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308 results on '"Chounet, L. -M."'

1. The camera of the fifth H.E.S.S. telescope. Part I: System description

Author: Bolmont, J., Corona, P., Gauron, P., Ghislain, P., Goffin, C., Riveros, L. Guevara, Huppert, J. -F., Martineau-Huynh, O., Nayman, P., Parraud, J. -M., Tavernet, J. -P., Toussenel, F., Vincent, D., Vincent, P., Bertoli, W., Espigat, P., Punch, M., Besin, D., Delagnes, E., Glicenstein, J. -F., Moudden, Y., Venault, P., Zaghia, H., Brunetti, L., David, P. -Y., Dubois, J-M., Fiasson, A., Geffroy, N., Monteiro, I. Gomes, Journet, L., Krayzel, F., Lamanna, G., Flour, T. Le, Lees, S., Lieunard, B., Maurin, G., Mugnier, P., Panazol, J. -L., Prast, J., Chounet, L. -M., Degrange, B., Edy, E., Fontaine, G., Giebels, B., Hormigos, S., Khélifi, B., Manigot, P., Maritaz, P., de Naurois, M., Compin, M., Feinstein, F., Fernandez, D., Mehault, J., Rivoire, S., Royer, S., Sanguillon, M., and Vasileiadis, G.
Subjects: Astrophysics - Instrumentation and Methods for Astrophysics, Physics - Instrumentation and Detectors
Abstract: In July 2012, as the four ground-based gamma-ray telescopes of the H.E.S.S. (High Energy Stereoscopic System) array reached their tenth year of operation in Khomas Highlands, Namibia, a fifth telescope took its first data as part of the system. This new Cherenkov detector, comprising a 614.5 m^2 reflector with a highly pixelized camera in its focal plane, improves the sensitivity of the current array by a factor two and extends its energy domain down to a few tens of GeV. The present part I of the paper gives a detailed description of the fifth H.E.S.S. telescope's camera, presenting the details of both the hardware and the software, emphasizing the main improvements as compared to previous H.E.S.S. camera technology., Comment: 16 pages, 13 figures, accepted for publication in NIM A
Published: 2013
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2. A multiwavelength view of the flaring state of PKS 2155-304 in 2006

Author: HESS Collaboration, Abramowski, A., Acero, F., Aharonian, F., Akhperjanian, A. G., Anton, G., Balzer, A., Barnacka, A., de Almeida, U. Barres, Becherini, Y., Becker, J., Behera, B., Benbow, W., Bernlöhr, K., Bochow, A., Boisson, C., Bolmont, J., Bordas, P., Boutelier, T., Brucker, J., Brun, F., Brun, P., Bulik, T., Büsching, I., Carrigan, S., Casanova, S., Cerruti, M., Chadwick, P. M., Charbonnier, A., Chaves, R. C. G., Cheesebrough, A., Chounet, L. -M., Clapson, A. C., Coignet, G., Cologna, G., Colom, P., Conrad, J., Coudreau, N., Dalton, M., Daniel, M. K., Davids, I. D., Degrange, B., Deil, C., Dickinson, H. J., Djannati-Ataï, A., Domainko, W., Drury, L. O'C., Dubois, F., Dubus, G., Dutson, K., Dyks, J., Dyrda, M., Edwards, P., Egberts, K., Eger, P., Espigat, P., Fallon, L., Farnier, C., Fegan, S., Feinstein, F., Fernandes, M. V., Fiasson, A., Fontaine, G., Förster, A., Füßling, M., Gallant, Y. A., Gast, H., Gaylard, M. J., Gérard, L., Gerbig, D., Giebels, B., Glicenstein, J. F., Glück, B., Goret, P., Göring, D., Häffner, S., Hague, J. D., Hampf, D., Hauser, M., Heinz, S., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A., Hoffmann, A., Hofmann, W., Hofverberg, P., Holler, M., Horns, D., Jacholkowska, A., de Jager, O. C., Jahn, C., Jamrozy, M., Jung, I., Kastendieck, M. A., Katarzyński, K., Katz, U., Kaufmann, S., Keogh, D., Khangulyan, D., Khélifi, B., Klein, M., Klochkov, D., Kluźniak, W., Kneiske, T., Komin, Nu., Kosack, K., Kossakowski, R., Kubanek, P., Laffon, H., Lamanna, G., Lennarz, D., Lenain, J. -P., Lohse, T., Lopatin, A., Lu, C. -C., Marandon, V., Marcowith, A., Martin, J. M., Masbou, J., Maurin, D., Maxted, N., McComb, T. J. L., Medina, M. C., Méhault, J., Melady, G., Nguyen, N., Moderski, R., Monard, B., Moulin, E., Naumann, C. L., Naumann-Godo, M., de Naurois, M., Nedbal, D., Nekrassov, D., Nicholas, B., Niemiec, J., Nolan, S. J., Ohm, S., Wilhelmi, E. de Oña, Opitz, B., Ostrowski, M., Oya, I., Panter, M., Arribas, M. Paz, Pedaletti, G., Pelletier, G., Petrucci, P. -O., Pita, S., Pühlhofer, G., Punch, M., Quirrenbach, A., Raue, M., Rayner, S. M., Reimer, A., Reimer, O., Renaud, M., Reyes, R. de los, Rieger, F., Ripken, J., Rob, L., Rosier-Lees, S., Rowell, G., Rudak, B., Rulten, C. B., Ruppel, J., Ryde, F., Sahakian, V., Santangelo, A., Schlickeiser, R., Schöck, F. M., Schulz, A., Schwanke, U., Schwarzburg, S., Schwemmer, S., Sikora, M., Skilton, J. L., Sol, H., Spengler, G., Stawarz, Ł., Steenkamp, R., Stegmann, C., Stinzing, F., Stycz, K., Sushch, I., Szostek, A., Tavernet, J. -P., Terrier, R., Tluczykont, M., Tzioumis, A., Valerius, K., van Eldik, C., Vasileiadis, G., Venter, C., Venter, L., Vialle, J. P., Viana, A., Vincent, P., Völk, H. J., Volpe, F., Vorobiov, S., Vorster, M., Wagner, S. J., Ward, M., White, R., Wierzcholska, A., Zacharias, M., Zajczyk, A., Zdziarski, A. A., Zech, A., and Zechlin, H. -S.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: Multiwavelength (MWL) observations of the blazar PKS 2155-304 during two weeks in July and August 2006, the period when two exceptional flares at very high energies (VHE, E>= 100 GeV) occurred, provide a detailed picture of the evolution of its emission. The complete data set from this campaign is presented, including observations in VHE gamma-rays (H.E.S.S.), X-rays (RXTE, CHANDRA, SWIFT XRT), optical (SWIFT UVOT, Bronberg, Watcher, ROTSE), and in the radio band (NRT, HartRAO, ATCA). Optical and radio light curves from 2004 to 2008 are compared to the available VHE data from this period, to put the 2006 campaign into the context of the long-term evolution of the source. The X-ray and VHE gamma-ray emission are correlated during the observed high state of the source, but show no direct connection with longer wavelengths. The long-term flux evolution in the optical and radio bands is found to be correlated and shows that the source reaches a high state at long wavelengths after the occurrence of the VHE flares. Spectral hardening is seen in the SWIFT XRT data. The nightly averaged high-energy spectra of the non-flaring nights can be reproduced by a stationary one-zone SSC model, with only small variations in the parameters. The spectral and flux evolution in the high-energy band during the night of the second VHE flare is modelled with multi-zone SSC models, which can provide relatively simple interpretations for the hour time-scale evolution of the high-energy emission, even for such a complex data set. For the first time in this type of source, a clear indication is found for a relation between high activity at high energies and a long-term increase in the low frequency fluxes., Comment: 23 pages, 13 figures, accepted for publication in Astronomy & Astrophysics
Published: 2012
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3. Discovery of hard-spectrum \gamma-ray emission from the BL Lac object 1ES 0414+009

Author: The HESS Collaboration, Abramowski, A., Acero, F., Aharonian, F., Akhperjanian, A. G., Anton, G., Balzer, A., Barnacka, A., de Almeida, U. Barres, Becherini, Y., Becker, J., Behera, B., Bernlöhr, K., Birsin, E., Biteau, J., Bochow, A., Boisson, C., Bolmont, J., Bordas, P., Brucker, J., Brun, F., Brun, P., Bulik, T., Büsching, I., Carrigan, S., Casanova, S., Cerruti, M., Chadwick, P. M., Charbonnier, A., Chaves, R. C. G., Cheesebrough, A., Chounet, L. -M., Clapson, A. C., Coignet, G., Cologna, G., Conrad, J., Dalton, M., Daniel, M. K., Davids, I. D., Degrange, B., Deil, C., Dickinson, H. J., Djannati-Ataï, A., Domainko, W., Drury, L. O'C., Dubois, F., Dubus, G., Dutson, K., Dyks, J., Dyrda, M., Egberts, K., Eger, P., Espigat, P., Fallon, L., Farnier, C., Feinstein, F., Fernandes, M. V., Fiasson, A., Fontaine, G., Förster, A., Füßling, M., Gallant, Y. A., Gast, H., Gérard, L., Gerbig, D., Giebels, B., Glicenstein, J. F., Glück, B., Goret, P., Göring, D., Häffner, S., Hague, J. D., Hampf, D., Hauser, M., Heinz, S., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A., Hoffmann, A., Hofmann, W., Hofverberg, P., Holler, M., Horns, D., Jacholkowska, A., de Jager, O. C., Jahn, C., Jamrozy, M., Jung, I., Kastendieck, M. A., Katarzynski, K., Katz, U., Kaufmann, S., Keogh, D., Khangulyan, D., Khélifi, B., Kluźniak, D. Klochkov W., Kneiske, T., Komin, Nu., Kosack, K., Kossakowski, R., Laffon, H., Lamanna, G., Lennarz, D., Lohse, T., Lopatin, A., Lu, C. -C., Marandon, V., Marcowith, A., Masbou, J., Maurin, D., Maxted, N., Mayer, M., McComb, T. J. L., Medina, M. C., Méhault, J., Moderski, R., Moulin, E., Naumann, C. L., Naumann-Godo, M., de Naurois, M., Nedbal, D., Nekrassov, D., Nguyen, N., Nicholas, B., Niemiec, J., Nolan, S. J., Ohm, S., Wilhelmi, E. de Ona, Opitz, B., Ostrowski, M., Oya, I., Panter, M., Arribas, M. Paz, Pedaletti, G., Pelletier, G., Petrucci, P. -O., Pita, S., Pühlhofer, G., Punch, M., Quirrenbach, A., Raue, M., Rayner, S. M., Reimer, A., Reimer, O., Renaud, M., Reyes, R. de los, Rieger, F., Ripken, J., Rob, L., Rosier-Lees, S., Rowell, G., Rudak, B., Rulten, C. B., Ruppel, J., Sahakian, V., Sanchez, D. A., Santangelo, A., Schlickeiser, R., Schöck, F. M., Schulz, A., Schwanke, U., Schwarzburg, S., Schwemmer, S., Sheidaei, F., Sikora, M., Skilton, J. L., Sol, H., Spengler, G., Stawarz, L., Steenkamp, R., Stegmann, C., Stinzing, F., Stycz, K., Sushch, I., Szostek, A., Tavernet, J. -P., Terrier, R., Tluczykont, M., Valerius, K., van Eldik, C., Vasileiadis, G., Venter, C., Vialle, J. P., Viana, A., Vincent, P., Völk, H. J., Volpe, F., Vorobiov, S., Vorster, M., Wagner, S. J., Ward, M., White, R., Wierzcholska, A., Zacharias, M., Zajczyk, A., Zdziarski, A. A., Zech, A., Zechlin, H. -S., Costamante, L., Fegan, S., and Ajello, M.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: 1ES 0414+009 (z = 0.287) is a distant high-frequency-peaked BL Lac object, and has long been considered a likely emitter of very-high energy (VHE, E>100 GeV) gamma-rays due to its high X-ray and radio flux. Observations in the VHE gamma-ray band and across the electromagnetic spectrum can provide insights into the origin of highly energetic particles present in the source and the radiation processes at work. Because of the distance of the source, the gamma-ray spectrum might provide further limits on the level of the Extragalactic Background Light (EBL). We report observations made between October 2005 and December 2009 with H.E.S.S., an array of four imaging atmospheric Cherenkov telescopes. Observations at high energies (HE, 100 MeV - 100 GeV) with the Fermi-LAT instrument in the first 20 months of its operation are also reported. To complete the multi-wavelength picture, archival UV and X-ray observations with the Swift satellite and optical observations with the ATOM telescope are also used. Based on the observations with H.E.S.S., 1ES 0414+009 is detected for the first time in the VHE band. An excess of 224 events is measured, corresponding to a significance of 7.8 sigma. The photon spectrum of the source is well described by a power law, with photon index of 3.45 \pm 0.25stat \pm 0.20syst. The integral flux above 200 GeV is (1.88 \pm 0.20stat \pm 0.38syst) \times10-12 cm-2 s-1. Observations with the Fermi-LAT in the first 20 months of operation show a flux between 200 MeV and 100 GeV of (2.3 \pm 0.2stat) \times 10-9 erg cm-2 s-1, and a spectrum well described by a power-law function with a photon index 1.85 \pm 0.18. Swift/XRT observations show an X-ray flux between 2 and 10 keV of (0.8 - 1) \times 10-11 erg cm-2 s-1, and a steep spectrum (2.2 - 2.3). Combining X-ray with optical-UV data, a fit with a log-parabolic function locates the synchrotron peak around 0.1 keV. ..., Comment: 9 pages, 4 figures, accepted for publication in A&A
Published: 2012
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4. Simultaneous multi-wavelength campaign on PKS 2005-489 in a high state

Author: Collaboration, The H. E. S. S., Collaboration, the Fermi LAT, Abramowski, A., Acero, F., Aharonian, F., Akhperjanian, A. G., Anton, G., Barnacka, A., de Almeida, U. Barres, Bazer-Bachi, A. R., Becherini, Y., Becker, J., Behera, B., Bernlöhr, K., Bochow, A., Boisson, C., Bolmont, J., Bordas, P., Borrel, V., Brucker, J., Brun, F., Brun, P., Bulik, T., Büsching, I., Casanova, S., Cerruti, M., Chadwick, P. M., Charbonnier, A., Chaves, R. C. G., Cheesebrough, A., Chounet, L. -M., Clapson, A. C., Coignet, G., Conrad, J., Dalton, M., Daniel, M. K., Davids, I. D., Degrange, B., Deil, C., Dickinson, H. J., Djannati-Ataï, A., Domainko, W., Drury, L. O'C., Dubois, F., Dubus, G., Dyks, J., Dyrda, M., Egberts, K., Eger, P., Espigat, P., Fallon, L., Farnier, C., Fegan, S., Feinstein, F., Fernandes, M. V., Fiasson, A., Fontaine, G., Förster, A., Füßling, M., Gabici, S., Gallant, Y. A., Gast, H., Gérard, L., Gerbig, D., Giebels, B., Glicenstein, J. F., Glück, B., Goret, P., Göring, D., Hague, J. D., Hampf, D., Hauser, M., Heinz, S., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A., Hoffmann, A., Hofmann, W., Hofverberg, P., Horns, D., Jacholkowska, A., de Jager, O. C., Jahn, C., Jamrozy, M., Jung, I., Kastendieck, M. A., Katarzyński, K., Katz, U., Kaufmann, S., Keogh, D., Kerschhaggl, M., Khangulyan, D., Khélifi, B., Klochkov, D., Kluźniak, W., Kneiske, T., Komin, Nu., Kosack, K., Kossakowski, R., Laffon, H., Lamanna, G., Lenain, J. -P., Lennarz, D., Lohse, T., Lopatin, A., Lu, C. -C., Marandon, V., Marcowith, A., Masbou, J., Maurin, D., Maxted, N., McComb, T. J. L., Medina, M. C., Méhault, J., Nguyen, N., Moderski, R., Moulin, E., Naumann-Godo, M., de Naurois, M., Nedbal, D., Nekrassov, D., Nicholas, B., Niemiec, J., Nolan, S. J., Ohm, S., Olive, J-F., Wilhelmi, E. de Oña, Opitz, B., Ostrowski, M., Panter, M., Arribas, M. Paz, Pedaletti, G., Pelletier, G., Petrucci, P. -O., Pita, S., Pühlhofer, G., Punch, M., Quirrenbach, A., Raue, M., Rayner, S. M., Reimer, A., Reimer, O., Renaud, M., Reyes, R. de los, Rieger, F., Ripken, J., Rob, L., Rosier-Lees, S., Rowell, G., Rudak, B., Rulten, C. B., Ruppel, J., Ryde, F., Sahakian, V., Santangelo, A., Schlickeiser, R., Schöck, F. M., Schönwald, A., Schwanke, U., Schwarzburg, S., Schwemmer, S., Shalchi, A., Sikora, M., Skilton, J. L., Sol, H., Spengler, G., Stawarz, Ł., Steenkamp, R., Stegmann, C., Stinzing, F., Sushch, I., Szostek, A., Tam, P. H., Tavernet, J. -P., Terrier, R., Tibolla, O., Tluczykont, M., Valerius, K., van Eldik, C., Vasileiadis, G., Venter, C., Vialle, J. P., Viana, A., Vincent, P., Vivier, M., Völk, H. J., Volpe, F., Vorobiov, S., Vorster, M., Wagner, S. J., Ward, M., Wierzcholska, A., Zajczyk, A., Zdziarski, A. A., Zech, A., Zechlin, H. -S., Abdo, A. A., Ackermann, M., Ajello, M., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Berenji, B., Blandford, R. D., Bonamente, E., Borgland, A. W., Bregeon, J., Brez, A., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Cannon, A., Caraveo, P. A., Carrigan, S., Casandjian, J. M., Cavazzuti, E., Cecchi, C., Çelik, Ö., Chekhtman, A., Cheung, C. C., Chiang, J., Ciprini, S., Claus, R., Cohen-Tanugi, J., Cutini, S., Dermer, C. D., de Palma, F., Silva, E. do Couto e, Drell, P. S., Dubois, R., Dumora, D., Escande, L., Favuzzi, C., Ferrara, E. C., Focke, W. B., Fortin, P., Frailis, M., Fukazawa, Y., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Germani, S., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Grove, J. E., Guiriec, S., Hadasch, D., Hays, E., Horan, D., Hughes, R. E., Jóhannesson, G., Johnson, A. S., Johnson, W. N., Kamae, T., Katagiri, H., Kataoka, J., Knödlseder, J., Kuss, M., Lande, J., Latronico, L., Lee, S. -H., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Madejski, G. M., Makeev, A., Mazziotta, M. N., McConville, W., McEnery, J. E., Michelson, P. F., Mizuno, T., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nakamori, T., Nishino, S., Nolan, P. L., Norris, J. P., Nuss, E., Ohsugi, T., Okumura, A., Omodei, N., Orlando, E., Ormes, J. F., Ozaki, M., Paneque, D., Panetta, J. H., Parent, D., Pelassa, V., Pepe, M., Pesce-Rollins, M., Piron, F., Porter, T. A., Rainò, S., Rando, R., Razzano, M., Sadrozinski, H. F. -W., Sanchez, D., Sander, A., Sgrò, C., Siskind, E. J., Smith, P. D., Spandre, G., Spinelli, P., Strickman, M. S., Suson, D. J., Takahashi, H., Takahashi, T., Tanaka, T., Thayer, J. B., Thayer, J. G., Thompson, D. J., Tibaldo, L., Torres, D. F., Tosti, G., Tramacere, A., Troja, E., Uehara, T., Usher, T. L., Vandenbroucke, J., Vianello, G., Vilchez, N., Vitale, V., Waite, A. P., Wang, P., Winer, B. L., Wood, K. S., Yang, Z., Ylinen, T., and Ziegler, M.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: The high-frequency peaked BL Lac object PKS 2005-489 was the target of a multi-wavelength campaign with simultaneous observations in the TeV gamma-ray (H.E.S.S.), GeV gamma-ray (Fermi/LAT), X-ray (RXTE, Swift), UV (Swift) and optical (ATOM, Swift) bands. This campaign was carried out during a high flux state in the synchrotron regime. The flux in the optical and X-ray bands reached the level of the historical maxima. The hard GeV spectrum observed with Fermi/LAT connects well to the very high energy (VHE, E>100GeV) spectrum measured with H.E.S.S. with a peak energy between ~5 and 500 GeV. Compared to observations with contemporaneous coverage in the VHE and X-ray bands in 2004, the X-ray flux was ~50 times higher during the 2009 campaign while the TeV gamma-ray flux shows marginal variation over the years. The spectral energy distribution during this multi-wavelength campaign was fit by a one zone synchrotron self-Compton model with a well determined cutoff in X-rays. The parameters of a one zone SSC model are inconsistent with variability time scales. The variability behaviour over years with the large changes in synchrotron emission and small changes in the inverse Compton emission does not warrant an interpretation within a one-zone SSC model despite an apparently satisfying fit to the broadband data in 2009., Comment: published in A&A, 9pages, 4figures. Due to some style difficulties using the standard style file with the long author list, the abstract has been included manually. A version with the correct style can be found in the website http://www.lsw.uni-heidelberg.de/users/skaufman/publications/aa16170-10published.pdf
Published: 2011
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5. Discovery of extended VHE \gamma-ray emission from the vicinity of the young massive stellar cluster Westerlund 1

