Author: "Eichhorn, F." / Database: OpenAIRE - Searchworks@Jio Institute Digital Library Search Results

Your search keyword '"Eichhorn, F."' showing total 115 results

Start Over Author "Eichhorn, F." Database OpenAIRE

115 results on '"Eichhorn, F."'

1. Combined dark matter searches towards dwarf spheroidal galaxies with Fermi-LAT, HAWC, H.E.S.S., MAGIC, and VERITAS

Author: Charles, E., Di Mauro, M., Giuri, C., Salazar-Gallegos, D., Zitzer, B., Abeysekara, A. U., Albert, A., Alfaro, R., Alvarez, C., Álvarez, J. D., Angeles Camacho, J. R., Arteaga-Velázquez, J. C., Arunbabu, K. P., Avila Rojas, D., Ayala Solares, H. A., Babu, R., Baghmanyan, V., Barber, A. S., Becerra Gonzalez, J., Belmont-Moreno, E., Benzvi, S. Y., Berley, D., Brisbois, C., Caballero-Mora, K. S., Capistrán, T., Carramiñana, A., Casanova, S., Chaparro-Amaro, O., Cotti, U., Cotzomi, J., Coutiño León, S., La Fuente, E., León, C., Diaz-Cruz, L., Diaz Hernandez, R., Díaz-Vélez, J. C., Dingus, B. L., Durocher, M., Duvernois, M. A., Ellsworth, R. W., Engel, K., Espinoza, C., Fan, K. L., Fang, K., Fernández Alonso, M., Fick, B., Fleischhack, H., Flores, J. L., Fraija, N. I., Garcia, D., García-González, J. A., García-Luna, J. L., García-Torales, G., Garfias, F., Giacinti, G., Goksu, H., González, M. M., Goodman, J. A., Harding, J. P., Hernandez, S., Herzog, I., Hinton, J., Hona, B., Huang, D., Hueyotl-Zahuantitla, F., Hui, C. M., Humensky, B., Hüntemeyer, P., Iriarte, A., Jardin-Blicq, A., Jhee, H., Joshi, V., Kieda, D., Kunde, G. J., Kunwar, S., Lara, A., Lee, J., Lee, W. H., Lennarz, D., León Vargas, H., Linnemann, J., Longinotti, A. L., López-Coto, R., Luis-Raya, G., Lundeen, J., Malone, K., Marandon, V., Martinez, O., Martinez-Castellanos, I., Martínez-Huerta, H., Martínez-Castro, J., Matthews, J. A. J., Mcenery, J., Miranda-Romagnoli, P., Morales-Soto, J. A., Moreno, E., Mostafá, M., Nayerhoda, A., Nellen, L., Newbold, M., Nisa, M. U., Noriega-Papaqui, R., Olivera-Nieto, L., Omodei, N., Peisker, A., Pérez Araujo, Y., Pérez-Pérez, E. G., Rho, C. D., Rivière, C., Rosa-Gonzalez, D., Ruiz-Velasco, E., Ryan, J., Salazar, H., Salesa Greus, F., Sandoval, A., Schneider, M., Schoorlemmer, H., Serna-Franco, J., Sinnis, G., Smith, A. J., Springer, R. W., Surajbali, P., Taboada, I., Tanner, M., Tollefson, K., Torres, I., Torres-Escobedo, R., Turner, R., Ureña-Mena, F., Villaseñor, L., Wang, X., Watson, I. J., Weisgarber, T., Werner, F., Willox, E., Wood, J., Yodh, G. B., Zepeda, A., Zhou, H., Abdallah, H., Adam, R., Aharonian, F., Ait Benkhali, F., Angüner, E. O., Arcaro, C., Armand, C., Armstrong, T., Ashkar, H., Backes, M., Barbosa Martins, V., Barnacka, A., Barnard, M., Becherini, Y., Berge, D., Bernlöhr, K., Bi, B., Böttcher, M., Boisson, C., Bolmont, J., Bony