Dokument-ID Dokumenttyp Verfasser/Autoren Herausgeber Haupttitel Abstract Auflage Verlagsort Verlag Erscheinungsjahr Seitenzahl Schriftenreihe Titel Schriftenreihe Bandzahl ISBN Quelle der Hochschulschrift Konferenzname Quelle:Titel Quelle:Jahrgang Quelle:Heftnummer Quelle:Erste Seite Quelle:Letzte Seite URN DOI Abteilungen OPUS4-34578 Wissenschaftlicher Artikel Abramowski, Attila; Acero, F.; Aharonian, Felix A.; Benkhali, Faical Ait; Akhperjanian, A. G.; Angüner, Ekrem Oǧuzhan; Anton, Gisela; Balenderan, Shangkari; Balzer, Arnim; Barnacka, Anna; Becherini, Yvonne; Tjus, J. Becker; Bernlöhr, K.; Birsin, E.; Bissaldi, E.; Biteau, Jonathan; Boisson, Catherine; Bolmont, J.; Bordas, Pol; Brucker, J.; Brun, Francois; Brun, Pierre; Bulik, Tomasz; Carrigan, Svenja; Casanova, Sabrina; Cerruti, M.; Chadwick, Paula M.; Chalme-Calvet, R.; Chaves, Ryan C. G.; Cheesebrough, A.; Chretien, M.; Colafrancesco, Sergio; Cologna, Gabriele; Conrad, Jan; Couturier, C.; Dalton, M.; Daniel, M. K.; Davids, I. D.; Degrange, B.; Deil, C.; deWilt, P.; Dickinson, H. J.; Djannati-Ataï, A.; Domainko, W.; Drury, L. O'C.; Dubus, G.; Dutson, K.; Dyks, J.; Dyrda, M.; Edwards, T.; Egberts, Kathrin; Eger, P.; Espigat, P.; Farnier, C.; Fegan, S.; Feinstein, F.; Fernandes, M. V.; Fernandez, D.; Fiasson, A.; Fontaine, G.; Foerster, A.; Fuessling, M.; Gajdus, M.; Gallant, Y. A.; Garrigoux, T.; Gast, H.; Giebels, B.; Glicenstein, J. F.; Goering, D.; Grondin, M. -H.; Grudzinska, M.; Haeffner, S.; Hague, J. D.; Hahn, J.; Harris, J.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hervet, O.; Hillert, A.; Hinton, James Anthony; Hofmann, W.; Hofverberg, P.; Holler, Markus; Horns, D.; Jacholkowska, A.; Jahn, C.; Jamrozy, M.; Janiak, M.; Jankowsky, F.; Jung, I.; Kastendieck, M. A.; Katarzynski, K.; Katz, U.; Kaufmann, S.; Khelifi, B.; Kieffer, M.; Klepser, S.; Klochkov, D.; Kluzniak, W.; Kneiske, T.; Kolitzus, D.; Komin, Nu.; Kosack, K.; Krakau, S.; Krayzel, F.; Krueger, P. P.; Laffon, H.; Lamanna, G.; Lefaucheur, J.; Lemoine-Goumard, M.; Lenain, J-P.; Lennarz, D.; Lohse, T.; Lopatin, A.; Lu, C-C.; Marandon, V.; Marcowith, A.; Marx, R.; Maurin, G.; Maxted, N.; Mayer, M.; McComb, T. J. L.; Medina, M. C.; Mehault, J.; Menzler, U.; Meyer, M.; Moderski, R.; Mohamed, M.; Moulin, E.; Murach, T.; Naumann, C. L.; de Naurois, M.; Nedbal, D.; Niemiec, J.; Nolan, S. J.; Oakes, L.; Ohm, S.; Wilhelmi, E. de Ona; Opitz, B.; Ostrowski, M.; Oya, I.; Panter, M.; Parsons, R. D.; Arribas, M. Paz; Pekeur, N. W.; Pelletier, G.; Perez, J.; Petrucci, P-O.; Peyaud, B.; Pita, S.; Poon, H.; Puehlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Raue, M.; Reimer, A.; Reimer, O.; Renaud, M.; de los Reyes, R.; Rieger, F.; Rob, L.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Sanchez, David M.; Santangelo, A.; Schlickeiser, R.; Schuessler, F.; Schulz, A.; Schwanke, U.; Schwarzburg, S.; Schwemmer, S.; Sol, H.; Spengler, G.; Spiess, F.; Stawarz, L.; Steenkamp, R.; Stegmann, Christian; Stinzing, F.; Stycz, K.; Sushch, Iurii; Szostek, A.; Tavernet, J-P.; Terrier, R.; Tluczykont, M.; Trichard, C.; Valerius, K.; van Eldik, C.; Vasileiadis, G.; Venter, C.; Viana, A.; Vincent, P.; Voelk, H. J.; Volpe, F.; Vorster, M.; Wagner, S. J.; Wagner, P.; Ward, M.; Weidinger, M.; Weitzel, Q.; White, R.; Wierzcholska, A.; Willmann, P.; Woernlein, A.; Wouters, D.; Zacharias, M.; Zajczyk, A.; Zdziarski, A. A.; Zech, Alraune; Zechlin, H-S. Constraints on axionlike particles with HESS from the irregularity of the PKS 2155-304 energy spectrum Axionlike particles (ALPs) are hypothetical light (sub-eV) bosons predicted in some extensions of the Standard Model of particle physics. In astrophysical environments comprising high-energy gamma rays and turbulent magnetic fields, the existence of ALPs can modify the energy spectrum of the gamma rays for a sufficiently large coupling between ALPs and photons. This modification would take the form of an irregular behavior of the energy spectrum in a limited energy range. Data from the H. E. S. S. observations of the distant BL Lac object PKS 2155 - 304 (z = 0.116) are used to derive upper limits at the 95% C. L. on the strength of the ALP coupling to photons, g(gamma a) < 2.1 x 10(-11) GeV-1 for an ALP mass between 15 and 60 neV. The results depend on assumptions on the magnetic field around the source, which are chosen conservatively. The derived constraints apply to both light pseudoscalar and scalar bosons that couple to the electromagnetic field. College Park American Physical Society 2013 12 Physical review : D, Particles, fields, gravitation, and cosmology 88 10 10.1103/PhysRevD.88.102003 Institut für Physik und Astronomie OPUS4-34960 Wissenschaftlicher Artikel Abramowski, Attila; Acero, F.; Aharonian, Felix A.; Akhperjanian, A. G.; Angüner, Ekrem Oǧuzhan; Anton, Gisela; Balenderan, Shangkari; Balzer, Arnim; Barnacka, Anna; Becherini, Yvonne; Tjus, J. Becker; Bernlöhr, K.; Birsin, E.; Bissaldi, E.; Biteau, Jonathan; Boisson, Catherine; Bolmont, J.; Bordas, Pol; Brucker, J.; Brun, Francois; Brun, Pierre; Bulik, Tomasz; Carrigan, Svenja; Casanova, Sabrina; Cerruti, M.; Chadwick, Paula M.; Chalme-Calvet, R.; Chaves, Ryan C. G.; Cheesebrough, A.; Chretien, M.; Colafrancesco, Sergio; Cologna, Gabriele; Conrad, Jan; Couturier, C.; Dalton, M.; Daniel, M. K.; Davids, I. D.; Degrange, B.; Deil, C.; deWilt, P.; Dickinson, H. J.; Djannati-Ataï, A.; Domainko, W.; Drury, L. O'C.; Dubus, G.; Dutson, K.; Dyks, J.; Dyrda, M.; Edwards, T.; Egberts, Kathrin; Eger, P.; Espigat, P.; Farnier, C.; Fegan, S.; Feinstein, F.; Fernandes, M. V.; Fernandez, D.; Fiasson, A.; Fontaine, G.; Foerster, A.; Fuessling, M.; Gajdus, M.; Gallant, Y. A.; Garrigoux, T.; Gast, H.; Giebels, B.; Glicenstein, J. F.; Goering, D.; Grondin, M. -H.; Grudzinska, M.; Haeffner, S.; Hague, J. D.; Hahn, J.; Harris, J.