Author: HESS Collaboration, Abramowski, A., Acero, F., Aharonian, F., Akhperjanian, A. G., Anton, G., Balzer, A., Barnacka, A., de Almeida, U. Barres, Becherini, Y., Becker, J., Behera, B., Bernlöhr, K., Birsin, E., Biteau, J., Bochow, A., Boisson, C., Bolmont, J., Bordas, P., Brucker, J., Brun, F., Brun, P., Bulik, T., Büsching, I., Carrigan, S., Casanova, S., Cerruti, M., Chadwick, P. M., Charbonnier, A., Chaves, R. C. G., Cheesebrough, A., Chounet, L. -M., Clapson, A. C., Coignet, G., Cologna, G., Conrad, J., Dalton, M., Daniel, M. K., Davids, I. D., Degrange, B., Deil, C., Dickinson, H. J., Djannati-Ataï, A., Domainko, W., Drury, L. O'C., Dubois, F., Dubus, G., Dutson, K., Dyks, J., Dyrda, M., Egberts, K., Eger, P., Espigat, P., Fallon, L., Farnier, C., Fegan, S., Feinstein, F., Fernandes, M. V., Fiasson, A., Fontaine, G., Förster, A., Füßling, M., Gallant, Y. A., Gast, H., Gérard, L., Gerbig, D., Giebels, B., Glicenstein, J. F., Glück, B., Goret, P., Göring, D., Häffner, S., Hague, J. D., Hampf, D., Hauser, M., Heinz, S., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A., Hoffmann, A., Hofmann, W., Hofverberg, P., Holler, M., Horns, D., Jacholkowska, A., de Jager, O. C., Jahn, C., Jamrozy, M., Jung, I., Kastendieck, M. A., Katarzynski, K., Katz, U., Kaufmann, S., Keogh, D., Khangulyan, D., Khélifi, B., Klochkov, D., Kluźniak, W., Kneiske, T., Komin, Nu., Kosack, K., Kossakowski, R., Laffon, H., Lamanna, G., Lennarz, D., Lohse, T., Lopatin, A., Lu, C. -C., Marandon, V., Marcowith, A., Masbou, J., Maurin, D., Maxted, N., Mayer, M., McComb, T. J. L., Medina, M. C., Méhault, J., Moderski, R., Moulin, E., Naumann, C. L., Naumann-Godo, M., de Naurois, M., Nedbal, D., Nekrassov, D., Nguyen, N., Nicholas, B., Niemiec, J., Nolan, S. J., Ohm, S., Wilhelmi, E. de Ona, Opitz, B., Ostrowski, M., Oya, I., Panter, M., Arribas, M. Paz, Pedaletti, G., Pelletier, G., Petrucci, P. -O., Pita, S., Pühlhofer, G., Punch, M., Quirrenbach, A., Raue, M., Rayner, S. M., Reimer, A., Reimer, O., Renaud, M., Reyes, R. de los, Rieger, F., Ripken, J., Rob, L., Rosier-Lees, S., Rowell, G., Rudak, B., Rulten, C. B., Ruppel, J., Sahakian, V., Sanchez, D., Santangelo, A., Schlickeiser, R., Schöck, F. M., Schulz, A., Schwanke, U., Schwarzburg, S., Schwemmer, S., Sheidaei, F., Sikora, M., Skilton, J. L., Sol, H., Spengler, G., Stawarz, L., Steenkamp, R., Stegmann, C., Stinzing, F., Stycz, K., Sushch, I., Szostek, A., Tavernet, J. -P., Terrier, R., Tluczykont, M., Valerius, K., van Eldik, C., Vasileiadis, G., Venter, C., Vialle, J. P., Viana, A., Vincent, P., Völk, H. J., Volpe, F., Vorobiov, S., Vorster, M., Wagner, S. J., Ward, M., White, R., Wierzcholska, A., Zacharias, M., Zajczyk, A., Zdziarski, A. A., Zech, A., and Zechlin, H. -S.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Galaxy Astrophysics
Abstract: Results obtained in very-high-energy (VHE; E > 100 GeV) \gamma-ray observations performed with the H.E.S.S. telescope array are used to investigate particle acceleration processes in the vicinity of the young massive stellar cluster Westerlund 1 (Wd 1). Imaging of Cherenkov light from \gamma-ray induced particle cascades in the Earth's atmosphere is used to search for VHE \gamma\ rays from the region around Wd 1. Possible catalogued counterparts are searched for and discussed in terms of morphology and energetics of the H.E.S.S. source. The detection of the degree-scale extended VHE \gamma-ray source HESS J1646-458 is reported based on 45 hours of H.E.S.S. observations performed between 2004 and 2008. The VHE \gamma-ray source is centred on the nominal position of Wd 1 and detected with a total statistical significance of ~20\sigma. The emission region clearly extends beyond the H.E.S.S. point-spread function (PSF). The differential energy spectrum follows a power law in energy with an index of \Gamma=2.19 \pm 0.08_{stat} \pm 0.20_{sys} and a flux normalisation at 1 TeV of \Phi_0 = (9.0 \pm 1.4_{stat} \pm 1.8_{sys}) x 10^{-12} TeV^{-1} cm^{-2} s^{-1}. The integral flux above 0.2 TeV amounts to (5.2 \pm 0.9) x 10^{-11} cm^{-2} s^{-1}. Four objects coincident with HESS J1646-458 are discussed in the search of a counterpart, namely the magnetar CXOU J164710.2-455216, the X-ray binary 4U 1642-45, the pulsar PSR J1648-4611 and the massive stellar cluster Wd 1. In a single-source scenario, Wd 1 is favoured as site of VHE particle acceleration. Here, a hadronic parent population would be accelerated within the stellar cluster. Beside this, there is evidence for a multi-source origin, where a scenario involving PSR J1648-4611 could be viable to explain parts of the VHE \gamma-ray emission of HESS J1646-458., Comment: 11 pages, 6 figures, accepted for publication in A&A
Published: 2011
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6. Discovery of the source HESS J1356-645 associated with the young and energetic PSR J1357-6429

Author: HESS Collaboration, Abramowski, A., Acero, F., Aharonian, F., Akhperjanian, A. G., Anton, G., Balzer, A., Barnacka, A., de Almeida, U. Barres, Becherini, Y., Becker, J., Behera, B., Bernlöhr, K., Bochow, A., Boisson, C., Bolmont, J., Bordas, P., Brucker, J., Brun, F., Brun, P., Bulik, T., Büsching, I., Carrigan, S., Casanova, S., Cerruti, M., Chadwick, P. M., Charbonnier, A., Chaves, R. C. G., Cheesebrough, A., Chounet, L. -M., Clapson, A. C., Coignet, G., Cologna, G., Conrad, J., Dalton, M., Daniel, M. K., Davids, I. D., Degrange, B., Deil, C., Dickinson, H. J., Djannati-Ataï, A., Domainko, W., Drury, L. O'C., Dubois, F., Dubus, G., Dutson, K., Dyks, J., Dyrda, M., Egberts, K., Eger, P., Espigat, P., Fallon, L., Farnier, C., Fegan, S., Feinstein, F., Fernandes, M. V., Fiasson, A., Fontaine, G., Förster, A., Füssling, M., Gallant, Y. A., Gast, H., Gérard, L., Gerbig, D., Giebels, B., Glicenstein, J. F., Glück, B., Goret, P., Göring, D., Häffner, S., Hague, J. D., Hampf, D., Hauser, M., Heinz, S., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A., Hoffmann, A., Hofmann, W., Hofverberg, P., Holler, M., Horns, D., Jacholkowska, A., de Jager, O. C., Jahn, C., Jamrozy, M., Jung, I., Kastendieck, M. A., Katarzynski, K., Katz, U., Kaufmann, S., Keogh, D., Khangulyan, D., Khélifi, B., Klochkov, D., Kluzniak, W., Kneiske, T., Komin, Nu., Kosack, K., Kossakowski, R., Laffon, H., Lamanna, G., Lennarz, D., Lohse, T., Lopatin, A., Lu, C. -C., Marandon, V., Marcowith, A., Masbou, J., Maurin, D., Maxted, N., Mayer, M., McComb, T. J. L., Medina, M. C., Méhault, J., Moderski, R., Moulin, E., Naumann, C. L., Naumann-Godo, M., de Naurois, M., Nedbal, D., Nekrassov, D., Nguyen, N., Nicholas, B., Niemiec, J., Nolan, S. J., Ohm, S., Wilhelmi, E. de Ona, Opitz, B., Ostrowski, M., Oya, I., Panter, M., Arribas, M. Paz, Pedaletti, G., Pelletier, G., Petrucci, P. -O., Pita, S., Pühlhofer, G., Punch, M., Quirrenbach, A., Raue, M., Rayner, S. M., Reimer, A., Reimer, O., Renaud, M., Reyes, R. de los, Rieger, F., Ripken, J., Rob, L., Rosier-Lees, S., Rowell, G., Rudak, B., Rulten, C. B., Ruppel, J., Sahakian, V., Sanchez, D., Santangelo, A., Schlickeiser, R., Schöck, F. M., Schulz, A., Schwanke, U., Schwarzburg, S., Schwemmer, S., Sikora, M., Skilton, J. L., Sol, H., Spengler, G., Stawarz, L., Steenkamp, R., Stegmann, C., Stinzing, F., Stycz, K., Sushch, I., Szostek, A., Tavernet, J. -P., Terrier, R., Tluczykont, M., Valerius, K., van Eldik, C., Vasileiadis, G., Venter, C., Vialle, J. P., Viana, A., Vincent, P., Völk, H. J., Volpe, F., Vorobiov, S., Vorster, M., Wagner, S. J., Ward, M., White, R., Wierzcholska, A., Zacharias, M., Zajczyk, A., Zdziarski, A. A., Zech, A., and Zechlin, H. -S.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: Several newly discovered very-high-energy (VHE; E > 100 GeV) gamma-ray sources in the Galaxy are thought to be associated with energetic pulsars. Among them, middle-aged (> 1E+4 yr) systems exhibit large centre-filled VHE nebulae, offset from the pulsar position, which result from the complex relationship between the pulsar wind and the surrounding medium, and reflect the past evolution of the pulsar. Imaging Atmospheric Cherenkov Telescopes (IACTs) have been successful in revealing extended emission from these sources in the VHE regime. Together with radio and X-ray observations, this observational window allows one to probe the energetics and magnetic field inside these large-scale nebulae. H.E.S.S., with its large field of view, angular resolution of < 0.1deg and unprecedented sensitivity, has been used to discover a large population of such VHE sources. In this paper, the H.E.S.S. data from the continuation of the Galactic Plane Survey (-80deg < l < 60deg, |b| < 3deg), together with the existing multi-wavelength observations, are used. A new VHE gamma-ray source was discovered at R.A. (J2000) = 13h56m00s, Dec. (J2000) = -64d30m00s with a 2' statistical error in each coordinate, namely HESS J1356-645. The source is extended, with an intrinsic Gaussian width of (0.20 +/- 0.02)deg. Its integrated energy flux between 1 and 10 TeV of 8E-12 erg cm-2 s-1 represents ~ 11% of the Crab Nebula flux in the same energy band. The energy spectrum between 1 and 20 TeV is well described by a power law dN/dE ~ E-Gamma with photon index Gamma = 2.2 +/- 0.2stat +/- 0.2sys. The inspection of archival radio images at three frequencies and the analysis of X-ray data from ROSAT/PSPC and XMM-Newton/MOS reveal the presence of faint non-thermal diffuse emission coincident with HESS J1356-645. HESS J1356-645 is most likely associated with the young and energetic pulsar PSR J1357-6429 (Abridged), Comment: Accepted for publication in A&A (August 08th 2011); 11 pages, 7 figures, 1 table
Published: 2011
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7. Very-high-energy gamma-ray emission from the direction of the Galactic globular cluster Terzan 5

Author: HESS Collaboration, Abramowski, A., Acero, F., Aharonian, F., Akhperjanian, A. G., Anton, G., Balzer, A., Barnacka, A., de Almeida, U. Barres, Becherini, Y., Becker, J., Behera, B., Bernloehr, K., Bochow, A., Boisson, C., Bolmont, J., Bordas, P., Brucker, J., Brun, F., Brun, P., Bulik, T., Buesching, I., Carrigan, S., Casanova, S., Cerruti, M., Chadwick, P. M., Charbonnier, A., Chaves, R. C. G., Cheesebrough, A., Chounet, L. -M., Clapson, A. C., Coignet, G., Cologna, G., Conrad, J., Dalton, M., Daniel, M. K., Davids, I. D., Degrange, B., Deil, C., Dickinson, H. J., Djannati-Atai, A., Domainko, W., Drury, L. O'C., Dubois, F., Dubus, G., Dutson, K., Dyks, J., Dyrda, M., Egberts, K., Eger, P., Espigat, P., Fallon, L., Farnier, C., Fegan, S., Feinstein, F., Fernandes, M. V., Fiasson, A., Fontaine, G., Foerster, A., Fuessling, M., Gallant, Y. A., Gast, H., Gerard, L., Gerbig, D., Giebels, B., Glicenstein, J. F., Glueck, B., Goret, P., Goering, D., Haeffner, S., Hague, J. D., Hampf, D., Hauser, M., Heinz, S., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A., Hoffmann, A., Hofmann, W., Hofverberg, P., Holler, M., Horns, D., Jacholkowska, A., de Jager, O. C., Jahn, C., Jamrozy, M., Jung, I., Kastendieck, M. A., Katarzynski, K., Katz, U., Kaufmann, S., Keogh, D., Khangulyan, D., Khelifi, B., Klochkov, D., Kluzniak, W., Kneiske, T., Komin, Nu., Kosack, K., Kossakowski, R., Laffon, H., Lamanna, G., Lennarz, D., Lohse, T., Lopatin, A., Lu, C. -C., Marandon, V., Marcowith, A., Masbou, J., Maurin, D., Maxted, N., McComb, T. J. L., Medina, M. C., Mehault, J., Nguyen, N., Moderski, R., Moulin, E., Naumann, C. L., Naumann-Godo, M., de Naurois, M., Nedbal, D., Nekrassov, D., Nicholas, B., Niemiec, J., Nolan, S. J., Ohm, S., Wilhelmi, E. de Ona, Opitz, B., Ostrowski, M., Oya, I., Panter, M., Arribas, M. Paz, Pedaletti, G., Pelletier, G., Petrucci, P. -O., Pita, S., Puehlhofer, G., Punch, M., Quirrenbach, A., Raue, M., Rayner, S. M., Reimer, A., Reimer, O., Renaud, M., Reyes, R. de los, Rieger, F., Ripken, J., Rob, L., Rosier-Lees, S., Rowell, G., Rudak, B., Rulten, C. B., Ruppel, J., Ryde, F., Sahakian, V., Santangelo, A., Schlickeiser, R., Schoeck, F. M., Schulz, A., Schwanke, U., Schwarzburg, S., Schwemmer, S., Sikora, M., Skilton, J. L., Sol, H., Spengler, G., Stawarz, L., Steenkamp, R., Stegmann, C., Stinzing, F., Stycz, K., Sushch, I., Szostek, A., Tavernet, J. -P., Terrier, R., Tluczykont, M., Valerius, K., van Eldik, C., Vasileiadis, G., Venter, C., Vialle, J. P., Viana, A., Vincent, P., Voelk, H. J., Volpe, F., Vorobiov, S., Vorster, M., Wagner, S. J., Ward, M., White, R., Wierzcholska, A., Zacharias, M., Zajczyk, A., Zdziarski, A. A., Zech, A., and Zechlin, H. -S.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: The H.E.S.S. very-high-energy (VHE, E > 0.1 TeV) gamma-ray telescope system has discovered a new source, HESS J1747-248. The measured integral flux is (1.2 +/- 0.3) \times 10^-12 cm-2 s-1 above 440 GeV for a power-law photon spectral index of 2.5 +/- 0.3 stat +/- 0.2 sys. The VHE gamma-ray source is located in the close vicinity of the Galactic globular cluster Terzan 5 and extends beyond the H.E.S.S. point spread function (0.07 degree). The probability of a chance coincidence with Terzan 5 and an unrelated VHE source is quite low (~ 10^-4). With the largest population of identified millisecond pulsars (msPSRs), a very high core stellar density and the brightest GeV range flux as measured by Fermi-LAT, Terzan 5 stands out among Galactic globular clusters. The properties of the VHE source are briefly discussed in the context of potential emission mechanisms, notably in relation to msPSRs. Interpretation of the available data accommodates several possible origins for this VHE gamma-ray source, although none of them offers a satisfying explanation of its peculiar morphology., Comment: 5 pages, 2 figures, accepted for publication in A&A, full author list
Published: 2011
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8. A new SNR with TeV shell-type morphology: HESS J1731-347

Author: HESS Collaboration, Abramowski, A., Acero, F., Aharonian, F., Akhperjanian, A. G., Anton, G., Balzer, A., Barnacka, A., de Almeida, U. Barres, Bazer-Bachi, A. R., Becherini, Y., Becker, J., Behera, B., Bernlöhr, K., Bochow, A., Boisson, C., Bolmont, J., Bordas, P., Borrel, V., Brucker, J., Brun, F., Brun, P., Bulik, T., Büsching, I., Carrigan, S., Casanova, S., Cerruti, M., Chadwick, P. M., Charbonnier, A., Chaves, R. C. G., Cheesebrough, A., Chounet, L. -M., Clapson, A. C., Coignet, G., Conrad, J., Dalton, M., Daniel, M. K., Davids, I. D., Degrange, B., Deil, C., Dickinson, H. J., Djannati-Ataï, A., Domainko, W., Drury, L. O'C., Dubois, F., Dubus, G., Dyks, J., Dyrda, M., Egberts, K., Eger, P., Espigat, P., Fallon, L., Farnier, C., Fegan, S., Feinstein, F., Fernandes, M. V., Fiasson, A., Fontaine, G., Förster, A., Füßling, M., Gallant, Y. A., Gast, H., Gérard, L., Gerbig, D., Giebels, B., Glicenstein, J. F., Glück, B., Goret, P., Göring, D., Häffner, S., Hague, J. D., Hampf, D., Hauser, M., Heinz, S., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A., Hoffmann, A., Hofmann, W., Hofverberg, P., Holler, M., Horns, D., Jacholkowska, A., de Jager, O. C., Jahn, C., Jamrozy, M., Jung, I., Kastendieck, M. A., Katarzynski, K., Katz, U., Kaufmann, S., Keogh, D., Khangulyan, D., Khélifi, B., Klochkov, D., Kluzniak, W., Kneiske, T., Komin, Nu., Kosack, K., Kossakowski, R., Laffon, H., Lamanna, G., Lennarz, D., Löhse, T., Lopatin, A., Lu, C. -C., Marandon, V., Marcowith, A., Masbou, J., Maurin, D., Maxted, N., McComb, T. J. L., Medina, M. C., Méhault, J., Moderski, R., Moulin, E., Naumann, C. L., Naumann-Godo, M., de Naurois, M., Nedbal, D., Nekrassov, D., Nguyen, N., Nicholas, B., Niemiec, J., Nolan, S. J., Ohm, S., Olive, J-P., Wilhelmi, E. de Oña, Opitz, B., Ostrowski, M., Panter, M., Arribas, M. Paz, Pedaletti, G., Pelletier, G., Petrucci, P. -O., Pita, S., Pühlhofer, G., Punch, M., Quirrenbach, A., Raue, M., Rayner, S. M., Reimer, A., Reimer, O., Renaud, M., Reyes, R. de los, Rieger, F., Ripken, J., Rob, L., Rosier-Lees, S., Rowell, G., Rudak, B., Rulten, C. B., Ruppel, J., Ryde, F., Sahakian, V., Santangelo, A., Schlickeiser, R., Schöck, F. M., Schulz, A., Schwanke, U., Schwarzburg, S., Schwemmer, S., Sikora, M., Skilton, J. L., Sol, H., Spengle, G., Stawarz, L., Steenkamp, R., Stegmann, C., Stinzing, F., Stycz, K., Sushch, I., Szostek, A., Tavernet, J. -P., Terrier, R., Tibolla3, O., Tluczykont, M., Valerius, K., van Eldik, C., Vasileiadis, G., Venter, C., Vialle, J. P., Viana, A., Vincent, P., Vivier, M., Völk, H. J., Volpe, F., Vorobiov, S., Vorster, M., Wagner, S. J., Ward, M., Wierzcholska, A., Zacharias, M., Zajczyk, A., Zdziarski, A. A., Zech, A., and Zechlin, H. -S.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: The recent discovery of the radio shell-type supernova remnant (SNR), G353.6-0.7, in spatial coincidence with the unidentified TeV source HESS J1731-347 has motivated further observations of the source with the High Energy Stereoscopic System (H.E.S.S.) Cherenkov telescope array to test a possible association of the gamma-ray emission with the SNR. With a total of 59 hours of observation, representing about four times the initial exposure available in the discovery paper of HESS J1731-347, the gamma-ray morphology is investigated and compared with the radio morphology. An estimate of the distance is derived by comparing the interstellar absorption derived from X-rays and the one obtained from 12CO and HI observations. The deeper gamma-ray observation of the source has revealed a large shell-type structure with similar position and extension (r~0.25{\deg}) as the radio SNR, thus confirming their association. By accounting for the H.E.S.S. angular resolution and projection effects within a simple shell model, the radial profile is compatible with a thin, spatially unresolved, rim. Together with RX J1713.7-3946, RX J0852.0-4622 and SN 1006, HESS J1731-347 is now the fourth SNR with a significant shell morphology at TeV energies. The derived lower limit on the distance of the SNR of 3.2 kpc is used together with radio and X-ray data to discuss the possible origin of the gamma-ray emission, either via inverse Compton scattering of electrons or the decay of neutral pions resulting from proton-proton interaction., Comment: 10 pages, 10 figures, accepted for publication in A&A
Published: 2011
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9. H.E.S.S. observations of the globular clusters NGC 6388 and M 15 and search for a Dark Matter signal

Author: HESS Collaboration, Abramowski, A., Acero, F., Aharonian, F., Akhperjanian, A. G., Anton, G., Balzer, A., Barnacka, A., de Almeida, U. Barres, Bazer-Bachi, A. R., Becherini, Y., Becker, J., Behera, B., Bernlöhr, K., Bochow, A., Boisson, C., Bolmont, J., Bordas, P., Borrel, V., Brucker, J., Brun, F., Brun, P., Bulik, T., Büsching, I., Carrigan, S., Casanova, S., Cerruti, M., Chadwick, P. M., Charbonnier, A., Chaves, R. C. G., Cheesebrough, A., Chounet, L. -M., Clapson, A. C., Coignet, G., Conrad, J., Dalton, M., Daniel, M. K., Davids, I. D., Degrange, B., Deil, C., Dickinson, H. J., Djannati-Ataï, A., Domainko, W., Drury, L. O'C., Dubois, F., Dubus, G., Dyks, J., Dyrda, M., Egberts, K., Eger, P., Espigat, P., Fallon, L., Farnier, C., Fegan, S., Feinstein, F., Fernandes, M. V., Fiasson, A., Fontaine, G., Förster, A., Füßling, M., Gallant, Y. A., Gast, H., Gérard, L., Gerbig, D., Giebels, B., Glicenstein, J. F., Glück, B., Goret, P., Göring, D., Häffner, S., Hague, J. D., Hampf, D., Hauser, M., Heinz, S., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A., Hoffmann, A., Hofmann, W., Hofverberg, P., Holler, M., Horns, D., Jacholkowska, A., de Jager, O. C., Jahn, C., Jamrozy, M., Jung, I., Kastendieck, M. A., Katarzynski, K., Katz, U., Kaufmann, S., Keogh, D., Khangulyan, D., Khélifi, B., Klochkov, D., Kluzniak, W., Kneiske, T., Komin, Nu., Kosack, K., Kossakowski, R., Laffon, H., Lamanna, G., Lennarz, D., Löhse, T., Lopatin, A., Lu, C. -C., Marandon, V., Marcowith, A., Masbou, J., Maurin, D., Maxted, N., McComb, T. J. L., Medina, M. C., Méhault, J., Moderski, R., Moulin, E., Naumann, C. L., Naumann-Godo, M., de Naurois, M., Nedbal, D., Nekrassov, D., Nguyen, N., Nicholas, B., Niemiec, J., Nolan, S. J., Ohm, S., Olive, J-P., Wilhelmi, E. de Oña, Opitz, B., Ostrowski, M., Panter, M., Arribas, M. Paz, Pedaletti, G., Pelletier, G., Petrucci, P. -O., Pita, S., Pühlhofer, G., Punch, M., Quirrenbach, A., Raue, M., Rayner, S. M., Reimer, A., Reimer, O., Renaud, M., Reyes, R. de los, Rieger, F., Ripken, J., Rob, L., Rosier-Lees, S., Rowell, G., Rudak, B., Rulten, C. B., Ruppel, J., Ryde, F., Sahakian, V., Santangelo, A., Schlickeiser, R., Schöck, F. M., Schulz, A., Schwanke, U., Schwarzburg, S., Schwemmer, S., Sikora, M., Skilton, J. L., Sol, H., Spengle, G., Stawarz, L., Steenkamp, R., Stegmann, C., Stinzing, F., Stycz, K., Sushch, I., Szostek, A., Tavernet, J. -P., Terrier, R., Tibolla3, O., Tluczykont, M., Valerius, K., van Eldik, C., Vasileiadis, G., Venter, C., Vialle, J. P., Viana, A., Vincent, P., Vivier, M., Völk, H. J., Volpe, F., Vorobiov, S., Vorster, M., Wagner, S. J., Ward, M., Wierzcholska, A., Zacharias, M., Zajczyk, A., Zdziarski, A. A., Zech, A., and Zechlin, H. -S.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: Observations of the globular clusters NGC 6388 and M 15 were carried out by the H.E.S.S. array of Cherenkov telescopes for a live time of 27.2 and 15.2 hours respectively. No gamma-ray signal is found at the nominal target position of NGC 6388 and M 15. In the primordial formation scenario, globular clusters are formed in a dark matter halo and dark matter could still be present in the baryon-dominated environment of globular clusters. This opens the possibility of observing a dark matter self-annihilation signal. The dark matter content of the globular clusters NGC 6388 and M 15 is modelled taking into account the astrophysical processes that can be expected to influence the dark matter distribution during the evolution of the globular cluster: the adiabatic contraction of dark matter by baryons, the adiabatic growth of a black hole in the dark matter halo and the kinetic heating of dark matter by stars. 95% confidence level exclusion limits on the dark matter particle velocity-weighted annihilation cross section are derived for these dark matter haloes. In the TeV range, the limits on the velocity-weighted annihilation cross section are derived at the 10-25 cm3 s-1 level and a few 10-24 cm3 s-1 for NGC 6388 and M 15 respectively., Comment: 10 pages, 5 figures, 4 tables, accepted for publication in ApJ
Published: 2011
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10. Search for a Dark Matter annihilation signal from the Galactic Center halo with H.E.S.S

