katarzynski, U. Katz, D. Khangulyan, B. Khelifi, S. Klepser, W. Kluzniak, Nu. Komin, R. Konno, K. Kosack, D. Kostunin, M. Kreter, G. Lamanna, A. Lemiere, M. Lemoine-Goumard, J. -P. Lenain, C. Levy, T. Lohse, I. Lypova, J. Mackey, J. Majumdar, D. Malyshev, D. Malyshev, V. Marandon, P. Marchegiani, A. Marcowith, A. Mares, G. Marti-Devesa, R. Marx, G. Maurin, P. J. Meintjes, M. Meyer, A. Mitchell, R. Moderski, M. Mohamed, L. Mohrmann, A. Montanari, C. Moore, P. Morris, E. Moulin, J. Muller, T. Murach, K. Nakashima, A. Nayerhoda, M. de Naurois, H. Ndiyavala, F. Niederwanger, J. Niemiec, L. Oakes, Patrick O'Brien, H. Odaka, S. Ohm, L. Olivera-Nieto, E. de Ona Wilhelmi, M. Ostrowski, I. Oya, M. Panter, S. Panny, R. D. Parsons, G. Peron, B. Peyaud, Q. Piel, S. Pita, V. Poireau, A. Priyana Noel, D. A. Prokhorov, H. Prokoph, G. Puhlhofer, M. Punch, A. Quirrenbach, S. Raab, R. Rauth, P. Reichherzer, A. Reimer, O. Reimer, Q. Remy, M. Renaud, F. Rieger, L. Rinchiuso, C. Romoli, G. Rowell, B. Rudak, E. Ruiz-Velasco, V. Sahakian, S. Sailer, D. A. Sanchez, A. Santangelo, M. Sasaki, M. Scalici, F. Schussler, H. M. Schutte, U. Schwanke, S. Schwemmer, M. Seglar-Arroyo, M. Senniappan, A. S. Seyffert, N. Shafi, K. Shiningayamwe, R. Simoni, A. Sinha, H. Sol, A. Specovius, S. Spencer, M. Spir-Jacob, L. Stawarz, L. Sun, R. Steenkamp, C. Stegmann, S. Steinmassl, C. Steppa, T. Takahashi, T. Tavernier, A. M. Taylor, R. Terrier, D. Tiziani, M. Tluczykont, L. Tomankova, C. Trichard, M. Tsirou, R. Tuffs, Y. Uchiyama, D. J. van der Walt, C. van Eldik, C. van Rensburg, B. van Soelen, G. Vasileiadis, J. Veh, C. Venter, P. Vincent, J. Vink, H. J. Volk, T. Vuillaume, Z. Wadiasingh, S. J. Wagner, J. Watson, F. Werner, R. White, A. Wierzcholska, Yu Wun Wong, A. Yusafzai, M. Zacharias, R. Zanin, D. Zargaryan, A. A. Zdziarski, Alraune Zech, S. J. Zhu, A. Ziegler, J. Zorn, S. Zouari, N. Zywucka

• The unidentified very-high-energy (VHE; E > 0.1 TeV) gamma -ray source, HESS J1826-130, was discovered with the High Energy Stereoscopic System (HESS) in the Galactic plane. The analysis of 215 h of HESS data has revealed a steady gamma -ray flux from HESS J1826-130, which appears extended with a half-width of 0.21 degrees +/- 0.02 <br /> (stat)degrees <br /> stat degrees +/- 0.05 <br /> (sys)degrees sys degrees . The source spectrum is best fit with either a power-law function with a spectral index Gamma = 1.78 +/- 0.10(stat) +/- 0.20(sys) and an exponential cut-off at 15.2 <br /> (+5.5)(-3.2) -3.2+5.5 TeV, or a broken power-law with Gamma (1) = 1.96 +/- 0.06(stat) +/- 0.20(sys), Gamma (2) = 3.59 +/- 0.69(stat) +/- 0.20(sys) for energies below and above E-br = 11.2 +/- 2.7 TeV, respectively. The VHE flux from HESS J1826-130 is contaminated by the extended emission of the bright, nearby pulsar wind nebula, HESS J1825-137, particularly at the low end of the energy spectrum. Leptonic scenarios for the origin of HESS J1826-130 VHEThe unidentified very-high-energy (VHE; E > 0.1 TeV) gamma -ray source, HESS J1826-130, was discovered with the High Energy Stereoscopic System (HESS) in the Galactic plane. The analysis of 215 h of HESS data has revealed a steady gamma -ray flux from HESS J1826-130, which appears extended with a half-width of 0.21 degrees +/- 0.02 <br /> (stat)degrees <br /> stat degrees +/- 0.05 <br /> (sys)degrees sys degrees . The source spectrum is best fit with either a power-law function with a spectral index Gamma = 1.78 +/- 0.10(stat) +/- 0.20(sys) and an exponential cut-off at 15.2 <br /> (+5.5)(-3.2) -3.2+5.5 TeV, or a broken power-law with Gamma (1) = 1.96 +/- 0.06(stat) +/- 0.20(sys), Gamma (2) = 3.59 +/- 0.69(stat) +/- 0.20(sys) for energies below and above E-br = 11.2 +/- 2.7 TeV, respectively. The VHE flux from HESS J1826-130 is contaminated by the extended emission of the bright, nearby pulsar wind nebula, HESS J1825-137, particularly at the low end of the energy spectrum. Leptonic scenarios for the origin of HESS J1826-130 VHE emission related to PSR J1826-1256 are confronted by our spectral and morphological analysis. In a hadronic framework, taking into account the properties of dense gas regions surrounding HESS J1826-130, the source spectrum would imply an astrophysical object capable of accelerating the parent particle population up to greater than or similar to 200 TeV. Our results are also discussed in a multiwavelength context, accounting for both the presence of nearby supernova remnants, molecular clouds, and counterparts detected in radio, X-rays, and TeV energies.…