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hervet, O.; Hillert, A.; Hinton, James Anthony; Hofmann, W.; Hofverberg, P.; Holler, Markus; Horns, D.; Jacholkowska, A.; Jahn, C.; Jamrozy, M.; Janiak, M.; Jankowsky, F.; Jung, I.; Kastendieck, M. A.; Katarzynski, K.; Katz, U.; Kaufmann, S.; Khelifi, B.; Kieffer, M.; Klepser, S.; Klochkov, D.; Kluzniak, W.; Kneiske, T.; Kolitzus, D.; Komin, Nu.; Kosack, K.; Krakau, S.; Krayzel, F.; Krueger, P. P.; Laffon, H.; Lamanna, G.; Lefaucheur, J.; Lemoine-Goumard, M.; Lenain, J. -P.; Lennarz, D.; Lohse, T.; Lopatin, A.; Lu, C. -C.; Marandon, V.; Marcowith, A.; Maxted, N.; Mayer, M.; McComb, T. J. L.; Medina, M. C.; Mehault, J.; Menzler, U.; Meyer, M.; Moderski, R.; Mohamed, M.; Moulin, E.; Murach, T.; Naumann, C. L.; de Naurois, M.; Nedbal, D.; Niemiec, J.; Nolan, S. J.; Oakes, L.; Ohm, S.; Wilhelmi, E. de Ona; Opitz, B.; Ostrowski, M.; Oya, I.; Panter, M.; Parsons, R. D.; Arribas, M. Paz; Pekeur, N. W.; Pelletier, G.; Perez, J.; Petrucci, P. -O.; Peyaud, B.; Pita, S.; Poon, H.; Punch, M.; Quirrenbach, A.; Raab, S.; Raue, M.; Reimer, A.; Reimer, O.; Renaud, M.; de los Reyes, R.; Rieger, F.; Rob, L.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Sanchez, David M.; Santangelo, A.; Schlickeiser, R.; Schuessler, F.; Schulz, A.; Schwanke, U.; Schwarzburg, S.; Schwemmer, S.; Sol, H.; Spengler, G.; Spiess, F.; Stawarz, L.; Steenkamp, R.; Stegmann, Christian; Stinzing, F.; Stycz, K.; Sushch, Iurii; Szostek, A.; Tavernet, J. -P.; Terrier, R.; Tluczykont, M.; Trichard, C.; Valerius, K.; van Eldik, C.; Vasileiadis, G.; Venter, C.; Viana, A.; Vincent, P.; Voelk, H. J.; Volpe, F.; Vorster, M.; Wagner, S. J.; Wagner, P.; Ward, M.; Weidinger, M.; White, R.; Wierzcholska, A.; Willmann, P.; Woernlein, A.; Wouters, D.; Zacharias, M.; Zajczyk, A.; Zdziarski, A. A.; Zech, Alraune; Zechlin, H. -S. Discovery of high and very high-energy emission from the BL Lacertae object SHBL J001355.9-185406 The detection of the high-frequency peaked BL Lac object (HBL) SHBL J001355.9-185406 (z = 0.095) at high (HE; 100 MeV < E < 300 GeV) and very high-energy (VHE; E > 100 GeV) with the Fermi Large Area Telescope (LAT) and the High Energy Stereoscopic System (H.E.S.S.) is reported. Dedicated observations were performed with the H. E. S. S. telescopes, leading to a detection at the 5.5 sigma significance level. The measured flux above 310 GeV is (8.3 +/- 1.7(stat) +/- 1.7(sys)) x 10(-13) photons cm(-2) s(-1) (about 0.6% of that of the Crab Nebula), and the power-law spectrum has a photon index of Gamma = 3.4 +/- 0.5(stat) +/- 0.2(sys). Using 3.5 years of publicly available Fermi-LAT data, a faint counterpart has been detected in the LAT data at the 5.5 sigma significance level, with an integrated flux above 300 MeV of (9.3 +/- 3.4(stat) +/- 0.8(sys)) x 10(-10) photons cm(-2) s(-1) and a photon index of Gamma = 1.96 +/- 0.20(stat) +/- 0.08(sys). X-ray observations with Swift-XRT allow the synchrotron peak energy in vF(v) representation to be located at similar to 1.0 keV. The broadband spectral energy distribution is modelled with a one-zone synchrotron self-Compton (SSC) model and the optical data by a black-body emission describing the thermal emission of the host galaxy. The derived parameters are typical of HBLs detected at VHE, with a particle-dominated jet. Les Ulis EDP Sciences 2013 8 Astronomy and astrophysics : an international weekly journal 554 10.1051/0004-6361/201220996 Institut für Physik und Astronomie OPUS4-37483 Wissenschaftlicher Artikel Abramowski, Attila; Aharonian, Felix A.; Benkhali, Faical Ait; Akhperjanian, A. G.; Uner, E. O. Ang; Backes, Michael; Balenderan, Shangkari; Balzer, Arnim; Barnacka, Anna; Becherini, Yvonne; Tjus, J. Becker; Berge, David; Bernhard, Sabrina; Bernlöhr, K.; Birsin, E.; Biteau, Jonathan; Boettcher, Markus; Boisson, Catherine; Bolmont, J.; Bordas, Pol; Bregeon, Johan; Brun, Francois; Brun, Pierre; Bryan, Mark; Bulik, Tomasz; Carrigan, Svenja; Casanova, Sabrina; Chadwick, Paula M.; Chakraborty, N.; Chalme-Calvet, R.; Chaves, Ryan C. G.; Chretien, M.; Colafrancesco, Sergio; Cologna, Gabriele; Conrad, Jan; Couturier, C.; Cui, Y.; Dalton, M.; Davids, I. D.; Degrange, B.; Deil, C.; deWilt, P.; Djannati-Ataï, A.; Domainko, W.; Donath, A.; Dubus, G.; Dutson, K.; Dyks, J.; Dyrda, M.; Edwards, T.; Egberts, Kathrin; Eger, P.; Espigat, P.; Farnier, C.; Fegan, S.; Feinstein, F.; Fernandes, M. V.; Fernandez, D.; Fiasson, A.; Fontaine, G.; Foerster, A.; Fuessling, M.; Gabici, S.; Gajdus, M.; Gallant, Y. A.; Garrigoux, T.; Giavitto, G.; Giebels, B.; Glicenstein, J. F.; Gottschall, D.; Grondin, M. -H.; Grudzinska, M.; Hadasch, D.; Haeffner, S.; Hahn, J.; Harris, J.