Author: Collaboration, H. E. S. S., Abramowski, A., Acero, F., Aharonian, F., Akhperjanian, A. G., Anton, G., Barnacka, A., de Almeida, U. Barres, Bazer-Bachi, A. R., Becherini, Y., Becker, J., Behera, B., Bernlöhr, K., Bochow, A., Boisson, C., Bolmont, J., Bordas, P., Borrel, V., Brucker, J., Brun, F., Brun, P., Bulik, T., Büsching, I., Carrigan, S., Casanova, S., Cerruti, M., Chadwick, P. M., Charbonnier, A., Chaves, R. C. G., Cheesebrough, A., Chounet, L. -M., Clapson, A. C., Coignet, G., Conrad, J., Dalton, M., Daniel, M. K., Davids, I. D., Degrange, B., Deil, C., Dickinson, H. J., Djannati-Ataï, A., Domainko, W., Drury, L. O'C., Dubois, F., Dubus, G., Dyks, J., Dyrda, M., Egberts, K., Eger, P., Espigat, P., Fallon, L., Farnier, C., Fegan, S., Feinstein, F., Fernandes, M. V., Fiasson, A., Fontaine, G., Förster, A., Füßling, M., Gallant, Y. A., Gast, H., Gérard, L., Gerbig, D., Giebels, B., Glicenstein, J. F., Glück, B., Goret, P., Göring, D., Hague, J. D., Hampf, D., Hauser, M., Heinz, S., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A., Hoffmann, A., Hofmann, W., Hofverberg, P., Horns, D., Jacholkowska, A., de Jager, O. C., Jahn, C., Jamrozy, M., Jung, I., Kastendieck, M. A., Katarzynski, K., Katz, U., Kaufmann, S., Keogh, D., Kerschhaggl, M., Khangulyan, D., Khélifi, B., Klochkov, D., Kluźniak, W., Kneiske, T., Komin, Nu., Kosack, K., Kossakowski, R., Laffon, H., Lamanna, G., Lennarz, D., Lohse, T., Lopatin, A., Lu, C. -C, Marandon, V., Marcowith, A., Masbou, J., Maurin, D., Maxted, N., McComb, T. J. L., Medina, M. C., Méhault, J., Moderski, R., Moulin, E., Naumann, C. L., Naumann-Godo, M., de Naurois, M., Nedbal, D., Nekrassov, D., Nguyen, N., Nicholas, B., Niemiec, J., Nolan, S. J., Ohm, S., Olive, J-F., Wilhelmi, E. de Oña, Opitz, B., Ostrowski, M., Panter, M., Arribas, M. Paz, Pedaletti, G., Pelletier, G., Petrucci, P. -O., Pita, S., Pühlhofer, G., Punch, M., Quirrenbach, A., Raue, M., Rayner, S. M., Reimer, A., Reimer, O., Renaud, M., Reyes, R. de los, Rieger, F., Ripken, J., Rob, L., Rosier-Lees, S., Rowell, G., Rudak, B., Rulten, C. B., Ruppel, J., Ryde, F., Sahakian, V., Santangelo, A., Schlickeiser, R., Schöck, F. M., Schönwald, A., Schwanke, U., Schwarzburg, S., Schwemmer, S., Shalchi, A., Sikora, M., Skilton, J. L., Sol, H., Spengler, G., Stawarz, Ł., Steenkamp, R., Stegmann, C., Stinzing, F., Sushch, I., Szostek, A., Tavernet, J. -P., Terrier, R., Tibolla, O., Tluczykont, M., Valerius, K., van Eldik, C., Vasileiadis, G., Venter, C., Vialle, J. P., Viana, A., Vincent, P., Vivier, M., Völk, H. J., Volpe, F., Vorobiov, S., Vorster, M., Wagner, S. J., Ward, M., Wierzcholska, A., Zajczyk, A., Zdziarski, A. A., Zech, A., and Zechlin, H. -S.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, High Energy Physics - Phenomenology
Abstract: A search for a very-high-energy (VHE; >= 100 GeV) gamma-ray signal from self-annihilating particle Dark Matter (DM) is performed towards a region of projected distance r ~ 45-150 pc from the Galactic Center. The background-subtracted gamma-ray spectrum measured with the High Energy Stereoscopic System (H.E.S.S.) gamma-ray instrument in the energy range between 300 GeV and 30 TeV shows no hint of a residual gamma-ray flux. Assuming conventional Navarro-Frenk-White (NFW) and Einasto density profiles, limits are derived on the velocity-weighted annihilation cross section < \sigma v> as a function of the DM particle mass. These are among the best reported so far for this energy range. In particular, for the DM particle mass of ~1 TeV, values for <\sigma v> above 3 * 10^(-25) cm^3 s^(-1) are excluded for the Einasto density profile. The limits derived here differ much less for the chosen density profile parametrizations, as opposed to limits from gamma-ray observations of dwarf galaxies or the very center of the Milky Way, where the discrepancy is significantly larger., Comment: 6 Pages, accepted for publication in Phys. Rev. Lett
Published: 2011
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11. HESS J1943+213: a candidate extreme BL Lacertae object

Author: Collaboration, H. E. S. S., Abramowski, A., Acero, F., Aharonian, F., Akhperjanian, A. G., Anton, G., Balzer, A., Barnacka, A., de Almeida, U. Barres, Bazer-Bachi, A. R., Becherini, Y., Becker, J., Behera, B., Bernlöhr, K., Bochow, A., Boisson, C., Bolmont, J., Bordas, P., Borrel, V., Brucker, J., Brun, F., Brun, P., Bulik, T., Büsching, I., Carrigan, S., Casanova, S., Cerruti, M., Chadwick, P. M., Charbonnier, A., Chaves, R. C. G., Cheesebrough, A., Chounet, L. -M., Clapson, A. C., Coignet, G., Colom, P., Conrad, J., Dalton, M., Daniel, M. K., Davids, I. D., Degrange, B., Deil, C., Dickinson, H. J., Djannati-Ataï, A., Domainko, W., Drury, L. O'C., Dubois, F., Dubus, G., Dyks, J., Dyrda, M., Egberts, K., Eger, P., Espigat, P., Fallon, L., Farnier, C., Fegan, S., Feinstein, F., Fernandes, M. V., Fiasson, A., Fontaine, G., Förster, A., Füßling, M., Gallant, Y. A., Gast, H., Gérard, L., Gerbig, D., Giebels, B., Glicenstein, J. F., Glück, B., Goret, P., Göring, D., Häffner, S., Hague, J. D., Hampf, D., Hauser, M., Heinz, S., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A., Hoffmann, A., Hofmann, W., Hofverberg, P., Holler, M., Horns, D., Jacholkowska, A., de Jager, O. C., Jahn, C., Jamrozy, M., Jung, I., Kastendieck, M. A., Katarzyński, K., Katz, U., Kaufmann, S., Keogh, D., Khangulyan, D., Khélifi, B., Klochkov, D., Kluźniak, W., Kneiske, T., Komin, Nu., Kosack, K., Kossakowski, R., Laffon, H., Lamanna, G., Lennarz, D., Lohse, T., Lopatin, A., Lu, C. -C., Marandon, V., Marcowith, A., Masbou, J., Maurin, D., Maxted, N., McComb, T. J. L., Medina, M. C., Méhault, J., Nguyen, N., Moderski, R., Moulin, E., Naumann, C. L., Naumann-Godo, M., de Naurois, M., Nedbal, D., Nekrassov, D., Nicholas, B., Niemiec, J., Nolan, S. J., Ohm, S., Olive, J-F., Wilhelmi, E. de Oña, Opitz, B., Ostrowski, M., Panter, M., Arribas, M. Paz, Pedaletti, G., Pelletier, G., Petrucci, P. -O., Pita, S., Pühlhofer, G., Punch, M., Quirrenbach, A., Raue, M., Rayner, S. M., Reimer, A., Reimer, O., Renaud, M., Reyes, R. de los, Rieger, F., Ripken, J., Rob, L., Rosier-Lees, S., Rowell, G., Rudak, B., Rulten, C. B., Ruppel, J., Ryde, F., Sahakian, V., Santangelo, A., Schlickeiser, R., Schöck, F. M., Schönwald, A., Schulz, A., Schwanke, U., Schwarzburg, S., Schwemmer, S., Shalchi, A., Sikora, M., Skilton, J. L., Sol, H., Spengler, G., Stawarz, Ł., Steenkamp, R., Stegmann, C., Stinzing, F., Stycz, K., Sushch, I., Szostek, A., Tavernet, J. -P., Terrier, R., Tibolla, O., Tluczykont, M., Valerius, K., van Eldik, C., Vasileiadis, G., Venter, C., Vialle, J. P., Viana, A., Vincent, P., Vivier, M., Völk, H. J., Volpe, F., Vorobiov, S., Vorster, M., Wagner, S. J., Ward, M., Wierzcholska, A., Zajczyk, A., Zdziarski, A. A., Zech, A., Zechlin, H. -S., Burnett, T. H., and Hill, A. B.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: We report on a newly detected point-like source, HESS J1943+213 located in the Galactic plane. This source coincides with an unidentified hard X-ray source IGR J19443+2117, which was proposed to have radio and infrared counterparts. HESS J1943+213 is detected at the significance level of 7.9 \sigma (post-trials) at RA(J2000)=19h 43m 55s +- 1s (stat) +- 1s (sys), DEC(J2000) = +21deg 18' 8" +- 17" (stat) +- 20" (sys). The source has a soft spectrum with photon index Gamma = 3.1 +- 0.3 (stat) +- 0.2 (sys) and a flux above 470 GeV of 1.3 +- 0.2 (stat) +- 0.3 (sys) x 10^{-12} cm^{-2} s^{-1}. There is no Fermi/LAT counterpart down to a flux limit of 6 x 10^{-9} cm^{-2} s^{-1} in the 0.1-100 GeV energy range (95% confidence upper limit calculated for an assumed power-law model with a photon index Gamma=2.0). The data from radio to VHE gamma-rays do not show any significant variability. We combine new H.E.S.S., Fermi/LAT and Nancay Radio Telescope observations with pre-existing non-simultaneous multi-wavelength observations of IGR J19443+2117 and discuss the likely source associations as well as the interpretation as an active galactic nucleus, a gamma-ray binary or a pulsar wind nebula. The lack of a massive stellar counterpart disfavors the binary hypothesis, while the soft VHE spectrum would be very unusual in case of a pulsar wind nebula. In addition, the distance estimates for Galactic counterparts places them outside of the Milky Way. All available observations favor an interpretation as an extreme, high-frequency peaked BL Lac object with a redshift z>0.14. This would be the first time a blazar is detected serendipitously from ground-based VHE observations, and the first VHE AGN detected in the Galactic Plane., Comment: 10 pages, 7 figures, in press at A&A
Published: 2011
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12. Detection of very-high-energy gamma-ray emission from the vicinity of PSR B1706-44 and G343.1-2.3 with H.E.S.S

Author: Collaboration, H. E. S. S., Abramowski, A., Acero, F., Aharonian, F., Akhperjanian, A. G., Anton, G., Barnacka, A., de Almeida, U. Barres, Bazer-Bachi, A. R., Becherini, Y., Becker, J., Behera, B., Bernlöhr, K., Bochow, A., Boisson, C., Bolmont, J., Bordas, P., Borrel, V., Brucker, J., Brun, F., Brun, P., Bulik, T., Büsching, I., Carrigan, S., Casanova, S., Cerruti, M., Chadwick, P. M., Charbonnier, A., Chaves, R. C. G., Cheesebrough, A., Conrad, J., Chounet, L. -M., Clapson, A. C., Coignet, G., Dalton, M., Daniel, M. K., Davids, I. D., Degrange, B., Deil, C., Dickinson, H. J., Djannati-Ataï, A., Domainko, W., Drury, L. O'C., Dubois, F., Dubus, G., Dyks, J., Dyrda, M., Egberts, K., Eger, P., Espigat, P., Fallon, L., Farnier, C., Fegan, S., Feinstein, F., Fernandes, M. V., Fiasson, A., Förster, A., Fontaine, G., Füßling, M., Gabici, S., Gallant, Y. A., Gast, H., Gérard, L., Gerbig, D., Giebels, B., Glicenstein, J. F., Glück, B., Goret, P., Göring, D., Hague, J. D., Hampf, D., Hauser, M., Heinz, S., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A., Hoffmann, A., Hofmann, W., Hofverberg, P., Holleran, M., Hoppe, S., Horns, D., Jacholkowska, A., de Jager, O. C., Jahn, C., Jamrozy, M., Jung, I., Kastendieck, M. A., Katarzyński, K., Katz, U., Kaufmann, S., Kerschhaggl, M., Khangulyan, D., Khélifi, B., Keogh, D., Kluźniak, W., Kneiske, T., Komin, Nu., Kosack, K., Kossakowski, R., Laffont, H., Lamanna, G., Lemoine-Goumard, M., Lenain, J. -P., Lennarz, D., Lohse, T., Lopatin, A., Lu, C. -C., Marandon, V., Marcowith, A., Masbou, J., Maurin, D., Maxted, N., McComb, T. J. L., Medina, M. C., Méhault, J., Moderski, R., Moulin, E., Naumann-Godo, M., de Naurois, M., Nedbal, D., Nekrassov, D., Nguyen, N., Nicholas, B., Niemiec, J., Nolan, S. J., Ohm, S., Olive, J-F., Wilhelmi, E. de Oña, Opitz, B., Ostrowski, M., Panter, M., Arribas, M. Paz, Pedaletti, G., Pelletier, G., Petrucci, P. -O., Pita, S., Pühlhofer, G., Punch, M., Quirrenbach, A., Raue, M., Rayner, S. M., Reimer, A., Reimer, O., Renaud, M., Reyes, R. de los, Rieger, F., Ripken, J., Rob, L., Rosier-Lees, S., Rowell, G., Rudak, B., Rulten, C. B., Ruppel, J., Ryde, F., Sahakian, V., Santangelo, A., Schlickeiser, R., Schöck, F. M., Schönwald, A., Schwanke, U., Schwarzburg, S., Schwemmer, S., Shalchi, A., Sushch, I., Sikora, M., Skilton, J. L., Sol, H., Spengler, G., Stawarz, Ł., Steenkamp, R., Stegmann, C., Stinzing, F., Szostek, A., Tam, P. H., Tavernet, J. -P., Terrier, R., Tibolla, O., Tluczykont, M., Valerius, K., van Eldik, C., Vasileiadis, G., Venter, C., Vialle, J. P., Viana, A., Vincent, P., Vivier, M., Völk, H. J., Volpe, F., Vorobiov, S., Wagner, S. J., Ward, M., Wierzcholska, A., Zajczyk, A., Zdziarski, A. A., Zech, A., Zechlin, H. -S., Dubner, G., and Giacani, E.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: The gamma-ray pulsar PSR B1706-44 and the adjacent supernova remnant (SNR) candidate G343.1-2.3 were observed by H.E.S.S. during a dedicated observation campaign in 2007. As a result of this observation campaign, a new source of very-high-energy (VHE; E > 100 GeV) gamma-ray emission, HESS J1708-443, was detected with a statistical significance of 7 sigma, although no significant point-like emission was detected at the position of the energetic pulsar itself. In this paper, the morphological and spectral analyses of the newly-discovered TeV source are presented. The centroid of HESS J1708-443 is considerably offset from the pulsar and located near the apparent center of the SNR, at RA(J2000) = 17h08m11s +/- 17s and Dec(J2000) = -44d20' +/- 4'. The source is found to be significantly more extended than the H.E.S.S. point spread function (~0.1 deg), with an intrinsic Gaussian width of 0.29 deg +/- 0.04 deg. Its integral flux between 1 and 10 TeV is ~ 3.8 x 10^-12 ph cm^-2 s^-1, equivalent to 17% of the Crab Nebula flux in the same energy range. The measured energy spectrum is well-fit by a power law with a relatively hard photon index Gamma = 2.0 +/- 0.1 (stat) +/- 0.2 (sys). Additional multi-wavelength data, including 330 MHz VLA observations, were used to investigate the VHE gamma-ray source's possible associations with the pulsar wind nebula of PSR B1706-44 and/or with the complex radio structure of the partial shell-type SNR G343.1-2.3., Comment: 15 pages, 6 figures, 3 tables; Accepted for publication in A&A; v2 paper remains the same, but all authors are now explicitly listed in arXiv entry
Published: 2011
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13. Search for Lorentz Invariance breaking with a likelihood fit of the PKS 2155-304 flare data taken on MJD 53944

Author: HESS Collaboration, Abramowski, A., Acero, F., Aharonian, F., Akhperjanian, A. G., Anton, G., Barnacka, A., de Almeida, U. Barres, Bazer-Bachi, A. R., Becherini, Y., Becker, J., Behera, B., Bernlöhr, K., Bochow, A., Boisson, C., Bolmont, J., Bordas, P., Borrel, V., Brucker, J., Brun, F., Brun, P., Bulik, T., Büsching, I., Bühler, R., Carrigan, S., Casanova, S., Cerruti, M., Chadwick, P. M., Charbonnier, A., Chaves, R. C. G., Cheesebrough, A., Chounet, L. -M., Clapson, A. C., Coignet, G., Conrad, J., Dalton, M., Daniel, M. K., Davids, I. D., Degrange, B., Deil, C., Dickinson, H. J., Djannati-Ataï, A., Domainko, W., Drury, L. O'C., Dubois, F., Dubus, G., Dyks, J., Dyrda, M., Egberts, K., Eger, P., Espigat, P., Fallon, L., Farnier, C., Fegan, S., Feinstein, F., Fernandes, M. V., Fiasson, A., Frster, A., Fontaine, G., Füßling, M., Gallant, Y. A., Gast, H., Gérard, L., Gerbig, D., Giebels, B., Glicenstein, J. F., Glück, B., Goret, P., Göring, D., Hague, J. D., Hampf, D., Hauser, M., Heinz, S., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A., Hoffmann, A., Hofmann, W., Hofverberg, P., Horns, D., Jacholkowska, A., de Jager, O. C., Jahn, C., Jamrozy, M., Jung, I., Kastendieck, M. A., Katarzyński, K., Katz, U., Kaufmann, S., Keogh, D., Kerschhaggl, M., Khangulyan, D., Khélifi, B., Klochkov, D., Kluźniak, W., Kneiske, T., Komin, Nu., Kosack, K., Kossakowski, R., Laffon, H., Lamanna, G., Lennarz, D., Lohse, T., Lopatin, A., Lu, C. -C., Marandon, V., Marcowith, A., Masbou, J., Maurin, D., Maxted, N., McComb, T. J. L., Medina, M. C., Méhault, J., Moderski, R., Moulin, E., Naumann, C. L., Naumann-Godo, M., de Naurois, M., Nedbal, D., Nekrassov, D., Nguyen, N., Nicholas, B., Niemiec, J., Nolan, S. J., Ohm, S., Olive, J-F., Wilhelmi, E. de Oña, Opitz, B., Ostrowski, M., Panter, M., Arribas, M. Paz, Pedaletti1, G., Pelletier, G., Petrucci, P. -O., Pita, S., Pühlhofer, G., Punch, M., Quirrenbach, A., Raue, M., Rayner, S. M., Reimer, A., Reimer, O., Renaud, M., Reyes, R. de los, Rieger, F., Ripken, J., Rob, L., Rosier-Lees, S., Rowell, G., Rudak, B., Rulten, C. B., Ruppel, J., Ryde, F., Sahakian, V., Santangelo, A., Schlickeiser, R., Schöck, F. M., Schönwald, A., Schwanke, U., Schwarzburg, S., Schwemmer, S., Shalchi, A., Sikora, M., Skilton, J. L., Sol, H., Spengler, G., Stawarz, Ł., Steenkamp, R., Stegmann, C., Stinzing, F., Sushch, I., Szostek, A., Tavernet, J. -P., Terrier, R., Tibolla, O., Tluczykont, M., Valerius, K., van Eldik, C., Vasileiadis, G., Venter, C., Vialle, J. P., Viana, A., Vincent, P., Vivier, M., Völk, H. J., Volpe, F., Vorobiov, S., Vorster, M., Wagner, S. J., Ward, M., Wierzcholska, A., Zajczyk, A., Zdziarski, A. A., Zech, A., and Zechlin, H. -S.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, General Relativity and Quantum Cosmology
Abstract: Several models of Quantum Gravity predict Lorentz Symmetry breaking at energy scales approaching the Planck scale (10^{19} GeV). With present photon data from the observations of distant astrophysical sources, it is possible to constrain the Lorentz Symmetry breaking linear term in the standard photon dispersion relations. Gamma-ray Bursts (GRB) and flaring Active Galactic Nuclei (AGN) are complementary to each other for this purpose, since they are observed at different distances in different energy ranges and with different levels of variability. Following a previous publication of the High Energy Stereoscopic System (H.E.S.S.) collaboration, a more sensitive event-by-event method consisting of a likelihood fit is applied to PKS 2155-304 flare data of MJD 53944 (July 28, 2006) as used in the previous publication. The previous limit on the linear term is improved by a factor of ~3 up to M^{l}_{QG} > 2.1x10^{18} GeV and is currently the best result obtained with blazars. The sensitivity to the quadratic term is lower and provides a limit of M^{q}_{QG} > 6.4x10^10 GeV, which is the best value obtained so far with an AGN and similar to the best limits obtained with GRB., Comment: 24 pages, 9 figures. Accepted for publication in Astropart. Phys. Rev1 is the final accepted version (typo corrections)
Published: 2011
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14. H.E.S.S. constraints on Dark Matter annihilations towards the Sculptor and Carina Dwarf Galaxies

Author: HESS Collaboration, Abramowski, A., Acero, F., Aharonian, F., Akhperjanian, A. G., Anton, G., Barnacka, A., de Almeida, U. Barres, Bazer-Bachi, A. R., Becherini, Y., Becker, J., Behera, B., Bernlöhr, K., Bochow, A., Boisson, C., Bolmont, J., Bordas, P., Borrel, V., Brucker, J., Brun, F., Brun, P., Bulik, T., Büsching, I., Carrigan, S., Casanova, S., Cerruti, M., Chadwick, P. M., Charbonnier, A., Chaves, R. C. G., Cheesebrough, A., Chounet, L. -M., Clapson, A. C., Coignet, G., Conrad, J., Dalton, M., Daniel, M. K., Davids, I. D., Degrange, B., Deil, C., Dickinson, H. J., Djannati-Ataï, A., Domainko, W., Drury, L. O'C., Dubois, F., Dubus, G., Dyks, J., Dyrda, M., Egberts, K., Eger, P., Espigat, P., Fallon, L., Farnier, C., Fegan, S., Feinstein, F., Fernandes, M. V., Fiasson, A., Frster, A., Fontaine, G., Füßling, M., Gallant, Y. A., Gast, H., Gérard, L., Gerbig, D., Giebels, B., Glicenstein, J. F., Glück, B., Goret, P., Göring, D., Hague, J. D., Hampf, D., Hauser, M., Heinz, S., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A., Hoffmann, A., Hofmann, W., Hofverberg, P., Horns, D., Jacholkowska, A., de Jager, O. C., Jahn, C., Jamrozy, M., Jung, I., Kastendieck, M. A., Katarzyński, K., Katz, U., Kaufmann, S., Keogh, D., Kerschhaggl, M., Khangulyan, D., Khélifi, B., Klochkov, D., Kluźniak, W., Kneiske, T., Komin, Nu., Kosack, K., Kossakowski, R., Laffon, H., Lamanna, G., Lennarz, D., Lohse, T., Lopatin, A., Lu, C. -C., Marandon, V., Marcowith, A., Masbou, J., Maurin, D., Maxted, N., McComb, T. J. L., Medina, M. C., Méhault, J., Moderski, R., Moulin, E., Naumann, C. L., Naumann-Godo, M., de Naurois, M., Nedbal, D., Nekrassov, D., Nguyen, N., Nicholas, B., Niemiec, J., Nolan, S. J., Ohm, S., Olive, J-F., Wilhelmi, E. de Oña, Opitz, B., Ostrowski, M., Panter, M., Arribas, M. Paz, Pedaletti1, G., Pelletier, G., Petrucci, P. -O., Pita, S., Pühlhofer, G., Punch, M., Quirrenbach, A., Raue, M., Rayner, S. M., Reimer, A., Reimer, O., Renaud, M., Reyes, R. de los, Rieger, F., Ripken, J., Rob, L., Rosier-Lees, S., Rowell, G., Rudak, B., Rulten, C. B., Ruppel, J., Ryde, F., Sahakian, V., Santangelo, A., Schlickeiser, R., Schöck, F. M., Schönwald, A., Schwanke, U., Schwarzburg, S., Schwemmer, S., Shalchi, A., Sikora, M., Skilton, J. L., Sol, H., Spengler, G., Stawarz, Ł., Steenkamp, R., Stegmann, C., Stinzing, F., Sushch, I., Szostek, A., Tavernet, J. -P., Terrier, R., Tibolla, O., Tluczykont, M., Valerius, K., van Eldik, C., Vasileiadis, G., Venter, C., Vialle, J. P., Viana, A., Vincent, P., Vivier, M., Völk, H. J., Volpe, F., Vorobiov, S., Vorster, M., Wagner, S. J., Ward, M., Wierzcholska, A., Zajczyk, A., Zdziarski, A. A., Zech, A., and Zechlin, H. -S.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: The Sculptor and Carina Dwarf spheroidal galaxies were observed with the H.E.S.S. Cherenkov telescope array between January 2008 and December 2009. The data sets consist of a total of 11.8 and 14.8 hours of high quality data, respectively. No gamma-ray signal was detected at the nominal positions of these galaxies above 220 GeV and 320 GeV, respectively. Upper limits on the gamma-ray fluxes at 95% C.L. assuming two forms for the spectral energy distribution (a power law shape and one derived from dark matter annihilation) are obtained at the level of 10^-13 to 10^-12 cm^-2s^-1 in the TeV range. Constraints on the velocity weighted dark matter particle annihilation cross section for both Sculptor and Carina dwarf galaxies range from <\sigma v> ~ 10^-21 cm^3s^-1 down to <\sigma v> ~ 10^-22 cm^3s^-1 depending on the dark matter halo model used. Possible enhancements of the gamma-ray flux are studied: the Sommerfeld effect, which is found to exclude some dark matter particle masses, the internal Bremsstrahlung and clumps in the dark-matter halo distributions., Comment: Accepted for publication on Astroparticle Physics, 25 pages, 12 figures
Published: 2010
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15. Discovery and follow-up studies of the extended, off-plane, VHE gamma-ray source HESS J1507-622

Author: Collaboration, H. E. S. S., Acero, F., Aharonian, F., Akhperjanian, A. G., Anton, G., de Almeida, U. Barres, Bazer-Bachi, A. R., Becherini, Y., Behera, B., Bernlöhr, K., Bochow, A., Boisson, C., Bolmont, J., Borrel, V., Brucker, J., Brun, F., Brun, P., Bühler, R., Bulik, T., Büsching, I., Boutelier, T., Chadwick, P. M., Charbonnier, A., Chaves, R. C. G., Cheesebrough, A., Chounet, L. -M., Clapson, A. C., Coignet, G., Dalton, M., Daniel, M. K., Davids, I. D., Degrange, B., Deil, C., Dickinson, H. J., Djannati-Ataï, A., Domainko, W., Drury, L. O'C., Dubois, F., Dubus, G., Dyks, J., Dyrda, M., Egberts, K., Emmanoulopoulos, D., Espigat, P., Farnier, C., Feinstein, F., Fiasson, A., Förster, A., Fontaine, G., Füssling, M., Gabici, S., Gallant, Y. A., Gérard, L., Gerbig, D., Giebels, B., Glicenstein, J. F., Glück16, B., Goret, P., Göring, D., Hauser, D., Hauser, M., Heinz, S., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A., Hoffmann, A., Hofmann, W., Holleran, M., Hoppe, S., Horns, D., Jacholkowska, A., de Jager, O. C., Jahn, C., Jung, I., Katarzyński, K., Katz, U., Kaufmann, S., Kerschhaggl, M., Khangulyan, D., Khélifi, B., Keogh, D., Klochkov, D., Kluźniak, W., Kneiske, T., Komin, Nu., Kosack, K., Kossakowski, R., Lamanna, G., Lenain, J. -P., Lohse, T., Marandon, V., Martineau-Huynh, O., Marcowith, A., Masbou, J., Maurin, D., McComb, T. J. L., Medina, M. C., Méhault, J., Moderski, R., Moulin, E., Naumann-Godo, M., de Naurois, M., Nedbal, D., Nekrassov, D., Nicholas, B., Niemiec, J., Nolan, S. J., Ohm, S., Olive, J-F., Wilhelmi, E. de Oña, Orford, K. J., Ostrowski, M., Panter, M., Arribas, M. Paz, Pedaletti, G., Pelletier, G., Petrucci, P. -O., Pita, S., Pühlhofer, G., Punch, M., Quirrenbach, A., Raubenheimer, B. C., Raue, M., Rayner, S. M., Reimer, O., Renaud, M., Rieger, F., Ripken, J., Rob, L., Rosier-Lees, S., Rowell, G., Rudak, B., Rulten, C. B., Ruppel, J., Sahakian, V., Santangelo, A., Schlickeiser, R., Schöck, F. M., Schwanke, U., Schwarzburg, S., Schwemmer, S., Shalchi, A., Sikora, M., Skilton, J. L., Sol, H., Stawarz, Ł., Steenkamp, R., Stegmann, C., Stinzing, F., Superina, G., Szostek, A., Tam, P. H., Tavernet, J. -P., Terrier, R., Tibolla, O., Tluczykont, M., van Eldik, C., Vasileiadis, G., Venter, C., Venter, L., Vialle, J. P., Vincent, P., Vivier, M., Völk, H. J., Volpe, F., Wagner, S. J., Ward, M., Zdziarski, A. A., and Zech, A.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: Context: The detection of gamma-rays in the very-high-energy (VHE) range (100 GeV-100 TeV) offers the possibility of studying the parent population of ultrarelativistic particles found in astrophysical sources, so it is useful for understanding the underlying astrophysical processes in nonthermal sources. Aim: The discovery of the VHE gamma-ray source HESS J1507-622 is reported and possibilities regarding its nature are investigated. Methods: The H.E.S.S. array of imaging atmospheric Cherenkov telescopes (IACTs) has a high sensitivity compared with previous instruments (~1% of the Crab flux in 25 hours observation time for a 5 sigma point-source detection) and has a large field of view (~5 deg in diameter). HESS J1507-622 was discovered within the ongoing H.E.S.S. survey of the inner Galaxy, and the source was also studied by means of dedicated multiwavelength observations. Results: A Galactic gamma-ray source, HESS J1507-622, located ~3.5 deg from the Galactic plane was detected with a statistical significance > 9 sigma. Its energy spectrum is well fitted by a power law with spectral index \Gamma = 2.24 +/- 0.16_{stat} +/- 0.20_{sys} and a flux above 1 TeV of (1.5 +/- 0.4_{stat} +/- 0.3_{sys}) X 10^{-12} cm^{-2} s^{-1}. Possible interpretations (considering both hadronic and leptonic models) of the VHE gamma-ray emission are discussed in the absence of an obvious counterpart., Comment: Accepted for publication in A&A
Published: 2010
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16. Revisiting the Westerlund 2 Field with the H.E.S.S. Telescope Array

Author: The HESS Collaboration, Abramowski, A., Acero, F., Aharonian, F., Akhperjanian, A. G., Anton, G., Barnacka, A., de Almeida, U. Barres, Bazer-Bachi, A. R., Becherini, Y., Becker, J., Behera, B., Bernlöhr, K., Bochow, A., Boisson, C., Bolmont, J., Bordas, P., Borrel, V., Brucker, J., Brun, F., Brun, P., Bulik, T., Büsching, I., Boutelier, T., Casanova, S., Cerruti, M., Chadwick, P. M., Charbonnier, A., Chaves, R. C. G., Cheesebrough, A., Conrad, J., Chounet, L. -M., Clapson, A. C., Coignet, G., Dalton, M., Daniel, M. K., Davids, I. D., Degrange, B., Deil, C., Dickinson, H. J., Djannati-Ataï, A., Domainko, W., Drury, L. O'C., Dubois, F., Dubus, G., Dyks, J., Dyrda, M., Egberts, K., Eger, P., Espigat, P., Fallon, L., Farnier, C., Fegan, S., Feinstein, F., Fernandes, M. V., Fiasson, A., Förster, A., Fontaine, G., Füßling, M., Gabici, S., Gallant, Y. A., Gérard, L., Gerbig, D., Giebels, B., Glicenstein, J. F., Glück, B., Goret, P., Göring, D., Hague, J. D., Hampf, D., Hauser, M., Heinz, S., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A., Hoffmann, A., Hofmann, W., Hofverberg, P., Holleran, M., Hoppe, S., Horns, D., Jacholkowska, A., de Jager, O. C., Jahn, C., Jung, I., Katarzyński, K., Katz, U., Kaufmann, S., Kerschhaggl, M., Khangulyan, D., Khélifi, B., Keogh, D., Klochkov, D., Kluźniak24, W., Kneiske, T., Komin, Nu., Kosack, K., Kossakowski, R., Lamanna, G., Lenain, J. -P., Lennarz, D., Lohse, T., Lu, C. -C., Marandon, V., Marcowith, A., Masbou, J., Maurin, D., McComb, T. J. L., Medina, M. C., Méhault, J., Moderski, R., Moulin, E., Naumann-Godo, M., de Naurois, M., Nedbal, D., Nekrassov, D., Nguyen, N., Nicholas, B., Niemiec, J., Nolan, S. J., Ohm, S., Olive, J-F., Wilhelmi, E. de Oña, Opitz, B., Orford, K. J., Ostrowski, M., Panter, M., Arribas, M. Paz, Pedaletti1, G., Pelletier, G., Petrucci, P. -O., Pita1, S., Pühlhofer, G., Punch, M., Quirrenbach, A., Raue, M., Rayner, S. M., Reimer, A., Reimer, O., Renaud, M., Reyes, R. de los, Rieger1, F., Ripken, J., Rob, L., Rosier-Lees, S., Rowell, G., Rudak, B., Rulten, C. B., Ruppel, J., Ryde, F., Sahakian, V., Santangelo, A., Schlickeiser, R., Schöck, F. M., Schönwald, A., Schwanke, U., Schwarzburg, S., Schwemmer, S., Shalchi, A., Sushch, I., Sikora, M., Skilton, J. L., Sol, H., Spengler, G., Stawarz, Ł., Steenkamp, R., Stegmann, C., Stinzing, F., Szostek, A., Tam, P. H., Tavernet, J. -P., Terrier, R., Tibolla, O., Tluczykont, M., Valerius, K., van Eldik, C., Vasileiadis, G., Venter, C., Vialle, J. P., Viana, A., Vincent, P., Vivier, M., Völk, H. J., Volpe, F., Vorobiov, S., Wagner, S. J., Ward, M., Zdziarski, A. A., Zech, A., Zechlin, H. -S., Fukui, Y., Furukawa, N., Ohama, A., Sano, H., Dawson, J., and Kawamura, A.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: Aims. Previous observations with the H.E.S.S. telescope array revealed the existence of extended very-high-energy (VHE; E>100 GeV) {\gamma}-ray emission, HESS J1023-575, coincident with the young stellar cluster Westerlund 2. At the time of discovery, the origin of the observed emission was not unambiguously identified, and follow-up observations have been performed to further investigate the nature of this {\gamma}-ray source. Methods. The Carina region towards the open cluster Westerlund 2 has been re-observed, increasing the total exposure to 45.9 h. The combined dataset includes 33 h of new data and now permits a search for energy-dependent morphology and detailed spectroscopy. Results. A new, hard spectrum VHE {\gamma}-ray source, HESSJ1026-582, was discovered with a statistical significance of 7{\sigma}. It is positionally coincident with the Fermi LAT pulsar PSR J1028-5819. The positional coincidence and radio/{\gamma}-ray characteristics of the LAT pulsar favors a scenario where the TeV emission originates from a pulsar wind nebula. The nature of HESS J1023-575 is discussed in light of the deep H.E.S.S. observations and recent multi-wavelength discoveries, including the Fermi LAT pulsar PSRJ1022-5746 and giant molecular clouds in the region. Despite the improved VHE dataset, a clear identification of the object responsible for the VHE emission from HESS J1023-575 is not yet possible, and contribution from the nearby high-energy pulsar and/or the open cluster remains a possibility., Comment: Accepted for publication on A&A
Published: 2010
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17. Discovery of VHE gamma-rays from the BL Lac object PKS 0548-322

Author: collaboration, H. E. S. S., Aharonian, F., Akhperjanian, A. G., Anton, G., de Almeida, U. Barres, Bazer-Bachi, A. R., Becherini, Y., Behera, B., Benbow, W., Bernlöhr, K., Bochow, A., Boisson, C., Bolmont, J., Borrel, V., Brucker, J., Brun, F., Brun, P., Bühler, R., Bulik, T., Büsching, I., Boutelier, T., Chadwick, P. M., Charbonnier, A., Chaves, R. C. G., Cheesebrough, A., Chounet, L. -M., Clapson, A. C., Coignet, G., Dalton, M., Daniel, M. K., Davids, I. D., Degrange, B., Deil, C., Dickinson, H. J., Djannati-Ataï, A., Domainko, W., Drury, L. O'C., Dubois, F., Dubus, G., Dyks, J., Dyrda, M., Egberts, K., Emmanoulopoulos, D., Espigat, P., Farnier, C., Feinstein, F., Fiasson, A., Förster, A., Fontaine, G., Füssling, M., Gabici, S., Gallant, Y. A., Gérard, L., Gerbig, D., Giebels, B., Glicenstein, J. F., Glück, B., Goret, P., Göring, D., Hauser, D., Hauser, M., Heinz, S., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A., Hoffmann, A., Hofmann, W., Holleran, M., Hoppe, S., Horns, D., Jacholkowska, A., de Jager, O. C., Jahn, C., Jung, I., Katarzyński, K., Katz, U., Kaufmann, S., Kendziorra, E., Kerschhagg, M., Khangulyan, D., Khélifi, B., Keogh, D., Kluźniak, W., Kneiske, T., Komin, Nu., Kosack, K., Lamanna, G., Lenain, J. -P., Lohse, T., Marandon, V., Martin, J. M., Martineau-Huynh, O., Marcowith, A., Masbou, J., Maurin, D., McComb, T. J. L., Medina, M. C., Moderski, R., Moulin, E., Naumann-Godo, M., de Naurois, M., Nedbal, D., Nekrassov, D., Nicholas, B., Niemiec, J., Nolan, S. J., Ohm, S., Olive, J-F., Wilhelm, E. de Oña, Orford, K. J., Ostrowski, M., Panter, M., Arribas, M. Paz, Pedaletti, G., Pelletier, G., Petrucci, P. -O., Pita, S., Pühlhofer, G., Punch, M., Quirrenbach, A., Raubenheimer, B. C., Raue, M., Rayner, S. M., Renaud, M., Rieger, F., Ripken, J., Rob, L., Rosier-Lees, S., Rowell, G., Rudak, B., Rulten, C. B., Ruppel, J., Sahakian, V., Santangelo, A., Schlickeiser, R., Schöck, F. M., Schröder, R., Schwanke, U., Schwarzburg, S., Schwemmer, S., Shalchi, A., Sikora, M., Skilton, J. L., Sol, H., Spangler, D., Stawarz, L., Steenkamp, R., Stegmann, C., Stinzing, F., Superina, G., Szostek, A., Tam, P. H., Tavernet, J. -P., Terrier, R., Tibolla, O., Tluczykont, M., van Eldik, C., Vasileiadis, G., Venter, C., Venter, L., Vialle, J. P., Vincent, P., Vivier, M., Völk, H. J., Volp, F., Wagner, S. J., Ward, M., Zdziarski, A. A., and Zech, A.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: PKS 0548-322 (z=0.069) is a ``high-frequency-peaked'' BL Lac object and a candidate very high energy (VHE, E>100 GeV) gamma-ray emitter, due to its high X-ray and radio flux. Observations at the VHE band provide insights into the origin of very energetic particles present in this source and the radiation processes at work. We report observations made between October 2004 and January 2008 with the H.E.S.S. array, a four imaging atmospheric-Cherenkov telescopes. Contemporaneous UV and X-ray observations with the Swift satellite in November 2006 are also reported. PKS 0548-322 is detected for the first time in the VHE band with H.E.S.S. We measure an excess of 216 gamma-rays corresponding to a significance of 5.6 standard deviations. The photon spectrum of the source is described by a power-law, with a photon index of Gamma=2.86 +/- 0.34 (stat) +/- 0.10 (sys). The integral flux above 200 GeV is 1.3 % of the flux of the Crab Nebula, and is consistent with being constant in time. Contemporaneous Swift/XRT observations reveal an X-ray flux between 2 and 10 keV of F_{2-10 keV}=2.3 +/- 0.2 x 10^{-11} erg.cm^{-2}. s^{-1}, an intermediate intensity state with respect to previous observations. The spectral energy distribution can be reproduced using a simple one-zone synchrotron self Compton model, with parameters similar those observed for other sources of this type., Comment: 6 pages, 3 figures, Accepted for publication in Astronomy and Astrophysics
Published: 2010
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18. VHE gamma-ray emission of PKS 2155-304: spectral and temporal variability

Author: HESS Collaboration, Abramowski, A., Acero, F., Aharonian, F., Akhperjanian, A. G., Anton, G., de Almeida, U. Barres, Bazer-Bachi, A. R., Becherini, Y., Behera, B., Benbow, W., Bernlohr, K., Bochow, A., Boisson, C., Bolmont, J., Borrel, V., Brucker, J., Brun, F., Brun, P., Buhler, R., Bulik, T., Busching, I., Boutelier, T., Chadwick, P. M., Charbonnier, A., Chaves, R. C. G., Cheesebrough, A., Conrad, J., Chounet, L. -M., Clapson, A. C., Coignet, G., Costamante, L., Dalton, M., Daniel, M. K., Davids, I. D., Degrange, B., Deil, C., Dickinson, H. J., Djannati-Atai, A., Domainko, W., Drury, L. O'C., Dubois, F., Dubus, G., Dyks, J., Dyrda, M., Egberts, K., Eger, P., Espigat, P., Fallon, L., Farnier, C., Fegan, S., Feinstein, F., Fernandes, M. V., Fiasson, A., Foerster, A., Fontaine, G., Fussling, M., Gabici, S., Gallant, Y. A., Gerard, L., Gerbig, D., Giebels, B., Glicenstein, J. F., Glueck, B., Goret, P., Goering, D., Hampf, D., Hauser, M., Heinz, S., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A., Hoffmann, A., Hofmann, W., Hofverberg, P., Holleran, M., Hoppe, S., Horns, D., Jacholkowska, A., de Jager, O. C., Jahn, C., Jung, I., Katarzynski, K., Katz, U., Kaufmann, S., Kerschhaggl, M., Khangulyan, D., Khelifi, B., Keogh, D., Klochkov, D., Kluzniak, W., Kneiske, T., Komin, Nu., Kosack, K., Kossakowski, R., Lamanna, G., Lenain, J. -P., Lohse, T., Lu, C. -C., Marandon, V., Marcowith, A., Masbou, J., Maurin, D., McComb, T. J. L., Medina, M. C., Mehault, J., Moderski, R., Moulin, E., Naumann-Godo, M., de Naurois, M., Nedbal, D., Nekrassov, D., Nguyen, N., Nicholas, B., Niemiec, J., Nolan, S. J., Ohm, S., Olive, J-F., Wilhelmi, E. de Ona, Opitz, B., Orford, K. J., Ostrowski, M., Panter, M., Arribas, M. Paz, Pedaletti, G., Pelletier, G., Petrucci, P. -O., Pita, S., Puehlhofer, G., Punch, M., Quirrenbach, A., Raubenheimer, B. C., Raue, M., Rayner, S. M., Reimer, O., Renaud, M., Reyes, R. de los, Rieger, F., Ripken, J., Rob, L., Rosier-Lees, S., Rowell, G., Rudak, B., Rulten, C. B., Ruppel, J., Ryde, F., Sahakian, V., Santangelo, A., Schlickeiser, R., Schoeck, F. M., Schoenwald, A., Schwanke, U., Schwarzburg, S., Schwemmer, S., Shalchi, A., Sushch, I., Sikora, M., Skilton, J. L., Sol, H., Stawarz, L., Steenkamp, R., Stegmann, C., Stinzing, F., Superina, G., Szostek, A., Tam, P. H., Tavernet, J. -P., Terrier, R., Tibolla, O., Tluczykont, M., Valerius, K., van Eldik, C., Vasileiadis, G., Venter, C., Venter, L., Vialle, J. P., Viana, A., Vincent, P., Vivier, M., Voelk, H. J., Volpe, F., Vorobiov, S., Wagner, S. J., Ward, M., Zdziarski, A. A., Zech, A., and Zechlin, H. -S.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: Observations of very high energy gamma-rays from blazars provide information about acceleration mechanisms occurring in their innermost regions. Studies of variability in these objects allow a better understanding of the mechanisms at play. To investigate the spectral and temporal variability of VHE (>100 GeV) gamma-rays of the well-known high-frequency-peaked BL Lac object PKS 2155-304 with the H.E.S.S. imaging atmospheric Cherenkov telescopes over a wide range of flux states. Data collected from 2005 to 2007 are analyzed. Spectra are derived on time scales ranging from 3 years to 4 minutes. Light curve variability is studied through doubling timescales and structure functions, and is compared with red noise process simulations. The source is found to be in a low state from 2005 to 2007, except for a set of exceptional flares which occurred in July 2006. The quiescent state of the source is characterized by an associated mean flux level of 4.32 +/-0.09 x 10^-11 cm^-2 s^-1 above 200 GeV, or approximately 15% of the Crab Nebula, and a power law photon index of 3.53 +/-0.06. During the flares of July 2006, doubling timescales of ~2 min are found. The spectral index variation is examined over two orders of magnitude in flux, yielding different behaviour at low and high fluxes,which is a new phenomenon in VHE gamma-ray emitting blazars. The variability amplitude characterized by the fractional r.m.s. is strongly energy-dependent and is proportional to E^(0.19 +/- 0.01). The light curve r.m.s. correlates with the flux. This is the signature of a multiplicative process which can be accounted for as a red noise with a Fourier index of ~2. This unique data set shows evidence for a low level gamma-ray emission state from PKS 2155-304, which possibly has a different origin than the outbursts. The discovery of the light curve lognormal behaviour might be an indicator .., Comment: 17 pages, 13 figures, Accepted for publication to Astronomy & Astrophysics
Published: 2010
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19. First detection of VHE gamma-rays from SN 1006 by H.E.S.S