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hervet, O.; Hillert, A.; Hinton, James Anthony; Hofmann, W.; Hofverberg, P.; Holler, Markus; Horns, D.; Ivascenko, A.; Jacholkowska, A.; Jahn, C.; Jamrozy, M.; Janiak, M.; Jankowsky, F.; Jung-Richardt, I.; Kastendieck, M. A.; Katarzynski, K.; Katz, U.; Kaufmann, S.; Khelifi, B.; Kieffer, M.; Klepser, S.; Klochkov, D.; Kluzniak, W.; Kolitzus, D.; Komin, Nu.; Kosack, K.; Krakau, S.; Krayzel, F.; Krueger, P. P.; Laffon, H.; Lamanna, G.; Lau, J.; Lefaucheur, J.; Lefranc, V.; Lemiere, A.; Lemoine-Goumard, M.; Lenain, J. -P.; Lohse, T.; Lopatin, A.; Lu, C. -C.; Marandon, V.; Marcowith, A.; Marx, R.; Maurin, G.; Maxted, N.; Mayer, M.; McComb, T. J. L.; Mehault, J.; Meintjes, P. J.; Menzler, U.; Meyer, M.; Mitchell, A. M. W.; Moderski, R.; Mohamed, M.; Mora, K.; Moulin, E.; Murach, T.; de Naurois, M.; Niemiec, J.; Nolan, S. J.; Oakes, L.; Odaka, H.; Ohm, S.; Opitz, B.; Ostrowski, M.; Oya, I.; Panter, M.; Parsons, R. D.; Arribas, M. Paz; Pekeur, N. W.; Pelletier, G.; Petrucci, P. -O.; Peyaud, B.; Pita, S.; Poon, H.; Puehlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Reichardt, I.; Reimer, A.; Reimer, O.; Renaud, M.; Reyes, R. de Los; Rieger, F.; Romoli, C.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Salek, D.; Sanchez, David M.; Santangelo, A.; Schlickeiser, R.; Schuessler, F.; Schulz, A.; Schwanke, U.; Schwarzburg, S.; Schwemmer, S.; Sol, H.; Spanier, F.; Spengler, G.; Spies, F.; Stawarz, L.; Steenkamp, R.; Stegmann, Christian; Stinzing, F.; Stycz, K.; Sushch, Iurii; Tavernet, J. -P.; Tavernier, T.; Taylor, A. M.; Terrier, R.; Tluczykont, M.; Trichard, C.; Valerius, K.; Van Eldik, C.; van Soelen, B.; Vasileiadis, G.; Veh, J.; Venter, C.; Viana, A.; Vincent, P.; Vink, J.; Voelk, H. J.; Volpe, F.; Vorster, M.; Vuillaume, T.; Wagner, S. J.; Wagner, P.; Wagner, R. M.; Ward, M.; Weidinger, M.; Weitzel, Q.; White, R.; Wierzcholska, A.; Willmann, P.; Woernlein, A.; Wouters, D.; Yang, R.; Zabalza, V.; Zaborov, D.; Zacharias, M.; Zdziarski, A. A.; Zech, Alraune; Zechlin, H. -S.; Fukui, Y.; Sano, H.; Fukuda, T.; Yoshiike, S. Discovery of the hard spectrum VHE gamma-ray source Hess J1641-463 This Letter reports the discovery of a remarkably hard spectrum source, HESS J1641-463, by the High Energy Stereoscopic System (H.E.S.S.) in the very high energy (VHE) domain. HESS J1641-463 remained unnoticed by the usual analysis techniques due to confusion with the bright nearby source HESS J1640-465. It emerged at a significance level of 8.5 standard deviations after restricting the analysis to events with energies above 4 TeV. It shows a moderate flux level of phi(E > 1TeV) = (3.64 +/- 0.44(stat)+/- 0.73(sys)) x 10(-13) cm(-2) s(-1), corresponding to 1.8% of the Crab Nebula flux above the same energy, and a hard spectrum with a photon index of Gamma = 2.07 +/- 0.11(stat)+/- 0.20(sys). It is a point-like source, although an extension up to a Gaussian width of sigma = 3 arcmin cannot be discounted due to uncertainties in the H.E.S.S. point-spread function. The VHE gamma-ray flux of HESS J1641-463 is found to be constant over the observed period when checking time binnings from the year-by-year to the 28 minute exposure timescales. HESS J1641-463 is positionally coincident with the radio supernova remnant SNR G338.5+0.1. No X-ray candidate stands out as a clear association; however, Chandra and XMM-Newton data reveal some potential weak counterparts. Various VHE gamma-ray production scenarios are discussed. If the emission from HESS J1641-463 is produced by cosmic ray protons colliding with the ambient gas, then their spectrum must extend close to 1 PeV. This object may represent a source population contributing significantly to the galactic cosmic ray flux around the knee. Bristol IOP Publ. Ltd. 2014 6 The astrophysical journal : an international review of spectroscopy and astronomical physics ; Part 2, Letters 794 1 10.1088/2041-8205/794/1/L1 Institut für Physik und Astronomie OPUS4-39253 Wissenschaftlicher Artikel Abramowski, Attila; Acero, F.; Aharonian, Felix A.; Benkhali, Faical Ait; Akhperjanian, A. G.; Angüner, Ekrem Oǧuzhan; Anton, Gisela; Balenderan, Shangkari; Balzer, Arnim; Barnacka, Anna; Becherini, Yvonne; Tjus, J. Becker; Bernlöhr, K.; Birsin, E.; Bissaldi, E.; Biteau, Jonathan; Boettcher, Markus; Boisson, Catherine; Bolmont, J.; Bordas, Pol; Brucker, J.; Brun, Francois; Brun, Pierre; Bulik, Tomasz; Carrigan, Svenja; Casanova, Sabrina; Cerruti, M.; Chadwick, Paula M.; Chalme-Calvet, R.; Chaves, Ryan C. G.; Cheesebrough, A.; Chretien, M.; Clapson, A. C.; Colafrancesco, Sergio; Cologna, Gabriele; Conrad, Jan; Couturier, C.; Cui, Y.; Dalton, M.; Daniel, M. K.; Davids, I. D.; Degrange, B.; Deil, C.; deWilt, P.; Dickinson, H. J.; Djannati-Ataï, A.; Domainko, W.; Dubus, G.; Dutson, K.; Dyks, J.; Dyrda, M.; Edwards, T.; Egberts, Kathrin; Eger, P.; Espigat, P.; Farnier, C.; Fegan, S.; Feinstein, F.; Fernandes, M. V.; Fernandez, D.; Fiasson, A.; Fontaine, G.; Foerster, A.; Fuessling, M.; Gajdus, M.; Gallant, Y. A.; Garrigoux, T.; Giavitto, G.; Giebels, B.; Glicenstein, J. F.; Grondin, M. -H.; Grudzinska, M.; Haeffner, S.; Hahn, J.; Harris, J.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hervet, O.; Hillert, A.; Hinton, James Anthony; Hofmann, W.; Hofverberg, P.; Holler, Markus; Horns, D.; Jacholkowska, A.; Jahn, C.; Jamrozy, Marek; Janiak, M.; Jankowsky, F.; Jung, I.; Kastendieck, M. A.; Katarzynski, Krzysztof; Katz, Uli; Kaufmann, S.; Khelifi, B.; Kieffer, M.; Klepser, S.; Klochkov, D.; Kluzniak, W.; Kneiske, T.; Kolitzus, D.; Komin, Nu.; Kosack, K.; Krakau, S.; Krayzel, F.; Krueger, P. P.; Laffon, H.; Lamanna, G.; Lefaucheur, J.; Lemiere, A.; Lemoine-Goumard, M.; Lenain, J. -P.; Lennarz, D.; Lohse, T.; Lopatin, A.; Lu, C. -C.; Marandon, V.; Marcowith, A.; Marx, R.; Maurin, G.; Maxted, N.; Mayer, M.; McComb, T. J. L.; Mehault, J.; Meintjes, P. J.; Menzler, U.; Meyer, Manuel; Moderski, R.; Mohamed, M.; Moulin, E.; Murach, T.; Naumann, C. L.; de Naurois, M.; Niemiec, J.; Nolan, S. J.; Oakes, L.; Ohm, S.; Wilhelmi, E. de Ona; Opitz, B.; Ostrowski, M.; Oya, I.; Panter, M.; Parsons, R. D.; Arribas, M. Paz; Pekeur, N. W.; Pelletier, G.; Perez, J.; Petrucci, P. -O.; Peyaud, B.; Pita, S.; Poon, H.; Puehlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Raue, M.; Reimer, A.; Reimer, O.; Renaud, M.; de los Reyes, R.; Rieger, F.; Rob, L.; Romoli, C.