Author: HESS Collaboration, Acero, F., Aharonian, F., Akhperjanian, A. G., Anton, G., de Almeida, U. Barres, Bazer-Bachi, A. R., Becherini, Y., Behera, B., Beilicke, M., Bernlöhr, K., Bochow, A., Boisson, C., Bolmont, J., Borrel, V., Brucker, J., Brun, F., Brun, P., Bühler, R., Bulik, T., Büsching, I., Boutelier, T., Chadwick, P. M., Charbonnier, A., Chaves, R. C. G., Cheesebrough, A., Conrad, J., Chounet, L. -M., Clapson, A. C., Coignet, G., Dalton, M., Daniel, M. K., Davids, I. D., Degrange, B., Deil, C., Dickinson, H. J., Djannati-Ataï, A., Domainko, W., Drury, L. O'C., Dubois, F., Dubus, G., Dyks, J., Dyrda, M., Egberts, K., Eger, P., Espigat, P., Fallon, L., Farnier, C., Fegan, S., Feinstein, F., Fiasson, A., Förster, A., Fontaine, G., Füßling, M., Gabici, S., Gallant, Y. A., Gérard, L., Gerbig, D., Giebels, B., Glicenstein, J. F., Glück, B., Goret, P., Göring, D., Hauser, D., Hauser, M., Heinz, S., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A., Hoffmann, A., Hofmann, W., Hofverberg, P., Holleran, M., Hoppe, S., Horns, D., Jacholkowska, A., de Jager, O. C., Jahn, C., Jung, I., Katarzy'nski, K., Katz, U., Kaufmann, S., Kerschhaggl, M., Khangulyan, D., Khélifi, B., Keogh, D., Klochkov, D., Klu'zniak, W., Kneiske, T., Komin, Nu., Kosack, K., Kossakowski, R., Lamanna, G., Lemoine-Goumard, M., Lenain, J. -P., Lohse, T., Marandon, V., Marcowith, A., Masbou, J., Maurin, D., McComb, T. J. L., Medina, M. C., Méhault, J., Moulin, E., Naumann-Godo, M., de Naurois, M., Nedbal, D., Nekrassov, D., Nicholas, B., Niemiec, J., Nolan, S. J., Ohm, S., Olive, J-F., Orford, E. de Ona Wilhelmi K. J., Ostrowski, M., Panter, M., Pedaletti, M. Paz Arribas G., Pelletier, G., Petrucci, P. -O., Pita, S., Pühlhofer, 12 G., Punch, M., Quirrenbach, A., Raubenheimer, B. C., Raue, M., Rayner, S. M., Reimer, O., Renaud, M., Reyes, R. de los, Rieger, F., Ripken, J., Rob, L., Rosier-Lees, S., Rowell, G., Rudak, B., Rulten, C. B., Ruppel, J., Ryde, F., Sahakian, V., Santangelo, A., Schlickeiser, R., Schöck, F. M., Schönwald, A., Schwanke, U., Schwarzburg, S., Schwemmer, S., Shalchi, A., Sushch, I., Sikora, M., Skilton, J. L., Sol, H., Stawarz, Ł., Steenkamp, R., Stegmann, C., Stinzing, F., Superina, G., Szostek, A., Tam, P. H., Tavernet, J. -P., Terrier, R., Tibolla, O., Tluczykont, M., van Eldik, C., Vasileiadis, G., Venter, C., Venter, L., Vialle, J. P., Vincent, P., Vink, J., Vivier, M., Völk, H. J., Volpe, F., Vorobiov, S., Wagner, S. J., Ward, M., Zdziarski, A. A., and Zech, A.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Galaxy Astrophysics
Abstract: Recent theoretical predictions of the lowest very high energy (VHE) luminosity of SN 1006 are only a factor 5 below the previously published H.E.S.S. upper limit, thus motivating further in-depth observations of this source. Deep observations at VHE energies (above 100 GeV) were carried out with the High Energy Stereoscopic System (H.E.S.S.) of Cherenkov Telescopes from 2003 to 2008. More than 100 hours of data have been collected and subjected to an improved analysis procedure. Observations resulted in the detection of VHE gamma-rays from SN 1006. The measured gamma-ray spectrum is compatible with a power-law, the flux is of the order of 1% of that detected from the Crab Nebula, and is thus consistent with the previously established H.E.S.S. upper limit. The source exhibits a bipolar morphology, which is strongly correlated with non-thermal X-rays. Because the thickness of the VHE-shell is compatible with emission from a thin rim, particle acceleration in shock waves is likely to be the origin of the gamma-ray signal. The measured flux level can be accounted for by inverse Compton emission, but a mixed scenario that includes leptonic and hadronic components and takes into account the ambient matter density inferred from observations also leads to a satisfactory description of the multi-wavelength spectrum., Comment: 7 pages, 8 figures, accepted for publication in A&A
Published: 2010
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20. Multi-wavelength Observations of H 2356-309

Author: HESS Collaboration, Abramowski, A., Acero, F., Aharonian, F., Akhperjanian, A. G., Anton, G., de Almeida, U. Barres, Bazer-Bachi, A. R., Becherini, Y., Behera, B., Benbow, W., Bernloehr, K., Bochow, A., Boisson, C., Bolmont, J., Borrel, V., Brucker, J., Brun, F., Brun, P., Buehler, R., Bulik, T., Buesching, I., Boutelier, T., Chadwick, P. M., Charbonnier, A., Chaves, R. C. G., Cheesebrough, A., Conrad, J., Chounet, L. -M., Clapson, A. C., Coignet, G., Costamante, L., Dalton, M., Daniel, M. K., Davids, I. D., Degrange, B., Deil, C., Dickinson, H. J., Djannati-Atai, A., Domainko, W., Drury, L. O'C., Dubois, F., Dubus, G., Dyks, J., Dyrda, M., Egberts, K., Eger, P., Espigat, P., Fallon, L., Farnier, C., Fegan, S., Feinstein, F., Fernandes, M. V., Fiasson, A., Foerster, A., Fontaine, G., Fuessling, M., Gabici, S., Gallant, Y. A., Gerard, L., Gerbig, D., Giebels, B., Glicenstein, J. F., Glueck, B., Goret, P., Goering, D., Hampf, D., Hauser, M., Heinz, S., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A., Hoffmann, A., Hofmann, W., Hofverberg, P., Holleran, M., Hoppe, S., Horns, D., Jacholkowska, A., de Jager, O. C., Jahn, C., Jung, I., Katarzynski, K., Katz, U., Kaufmann, S., Kerschhaggl, M., Khangulyan, D., Khelifi, B., Keogh, D., Klochkov, D., Kluzniak, W., Kneiske, T., Komin, Nu., Kosack, K., Kossakowski, R., Lamanna, G., Lenain, J. -P., Lohse, T., Lu, C. -C., Marandon, V., Marcowith, A., Masbou, J., Maurin, D., McComb, T. J. L., Medina, M. C., Mehault, J., Moderski, R., Moulin, E., Naumann-Godo, M., de Naurois, M., Nedbal, D., Nekrassov, D., Nguyen, N., Nicholas, B., Niemiec, J., Nolan, S. J., Ohm, S., Olive, J-F., Wilhelmi, E. de Ona, Opitz, B., Orford, K. J., Ostrowski, M., Panter, M., Arribas, M. Paz, Pedaletti, G., Pelletier, G., Petrucci, P. -O., Pita, S., Puehlhofer, G., Punch, M., Quirrenbach, A., Raubenheimer, B. C., Raue, M., Rayner, S. M., Reimer, O., Renaud, M., Reyes, R. de los, Rieger, F., Ripken, J., Rob, L., Rosier-Lees, S., Rowell, G., Rudak, B., Rulten, C. B., Ruppel, J., Ryde, F., Sahakian, V., Santangelo, A., Schlickeiser, R., Schoeck, F. M., Schoenwald, A., Schwanke, U., Schwarzburg, S., Schwemmer, S., Shalchi, A., Sushch, I., Sikora, M., Skilton, J. L., Sol, H., Stawarz, L., Steenkamp, R., Stegmann, C., Stinzing, F., Szostek, A., Tam, P. H., Tavernet, J. -P., Terrier, R., Tibolla, O., Tluczykont, M., Valerius, K., van Eldik, C., Vasileiadis, G., Venter, C., Venter, L., Vialle, J. P., Viana, A., Vincent, P., Vivier, M., Voelk, H. J., Volpe, F., Vorobiov, S., Wagner, S. J., Ward, M., Zdziarski, A. A., Zech, A., and Zechlin, H. -S.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: AIMS: The properties of the broad-band emission from the high-frequency peaked BL Lac H 2356-309 (z=0.165) are investigated. METHODS: Very High Energy (VHE; E > 100 GeV) observations of H 2356-309 were performed with the High Energy Stereoscopic System (HESS) from 2004 through 2007. Simultaneous optical/UV and X-ray observations were made with the XMM-Newton satellite on June 12/13 and June 14/15, 2005. NRT radio observations were also contemporaneously performed in 2005. ATOM optical monitoring observations were also made in 2007. RESULTS: A strong VHE signal, ~13 sigma total, was detected by HESS after the four years HESS observations (116.8 hrs live time). The integral flux above 240 GeV is I(>240 GeV) = (3.06 +- 0.26 {stat} +- 0.61 {syst}) x 10^{-12} cm^{-2} s^{-1}, corresponding to ~1.6% of the flux observed from the Crab Nebula. A time-averaged energy spectrum is measured from 200 GeV to 2 TeV and is characterized by a power law (photon index of Gamma = 3.06 +- 0.15 {stat} +- 0.10 {syst}). Significant small-amplitude variations in the VHE flux from H 2356-309 are seen on time scales of months and years, but not on shorter time scales. No evidence for any variations in the VHE spectral slope are found within these data. The XMM-Newton X-ray measurements show a historically low X-ray state, characterized by a hard, broken-power-law spectrum on both nights. CONCLUSIONS: The broad-band spectral energy distribution (SED) of the blazar can be adequately fit using a simple one-zone synchrotron self-Compton (SSC) model. In the SSC scenario, higher VHE fluxes could be expected in the future since the observed X-ray flux is at a historically low level., Comment: 11 pages; 13 figures; Accepted for publication in Astronomy & Astrophysics; Figure 8 (SED) updated from V1 to have erroneously plotted optical point (without host galaxy subtracted) removed.
Published: 2010
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21. Temporal and spectral gamma-ray properties of Mkn421 above 250 GeV from CAT observations between 1996 and 2000

Author: Piron, F., Djannati-Atai, A., Punch, M., Tavernet, J. -P., Barrau, A., Bazer-Bachi, R., Chounet, L. -M., Debiais, G., Degrange, B., Dezalay, J. -P., Espigat, P., Fabre, B., Fleury, P., Fontaine, G., Goret, P., Gouiffes, C., Khelifi, B., Malet, I., Masterson, C., Mohanty, G., Nuss, E., Renault, C., Rivoal, M., Rob, L., and Vorobiov, S.
Subjects: Astrophysics
Abstract: The gamma-ray emission above 250 GeV from the BL Lac object Markarian 421 was observed by the CAT Cherenkov imaging telescope between December, 1996, and June, 2000. In 1998, the source produced a series of small flares, making it the second extragalactic source detected by CAT. The time-averaged differential spectrum has been measured from 0.3 to 5 TeV, which is well fitted with a power law with an index of -2.88+-0.12(stat)+-0.06(syst). In 2000, the source showed an unprecedented activity, with variability time-scales as short as one hour, as for instance observed during the night between 4 and 5 February. The 2000 time-averaged spectrum measured is compatible with that of 1998, but some indication of a spectral curvature is found between 0.3 and 5 TeV. The possibility of TeV spectral hardening during flares is also discussed, and the results are compared to those obtained on the other TeV BL Lac, Markarian 501., Comment: Latex2e, 11 pages, 7 figures, accepted for publication in Astronomy & Astrophysics
Published: 2001
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22. Very High Energy Gamma-ray spectral properties of Mrk 501 from CAT Cerenkov telescope observations in 1997

Author: Djannati-Atai, A., Piron, F., Barrau, A., Iacoucci, L., Punch, M., Tavernet, J. -P., Bazer-Bachi, R., Cabot, H., Chounet, L. -M., Debiais, G., Degrange, B., Dezalay, J. -P., Dumora, D., Espigat, P., Fabre, B., Fleury, P., Fontaine, G., Ghesquière, C., Goret, P., Gouiffes, C., Grenier, I. A., Bohec, S. Le, Malet, I., Meynadier, C., Mohanty, G., Nuss, E., Paré, E., Québert, J., Ragan, K., Renault, C., Rivoal, M., Rob, L., Schahmaneche, K., and Smith, D. A.
Subjects: Astrophysics
Abstract: The BL Lac object Mrk 501 went into a very high state of activity during 1997, both in VHE gamma-rays and X-rays. We present here results from observations at energies above 250 GeV carried out between March and October 1997 with the CAT Cerenkov imaging Telescope. The average differential spectrum between 30 GeV and 13 TeV shows significant curvature and is well represented by phi_0 * E_TeV^{-(alpha + beta*log10(E_TeV))}, with: phi_0 = 5.19 +/- 0.13 {stat} +/- 0.12 {sys-MC} +1.66/-1.04 {sys-atm} * 10^-11 /cm^2/s/TeV alpha = 2.24 +/- 0.04 {stat} +/- 0.05 {sys} beta = 0.50 +/- 0.07 {stat} (negligible systematics). The TeV spectral energy distribution of Mrk 501 clearly peaks in the range 500 GeV-1 TeV. Investigation of spectral variations shows a significant hardness-intensity correlation with no measurable effect on the curvature. This can be described as an increase of the peak TeV emission energy with intensity. Simultaneous and quasi-simultaneous CAT VHE gamma-ray and BeppoSAX hard X-ray detections for the highest recorded flare on 16th April and for lower-activity states of the same period show correlated variability with a higher luminosity in X-rays than in gamma-rays. The observed spectral energy distribution and the correlated variability between X-rays and gamma-rays, both in amplitude and in hardening of spectra, favour a two-component emission scheme where the low and high energy components are attributed to synchrotron and inverse Compton (IC) radiation, respectively., Comment: Submitted to Astronomy and Astrophysics, 8 pages including 6 figures. Published with minor changes
Published: 1999

23. A new analysis method for very high definition Imaging Atmospheric Cherenkov Telescopes as applied to the CAT telescope

Author: Bohec, S. Le, Degrange, B., Punch, M., Barrau, A., Bazer-Bachi, R., Cabot, H., Chounet, L. M, Debiais, G., Dezalay, J. P., Djannati-Atai, A., Dumora, D., Espigat, P., Fabre, B., Fleury, P., Fontaine, G., George, R., Ghesquiere, C., Goret, P., Gouiffes, C., Grenier, I. A., Iacoucci, L., Malet, I., Meynadier, C., Munz, F., Palfrey, T. A., Pare, E., Pons, Y., Quebert, J., Ragan, K., renault, C., Rivoal, M., Rob, L., Schovaneck, P., Smith, D., Tavernet, J. P., and Vrana, J.
Subjects: Astrophysics, High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract: A new method of shower-image analysis is presented which appears very powerful as applied to those Cherenkov Imaging Telescopes with very high definition imaging capability. It provides hadron rejection on the basis of a single cut on the image shape, and simultaneously determines the energy of the electromagnetic shower and the position of the shower axis with respect to the detector. The source location is also reconstructed for each individual gamma-ray shower, even with one single telescope, so for a point source the hadron rejection can be further improved. As an example, this new method is applied to data from the CAT (Cherenkov Array at Themis) imaging telescope, which has been operational since Autumn, 1996., Comment: 22 pages. submitted to Elsevier Preprint
Published: 1998
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24. The CAT Imaging Telescope for Very-High-Energy Gamma-Ray Astronomy

Author: Barrau, A., Bazer-Bachi, R., Beyer, E., Cabot, H., Cerutti, M., Chounet, L. M., Debiais, G., Degrange, B., Delchini, H., Denance, J. P., Descotes, G., Dezalay, J. P., Djannati-Atai, A., Dumora, D., Espigat, P., Fabre, B., Fleury, P., Fontaine, G., George, R., Ghesquiere, C., Gilly, J., Goret, P., Gouiffes, C., Gouillaud, J. C., Gregory, C., Grenier, I. A., Iacoucci, L., Kalt, L., Bohec, S. Le, Malet, I., Meynadier, C., Mols, J. P., de Freitas, P. Mora, Morano, R., Morinaud, G., Munz, F., Palatka, M., Palfrey, T. A., Pare, E., Pons, Y., Punch, M., Quebert, J., Ragan, K., Renault, C., Rivoal, M., Rob, L., Schovanek, P., Smith, D., Tabary, A., Tavernet, J. P., Toussenel, F., and Vrana, J.
Subjects: Astrophysics, High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract: The CAT (Cherenkov Array at Themis) imaging telescope, equipped with a very-high-definition camera (546 fast phototubes with 0.12 degrees spacing surrounded by 54 larger tubes in two guard rings) started operation in Autumn 1996 on the site of the former solar plant Themis (France). Using the atmospheric Cherenkov technique, it detects and identifies very high energy gamma-rays in the range 250 GeV to a few tens of TeV. The instrument, which has detected three sources (Crab nebula, Mrk 421 and Mrk 501), is described in detail., Comment: 24 pages, 15 figures. submitted to Elsevier Preprint
Published: 1998
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25. Spectrum and Variability of Mrk501 as observed by the CAT Imaging Telescope

Author: Barrau, A., Bazer-Bachi, R., Cabot, H., Chounet, L. M., Debiais, G., Degrange, B., Dezalay, J. P., Djannati-Atai, A., Dumora, D., Espigat, P., Fabre, B., Fleury, P., Fontaine, G., George, R., ghesquiere, C., Goret, P., Gouiffes, C., Grenier, I. A., Iacoucci, L., Bohec, S. Le, Malet, I., Meynadier, C., Munz, P., Palfrey, T. A., Pare, E., Pons, Y., Punch, M., Quebert, J., Ragan, K., Renault, C., Rivoal, M., Rob, L., Schovanek, P., Smith, D., Tavernet, J. P., and Vrana, J.
Subjects: Astrophysics
Abstract: The CAT Imaging Telescope has observed the BL Lac object Markarian 501 between March and August 1997. We report here on the variability over this time including several large flares. We present also preliminary spectra for all these data, for the low emission state, and for the largest flare., Comment: 4 pages, 4 figures, Latex
Published: 1997

26. Performances of the CAT imaging telescope and some preliminary results on Mkn 180 and the Crab

Author: Barrau, A., Bazer-Bachi, R., Cabot, H., Chounet, L. M., Debiais, G., Degrange, B., Dezalay, J. P., Djannati-Atai, A., Dumora, D., Espigat, P., Fabre, B., Fleury, P., Fontaine, G., George, R., Ghesquiere, C., Goret, P., Gouiffes, C., Grenier, I. A., Iacoucci, L., Bohec, S. Le, Malet, I., Meynadier, C., Munz, P., Palfrey, T. A., Pare, E., Pons, Y., Punch, M., Quebert, J., Ragan, K., Renault, C., Rivoal, M., Rob, L., Schovanek, P., Smith, D., Tavernet, J. P., and Vrana, J.
Subjects: Astrophysics
Abstract: The CAT imaging telesope, which uses the Atmospheric Cherenkov Technique to observe TeV gamma-ray sources, has been operating since September 1996. Located in southern France, it features a fine grained camera consisting of 546 PMT with a pixel size of 0.12 degrees. Strong gamma-ray signals from Mkn 501 above 200 GeV were detected during observations made in April 1997. The high signal/noise ratio for these data enables direct characterization of the gamma-ray images as recorded in the camera. These results are used to validate the Monte-Carlo simulations of the response of the telescope to gamma-ray showers and to improve its performances. Observational results on Mkn 180 and the Crab nebula spectrum are presented., Comment: 6 pages, 3 figures, Latex
Published: 1997

27. Detection of Vhe Gamma-Rays from MRK 501 with the Cat Imaging Telescope

Author: Barrau, A., Bazer-Bachi, R., Cabot, H., Chounet, L. M., Debiais, G., Degrange, B., Dezalay, J. P., Djannati-Atai, A., Dumora, D., Espigat, P., Fabre, B., Fleury, P., Fontaine, G., George, R., Ghesquiere, C., Goret, P., Gouiffes, C., Grenier, I. A., Iacoucci, L., Bohec, S. Le, Mallet, I., Meynadier, C., Munz, F., Palfrey, T. A., Pare, E., Pons, Y., Punch, M., Quebert, J., Ragan, K., Renault, C., Rivoal, M., Rob, L., Schovanek, P., Smith, D., Tavernet, J. P., and Vrana, J.
Subjects: Astrophysics
Abstract: The CAT imaging telescope on the site on the former solar plant Themis has been observing gamma-rays from Mrk501 above 220 GeV in March and April 1997. This source is shown to be highly variable and the light curve is presented. The detected gamma-ray rate for the most intense flare is in excess of 10 per minute., Comment: 5 pages, 4 figures, Tex, contribution to 25th ICRC Durban
Published: 1997

28. The CAT Imaging Telescope

Author: Barrau, A., Bazer-Bachi, R., Cabot, H., Chounet, L. M., Debiais, G., Degrange, B., Dezalay, J. P., Djannati-Atai, A., Dumora, D., Espigat, P., Fabre, B., Fleury, P., Fontaine, G., George, R., Ghesquiere, C., Goret, P., Gouiffes, C., Grenier, I. A., Iacoucci, L., Bohec, S. Le, Mallet, I., Meynadier, C., Munz, F., Palfrey, T. A., Pare, E., Pons, Y., Punch, M., Quebert, J., Ragan, K., Renault, C., Rivoal, M., Rob, L., Schovanek, P., Smith, D., Tavernet, J. P., and Vrana, J.
Subjects: Astrophysics
Abstract: The VHE gamma-ray imaging telescope CAT started taking data in October 1996. Located at the Themis solar site in southern France, it features a 17.7 m^2 Davies-Cotton mirror equipped with 600 PMT camera at the focal plane. The mechanics and optics, the PMTs and the electronics are presented. The performance, based on the first 7 months of operation, is discribed., Comment: 4 pages, 2 figures, Tex, contribution to 25th ICRC Durban
Published: 1997

29. Observation of the Crab Nebula Gamma-Ray Emission Above 220 Gev by the Cat Cherenkov Imaging Telescope

Author: Barrau, A., Bazer-Bachi, R., Cabot, H., Chounet, L. M., Debiais, G., Degrange, B., Dezalay, J. P., Djannati-Atai, A., Dumora, D., Espigat, P., Fabre, B., Fleury, P., Fontaine, G., George, R., Ghesquiere, C., Goret, P., Gouiffes, C., Grenier, I. A., Iacoucci, L., Bohec, S. Le, Mallet, I., Meynadier, C., Munz, F., Palfrey, T. A., Pare, E., Pons, Y., Punch, M., Quebert, J., Ragan, K., Renault, C., Rivoal, M., Rob, L., Schovanek, P., Smith, D., Tavernet, J. P., and Vrana, J.
Subjects: Astrophysics
Abstract: The CAT imaging telescope, recently built on the site of the former solar plant Themis (French Pyrenees), observed gamma-rays from the Crab nebula from October 1996 to March 1997. This steady source, often considered as the standard candle of very-high-energy gamma-ray astronomy, is used as a test-beam to probe the performances of the new telescope, particularly its energy threshold (220 GeV at 20 degrees zenith angle) and the stability of its response. Due to the fine-grain camera, an accurate analysis of the longitudinal profiles of shower images is performed, yielding the source position in two dimensions for each individual shower., Comment: 5 pages, 3 figures, Tex, contribution to 25th ICRC Durban
Published: 1997

30. The camera of the fifth H.E.S.S. telescope. Part I: System description

Author: Bolmont, J., Corona, P., Gauron, P., Ghislain, P., Goffin, C., Guevara Riveros, L., Huppert, J.-F., Martineau-Huynh, O., Nayman, P., Parraud, J.-M., Tavernet, J.-P., Toussenel, F., Vincent, D., Vincent, P., Bertoli, W., Espigat, P., Punch, M., Besin, D., Delagnes, E., Glicenstein, J.-F., Moudden, Y., Venault, P., Zaghia, H., Brunetti, L., David, P.-Y., Dubois, J.-M., Fiasson, A., Geffroy, N., Gomes Monteiro, I., Journet, L., Krayzel, F., Lamanna, G., Le Flour, T., Lees, S., Lieunard, B., Maurin, G., Mugnier, P., Panazol, J-L., Prast, J., Chounet, L.-M., Degrange, B., Edy, E., Fontaine, G., Giebels, B., Hormigos, S., Khélifi, B., Manigot, P., Maritaz, P., de Naurois, M., Compin, M., Feinstein, F., Fernandez, D., Mehault, J., Rivoire, S., Royer, S., Sanguillon, M., and Vasileiadis, G.
Published: 2014
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31. Detection of Gamma Rays from a Starburst Galaxy

Author: Acero, F., Aharonian, F., Akhperjanian, A. G., Anton, G., de Almeida, U. Barres, Bazer-Bachi, A. R., Becherini, Y., Behera, B., Bernlöhr, K., Bochow, A., Boisson, C., Bolmont, J., Borrel, V., Brucker, J., Brun, F., Brun, P., Bühler, R., Bulik, T., Büsching, I., Boutelier, T., Chadwick, P. M., Charbonnier, A., Chaves, R. C. G., Cheesebrough, A., Chounet, L.-M., Clapson, A. C., Coignet, G., Dalton, M., Daniel, M. K., Davids, I. D., Degrange, B., Deil, C., Dickinson, H. J., Djannati-Ataï, A., Domainko, W., Drury, L. O'C., Dubois, F., Dubus, G., Dyks, J., Dyrda, M., Egberts, K., Emmanoulopoulos, D., Espigat, P., Farnier, C., Fegan, S., Feinstein, F., Fiasson, A., Förster, A., Fontaine, G., Füßling, M., Gabici, S., Gallant, Y. A., Gérard, L., Gerbig, D., Giebels, B., Glicenstein, J. F., Glück, B., Goret, P., Göring, D., Hauser, D., Hauser, M., Heinz, S., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A., Hoffmann, A., Hofmann, W., Hofverberg, P., Hoppe, S., Horns, D., Jacholkowska, A., de Jager, O. C., Jahn, C., Jung, I., Katarzyński, K., Katz, U., Kaufmann, S., Kerschhaggl, M., Khangulyan, D., Khélifi, B., Keogh, D., Klochkov, D., Kluźniak, W., Kneiske, T., Komin, Nu., Kosack, K., Kossakowski, R., Lamanna, G., Lenain, J.-P., Lohse, T., Marandon, V., Martineau-Huynh, O., Marcowith, A., Masbou, J., Maurin, D., McComb, T. J. L., Medina, M. C., Méhault, J., Moderski, R., Moulin, E., Naumann-Godo, M., de Naurois, M., Nedbal, D., Nekrassov, D., Nicholas, B., Niemiec, J., Nolan, S. J., Ohm, S., Olive, J-F., de Oña Wilhelmi, E., Orford, K. J., Ostrowski, M., Panter, M., Arribas, M. Paz, Pedaletti, G., Pelletier, G., Petrucci, P.-O., Pita, S., Pühlhofer, G., Punch, M., Quirrenbach, A., Raubenheimer, B. C., Raue, M., Rayner, S. M., Reimer, O., Renaud, M., Rieger, F., Ripken, J., Rob, L., Rosier-Lees, S., Rowell, G., Rudak, B., Rulten, C. B., Ruppel, J., Sahakian, V., Santangelo, A., Schlickeiser, R., Schöck, F. M., Schwanke, U., Schwarzburg, S., Schwemmer, S., Shalchi, A., Sikora, M., Skilton, J. L., Sol, H., Stawarz, Ł., Steenkamp, R., Stegmann, C., Stinzing, F., Superina, G., Szostek, A., Tam, P. H., Tavernet, J.-P., Terrier, R., Tibolla, O., Tluczykont, M., van Eldik, C., Vasileiadis, G., Venter, C., Venter, L., Vialle, J. P., Vincent, P., Vivier, M., Völk, H. J., Volpe, F., Wagner, S. J., Ward, M., Zdziarski, A. A., and Zech, A.
Published: 2009
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32. Search for Lorentz Invariance breaking with a likelihood fit of the PKS 2155-304 flare data taken on MJD 53944

Author: Abramowski, A., Acero, F., Aharonian, F., Akhperjanian, A.G., Anton, G., Barnacka, A., Barres de Almeida, U., Bazer-Bachi, A.R., Becherini, Y., Becker, J., Behera, B., Bernlöhr, K., Bochow, A., Boisson, C., Bolmont, J., Bordas, P., Borrel, V., Brucker, J., Brun, F., Brun, P., Bühler, R., Bulik, T., Büsching, I., Carrigan, S., Casanova, S., Cerruti, M., Chadwick, P.M., Charbonnier, A., Chaves, R.C.G., Cheesebrough, A., Chounet, L.-M., Clapson, A.C., Coignet, G., Conrad, J., Dalton, M., Daniel, M.K., Davids, I.D., Degrange, B., Deil, C., Dickinson, H.J., Djannati-Ataï, A., Domainko, W., Drury, L.O’C., Dubois, F., Dubus, G., Dyks, J., Dyrda, M., Egberts, K., Eger, P., Espigat, P., Fallon, L., Farnier, C., Fegan, S., Feinstein, F., Fernandes, M.V., Fiasson, A., Fontaine, G., Förster, A., Füßling, M., Gabici, S., Gallant, Y.A., Gast, H., Gérard, L., Gerbig, D., Giebels, B., Glicenstein, J.F., Glück, B., Goret, P., Göring, D., Hague, J.D., Hampf, D., Hauser, M., Heinz, S., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J.A., Hoffmann, A., Hofmann, W., Hofverberg, P., Horns, D., Jacholkowska, A., de Jager, O.C., Jahn, C., Jamrozy, M., Jung, I., Kastendieck, M.A., Katarzyński, K., Katz, U., Kaufmann, S., Keogh, D., Kerschhaggl, M., Khangulyan, D., Khélifi, B., Klochkov, D., Kluźniak, W., Kneiske, T., Komin, Nu., Kosack, K., Kossakowski, R., Laffon, H., Lamanna, G., Lenain, J.-P., Lennarz, D., Lohse, T., Lopatin, A., Lu, C.-C., Marandon, V., Marcowith, A., Masbou, J., Maurin, D., Maxted, N., McComb, T.J.L., Medina, M.C., Méhault, J., Moderski, R., Moulin, E., Naumann, C.L., Naumann-Godo, M., de Naurois, M., Nedbal, D., Nekrassov, D., Nguyen, N., Nicholas, B., Niemiec, J., Nolan, S.J., Ohm, S., Olive, J-F., de Oña Wilhelmi, E., Opitz, B., Ostrowski, M., Panter, M., Paz Arribas, M., Pedaletti, G., Pelletier, G., Petrucci, P.-O., Pita, S., Pühlhofer, G., Punch, M., Quirrenbach, A., Raue, M., Rayner, S.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., Ruppel, J., Ryde, F., Sahakian, V., Santangelo, A., Schlickeiser, R., Schöck, F.M., Schönwald, A., Schwanke, U., Schwarzburg, S., Schwemmer, S., Shalchi, A., Sikora, M., Skilton, J.L., Sol, H., Spengler, G., Stawarz, Ł., Steenkamp, R., Stegmann, C., Stinzing, F., Sushch, I., Szostek, A., Tam, P.H., Tavernet, J.-P., Terrier, R., Tibolla, O., Tluczykont, M., Valerius, K., van Eldik, C., Vasileiadis, G., Venter, C., Vialle, J.P., Viana, A., Vincent, P., Vivier, M., Völk, H.J., Volpe, F., Vorobiov, S., Vorster, M., Wagner, S.J., Ward, M., Wierzcholska, A., Zajczyk, A., Zdziarski, A.A., Zech, A., and Zechlin, H.-S.
Published: 2011
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33. H.E.S.S. constraints on dark matter annihilations towards the sculptor and carina dwarf galaxies

Author: Abramowski, A., Acero, F., Aharonian, F., Akhperjanian, A.G., Anton, G., Barnacka, A., Barres de Almeida, U., Bazer-Bachi, A.R., Becherini, Y., Becker, J., Behera, B., Bernlöhr, K., Bochow, A., Boisson, C., Bolmont, J., Bordas, P., Borrel, V., Brucker, J., Brun, F., Brun, P., Bulik, T., Büsching, I., Carrigan, S., Casanova, S., Cerruti, M., Chadwick, P.M., Charbonnier, A., Chaves, R.C.G., Cheesebrough, A., Chounet, L.-M., Clapson, A.C., Coignet, G., Conrad, J., Dalton, M., Daniel, M.K., Davids, I.D., Degrange, B., Deil, C., Dickinson, H.J., Djannati-Ataï, A., Domainko, W., Drury, L.O.C., Dubois, F., Dubus, G., Dyks, J., Dyrda, M., Egberts, K., Eger, P., Espigat, P., Fallon, L., Farnier, C., Fegan, S., Feinstein, F., Fernandes, M.V., Fiasson, A., Fontaine, G., Förster, A., Füßling, M., Gallant, Y.A., Gast, H., Gérard, L., Gerbig, D., Giebels, B., Glicenstein, J.F., Glück, B., Goret, P., Göring, D., Hague, J.D., Hampf, D., Hauser, M., Heinz, S., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J.A., Hoffmann, A., Hofmann, W., Hofverberg, P., Horns, D., Jacholkowska, A., de Jager, O.C., Jahn, C., Jamrozy, M., Jung, I., Kastendieck, M.A., Katarzyński, K., Katz, U., Kaufmann, S., Keogh, D., Kerschhaggl, M., Khangulyan, D., Khélifi, B., Klochkov, D., Kluźniak, W., Kneiske, T., Komin, Nu., Kosack, K., Kossakowski, R., Laffon, H., Lamanna, G., Lennarz, D., Lohse, T., Lopatin, A., Lu, C.-C., Marandon, V., Marcowith, A., Masbou, J., Maurin, D., Maxted, N., McComb, T.J.L., Medina, M.C., Méhault, J., Moderski, R., Moulin, E., Naumann, C.L., Naumann-Godo, M., de Naurois, M., Nedbal, D., Nekrassov, D., Nguyen, N., Nicholas, B., Niemiec, J., Nolan, S.J., Ohm, S., Olive, J.-F., de Oña Wilhelmi, E., Opitz, B., Ostrowski, M., Panter, M., Paz Arribas, M., Pedaletti, G., Pelletier, G., Petrucci, P.-O., Pita, S., Pühlhofer, G., Punch, M., Quirrenbach, A., Raue, M., Rayner, S.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., Ruppel, J., Ryde, F., Sahakian, V., Santangelo, A., Schlickeiser, R., Schöck, F.M., Schönwald, A., Schwanke, U., Schwarzburg, S., Schwemmer, S., Shalchi, A., Sikora, M., Skilton, J.L., Sol, H., Spengler, G., Stawarz, Ł., Steenkamp, R., Stegmann, C., Stinzing, F., Sushch, I., Szostek, A., Tavernet, J.-P., Terrier, R., Tibolla, O., Tluczykont, M., Valerius, K., van Eldik, C., Vasileiadis, G., Venter, C., Vialle, J.P., Viana, A., Vincent, P., Vivier, M., Völk, H.J., Volpe, F., Vorobiov, S., Vorster, M., Wagner, S.J., Ward, M., Wierzcholska, A., Zajczyk, A., Zdziarski, A.A., Zech, A., and Zechlin, H.-S.
Published: 2011
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34. Fast Variability of Tera-Electron Volt γ Rays from the Radio Galaxy M87

Author: Aharonian, F., Akhperjanian, A. G., Bazer-Bachi, A. R., Beilicke, M., Benbow, W., Berge, D., Bernlöhr, K., Boisson, C., Bolz, O., Borrel, V., Braun, I., Brown, A. M., Bühler, R., Büsching, I., Carrigan, S., Chadwick, P. M., Chounet, L.-M., Coignet, G., Cornils, R., Costamante, L., Degrange, B., Dickinson, H. J., Djannati-Ataï, A., Drury, L. O'C., Dubus, G., Egberts, K., Emmanoulopoulos, D., Espigat, P., Feinstein, F., Ferrero, E., Fiasson, A., Fontaine, G., Funk, Seb., Funk, S., Füßling, M., Gallant, Y. A., Giebels, B., Glicenstein, J. F., Goret, P., Hadjichristidis, C., Hauser, D., Hauser, M., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A., Hoffmann, A., Hofmann, W., Holleran, M., Hoppe, S., Horns, D., Jacholkowska, A., de Jager, O. C., Kendziorra, E., Kerschhaggl, M., Khélifi, B., Komin, Nu., Konopelko, A., Kosack, K., Lamanna, G., Latham, I. J., Le Gallou, R., Lemière, A., Lemoine-Goumard, M., Lenain, J.-P., Lohse, T., Martin, J. M., Martineau-Huynh, O., Marcowith, A., Masterson, C., Maurin, G., McComb, T. J. L., Moulin, E., de Naurois, M., Nedbal, D., Nolan, S. J., Noutsos, A., Orford, K. J., Osborne, J. L., Ouchrif, M., Panter, M., Pelletier, G., Pita, S., Pühlhofer, G., Punch, M., Ranchon, S., Raubenheimer, B. C., Raue, M., Rayner, S. M., Reimer, A., Ripken, J., Rob, L., Rolland, L., Rosier-Lees, S., Rowell, G., Sahakian, V., Santangelo, A., Saugé, L., Schlenker, S., Schlickeiser, R., Schröder, R., Schwanke, U., Schwarzburg, S., Schwemmer, S., Shalchi, A., Sol, H., Spangler, D., Spanier, F., Steenkamp, R., Stegmann, C., Superina, G., Tam, P. H., Tavernet, J.-P., Terrier, R., Tluczykont, M., van Eldik, C., Vasileiadis, G., Venter, C., Vialle, J. P., Vincent, P., Völk, H. J., Wagner, S. J., and Ward, M.
Published: 2006
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35. Observations of the Sagittarius dwarf galaxy by the HESS experiment and search for a dark matter signal

Author: Aharonian, F., Akhperjanian, A.G., Bazer-Bachi, A.R., Beilicke, M., Benbow, W., Berge, D., Bernlöhr, K., Boisson, C., Bolz, O., Borrel, V., Braun, I., Brion, E., Brown, A.M., Bühler, R., Büsching, I., Boutelier, T., Carrigan, S., Chadwick, P.M., Chounet, L.-M., Coignet, G., Cornils, R., Costamante, L., Degrange, B., Dickinson, H.J., Djannati-Ataï, A., Drury, L.O’C., Dubus, G., Egberts, K., Emmanoulopoulos, D., Espigat, P., Farnier, C., Feinstein, F., Ferrero, E., Fiasson, A., Fontaine, G., Funk, Seb., Funk, S., Füßling, M., Gallant, Y.A., Giebels, B., Glicenstein, J.F., Glück, B., Goret, P., Hadjichristidis, C., Hauser, D., Hauser, M., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J.A., Hoffmann, A., Hofmann, W., Holleran, M., Hoppe, S., Horns, D., Jacholkowska, A., de Jager, O.C., Kendziorra, E., Kerschhaggl, M., Khélifi, B., Komin, Nu., Kosack, K., Lamanna, G., Latham, I.J., Le Gallou, R., Lemière, A., Lemoine-Goumard, M., Lohse, T., Martin, J.M., Martineau-Huynh, O., Marcowith, A., Masterson, C., Maurin, G., McComb, T.J.L., Moulin, E., de Naurois, M., Nedbal, D., Nolan, S.J., Noutsos, A., Nuss, E., Olive, J.-P., Orford, K.J., Osborne, J.L., Panter, M., Pelletier, G., Petrucci, P.-O., Pita, S., Pühlhofer, G., Punch, M., Ranchon, S., Raubenheimer, B.C., Raue, M., Rayner, S.M., Ripken, J., Rob, L., Rolland, L., Rosier-Lees, S., Rowell, G., Sahakian, V., Santangelo, A., Saugé, L., Schlenker, S., Schlickeiser, R., Schröder, R., Schwanke, U., Schwarzburg, S., Schwemmer, S., Shalchi, A., Sol, H., Spangler, D., Spanier, F., Steenkamp, R., Stegmann, C., Superina, G., Tam, P.H., Tavernet, J.-P., Terrier, R., Tluczykont, M., van Eldik, C., Vasileiadis, G., Venter, C., Vialle, J.P., Vincent, P., Vivier, M., Völk, H.J., Wagner, S.J., and Ward, M.
Published: 2008
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36. A low level of extragalactic background light as revealed by γ-rays from blazars

Author: Aharonian, F., Akhperjanian, A. G., Bazer-Bachi, A. R., Beilicke, M., Benbow, W., Berge, D., Bernlöhr, K., Boisson, C., Bolz, O., Borrel, V., Braun, I., Breitling, F., Brown, A. M., Chadwick, P. M., Chounet, L.-M., Cornils, R., Costamante, L., Degrange, B., Dickinson, H. J., Djannati-Ataï, A., Drury, L. O'C., Dubus, G., Emmanoulopoulos, D., Espigat, P., Feinstein, F., Fontaine, G., Fuchs, Y., Funk, S., Gallant, Y. A., Giebels, B., Gillessen, S., Glicenstein, J. F., Goret, P., Hadjichristidis, C., Hauser, D., Hauser, M., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A., Hofmann, W., Holleran, M., Horns, D., Jacholkowska, A., de Jager, O. C., Khélifi, B., Klages, S., Komin, Nu., Konopelko, A., Latham, I. J., Le Gallou, R., Lemière, A., Lemoine-Goumard, M., Leroy, N., Lohse, T., Martin, J. M., Martineau-Huynh, O., Marcowith, A., Masterson, C., McComb, T. J. L., de Naurois, M., Nolan, S. J., Noutsos, A., Orford, K. J., Osborne, J. L., Ouchrif, M., Panter, M., Pelletier, G., Pita, S., Pühlhofer, G., Punch, M., Raubenheimer, B. C., Raue, M., Raux, J., Rayner, S. M., Reimer, A., Reimer, O., Ripken, J., Rob, L., Rolland, L., Rowell, G., Sahakian, V., Saugé, L., Schlenker, S., Schlickeiser, R., Schuster, C., Schwanke, U., Siewert, M., Sol, H., Spangler, D., Steenkamp, R., Stegmann, C., Tavernet, J.-P., Terrier, R., Théoret, C. G., Tluczykont, M., van Eldik, C., Vasileiadis, G., Venter, C., Vincent, P., Völk, H. J., and Wagner, S. J.
Published: 2006
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37. Fast variability of tera-electron volt [gamma] rays from the radio galaxy M87

Author: Aharonian, F., Akhperjanian, A.G., Bazer-Bachi, A.R., Beilicke, M., Benbow, W., Berge, D., Bernlohr, K., Boisson, C., Bolz, O., Borrel, V., Braun, I., Brown, A.M., Buhler, R., Busching, I., Carrigan, S., Chadwick, P.M., Chounet, L.-M., Coignet, G., Cornils, R., Costamante, L., Degrange, B., Dickinson, H.J., Djannati-Atai, A., Drury, L. O'C., Dubus, G., Egberts, K., Emmanoulopoulos, D., Espigat, P., Feinstein, F., Ferrero, E., Fiasson, A., Fontaine, G., Funk, Seb., Funk, S., Fussling, M., Gallant, Y.A., Giebels, B., Glicenstein, J.F., Goret, P., Hadjichristidis, C., Hauser, D., Hauser, M., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J.A., Hoffmann, A., Hofmann, W., Holleran, M., Hoppe, S., Horns, D., Jacholkowska, A., de Jager, O.C., Kendziorra, E., Kerschhaggl, M., Khelifi, B., Komin, Nu., Konopelko, A., Kosack, K., Lamanna, G., Latham, I.J., Le Gallou, R., Lemiere, A., Lemoine-Goumard, M., Lenain, J.-P., Lohse, T., Martin, J.M., Martineau-Huynh, O., Marcowith, A., Masterson, C., Maurin, G., McComb, T.J.L., Moulin, E., de Naurois, M., Nedbal, D., Nolan, S.J., Noutsos, A., Orford, K.J., Osborne, J.L., Ouchrif, M., Panter, M., Pelletier G., Pita, S., Puhlhofer, G., Punch, M., Ranchon, S., Raubenheimer, B.C., Raue, M., Rayner, S.M., Reimer, A., Ripken, J., Rob, L., Rolland, L., Rosier-Lees, S., Rowell, G., Sahakian, V., Santangelo, A., Sauge, L., Schlenker, S., Schlickeiser, R., Schroder, R., Schwanke, U., Schwarzburg, S., Schwemmer, S., Shalchi, A., Sol, H., Spangler, D., Spanier, F., Steenkamp, R., Stegmann, C., Superina, G., Tam, P.H., Tavernet, J.-P., Terrier, R., Tluczykont, M., van Eldik, C., Vasileiadis, G., Venter, C., Vialle, J.P., Vincent, P., Volk, H.J., Wagner, S.J., and Ward, M.
Subjects: Gamma rays -- Research, Gamma rays -- Analysis, Radiation -- Research, Radiation -- Analysis
Published: 2006

38. Discovery of very-high-energy γ-rays from the Galactic Centre ridge

Author: Aharonian, F., Akhperjanian, A. G., Bazer-Bachi, A. R., Beilicke, M., Benbow, W., Berge, D., Bernlohr, K., Boisson, C., Bolz, O., Borrel, V., Braun, I., Breitling, F., Brown, A. M., Chadwick, P. M., Chounet, L.-M., Cornils, R., Costamante, L., Degrange, B., Dickinson, H. J., Djannati-Atai, A., Drury, L. O'C., Dubus, G., Emmanoulopoulos, D., Espigat, P., Feinstein, F., Fontaine, G., Fuchs, Y., Funk, S., Gallant, Y. A., Giebels, B., Gillessen, S., Glicenstein, J. F., Goret, P., Hadjichristidis, C., Hauser, D., Hauser, M., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A., Hofmann, W., Holleran, M., Horns, D., Jacholkowska, A., de Jager, O. C., Khelifi, B., Klages, S., Komin, Nu., Konopelko, A., Latham, I. J., Le Gallou, R., Lemiere, A., Lemoine-Goumard, M., Leroy, N., Lohse, T., Marcowith, A., Martin, J. M., Martineau-Huynh, O., Masterson, C., McComb, T. J. L., de Naurois, M., Nolan, S. J., Noutsos, A., Orford, K. J., Osborne, J. L., Ouchrif, M., Panter, M., Pelletier, G., Pita, S., Puhlhofer, G., Punch, M., Raubenheimer, B. C., Raue, M., Raux, J., Rayner, S. M., Reimer, A., Reimer, O., Ripken, J., Rob, L., Rolland, L., Rowell, G., Sahakian, V., Sauge, L., Schlenker, S., Schlickeiser, R., Schuster, C., Schwanke, U., Siewert, M., Sol, H., Spangler, D., Steenkamp, R., Stegmann, C., Tavernet, J.-P., Terrier, R., Theoret, C. G., Tluczykont, M., van Eldik, C., Vasileiadis, G., Venter, C., Vincent, P., Volk, H. J., and Wagner, S. J.
Subjects: Environmental issues, Science and technology, Zoology and wildlife conservation
Abstract: Author(s): F. Aharonian [1]; A. G. Akhperjanian [2]; A. R. Bazer-Bachi [3]; M. Beilicke [4]; W. Benbow [1]; D. Berge [1]; K. Bernlohr [1, 5]; C. Boisson [6]; O. Bolz [...]
Published: 2006
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39. Discovery of very high energy gamma rays associated with an x-ray binary