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Sanchez, David M.; Santangelo, A.; Schlickeiser, R.; Schuessler, F.; Schulz, A.; Schwanke, U.; Schwarzburg, S.; Schwemmer, S.; Sol, H.; Spengler, G.; Spies, F.; Stawarz, L.; Steenkamp, R.; Stegmann, Christian; Stinzing, F.; Stycz, K.; Sushch, Iurii; Szostek, A.; Tavernet, J. -P.; Tavernier, T.; Taylor, A. M.; Terrier, R.; Tluczykont, M.; Trichard, C.; Valerius, K.; van Eldik, Christopher; van Soelen, B.; Vasileiadis, G.; Venter, C.; Viana, A.; Vincent, P.; Voelk, H. J.; Volpe, F.; Vorster, M.; Vuillaume, T.; Wagner, S. J.; Wagner, P.; Ward, M.; Weidinger, M.; Weitzel, Q.; White, R.; Wierzcholska, A.; Willmann, P.; Woernlein, A.; Wouters, D.; Zabalza, V.; Zacharias, M.; Zajczyk, A.; Zdziarski, A. A.; Zech, Alraune; Zechlin, H. -S. Discovery of the VHE gamma-ray source HESS J1832-093 in the vicinity of SNR G22.7-0.2 Oxford Oxford Univ. Press 2015 7 Monthly notices of the Royal Astronomical Society 446 2 1163 1169 10.1093/mnras/stu2148 Institut für Physik und Astronomie OPUS4-38708 misc Abramowski, Attila; Aharonian, Felix A.; Benkhali, Faical Ait; Akhperjanian, A. G.; Angüner, Ekrem Oǧuzhan; Backes, Michael; Balenderan, Shangkari; Balzer, Arnim; Barnacka, Anna; Becherini, Yvonne; Tjus, Julia Becker; Berge, David; Bernhard, Sabrina; Bernlöhr, Konrad; Birsin, E.; Biteau, Jonathan; Böttcher, Markus; Boisson, Catherine; Bolmont, J.; Bordas, Pol; Bregeon, Johan; Brun, Francois; Brun, Pierre; Bryan, Mark; Bulik, Tomasz; Carrigan, Svenja; Casanova, Sabrina; Chadwick, Paula M.; Chakraborty, Nachiketa; Chalme-Calvet, R.; Chaves, Ryan C. G.; Chretien, M.; Colafrancesco, Sergio; Cologna, Gabriele; Conrad, Jan; Couturier, Claire; Cui, Yudong; Davids, Isak Delberth; Degrange, Bernhard; Deil, Christoph; deWilt, P.; Djannati-Ataï, A.; Domainko, Wilfried; Donath, Axel; Dubus, G.; Dutson, K.; Dyks, J.; Dyrda, M.; Edwards, Tanya; Egberts, Kathrin; Eger, Peter; Espigat, P.; Farnier, C.; Fegan, Stephen; Feinstein, Fabrice; Fernandes, Milton Virgilio; Fernandez, Diane; Fiasson, A.; Fontaine, Gerard; Förster, Andreas; Fuessling, M.; Gabici, S.; Gajdus, M.; Gallant, Yves A.; Garrigoux, Tania; Giavitto, G.; Giebels, Berrie; Glicenstein, Jean-Francois; Gottschall, Daniel; Grondin, M. -H.; Grudzinska, M.; Hadasch, Daniela; Haeffner, S.; Hahn, Joachim; Harris, Jonathan; Heinzelmann, Götz; Henri, G.; Hermann, German; Hervet, O.; Hillert, Andreas; Hinton, James Anthony; Hofmann, Werner; Hofverberg, Petter; Holler, Markus; Horns, Dieter; Ivascenko, Alex; Jacholkowska, A.; Jahn, C.; Jamrozy, Marek; Janiak, M.; Jankowsky, F.; Jung-Richardt, I.; Kastendieck, Max Anton; Katarzynski, K.; Katz, U.; Kaufmann, S.; Khelifi, B.; Kieffer, Michel; Klepser, S.; Klochkov, Dmitry; Kluzniak, W.; Kolitzus, David; Komin, Nu; Kosack, Karl; Krakau, Steffen; Krayzel, F.; Krueger, Pat P.; Laffon, H.; Lamanna, G.; Lefaucheur, J.; Lefranc, Valentin; Lemiere, A.; Lemoine-Goumard, M.; Lenain, J. -P.; Lohse, Thomas; Lopatin, A.; Lu, Chia-Chun; Marandon, Vincent; Marcowith, Alexandre; Marx, Ramin; Maurin, G.; Maxted, Nigel; Mayer, Michael; McComb, T. J. Lowry; Mehault, J.; Meintjes, P. J.; Menzler, Ulf; Meyer, M.; Mitchell, Alison M. W.; Moderski, R.; Mohamed, M.; Mora, K.; Moulin, Emmanuel; Murach, Thomas; de Naurois, Mathieu; Niemiec, J.; Nolan, Sam J.; Oakes, Louise; Odaka, Hirokazu; Ohm, S.; Optiz, Björn; Ostrowski, Michal; Oya, I.; Panter, Michael; Parsons, R. Daniel; Arribas, M. Paz; Pekeur, Nikki W.; Pelletier, G.; Petrucci, P. -O.; Peyaud, B.; Pita, S.; Poon, Helen; Pühlhofer, Gerd; Punch, M.; Quirrenbach, A.; Raab, S.; Reichardt, I.; Reimer, Anita; Reimer, Olaf; Renaud, Metz; de los Reyes, Raquel; Rieger, Frank; Romoli, C.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, Vardan; Salek, D.; Sanchez, David M.; Santangelo, Andrea; Schlickeiser, Reinhard; Schuessler, F.; Schulz, A.; Schwanke, Ullrich; Schwarzburg, S.; Schwemmer, S.; Sol, H.; Spanier, Felix; Spengler, G.; Spies, Franziska; Stawarz, Lukasz; Steenkamp, Riaan; Stegmann, Christian; Stinzing, F.; Stycz, K.; Sushch, Iurii; Tavernet, J. -P.; Tavernier, T.; Taylor, A. M.; Terrier, R.; Tluczykont, Martin; Trichard, C.; Valerius, K.; van Eldik, C.; van Soelen, B.; Vasileiadis, Georges; Veh, J.; Venter, Christo; Viana, Aion; Vincent, P.; Vink, Jacco; Völk, Heinrich J.; Volpe, Francesca; Vorster, Martine; Vuillaume, T.; Wagner, S. J.; Wagner, P.; Wagner, R. M.; Ward, Martin; Weidinger, Matthias; Weitzel, Quirin; White, R.; Wierzcholska, A.; Willmann, P.; Woernlein, A.; Wouters, D.; Yang, Ruizhi; Zabalza, Victor; Zaborov, Dmitry; Zacharias, M.; Zdziarski, A. A.; Zech, Alraune; Zechlin, Hannes -S. H.E.S.S. detection of TeV emission from the interaction region between the supernova remnant G349.7+0.2 and a molecular cloud (vol 574, A100, 2015) Les Ulis EDP Sciences 2015 2 Astronomy and astrophysics : an international weekly journal 580 10.1051/0004-6361/201425070e Institut für Physik