Author: Aharonian, F., Akhperjanian, A.G., Aye, K.-M., Bazer-Bachi, A.R., Beilicke, M., Benbow, W., Berge, D., Berghaus, P., Bernlohr, K., Boisson, C., Bolz, O., Borrel, V., Braun, I., Breitling, F., Brown, A.M., Gordo, J. Bussons, Chadwick, P.M., Chounet, L.-M., Cornils, R., Costamante, L., Degrange, B., Dickinson, H.J., Djannati-Atai, A., Drury, L. O'C., Dubus, G., Emmanoulopoulos, D., Espigat, P., Feinstein, F., Fleury, P., Fontaine, G., Fuchs, Y., Funk, S., Gallant, Y.A., Giebels, B., Gillessen, S., Glicenstein, J.F., Goret, P., Hadjichristidis, C., Hauser, M., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J.A., Hofmann, W., Holleran, M., Horns, D., Jacholkowska, A., de Jager, O.C., Khelifi, B., Komin, Nu., Konopelko, A., Latham, I.J., Le Gallou, R., Lemiere, A., Lemoine-Goumard, M., Leroy, N., Lohse, T., Marcowith, A., Martin, J.-M., Martineau-Huynh, O., Masterson, C., McComb, T.J.L., de Naurois, M., Nolan, S.J., Noutsos, A., Orford, K.J., Osborne, J.L., Ouchrif, M., Panter, M., Pelletier, G., Pita, S., Puhlhofer, G., Punch, M., Raubenheimer, B.C., Raue, M., Raux, J., Rayner, S.M., Reimer, A., Reimer, O., Ripken, J., Rob, L., Rolland, L., Rowell, G., Sahakian, V., Sauge, L., Schlenker, S., Schlickeiser, R., Schuster, C., Schwanke, U., Siewert, M., Sol, H., Spangler, D., Steenkamp, R., Stegmann, C., Tavernet, J.-P., Terrier, R., Theoret, C.G., Tluczykont, M., Vasileiadis, G., Venter, C., Vincent, P., Volk, H.J., and Wagner, S.J.
Subjects: Quasars -- Models, Gamma ray astronomy -- Observations -- Models, Stars, Double -- Observations -- Models, Science and technology
Abstract: X-ray binaries are composed of a normal star in orbit around a neutron star or stellar-mass black hole. Radio and x-ray observations have led to the presumption that some x-ray binaries called microquasars behave as scaled-down active galactic nuclei. Microquasars have resolved radio emission that is thought to arise from a relativistic outflow akin to active galactic nuclei jets, in which particles can be accelerated to large energies. Very high energy γ-rays produced by the interactions of these particles have been observed from several active galactic nuclei. Using the High Energy Stereoscopic System, we find evidence for gamma-ray emission of >100 gigaelectron volts from a candidate microquasar, LS 5039, showing that particles are also accelerated to very high energies in these systems., High-resolution radio maps of x-ray binaries (XRBs) have revealed powerful outflows that are similar to the relativistic jets seen in active galactic nuclei (AGN) (1, 2). In both cases, the [...]
Published: 2005

40. A new population of very high energy gamma-ray sources in the Milky Way

Author: Aharonian, F., Akhperjanian, A.G., Aye, K.M., Bazer-Bachi, A.R., Beilicke, M., Benbow, W., Berge, D., Berghaus, P., Bernlohr, K., Boisson, C., Bolz, O., Borgmeier, C., Braun, I., Breitling, F., Brown, A.M., Gordo, J. Bussons, Chadwick, P.M., Chounet, L.-M., Cornils, R., Costamante, L., Degrange, B., Djannati-Atai, A., Drury, L.O'C., Dubus, G., Ergin, T., Espigat, P., Feinstein, F., Fleury, P., Fontaine, G., Funk, S., Gallant, Y.A., Giebels, B., Gillessen, S., Goret, P., Hadjichristidis, C., Hauser, M., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J.A., Hofmann, W., Holleran, M., Horns, D., de Jager, O.C., Jung, I., Khelifi, B., Komin, Nu, Konopelko, A., Latham, I.J., Le Gallou, R., Lemiere, A., Lemoine, M., Leroy, N., Lohse, T., Marcowith, A., Masterson, C., McComb, T.J.L., de Naurois, M., Nolan, S.J., Noutsos, A., Orford, K.J., Osborne, J.L., Ouchrif, M., Panter, M., Pelletier, G., Pita, S., Puhlhofer, G., Punch, M., Raubenheimer, B.C., Raue, M., Raux, J., Rayner, S.M., Redondo, I., Reimer, A., Reimer, O., Ripken, J., Rob, L., Rolland, L., Rowell, G., Sahakian, V., Sauge, L., Schlenker, S., Schlickeiser, R., Schuster, C., Schwanke, U., Siewert, M., Sol, H., Steenkamp, R., Stegmann, C., Tavernet, J.-P., Terrier, R., Theoret, C.G., Tluczykont, M., van der Walt, D.J., Vasileiadis, G., Venter, C., Vincent, P., Visser, B., Volk, H.J., and Wagner, S.J.
Subjects: Milky Way -- Research -- Observations -- Analysis, Gamma rays -- Research -- Observations -- Analysis, Science and technology
Abstract: Very high energy γ-rays probe the long-standing mystery of the origin of cosmic rays. Produced in the interactions of accelerated particles in astrophysical objects, they can be used to image cosmic particle accelerators. A first sensitive survey of the inner part of the Milky Way with the High Energy Stereoscopic System (HESS) reveals a population of eight previously unknown firmly detected sources of very high energy γ-rays. At least two have no known radio or x-ray counterpart and may be representative of a new class of 'dark' nucleonic cosmic ray sources., Very high energy (VHE) γ-rays with energies E > [10.sup.11] eV are probes of the nonthermal universe, providing access to energies far greater than those that can be produced in [...]
Published: 2005

41. Radio Imaging of the Very-High-Energy γ-Ray Emission Region in the Central Engine of a Radio Galaxy

Author: Acciari, V. A., Aliu, E., Arlen, T., Bautista, M., Beilicke, M., Benbow, W., Bradbury, S. M., Buckley, J. H., Bugaev, V., Butt, Y., Byrum, K., Cannon, A., Celik, O., Cesarini, A., Chow, Y. C., Ciupik, L., Cogan, P., Cui, W., Dickherber, R., Fegan, S. J., Finley, J. P., Fortin, P., Fortson, L, Furniss, A., Gall, D., Gillanders, G. H., Grube, J., Guenette, R., Gyuk, G., Hanna, D., Holder, J., Horan, D., Hui, C. M., Humensky, T. B., Imran, A., Kaaret, P., Karlsson, N., Kieda, D., Kildea, J., Konopelko, A., Krawczynski, H., Krennrich, F., Lang, M. J., LeBohec, S., Maier, G., McCann, A., McCutcheon, M., Millis, J., Moriarty, P., Ong, R. A., Otte, A. N., Pandel, D., Perkins, J. S., Petry, D., Pohl, M., Quinn, J., Ragan, K., Reyes, L C., Reynolds, P. T., Roache, E., Rose, H. J., Schroedter, M., Sembroski, G. H., Smith, A W., Swordy, S. P., Theiling, M., Toner, J. A, Vartotta, A., Vincent, S., Wakely, S. P., Ward, J. E., Weekes, T. C., Weinstein, A., Williams, D. A., Wissel, S., Wood, M., Walker, R. C., Davies, F., Hardee, P. E., Junor, W., Ly, C., Aharonian, F., Akhperjanian, A. G., Anton, G., de Almeida, U. Barres, Bazer-Bachi, A. R., Becherini, Y., Behera, B., Bernlöhr, K., Bochow, A., Boisson, C., Bolmont, J., Borrel, V., Brucker, J., Brun, F., Brun, P., Bühler, R., Bulik, T., Büsching, I., Boutelier, T., Chadwick, P. M., Charbonnier, A., Chaves, R. C. G., Cheesebrough, A., Chounet, L-M., Clapson, A. C., Coignet, G., Dalton, M., Daniel, M. K., Davids, I. D., Degrange, B., Deil, C., Dickinson, H. J., Djannati-Ataï, A., Domainko, W., OʼC. Drury, L, Dubois, F., Dubus, G., Dyks, J., Dyrda, M., Egberts, K., Emmanoulopoulos, D., Espigat, P., Farnier, C., Feinstein, F., Fiasson, A., Förster, A, Fontaine, G., Füling, M., Gabici, S., Gallant, Y. A., Gérard, L, Gerbig, D., Giebels, B., Glicenstein, J. F., Glück, B., Goret, P., Göhring, D., Hauser, D., Hauser, M., Heinz, S., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A, Hoffmann, A., Hofmann, W., Holleran, M., Hoppe, S., Horns, D., Jacholkowska, A., de Jager, O. C., Jahn, C., Jung, I., Katarzynski, K., Katz, U., Kaufmann, S., Kendziorra, E., Kerschhaggl, M., Khangulyan, D., Khélifi, B., Keogh, D., Kluzniak, W., Kneiske, T., Komin, Nu., Kosack, K., Lamanna, G., Lenain, J.-P., Lohse, T., Marandon, V., Martin, J. M., Martineau-Huynh, O., Marcowith, A., Maurin, D., L McComb, T. J., Medina, M. C., Moderski, R., Moulin, E., Naumann-Godo, M., de Naurois, M., Nedbal, D., Nekrassov, D., Nicholas, B., Niemiec, J., Nolan, S. J., Ohm, S., Olive, J.-F., de Oña Wilhelmi, E., Orford, K. J., Ostrowski, M., Panter, M., Arribas, M. Paz, Pedaletti, G., Pelletier, G., Petrucci, P.-O., Pita, S., Pühlhofer, G., Punch, M., Quirrenbach, A., Raubenheimer, B. C., Raue, M., Rayner, S. M., Renaud, M., Rieger, F., Ripken, J., Rob, L, Rosier-Lees, S., Rowell, G., Rudak, B., Rulten, C. B., Ruppel, J., Sahakian, V., Santangelo, A., Schlickeiser, R., Schöck, F. M., Schröder, R., Schwanke, U., Schwarzburg, S., Schwemmer, S., Shalchi, A, Sikora, M., Skilton, J. L, Sol, H., Spangler, D., Stawarz, L., Steenkamp, R., Stegmann, C., Stinzing, F., Superina, G., Szostek, A, Tam, P. H., Tavemet, J.-P., Terrier, R., Tibolla, O., Tluczykont, M., van Eldik, C., Vasileiadis, G., Venter, C., Venter, L, Vialle, J. P., Vincent, P., Vivier, M., Völk, H. J., Volpe, F., Wagner, S. J., Ward, M., Zdziarski, A. A., Zech, A., Anderhub, H., Antonelli, L. A., Antoranz, P., Backes, M., Baixeras, C., Balestra, S., Barrio, J. A., Bastieri, D., González, J. Becerra, Becker, J. K., Bednarek, W., Berger, K., Bernardini, E., Biland, A, Bock, R. K., Bonnoli, G., Bordas, P., Tridon, D. Borla, Bosch-Ramon, V., Bose, D., Braun, I., Bretz, T., Britvitch, I., Camara, M., Carmona, E., Commichau, S., Contreras, J. L, Cortina, J., Costado, M. T., Covino, S., Curtef, V., Dazzi, F., De Angelis, A., De Cea del Pozo, E., Mendez, C. Delgado, De los Reyes, R., De Lotto, B., De Maria, M., De Sabata, F., Dominguez, A., Dorner, D., Doro, M., Elsaesser, D., Errando, M., Ferenc, D., Fernández, E., Firpo, R., Fonseca, M. V., Font, L., Galante, N., Garcia López, R. J., Garczarczyk, M., Gaug, M., Goebel, F., Hadasch, D., Hayashida, M., Herrero, A., Hildebrand, D., Höhne-Mönch, D., Hose, J., Hsu, C. C., Jogler, T., Kranich, D., Barbera, A. La, Laille, A., Leonardo, E., Lindfors, E., Lombardi, S., Longo, F., López, M, Lorenz, E., Majumdar, P., Maneva, G., Mankuzhiyil, N., Mannheim, K., Maraschi, L, Mariotti, M., Martinez, M., Mazin, D., Meucci, M., Miranda, J. M., Mirzoyan, R., Miyamoto, H., Moldón, J., Moles, M., Moralejo, A., Nieto, D., Nilsson, K., Ninkovic, J., Oya, I., Paoletti, R., Paredes, J. M., Pasanen, M., Pascoli, D., Pauss, F., Pegna, R. G., Perez-Torres, M. A., Persic, M., Peruzzo, L, Prada, F., Prandini, E., Puchades, N., Reichardt, I., Rhode, W., Ribó, M., Rico, J., Rissi, M., Robert, A., Rügamer, S., Saggion, A., Saito, T. Y., Salvati, M., Sanchez-Conde, M., Satalecka, K., Scalzotto, V., Scapin, V., Schweizer, T., Shayduk, M., Shore, S. N., Sidro, N., Sierpowska-Bartosik, A., Sillanpää, A., Sitarek, J., Sobczynska, D., Spanier, F., Stamerra, A., Stark, L S., Takalo, L, Tavecchio, F., Temnikov, P., Tescaro, D., Teshima, M., Torres, D. F., Turini, N., Vankov, H., Wagner, R. M., Zabalza, V., Zandanel, F., Zanin, R., and Zapatero, J.
Published: 2009

42. Calibration of cameras of the H.E.S.S. detector

Author: Aharonian, F., Akhperjanian, A.G., Aye, K.-M., Bazer-Bachi, A.R., Beilicke, M., Benbow, W., Berge, D., Berghaus, P., Bernlöhr, K., Bolz, O., Boisson, C., Borgmeier, C., Breitling, F., Brown, A.M., Chadwick, P.M., Chitnis, V.R., Chounet, L.-M., Cornils, R., Costamante, L., Degrange, B., de Jager, O.C., Djannati-Ataï, A., Drury, L.O’C., Ergin, T., Espigat, P., Feinstein, F., Fleury, P., Fontaine, G., Funk, S., Gallant, Y.A., Giebels, B., Gillessen, S., Goret, P., Guy, J., Hadjichristidis, C., Hauser, M., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J., Hofmann, W., Holleran, M., Horns, D., Jung, I., Khélifi, B., Komin, Nu., Konopelko, A., Latham, I.J., Gallou, R. Le, Lemoine, M., Lemière, A., Leroy, N., Lohse, T., Marcowith, A., Masterson, C., McComb, T.J.L., de Naurois, M., Nolan, S.J., Noutsos, A., Orford, K.J., Osborne, J.L., Ouchrif, M., Panter, M., Pelletier, G., Pita, S., Pohl, M., Pühlhofer, G., Punch, M., Raubenheimer, B.C., Raue, M., Raux, J., Rayner, S.M., Redondo, I., Reimer, A., Reimer, O., Ripken, J., Rivoal, M., Rob, L., Rolland, L., Rowell, G., Sahakian, V., Sauge, L., Schlenker, S., Schlickeiser, R., Schuster, C., Schwanke, U., Siewert, M., Sol, H., Steenkamp, R., Stegmann, C., Tavernet, J.-P., Théoret, C.G., Tluczykont, M., van der Walt, D.J., Vasileiadis, G., Vincent, P., Visser, B., Volk, H.J., and Wagner, S.J.
Published: 2004
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43. High-energy particle acceleration in the shell of a supernova remnant

Author: Aharonian, F. A., Akhperjanian, A. G., Aye, K.-M., Bazer-Bachi, A. R., Beilicke, M., Benbow, W., Berge, D., Berghaus, P., Bernlöhr, K., Bolz, O., Boisson, C., Borgmeier, C., Breitling, F., Brown, A. M., Gordo, J. Bussons, Chadwick, P. M., Chitnis, V. R., Chounet, L.-M., Cornils, R., Costamante, L., Degrange, B., Djannati-Ataï, A., Drury, L. O'C., Ergin, T., Espigat, P., Feinstein, F., Fleury, P., Fontaine, G., Funk, S., Gallant, Y. A., Giebels, B., Gillessen, S., Goret, P., Guy, J., Hadjichristidis, C., Hauser, M., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A., Hofmann, W., Holleran, M., Horns, D., de Jager, O. C., Jung, I., Khélifi, B., Komin, Nu., Konopelko, A., Latham, I. J., Le Gallou, R., Lemoine, M., Lemière, A., Leroy, N., Lohse, T., Marcowith, A., Masterson, C., McComb, T. J. L., de Naurois, M., Nolan, S. J., Noutsos, A., Orford, K. J., Osborne, J. L., Ouchrif, M., Panter, M., Pelletier, G., Pita, S., Pohl, M., Pühlhofer, G., Punch, M., Raubenheimer, B. C., Raue, M., Raux, J., Rayner, S. M., Redondo, I., Reimer, A., Reimer, O., Ripken, J., Rivoal, M., Rob, L., Rolland, L., Rowell, G., Sahakian, V., Saugé, L., Schlenker, S., Schlickeiser, R., Schuster, C., Schwanke, U., Siewert, M., Sol, H., Steenkamp, R., Stegmann, C., Tavernet, J.-P., Théoret, C. G., Tluczykont, M., van der Walt, D. J., Vasileiadis, G., Vincent, P., Visser, B., Völk, H. J., and Wagner, S. J.
Published: 2004

44. Sunspace Performance within an Overall High Rise Building Retrofit

Author: Chounet, L. M., Clement, D., Franchisseur, R., Lahellec, A., Noppe, J., Winkelmann, F., and Den Ouden, C., editor
Published: 1984
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45. Detection of very high energy radiation from HESS J1908+063 confirms the Milagro unidentified source MGRO J1908+06

Author: Aharonian, F., Akhperjanian, A. G., Anton, G., Barres de Almeida, U., Bazer-Bachi, A. R., Becherini, Y., Behera, B., Benbow, W., Bernlöhr, K., Boisson, C., Bochow, A., Borrel, V., Braun, I., Brion, E., Brucker, J., Brun, P., Bühler, R., Bulik, T., Büsching, I., Boutelier, T., Carrigan, S., Chadwick, P. M., Charbonnier, A., Chaves, R. C. G., Cheesebrough, A., Chounet, L.-M., Clapson, A. C., Coignet, G., Dalton, M., Daniel, M. K., Degrange, B., Deil, C., Dickinson, H. J., Djannati-Ataï, A., Domainko, W., O'C. Drury, L., Dubois, F., Dubus, G., Dyks, J., Dyrda, M., Egberts, K., Emmanoulopoulos, D., Espigat, P., Farnier, C., Feinstein, F., Fiasson, A., Förster, A., Fontaine, G., Füssling, M., Gabici, S., Gallant, Y. A., Gérard, L., Giebels, B., Glicenstein, J. F., Glück, B., Goret, P., Hauser, D., Hauser, M., Heinz, S., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A., Hoffmann, A., Hofmann, W., Holleran, M., Hoppe, S., Horns, D., Jacholkowska, A., de Jager, O. C., Jung, I., Katarzyński, K., Katz, U., Kaufmann, S., Kendziorra, E., Kerschhaggl, M., Khangulyan, D., Khélifi, B., Keogh, D., Komin, N., Kosack, K., Lamanna, G., Lenain, J.-P., Lohse, T., Marandon, V., Martin, J. M., Martineau-Huynh, O., Marcowith, A., Maurin, D., Mccomb, T. J. L., Medina, M. C., Moderski, R., Moulin, Emmanuel, Naumann-Godo, M., de Naurois, M., Nedbal, D., Nekrassov, D., Niemiec, J., Nolan, S. J., Ohm, S., Olive, J.-F., de Oña Wilhelmi, E., Orford, K. J., Ostrowski, M., Panter, M., Paz Arribas, M., Pedaletti, G., Pelletier, G., Petrucci, P.-O., Pita, S., Pühlhofer, G., Punch, M., Quirrenbach, A., Raubenheimer, B. C., Raue, M., Rayner, S. M., Renaud, M., Reimer, O., Rieger, F., Ripken, J., Rob, L., Rosier-Lees, S., Rowell, G., Rudak, B., Rulten, C. B., Ruppel, J., Sahakian, V., Santangelo, A., Schlickeiser, R., Schöck, F. M., Schröder, R., Schwanke, U., Schwarzburg, S., Schwemmer, S., Shalchi, A., Skilton, J. L., Sol, H., Spangler, D., Stawarz, Ł., Steenkamp, R., Stegmann, C., Superina, G., Tam, P. H., Tavernet, J.-P., Terrier, R., Tibolla, O., van Eldik, C., Vasileiadis, G., Venter, C., Venter, L., Vialle, J. P., Vincent, P., Vivier, M., Völk, H. J., Volpe, F., Wagner, S. J., Ward, M., Zdziarski, A. A., Zech, A., Centre d'étude spatiale des rayonnements (CESR), Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, AstroParticule et Cosmologie (APC (UMR_7164)), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Laboratoire Univers et Théories (LUTH (UMR_8102)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire d'Astrophysique de Grenoble (LAOG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Pierre et Marie Curie - Paris 6 (UPMC), Laboratoire Leprince-Ringuet (LLR), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), APC - Astrophysique des Hautes Energies (APC - AHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Dipartimento di Astronomia, Universita degli Studi di Bologna, Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO)-Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO), Laboratoire Univers et Particules de Montpellier (LUPM), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Théorique et Astroparticules (LPTA), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), HESS, Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Annecy de Physique des Particules (LAPP/Laboratoire d'Annecy-le-Vieux de Physique des Particules), Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Dipartimento di Astronomia, Universita degli Studi di Bologna, Università di Bologna [Bologna] (UNIBO)-Università di Bologna [Bologna] (UNIBO)-AstroParticule et Cosmologie (APC (UMR_7164)), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, and Université de Montpellier (UM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), Physics, [PHYS.ASTR.HE]Physics [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], Photon, 010308 nuclear & particles physics, [SDU.ASTR.HE]Sciences of the Universe [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], FOS: Physical sciences, observations [gamma rays], Astronomy and Astrophysics, Astrophysics, Galactic plane, 01 natural sciences, Pulsar, Space and Planetary Science, 0103 physical sciences, Milagro, Astrophysics - High Energy Astrophysical Phenomena, 010303 astronomy & astrophysics, gamma rays: observations, Fermi Gamma-ray Space Telescope, Radiofrequency radiation
Abstract: Detection of a gamma-ray source above 300 GeV is reported, confirming the unidentified source MGRO J1908+06, discovered by the Milagro collaboration at a median energy of 20 TeV. The source was observed during 27 h as part of the extension of the H.E.S.S. Galactic plane survey to longitudes >30degr. HESS J1908+063 is detected at a significance level of 10.9 s with an integral flux above 1 TeV of (3.76+-0.29stat+-0.75sys)x10^-12 ph cm^-2 s^-1, and a spectral photon index Gamma = 2.10+-0.07stat+-0.2sys. The positions and fluxes of HESS 1908+063 and MGRO J1908+06 are in good agreement. Possible counterparts at other wavelengths and the origin of the gamma-ray emission are discussed. The nearby unidentified GeV source, GRO J1908+0556 (GeV) which also remains unidentified and the new Fermi pulsar 0FGL J1907.5+0617, may be connected to the TeV source., Accepted for publication on Astron. Astrophys
Published: 2009