und Astronomie OPUS4-39196 Wissenschaftlicher Artikel Abramowski, Attila; Aharonian, Felix A.; Benkhali, Faical Ait; Akhperjanian, A. G.; Angüner, Ekrem Oǧuzhan; Backes, Michael; Balenderan, Shangkari; Balzer, Arnim; Barnacka, Anna; Becherini, Yvonne; Tjus, J. Becker; Berge, David; Bernhard, Sabrina; Bernlöhr, K.; Birsin, E.; Biteau, Jonathan; Boettcher, Markus; Boisson, Catherine; Bolmont, J.; Bordas, Pol; Bregeon, Johan; Brun, Francois; Brun, Pierre; Bryan, Mark; Bulik, Tomasz; Carrigan, Svenja; Casanova, Sabrina; Chadwick, Paula M.; Chatraborty, N.; Chalme-Calvet, R.; Chaves, Ryan C. G.; Chretien, M.; Colafrancesco, Sergio; Cologna, Gabriele; Conrad, Jan; Couturier, C.; Cui, Y.; Davids, I. D.; Degrange, B.; Deil, C.; deWilt, P.; Djannati-Ataï, A.; Domainko, W.; Donath, A.; Dubus, G.; Dutson, K.; Dyks, J.; Dyrda, M.; Edwards, T.; Egberts, Kathrin; Eger, P.; Espigat, P.; Farnier, C.; Fegan, S.; Feinstein, F.; Fernandes, M. V.; Fernandez, D.; Fiasson, A.; Fontaine, G.; Foerster, A.; Fuessling, M.; Gabici, S.; Gajdus, M.; Gallant, Y. A.; Garrigoux, T.; Giavitto, G.; Giebels, B.; Glicenstein, J. F.; Gottschall, D.; Grondin, M. -H.; Grudzinska, M.; Hadasch, D.; Haeffner, S.; Hahn, J.; Harris, J.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hervet, O.; Hillert, A.; Hinton, James Anthony; Hofmann, W.; Hofverberg, P.; Holler, Markus; Horns, D.; Ivascenko, A.; Jacholkowska, A.; Jahn, C.; Jamrozy, M.; Janiak, M.; Jankowsky, F.; Jung-Richardt, O.; Kastendieck, M. A.; Katarzynski, K.; Katz, U.; Kaufmann, S.; Khelifi, B.; Kieffer, M.; Klepser, S.; Klochkov, D.; Kluzniak, W.; Kolitzus, D.; Komin, Nu; Kosack, K.; Krakau, S.; Krayzel, F.; Krueger, P. P.; Laffon, H.; Lamanna, G.; Lefaucheur, J.; Lefranc, V.; Lemiere, A.; Lemoine-Goumard, M.; Lenain, J. P.; Lohse, T.; Lopatin, A.; Lu, C-C; Marandon, V.; Marcowith, A.; Marx, R.; Maurin, G.; Maxted, N.; Mayer, Markus; McComb, T. J. L.; Mehault, J.; Meintjes, P. J.; Menzler, U.; Meyer, M.; Mitchell, A. M. W.; Moderski, R.; Mohamed, M.; Mora, K.; Moulin, E.; Murach, T.; de Naurois, M.; Niemiec, J.; Nolan, S. J.; Oakes, L.; Odaka, H.; Ohm, S.; Opitz, B.; Ostrowski, M.; Oya, I.; Panter, M.; Parsons, R. D.; Anibas, M. Paz; Pekeur, N. W.; Pelletier, G.; Petrucci, P-O; Peyaud, B.; Pita, S.; Poon, H.; Puehlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Reichardt, I.; Reimer, A.; Reimer, O.; Renaud, M.; de los Reyes, R.; Rieger, F.; Romoli, C.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Salek, D.; Sanchez, David M.; Santangelo, A.; Schlickeiser, R.; Schuessler, F.; Schulz, A.; Schwanke, U.; Schwarzburg, S.; Schwemmer, S.; Sol, H.; Spanier, F.; Spengler, G.; Spies, F.; Stawarz, L.; Steenkamp, R.; Stegmann, Christian; Stinzing, F.; Stycz, K.; Sushch, Iurii; Tavernet, J-P; Tavernier, T.; Taylor, A. M.; Terrier, R.; Tluczykont, M.; Trichard, C.; Valerius, K.; van Eldik, C.; van Soelen, B.; Vasileiadis, G.; Veh, J.; Venter, C.; Viana, A.; Vincent, P.; Vink, J.; Voelk, H. J.; Volpe, F.; Vorster, M.; Vuillaume, T.; Wagner, S. J.; Wagner, P.; Wagner, R. M.; Ward, M.; Weidinger, M.; Weitzel, Q.; White, R.; Wierzcholska, A.; Willmann, P.; Woernlein, A.; Wouters, D.; Yang, R.; Zabalza, V.; Zaborov, D.; Zacharias, M.; Zdziarski, A. A.; Zech, Alraune; Zechlin, H-S HESS detection of TeV emission from the interaction region between the supernova remnant G349.7+0.2 and a molecular cloud G349.7+0.2 is a young Galactic supernova remnant (SNR) located at the distance of 11.5 kpc and observed across the entire electromagnetic spectrum from radio to high energy (HE; 0.1 GeV < E < 100 GeV) gamma-rays. Radio and infrared observations indicate that the remnant is interacting with a molecular cloud. In this paper, the detection of very high energy (VHE, E > 100 GeV) gamma-ray emission coincident with this SNR with the High Energy Stereoscopic System (HESS.) is reported. This makes it one of the farthest Galactic SNR ever detected in this domain. An integral flux F(E > 400 GeV) = (6.5 +/- 1.1(stat) +/- 1.3(syst)) x 10-11 ph cm(-2) s(-1) corresponding to similar to 0.7% of that of the Crab Nebula and to a luminosity of similar to 10(34) erg s(-1) above the same energy threshold, and a steep photon index Gamma(VHE) = 2.8 +/- 0.27(stat) +/- 0.20(syst) are measured. The analysis of more than 5 yr of Fermi-LAT data towards this source shows a power-law like spectrum with a best-fit photon index Gamma(HE) = 2.2 +/- 0.04.2(stat-0.31sys)(+0.13), The combined gamma-ray spectrum of 0349.7+0.2 can be described by either a broken power law (I3PL) or a power law with exponential (or sub exponential) cutoff (PLC). In the former case, the photon break energy is found at E-br,E-gamma = 551(-30)(+70) GeV, slightly higher than what is usually observed in the HE/VHE gamma-ray emitting middle-aged SNRs known to be interacting with molecular clouds. In the latter case. the exponential (respectively sub-exponential) cutoff energy is measured at E-cat,E-gamma = 1.4(-0.55)(+1.6) (respectively 0.35(-0.21)(+0.75)) TeV. A pion decay process resulting from the interaction of the accelerated protons and nuclei with the dense surrounding medium is clearly the preferred scenario to explain the gamma-ray emission. The BPL with a spectral steepening of 0.5-1 and the PLC provide equally good fits to the data. The product or the average gas density and the total energy content of accelerated protons and nuclei amounts to nu W-p similar to 5 x 10(51) erg cm(-3) Les Ulis EDP Sciences 2015 7 Astronomy and astrophysics : an international weekly journal 574 10.1051/0004-6361/201425070 Institut für Physik und Astronomie OPUS4-34961 Wissenschaftlicher Artikel Abramowski, Attila; Acero, F.; Aharonian, Felix A.; Akhperjanian, A. G.; Anton, Gisela; Balenderan, Shangkari; Balzer, Arnim; Barnacka, Anna; Becherini, Yvonne; Tjus, J. Becker; Behera, B.; Bernlöhr, K.; Birsin, E.; Biteau, Jonathan; Bochow, A.; Boisson, Catherine; Bolmont, J.; Bordas, Pol; Brucker, J.; Brun, Francois; Brun, Pierre; Bulik, Tomasz; Carrigan, Svenja; Casanova, Sabrina; Cerruti, M.; Chadwick, Paula M.; Chaves, Ryan C. G.; Cheesebrough, A.; Colafrancesco, Sergio; Cologna, Gabriele; Conrad, Jan; Couturier, C.; Dalton, M.; Daniel, M. K.; Davids, I. D.; Degrange, B.; Deil, C.; deWilt, P.; Dickinson, H. J.; Djannati-Ataï, A.; Domainko, W.; Drury, L. O'C.; Dubus, G.; Dutson, K.; Dyks, J.; Dyrda, M.; Egberts, Kathrin; Eger, P.; Espigat, P.; Fallon, L.; Farnier, C.; Fegan, S.; Feinstein, F.; Fernandes, M. V.; Fernandez, D.; Fiasson, A.; Fontaine, G.; Foester, A.; Fuessling, M.; Gajdus, M.; Gallant, Y. A.; Garrigoux, T.; Gast, H.; Giebels, B.; Glicenstein, J. F.; Glueck, B.; Goeing, D.; Grondin, M. -H.; Grudzinska, M.; Haeffner, S.; Hague, J. D.; Hahn, J.; Hampf, D.; Harris, J.; Hauser, M.; Heinz, S.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hillert, A.; Hinton, James Anthony; Hofmann, W.; Hofverberg, P.; Holler, Markus; Horns, D.; Jacholkowska, A.; Jahn, C.; Jamrozy, M.; Jung, I.; Kastendieck, M. A.; Katarzynski, K.; Katz, U.; Kaufmann, S.; Khelifi, B.; Klepser, S.; Klochkov, D.; Kluzniak, W.; Kneiske, T.; Komin, Nu.; Kosack, K.; Kossakowski, R.; Krayzel, F.; Krueger, P. P.; Laffon, H.; Lamanna, G.; Lefaucheur, J.; Lemoine-Goumard, M.; Lenain, J. -P.; Lennarz, D.; Lohse, T.; Lopatin, A.; Lu, C. -C.; Marandon, V.; Marcowith, A.; Masbou, J.; Maurin, G.; Maxted, N.; Mayer, M.; McComb, T. J. L.; Medina, M. C.; Mehault, J.; Menzler, U.; Moderski, R.; Mohamed, M.; Moulin, E.; Naumann, C. L.; Naumann-Godo, M.; de Naurois, M.; Nedbal, D.; Nguyen, N.; Niemiec, J.; Nolan, S. J.; Ohm, S.; Wilhelmi, E. de Ona; Opitz, B.; Ostrowski, M.; Oya, I.; Panter, M.; Parsons, R. D.; Arribas, M. Paz; Pekeur, N. W.; Pelletier, G.; Perez, J.; Petrucci, P. -O.; Peyaud, B.; Pita, S.; Puehlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Raue, M.; Reimer, A.; Reimer, O.; Renaud, M.; de los Reyes, R.; Rieger, F.; Ripken, J.; Rob, L.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Sanchez, David M.; Santangelo, A.; Schlickeiser, R.; Schulz, A.; Schwanke, U.; Schwarzburg, S.; Schwemmer, S.; Sheidaei, F.; Skilton, J. L.; Sol, H.; Spengler, G.; Stawarz, L.; Steenkamp, R.; Stegmann, Christian; Stinzing, F.; Stycz, K.; Sushch, Iurii; Szostek, A.; Tavernet, J. -P.; Terrier, R.; Tluczykont, M.; Trichard, C.; Valerius, K.; van Eldik, C.; Vasileiadis, G.; Venter, C.; Viana, A.; Vincent, P.; Voelk, H. J.; Volpe, F.; Vorobiov, S.; Vorster, M.; Wagner, S. J.; Ward, M.; White, R.; Wierzcholska, A.; Wouters, D.; Zacharias, M.; Zajczyk, A.; Zdziarski, A. A.; Zech, Alraune; Zechlin, H. S. HESS discovery of VHE gamma-rays from the quasar PKS 1510-089 The quasar PKS 1510-089 (z = 0.361) was observed with the H.E.S.S. array of imaging atmospheric Cherenkov telescopes during high states in the optical and GeV bands, to search for very high energy (VHE, defined as E >= 0.1 TeV) emission. VHE gamma-rays were detected with a statistical significance of 9.2 standard deviations in 15.8 h of H. E. S. S. data taken during March and April 2009. A VHE integral flux of I(0.15 TeV < E < 1.0TeV) = (1.0 +/- 0.2(stat) +/- 0.2(sys)) x 10(-11) cm(-2) s(-1) is measured. The best-fit power law to the VHE data has a photon index of G = 5.4 +/- 0.7(stat) +/- 0.3(sys). The GeV and optical light curves show pronounced variability during the period of H.E.S.S. observations. However, there is insufficient evidence to claim statistically significant variability in the VHE data. Because of its relatively high redshift, the VHE flux from PKS 1510-089 should suffer considerable attenuation in the intergalactic space due to the extragalactic background light (EBL). Hence, the measured gamma-ray spectrum is used to derive upper limits on the opacity due to EBL, which are found to be comparable with the previously derived limits from relatively-nearby BL Lac objects. Unlike typical VHE-detected blazars where the broadband spectrum is dominated by nonthermal radiation at all wavelengths, the quasar PKS 1510-089 has a bright thermal component in the optical to UV frequency band. Among all VHE detected blazars, PKS 1510-089 has the most luminous broad line region. The detection of VHE emission from this quasar indicates a low level of gamma - gamma absorption on the internal optical to UV photon field. Les Ulis EDP Sciences 2013 7 Astronomy and astrophysics : an international weekly journal 554 6 10.1051/0004-6361/201321135 Institut für Physik und Astronomie OPUS4-35174 Wissenschaftlicher Artikel Abramowski, Attila; Acero, F.; Aharonian, Felix A.; Akhperjanian, A. G.; Anton, Gisela; Balenderan, Shangkari; Balzer, Arnim; Barnacka, Anna; Becherini, Yvonne; Tjus, J. Becker; Bernlöhr, K.; Birsin, E.; Biteau, Jonathan; Boisson, Catherine; Bolmont, J.; Bordas, Pol; Brucker, J.; Brun, Francois; Brun, Pierre; Bulik, Tomasz; Carrigan, Svenja; Casanova, Sabrina; Cerruti, M.; Chadwick, Paula M.; Chaves, Ryan C. G.; Cheesebrough, A.; Colafrancesco, Sergio; Cologna, Gabriele; Conrad, Jan; Couturier, C.; Dalton, M.; Daniel, M. K.; Davids, I. D.; Degrange, B.; Deil, C.; deWilt, P.; Dickinson, H. J.; Djannati-Ataï, A.; Domainko, W.; Drury, L. O'C.; Dubus, G.; Dutson, K.; Dyks, J.; Dyrda, M.; Egberts, Kathrin; Eger, P.; Espigat, P.; Fallon, L.; Farnier, C.; Fegan, S.; Feinstein, F.; Fernandes, M. V.; Fernandez, D.; Fiasson, A.; Fontaine, G.; Foerster, A.; Fuessling, M.; Gajdus, M.; Gallant, Y. A.; Garrigoux, T.; Gast, H.; Giebels, B.; Glicenstein, J. F.; Glueck, B.; Goering, D.; Grondin, M. -H.; Grudzinska, M.; Haeffner, S.; Hague, J. D.; Hahn, J.; Hampf, D.; Harris, J.; Heinz, S.