46. Observations of Mkn 421 in 2004 with HESS at large zenith angles

Author: Aharonian, F., G. Akhperjanian, A., Aye, K.-M., R. Bazer-Bachi, A., Beilicke, M., Benbow, W., Berge, D., Berghaus, P., Bernlöhr, K., Boisson, C., Bolz, O., Braun, I., Breitling, F., M. Brown, A., Bussons Gordo, J., M. Chadwick, P., Chounet, L.-M., Cornils, R., Costamante, L., Degrange, B., Djannati-Ataï, A., O'C. Drury, L., Dubus, G., Emmanoulopoulos, D., Espigat, P., Feinstein, F., Fleury, P., Fontaine, G., Fuchs, Y., Funk, S., Gallant, Y.A., Giebels, B., Gillessen, S., F. Glicenstein, J., Goret, P., Hadjichristidis, C., Hauser, M., Heinzelmann, G., Henri, G., Hermann, G., A. Hinton, J., Hofmann, W., Holleran, M., Horns, D., C. De Jager, O., Khélifi, B., Komin, Nu., Konopelko, A., J. Latham, I., Le Gallou, R., Lemière, A., Lemoine, M., Leroy, N., Lohse, T., Marcowith, A., Masterson, C., J. L. Mccomb, T., De Naurois, M., J. Nolan, S., Noutsos, A., J. Orford, K., L. Osborne, J., Ouchrif, M., Panter, M., Pelletier, G., Pita, S., Pühlhofer, G., Punch, M., C. Raubenheimer, B., Raue, M., Raux, J., M. Rayner, S., Redondo, I., Reimer, A., Reimer, O., Ripken, J., Rob, L., Rolland, L., Rowell, G., Sahakian, V., Saugé, L., Schlenker, S., Schlickeiser, R., Schuster, C., Schwanke, U., Siewert, M., Sol, H., Steenkamp, R., Stegmann, C., Tavernet, J.-P., Terrier, R., Théoret, C.G., Tluczykont, M., Vasileiadis, G., Venter, C., Vincent, P., J. Völk, H., J. Wagner, S., AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Théorique et Astroparticules (LPTA), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Leprince-Ringuet (LLR), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), HESS, Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), and Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Pierre et Marie Curie - Paris 6 (UPMC)
Subjects: Physics, Photon, Spectral shape analysis, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), FOS: Physical sciences, galaxies: individual: Mkn 421, Astronomy and Astrophysics, Astrophysics, 01 natural sciences, Standard deviation, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Amplitude, Flux (metallurgy), Space and Planetary Science, 0103 physical sciences, Cutoff, High Energy Stereoscopic System, 010303 astronomy & astrophysics, Zenith
Abstract: Mkn 421 was observed during a high flux state for nine nights in April and May 2004 with the fully operational High Energy Stereoscopic System (H.E.S.S.) in Namibia. The observations were carried out at zenith angles of 60$^\circ$--65$^\circ$, which result in an average energy threshold of 1.5 TeV and a collection area reaching 2~km$^2$ at 10~TeV. Roughly 7000 photons from Mkn~421 were accumulated with an average gamma-ray rate of 8 photons/min. The overall significance of the detection exceeds 100 standard deviations. The light-curve of integrated fluxes above 2~TeV shows changes of the diurnal flux up to a factor of 4.3. For nights of high flux, intra-night variability is detected with a decay time of less than 1 hour. The time averaged energy spectrum is curved and is well described by a power-law with a photon index $\egamm$ and an exponential cutoff at $\ecut$~TeV and an average integral flux above 2~TeV of 3 Crab flux units. Significant variations of the spectral shape are detected with a spectral hardening as the flux increases. Contemporaneous multi-wavelength observations at lower energies (X-rays and gamma-rays above $\approx 300$~GeV) indicate smaller relative variability amplitudes than seen above 2~TeV during high flux state observed in April 2004., Comment: 5 pages, 4 figures, published in A&A
Published: 2005

47. A form-factor analysis from a total polarization measurement in K+μ3 decay

Author: Bettels, J., Freudenreich, K., Haidt, D., Schultze, K., Stein, J., Caforio, A., Garelli, C. M., Natali, S., Piscitelli, G., Romano, F., Fett, E., Haatuft, A., Cundy, D. C., Lemonne, J., Møllerud, R., Myatt, G., Nikolic, M., Pedersen, T. I., Schneps, J., Behr, L., Brisson, V., Kluberg, L., Petiau, P., Esveld, C. D., de Jongh, G. A. T., van de Walle, R. T., Aubert, B., Chounet, L. M., Le Dong, I., Lowys, J. P., Pascaud, C., Baldo-Ceolin, M., Bobisut, F., Calimani, E., Ciampolillo, S., Huzita, H., Miari, G., Borreani, G., Marzari-Chiesa, A., Rinaudo, G., and Werbrouck, A.
Published: 1968
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48. Discovery of hard-spectrum $\gamma$-ray emission from the BL Lacertae object 1ES 0414+009

Author: Abramowski, A., Acero, F., Aharonian, F., Akhperjanian, A. G., Anton, G., Balzer, A., Barnacka, Anna, Barres de Almeida, U., Becherini, Y., Becker, J., Behera, B., Bernloehr, K., Birsin, E., Biteau, J., Bochow, A., Boisson, C., Bolmont, J., Bordas, P., Brucker, J., Brun, F., Brun, P., Bulik, T., Buesching, I., Carrigan, S., Casanova, S., Cerruti, M., Chadwick, P. M., Charbonnier, A., Chaves, R. C. G., Cheesebrough, A., Chounet, L.-M., Clapson, A. C., Coignet, G., Cologna, G., Conrad, J., Dalton, M., Daniel, M. K., Davids, I. D., Degrange, B., Deil, C., Dickinson, H. J., Djannati-Ataï, A., Domainko, W., Drury, L. O’C., Dubois, F., Dubus, G., Dutson, K., Dyks, J., Dyrda, M., Egberts, K., Eger, P., Espigat, P., Fallon, L., Farnier, C., Feinstein, F., Fernandes, M. V., Fiasson, A., Fontaine, G., Foerster, A., Fuesling, M., Gallant, Y. A., Gast, H., Gerard, L., Gerbig, D., Giebels, B., Glicenstein, J. F., Glueck, B., Goret, P., Goering, D., Haeffner, S., Hague, J. D., Hampf, D., Hauser, M., Heinz, S., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A., Hoffmann, A., Hofmann, W., Hofverberg, P., Holler, M., Horns, D., Jacholkowska, A., de Jager, O. C., Jahn, C., Jamrozy, Marek, Jung, I., Kastendieck, M. A., Katarzyński, K., Katz, U., Kaufmann, S., Keogh, D., Khangulyan, D., Khelifi, B., Klochkov, D., Kluzniak, W., Kneiske, T., Komin, Nu., Kosack, K., Kossakowski, R., Laffon, H., Lamanna, G., Lennarz, D., Lohse, T., Lopatin, A., Lu, C.-C., Marandon, V., Marcowith, A., Masbou, J., Maurin, D., Maxted, N., Mayer, M., McComb, T. J. L., Medina, M. C., Mehault, J., Moderski, R., Moulin, E., Naumann, C. L., Naumann-Godo, M., de Naurois, M., Nedbal, D., Nekrassov, D., Nguyen, N., Nicholas, B., Niemiec, J., Nolan, S. J., Ohm, S., de Oña Wilhelmi, E., Opitz, B., Ostrowski, Michał, Oya, I., Panter, M., Paz Arribas, M., Pedaletti, G., Pelletier, G., Petrucci, P.-O., Pita, S., Puehlhofer, G., Punch, M., Quirrenbach, A., Raue, M., Rayner, S. 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., Ruppel, J., Sahakian, V., Sanchez, D. A., Santangelo, A., Schlickeiser, R., Schoeck, F. M., Schulz, A., Schwanke, U., Schwarzburg, S., Schwemmer, S., Sheidaei, F., Sikora, M., Skilton, J. L., Sol, H., Spengler, G., Stawarz, Łukasz, Steenkamp, R., Stegmann, C., Stinzing, F., Stycz, K., Sushch, I., Szostek, Anna, Tavernet, J.-P., Terrier, R., Tluczykont, M., Valerius, K., van Eldik, C., Vasileiadis, G., Venter, C., Vialle, J. P., Viana, A., Vincent, P., Voelk, H. J., Volpe, F., Vorobiov, S., Vorster, M., Wagner, S. J., Ward, M., White, R., Wierzcholska, Alicja, Zacharias, M., Zajczyk, A., Zdziarski, A. A., Zech, A., Zechlin, H.-S. L., Costamante, L., Fegan, S., Ajello, M., Laboratoire Univers et Particules de Montpellier (LUPM), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire Leprince-Ringuet (LLR), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), AstroParticule et Cosmologie (APC (UMR_7164)), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), APC - Astrophysique des Hautes Energies (APC - AHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Dipartimento di Astronomia, Universita degli Studi di Bologna, Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO)-Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO), HESS, Université de Montpellier (UM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7), Laboratoire d'Annecy de Physique des Particules (LAPP/Laboratoire d'Annecy-le-Vieux de Physique des Particules), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Dipartimento di Astronomia, Universita degli Studi di Bologna, Università di Bologna [Bologna] (UNIBO)-Università di Bologna [Bologna] (UNIBO), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO)
Subjects: [PHYS.ASTR.HE]Physics [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], Photon, Electromagnetic spectrum, Astrophysics::High Energy Astrophysical Phenomena, jets [galaxies], general [Gamma rays], Flux, Astrophysics, 01 natural sciences, law.invention, Telescope, law, 0103 physical sciences, 010303 astronomy & astrophysics, Cherenkov radiation, Physics, 010308 nuclear & particles physics, [SDU.ASTR.HE]Sciences of the Universe [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], Gamma ray, Astronomy, Astronomy and Astrophysics, Extragalactic background light, 13. Climate action, Space and Planetary Science, active [galaxies], ddc:520, BL Lac object, individual: 1ES 0414+009 [BL Lacertae objects]
Abstract: 9 pages, 4 figures, accepted for publication in A&A; 1ES 0414+009 (z = 0.287) is a distant high-frequency-peaked BL Lac object, and has long been considered a likely emitter of very-high energy (VHE, E>100 GeV) gamma-rays due to its high X-ray and radio flux. Observations in the VHE gamma-ray band and across the electromagnetic spectrum can provide insights into the origin of highly energetic particles present in the source and the radiation processes at work. Because of the distance of the source, the gamma-ray spectrum might provide further limits on the level of the Extragalactic Background Light (EBL). We report observations made between October 2005 and December 2009 with H.E.S.S., an array of four imaging atmospheric Cherenkov telescopes. Observations at high energies (HE, 100 MeV - 100 GeV) with the Fermi-LAT instrument in the first 20 months of its operation are also reported. To complete the multi-wavelength picture, archival UV and X-ray observations with the Swift satellite and optical observations with the ATOM telescope are also used. Based on the observations with H.E.S.S., 1ES 0414+009 is detected for the first time in the VHE band. An excess of 224 events is measured, corresponding to a significance of 7.8 sigma. The photon spectrum of the source is well described by a power law, with photon index of 3.45 \pm 0.25stat \pm 0.20syst. The integral flux above 200 GeV is (1.88 \pm 0.20stat \pm 0.38syst) \times10-12 cm-2 s-1. Observations with the Fermi-LAT in the first 20 months of operation show a flux between 200 MeV and 100 GeV of (2.3 \pm 0.2stat) \times 10-9 erg cm-2 s-1, and a spectrum well described by a power-law function with a photon index 1.85 \pm 0.18. Swift/XRT observations show an X-ray flux between 2 and 10 keV of (0.8 - 1) \times 10-11 erg cm-2 s-1, and a steep spectrum (2.2 - 2.3). Combining X-ray with optical-UV data, a fit with a log-parabolic function locates the synchrotron peak around 0.1 keV. ...
Published: 2012

49. Discovery of hard-spectrum ��-ray emission from the BL Lac object 1ES 0414+009

Author: The HESS Collaboration, Abramowski, A., Acero, F., Aharonian, F., Akhperjanian, A. G., Anton, G., Balzer, A., Barnacka, A., de Almeida, U. Barres, Becherini, Y., Becker, J., Behera, B., Bernl��hr, K., Birsin, E., Biteau, J., Bochow, A., Boisson, C., Bolmont, J., Bordas, P., Brucker, J., Brun, F., Brun, P., Bulik, T., B��sching, I., Carrigan, S., Casanova, S., Cerruti, M., Chadwick, P. M., Charbonnier, A., Chaves, R. C. G., Cheesebrough, A., Chounet, L. -M., Clapson, A. C., Coignet, G., Cologna, G., Conrad, J., Dalton, M., Daniel, M. K., Davids, I. D., Degrange, B., Deil, C., Dickinson, H. J., Djannati-Ata��, A., Domainko, W., Drury, L. O'C., Dubois, F., Dubus, G., Dutson, K., Dyks, J., Dyrda, M., Egberts, K., Eger, P., Espigat, P., Fallon, L., Farnier, C., Feinstein, F., Fernandes, M. V., Fiasson, A., Fontaine, G., F��rster, A., F��ling, M., Gallant, Y. A., Gast, H., G��rard, L., Gerbig, D., Giebels, B., Glicenstein, J. F., Gl��ck, B., Goret, P., G��ring, D., H��ffner, S., Hague, J. D., Hampf, D., Hauser, M., Heinz, S., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A., Hoffmann, A., Hofmann, W., Hofverberg, P., Holler, M., Horns, D., Jacholkowska, A., de Jager, O. C., Jahn, C., Jamrozy, M., Jung, I., Kastendieck, M. A., Katarzynski, K., Katz, U., Kaufmann, S., Keogh, D., Khangulyan, D., Kh��lifi, B., Klu��niak, D. Klochkov W., Kneiske, T., Komin, Nu., Kosack, K., Kossakowski, R., Laffon, H., Lamanna, G., Lennarz, D., Lohse, T., Lopatin, A., Lu, C. -C., Marandon, V., Marcowith, A., Masbou, J., Maurin, D., Maxted, N., Mayer, M., McComb, T. J. L., Medina, M. C., M��hault, J., Moderski, R., Moulin, E., Naumann, C. L., Naumann-Godo, M., de Naurois, M., Nedbal, D., Nekrassov, D., Nguyen, N., Nicholas, B., Niemiec, J., Nolan, S. J., Ohm, S., Wilhelmi, E. de Ona, Opitz, B., Ostrowski, M., Oya, I., Panter, M., Arribas, M. Paz, Pedaletti, G., Pelletier, G., Petrucci, P. -O., Pita, S., P��hlhofer, G., Punch, M., Quirrenbach, A., Raue, M., Rayner, S. M., Reimer, A., Reimer, O., Renaud, M., Reyes, R. de los, Rieger, F., Ripken, J., Rob, L., Rosier-Lees, S., Rowell, G., Rudak, B., Rulten, C. B., Ruppel, J., Sahakian, V., Sanchez, D. A., Santangelo, A., Schlickeiser, R., Sch��ck, F. M., Schulz, A., Schwanke, U., Schwarzburg, S., Schwemmer, S., Sheidaei, F., Sikora, M., Skilton, J. L., Sol, H., Spengler, G., Stawarz, L., Steenkamp, R., Stegmann, C., Stinzing, F., Stycz, K., Sushch, I., Szostek, A., Tavernet, J. -P., Terrier, R., Tluczykont, M., Valerius, K., van Eldik, C., Vasileiadis, G., Venter, C., Vialle, J. P., Viana, A., Vincent, P., V��lk, H. J., Volpe, F., Vorobiov, S., Vorster, M., Wagner, S. J., Ward, M., White, R., Wierzcholska, A., Zacharias, M., Zajczyk, A., Zdziarski, A. A., Zech, A., Zechlin, H. -S., Costamante, L., Fegan, S., and Ajello, M.
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences
Abstract: 1ES 0414+009 (z = 0.287) is a distant high-frequency-peaked BL Lac object, and has long been considered a likely emitter of very-high energy (VHE, E>100 GeV) gamma-rays due to its high X-ray and radio flux. Observations in the VHE gamma-ray band and across the electromagnetic spectrum can provide insights into the origin of highly energetic particles present in the source and the radiation processes at work. Because of the distance of the source, the gamma-ray spectrum might provide further limits on the level of the Extragalactic Background Light (EBL). We report observations made between October 2005 and December 2009 with H.E.S.S., an array of four imaging atmospheric Cherenkov telescopes. Observations at high energies (HE, 100 MeV - 100 GeV) with the Fermi-LAT instrument in the first 20 months of its operation are also reported. To complete the multi-wavelength picture, archival UV and X-ray observations with the Swift satellite and optical observations with the ATOM telescope are also used. Based on the observations with H.E.S.S., 1ES 0414+009 is detected for the first time in the VHE band. An excess of 224 events is measured, corresponding to a significance of 7.8 sigma. The photon spectrum of the source is well described by a power law, with photon index of 3.45 \pm 0.25stat \pm 0.20syst. The integral flux above 200 GeV is (1.88 \pm 0.20stat \pm 0.38syst) \times10-12 cm-2 s-1. Observations with the Fermi-LAT in the first 20 months of operation show a flux between 200 MeV and 100 GeV of (2.3 \pm 0.2stat) \times 10-9 erg cm-2 s-1, and a spectrum well described by a power-law function with a photon index 1.85 \pm 0.18. Swift/XRT observations show an X-ray flux between 2 and 10 keV of (0.8 - 1) \times 10-11 erg cm-2 s-1, and a steep spectrum (2.2 - 2.3). Combining X-ray with optical-UV data, a fit with a log-parabolic function locates the synchrotron peak around 0.1 keV. ..., 9 pages, 4 figures, accepted for publication in A&A
Published: 2012
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50. Discovery of extended VHE ��-ray emission from the vicinity of the young massive stellar cluster Westerlund 1

Author: HESS Collaboration, Abramowski, A., Acero, F., Aharonian, F., Akhperjanian, A. G., Anton, G., Balzer, A., Barnacka, A., de Almeida, U. Barres, Becherini, Y., Becker, J., Behera, B., Bernl��hr, K., Birsin, E., Biteau, J., Bochow, A., Boisson, C., Bolmont, J., Bordas, P., Brucker, J., Brun, F., Brun, P., Bulik, T., B��sching, I., Carrigan, S., Casanova, S., Cerruti, M., Chadwick, P. M., Charbonnier, A., Chaves, R. C. G., Cheesebrough, A., Chounet, L. -M., Clapson, A. C., Coignet, G., Cologna, G., Conrad, J., Dalton, M., Daniel, M. K., Davids, I. D., Degrange, B., Deil, C., Dickinson, H. J., Djannati-Ata��, A., Domainko, W., Drury, L. O'C., Dubois, F., Dubus, G., Dutson, K., Dyks, J., Dyrda, M., Egberts, K., Eger, P., Espigat, P., Fallon, L., Farnier, C., Fegan, S., Feinstein, F., Fernandes, M. V., Fiasson, A., Fontaine, G., F��rster, A., F��ling, M., Gallant, Y. A., Gast, H., G��rard, L., Gerbig, D., Giebels, B., Glicenstein, J. F., Gl��ck, B., Goret, P., G��ring, D., H��ffner, S., Hague, J. D., Hampf, D., Hauser, M., Heinz, S., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A., Hoffmann, A., Hofmann, W., Hofverberg, P., Holler, M., Horns, D., Jacholkowska, A., de Jager, O. C., Jahn, C., Jamrozy, M., Jung, I., Kastendieck, M. A., Katarzynski, K., Katz, U., Kaufmann, S., Keogh, D., Khangulyan, D., Kh��lifi, B., Klochkov, D., Klu��niak, W., Kneiske, T., Komin, Nu., Kosack, K., Kossakowski, R., Laffon, H., Lamanna, G., Lennarz, D., Lohse, T., Lopatin, A., Lu, C. -C., Marandon, V., Marcowith, A., Masbou, J., Maurin, D., Maxted, N., Mayer, M., McComb, T. J. L., Medina, M. C., M��hault, J., Moderski, R., Moulin, E., Naumann, C. L., Naumann-Godo, M., de Naurois, M., Nedbal, D., Nekrassov, D., Nguyen, N., Nicholas, B., Niemiec, J., Nolan, S. J., Ohm, S., Wilhelmi, E. de Ona, Opitz, B., Ostrowski, M., Oya, I., Panter, M., Arribas, M. Paz, Pedaletti, G., Pelletier, G., Petrucci, P. -O., Pita, S., P��hlhofer, G., Punch, M., Quirrenbach, A., Raue, M., Rayner, S. M., Reimer, A., Reimer, O., Renaud, M., Reyes, R. de los, Rieger, F., Ripken, J., Rob, L., Rosier-Lees, S., Rowell, G., Rudak, B., Rulten, C. B., Ruppel, J., Sahakian, V., Sanchez, D., Santangelo, A., Schlickeiser, R., Sch��ck, F. M., Schulz, A., Schwanke, U., Schwarzburg, S., Schwemmer, S., Sheidaei, F., Sikora, M., Skilton, J. L., Sol, H., Spengler, G., Stawarz, L., Steenkamp, R., Stegmann, C., Stinzing, F., Stycz, K., Sushch, I., Szostek, A., Tavernet, J. -P., Terrier, R., Tluczykont, M., Valerius, K., van Eldik, C., Vasileiadis, G., Venter, C., Vialle, J. P., Viana, A., Vincent, P., V��lk, H. J., Volpe, F., Vorobiov, S., Vorster, M., Wagner, S. J., Ward, M., White, R., Wierzcholska, A., Zacharias, M., Zajczyk, A., Zdziarski, A. A., Zech, A., and Zechlin, H. -S.
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), Astrophysics of Galaxies (astro-ph.GA), FOS: Physical sciences
Abstract: Results obtained in very-high-energy (VHE; E > 100 GeV) ��-ray observations performed with the H.E.S.S. telescope array are used to investigate particle acceleration processes in the vicinity of the young massive stellar cluster Westerlund 1 (Wd 1). Imaging of Cherenkov light from ��-ray induced particle cascades in the Earth's atmosphere is used to search for VHE �� rays from the region around Wd 1. Possible catalogued counterparts are searched for and discussed in terms of morphology and energetics of the H.E.S.S. source. The detection of the degree-scale extended VHE ��-ray source HESS J1646-458 is reported based on 45 hours of H.E.S.S. observations performed between 2004 and 2008. The VHE ��-ray source is centred on the nominal position of Wd 1 and detected with a total statistical significance of ~20��. The emission region clearly extends beyond the H.E.S.S. point-spread function (PSF). The differential energy spectrum follows a power law in energy with an index of ��=2.19 \pm 0.08_{stat} \pm 0.20_{sys} and a flux normalisation at 1 TeV of ��_0 = (9.0 \pm 1.4_{stat} \pm 1.8_{sys}) x 10^{-12} TeV^{-1} cm^{-2} s^{-1}. The integral flux above 0.2 TeV amounts to (5.2 \pm 0.9) x 10^{-11} cm^{-2} s^{-1}. Four objects coincident with HESS J1646-458 are discussed in the search of a counterpart, namely the magnetar CXOU J164710.2-455216, the X-ray binary 4U 1642-45, the pulsar PSR J1648-4611 and the massive stellar cluster Wd 1. In a single-source scenario, Wd 1 is favoured as site of VHE particle acceleration. Here, a hadronic parent population would be accelerated within the stellar cluster. Beside this, there is evidence for a multi-source origin, where a scenario involving PSR J1648-4611 could be viable to explain parts of the VHE ��-ray emission of HESS J1646-458., 11 pages, 6 figures, accepted for publication in A&A
Published: 2011
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