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hillert, A.; Hinton, James Anthony; Hofmann, W.; Hofverberg, P.; Holler, Markus; Horns, D.; Jacholkowska, A.; Jahn, C.; Jamrozy, M.; Jung, I.; Kastendieck, M. A.; Katarzynski, K.; Katz, U.; Kaufmann, S.; Khelifi, B.; Klepser, S.; Klochkov, D.; Kluzniak, W.; Kneiske, T.; Kolitzus, D.; Komin, Nu; Kosack, K.; Kossakowski, R.; Krayzel, F.; Krueger, P. P.; Laffon, H.; Lamanna, G.; Lefaucheur, J.; Lemoine-Goumard, M.; Lenain, J. -P.; Lennarz, D.; Lohse, T.; Lopatin, A.; Lu, C. -C.; Marandon, V.; Marcowith, A.; Masbou, J.; Maurin, G.; Maxted, N.; Mayer, M.; McComb, T. J. L.; Medina, M. C.; Mehault, J.; Menzler, U.; Moderski, R.; Mohamed, M.; Moulin, E.; Naumann, C. L.; Naumann-Godo, M.; de Naurois, M.; Nedbal, D.; Nguyen, N.; Niemiec, J.; Nolan, S. J.; Oakes, L.; Ohm, S.; Wilhelmi, E. de Ona; Opitz, B.; Ostrowski, M.; Oya, I.; Panter, M.; Parsons, R. D.; Arribas, M. Paz; Pekeur, N. W.; Pelletier, G.; Perez, J.; Petrucci, P. -O.; Peyaud, B.; Pita, S.; Puehlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Raue, M.; Reimer, A.; Reimer, O.; Renaud, M.; de los Reyes, R.; Rieger, F.; Ripken, J.; Rob, L.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Sanchez, David M.; Santangelo, A.; Schlickeiser, R.; Schulz, A.; Schwanke, U.; Schwarzburg, S.; Schwemmer, S.; Sheidaei, F.; Skilton, J. L.; Sol, H.; Spengler, G.; Stawarz, L.; Steenkamp, R.; Stegmann, Christian; Stinzing, F.; Stycz, K.; Sushch, Iurii; Szostek, A.; Tavernet, J. -P.; Terrier, R.; Tluczykont, M.; Trichard, C.; Valerius, K.; van Eldik, C.; Vasileiadis, G.; Venter, C.; Viana, A.; Vincent, P.; Voelk, H. J.; Volpe, F.; Vorobiov, S.; Vorster, M.; Wagner, S. J.; Ward, M.; White, R.; Wierzcholska, A.; Willmann, P.; Wouters, D.; Zacharias, M.; Zajczyk, A.; Zdziarski, A. A.; Zech, Alraune; Zechlin, H. -S. HESS observations of the binary system PSR B1259-63/LS 2883 around the 2010/2011 periastron passage Aims. We present very high energy (VHE; E > 100 GeV) data from the gamma-ray binary system PSR B1259-63/LS 2883 taken around its periastron passage on 15th of December 2010 with the High Energy Stereoscopic System (H. E. S. S.) of Cherenkov Telescopes. We aim to search for a possible TeV counterpart of the GeV flare detected by the Fermi LAT. In addition, we aim to study the current periastron passage in the context of previous observations taken at similar orbital phases, testing the repetitive behaviour of the source. Methods. Observations at VHEs were conducted with H.E.S.S. from 9th to 16th of January 2011. The total dataset amounts to similar to 6 h of observing time. The data taken around the 2004 periastron passage were also re-analysed with the current analysis techniques in order to extend the energy spectrum above 3 TeV to fully compare observation results from 2004 and 2011. Results. The source is detected in the 2011 data at a significance level of 11.5 sigma revealing an averaged integral flux above 1 TeV of (1.01 +/- 0.18(stat) +/- 0.20(sys)) x 10(-12) cm(-2) s(-1). The differential energy spectrum follows a power-law shape with a spectral index Gamma = 2.92 +/- 0.30(stat) +/- 0.20(sys) and a flux normalisation at 1 TeV of N-0 = (1.95 +/- 0.32(stat) +/- 0.39(sys)) x 10(-12) TeV-1 cm(-2) s(-1). The measured light curve does not show any evidence for variability of the source on the daily scale. The re-analysis of the 2004 data yields results compatible with the published ones. The differential energy spectrum measured up to similar to 10 TeV is consistent with a power law with a spectral index Gamma = 2.81 +/- 0.10(stat) +/- 0.20(sys) and a flux normalisation at 1 TeV of N-0 = (1.29 +/- 0.08(stat) +/- 0.26(sys)) x 10(-12) TeV-1 cm(-2) s(-1). Conclusions. The measured integral flux and the spectral shape of the 2011 data are compatible with the results obtained around previous periastron passages. The absence of variability in the H.E.S.S. data indicates that the GeV flare observed by Fermi LAT in the time period covered also by H.E.S.S. observations originates in a different physical scenario than the TeV emission. Moreover, the comparison of the new results to the results from the 2004 observations made at a similar orbital phase provides a stronger evidence of the repetitive behaviour of the source. Les Ulis EDP Sciences 2013 7 Astronomy and astrophysics : an international weekly journal 551 10.1051/0004-6361/201220612 Institut für Physik und Astronomie OPUS4-37410 Wissenschaftlicher Artikel Abramowski, Attila; Aharonian, Felix A.; Benkhali, Faical Ait; Akhperjanian, A. G.; Angüner, Ekrem Oǧuzhan; Backes, Michael; Balenderan, Shangkari; Balzer, Arnim; Barnacka, Anna; Becherini, Yvonne; Tjus, J. Becker; Berge, David; Bernhard, Sabrina; Bernlöhr, K.; Birsin, E.; Biteau, Jonathan; Böttcher, Markus; Boisson, Catherine; Bolmont, J.; Bordas, Pol; Bregeon, Johan; Brun, Francois; Brun, Pierre; Bryan, Mark; Bulik, Tomasz; Carrigan, Svenja; Casanova, Sabrina; Chadwick, Paula M.; Chakraborty, N.; Chalme-Calvet, R.; Chaves, Ryan C. G.; Chretien, M.; Colafrancesco, Sergio; Cologna, Gabriele; Conrad, Jan; Couturier, C.; Cui, Y.; Dalton, M.; Davids, I. D.; Degrange, B.; Deil, C.; dewilt, P.; Djannati-Ataï, A.; Domainko, W.; Donath, A.; Dubus, G.; Dutson, K.; Dyks, J.; Dyrda, M.; Edwards, T.; Egberts, Kathrin; Eger, P.; Espigat, P.; Farnier, C.; Fegan, S.; Feinstein, F.; Fernandes, M. V.; Fernandez, D.; Fiasson, A.; Fontaine, G.; Forster, A.; Fuling, M.; Gabici, S.; Gajdus, M.; Gallant, Y. A.; Garrigoux, T.; Giavitto, G.; Giebels, B.; Glicenstein, J. F.; Gottschall, D.; Grondin, M. -H.; Grudzinska, M.; Hadsch, D.; Haeffner, S.; Hahn, J.; Harris, J.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hervet, O.; Hillert, A.; Hinton, James Anthony; Hofmann, W.; Hofverberg, P.; Holler, Markus; Horns, D.; Ivascenko, A.; Jacholkowska, A.; Jahn, C.; Jamrozy, M.; Janiak, M.; Jankowsky, F.; Jung, I.; Kastendieck, M. A.; Katarzynski, K.; Katz, U.; Kaufmann, S.; Khelifi, B.; Kiefeer, M.; Klepser, S.; Klochkov, D.; Kluzniak, W.; Kolitzus, D.; Komin, Nu.; Kosack, K.; Krakau, S.; Krayzel, F.; Kruger, P. P.; Laffon, H.; Lamanna, G.; Lefaucheur, J.; Lefranc, V.; Lemiere, A.; Lemoine-Goumard, M.; Lenain, J. -P.; Lohse, T.; Lopatin, A.; Lu, C. -C.; Marandon, V.; Marcowith, A.; Marx, R.; Maurin, G.; Maxted, N.; Mayer, M.; McComb, T. J. L.; Mehault, J.; Meintjes, P. J.; Menzler, U.; Meyer, M.; Mitchell, A. M. W.; Moderski, R.; Mohamed, M.; Mora, K.; Moulin, E.; Murach, T.; de Naurois, M.; Niemiec, J.; Nolan, S. J.; Oakes, L.; Odaka, H.; Ohm, S.; Opitz, B.; Ostrowski, M.; Oya, I.; Panter, M.; Parsons, R. D.; Arribas, M. Paz; Pekeur, N. W.; Pelletier, G.; Perez, J.; Petrucci, P. -O.; Peyaud, B.; Pita, S.; Poon, H.; Puhlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Reichardt, I.; Reimer, A.; Reimer, O.; Renaud, M.; de los Reyes, R.; Rieger, F.; Rob, L.; Romoli, C.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. 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Long-term monitoring of PKS2155-304 with ATOM and HESS:investigation of optical/gamma-ray correlations in different spectral states In this paper we report on the analysis of all the available optical and very high-energy gamma-ray (> 200 GeV) data for the BL Lac object PKS 2155-304, collected simultaneously with the ATOM and H.E.S.S. telescopes from 2007 until 2009. This study also includes X-ray (RXTE, Swift) and high-energy gamma-ray (Fermi-LAT) data. During the period analysed, the source was transitioning from its flaring to quiescent optical states, and was characterized by only moderate flux changes at different wavelengths on the timescales of days and months. A flattening of the optical continuum with an increasing optical flux can be noted in the collected dataset, but only occasionally and only at higher flux levels. We did not find any universal relation between the very high-energy gamma-ray and optical flux changes on the timescales from days and weeks up to several years. On the other hand, we noted that at higher flux levels the source can follow two distinct tracks in the optical flux-colour diagrams, which seem to be related to distinct gamma-ray states of the blazar. The obtained results therefore indicate a complex scaling between the optical and gamma-ray emission of PKS 2155 304, with different correlation patterns holding at different epochs, and a gamma-ray flux depending on the combination of an optical flux and colour rather than a flux alone. Les Ulis EDP Sciences 2014 10 Astronomy and astrophysics : an international weekly journal 571 10.1051/0004-6361/201424142 Institut für Physik und Astronomie OPUS4-6973 Dissertation Holler, Markus Photon reconstruction for the H.E.S.S. 28 m telescope and analysis of Crab Nebula and galactic centre observations In the presented thesis, the most advanced photon reconstruction technique of ground-based γ-ray astronomy is adapted to the H.E.S.S. 28 m telescope. The method is based on a semi-analytical model of electromagnetic particle showers in the atmosphere. The properties of cosmic γ-rays are reconstructed by comparing the camera image of the telescope with the Cherenkov emission that is expected from the shower model. To suppress the dominant background from charged cosmic rays, events are selected based on several criteria. The performance of the analysis is evaluated with simulated events. The method is then applied to two sources that are known to emit γ-rays. The first of these is the Crab Nebula, the standard candle of ground-based γ-ray astronomy. The results of this source confirm the expected performance of the reconstruction method, where the much lower energy threshold compared to H.E.S.S. I is of particular importance. A second analysis is performed on the region around the Galactic Centre. The analysis results emphasise the capabilities of the new telescope to measure γ-rays in an energy range that is interesting for both theoretical and experimental astrophysics. The presented analysis features the lowest energy threshold that has ever been reached in ground-based γ-ray astronomy, opening a new window to the precise measurement of the physical properties of time-variable sources at energies of several tens of GeV. 2014 urn:nbn:de:kobv:517-opus-72099 Institut für Physik und Astronomie