Lavergne, M., Breuhaus, M., Brun, F., Brun, P., Bryan, M., Büchele, M., Bulik, T., Bylund, T., Caroff, S., Carosi, A., Chand, T., Chandra, S., Chen, A., Cotter, G., Curyło, M., Damascene Mbarubucyeye, J., Davids, I. D., Davies, J., Deil, C., Devin, J., Dewilt, P., Dirson, L., Djannati-Ataï, A., Dmytriiev, A., Donath, A., Doroshenko, V., Duffy, C., Dyks, J., Egberts, K., Eichhorn, F., Einecke, S., Emery, G., Ernenwein, J. -P, Feijen, K., Fegan, S., Fiasson, A., Fichet Clairfontaine, G., Fontaine, G., Funk, S., Füßling, M., Gabici, S., Gallant, Y. A., Giavitto, G., Giunti, L., Glawion, D., Glicenstein, J. F., Gottschall, D., Grondin, M. -H, Hahn, J., Haupt, M., Hermann, G., Hinton, J. A., Hofmann, W., Hoischen, C., Holch, T. L., Holler, M., Hörbe, M., Horns, D., Huber, D., Jamrozy, M., Jankowsky, D., Jankowsky, F., Jung-Richardt, I., Kasai, E., Kastendieck, M. A., Katarzyński, K., Katz, U., Khangulyan, D., Khélifi, B., Klepser, S., Kluźniak, W., Komin, Nu, Konno, R., Kosack, K., Kostunin, D., Kreter, M., Lamanna, G., Lemière, A., Lemoine-Goumard, M., Lenain, J. -P, Levy, C., Lohse, T., Lypova, I., Mackey, J., Majumdar, J., Malyshev, D., Marchegiani, P., Marcowith, A., Mares, A., Martì-Devesa, G., Marx, R., Maurin, G., Meintjes, P. J., Meyer, M., Moderski, R., Mohamed, M., Mohrmann, L., Montanari, A., Moore, C., Morris, P., Moulin, E., Muller, J., Murach, T., Nakashima, K., Naurois, M., Ndiyavala, H., Niederwanger, F., Niemiec, J., Oakes, L., O’brien, P., Odaka, H., Ohm, S., Ona Wilhelmi, E., Ostrowski, M., Panter, M., Panny, S., Parsons, R. D., Peron, G., Peyaud, B., Piel, Q., Pita, S., Poireau, V., Priyana Noel, A., Prokhorov, D. A., Prokoph, H., Pühlhofer, G., Punch, M., Quirrenbach, A., Raab, S., Rauth, R., Reichherzer, P., Reimer, A., Reimer, O., Remy, Q., Renaud, M., Rieger, F., Rinchiuso, L., Romoli, C., Rowell, G., Rudak, B., Sahakian, V., Sailer, S., Sanchez, D. A., Santangelo, A., Sasaki, M., Scalici, M., Schüssler, F., Schutte, H. M., Schwanke, U., Schwemmer, S., Seglar-Arroyo, M., Senniappan, M., Seyffert, A. S., Shafi, N., Shiningayamwe, K., Simoni, R., Sinha, A., Sol, H., Specovius, A., Spencer, S., Spir-Jacob, M., Stawarz, Ł., Sun, L., Steenkamp, R., Stegmann, C., Steinmassl, S., Steppa, C., Takahashi, T., Tavernier, T., Taylor, A. M., Terrier, R., Tiziani, D., Tluczykont, M., Tomankova, L., Trichard, C., Tsirou, M., Tuffs, R., Uchiyama, Y., Walt, D. J., Eldik, C., Rensburg, C., Soelen, B., Vasileiadis, G., Veh, J., Venter, C., Vincent, P., Vink, J., Völk, H. J., Vuillaume, T., Wadiasingh, Z., Wagner, S. J., Watson, J., White, R., Wierzcholska, A., Wong, Y. W., Yusafzai, A., Zacharias, M., Zanin, R., Zargaryan, D., Zdziarski, A. A., Zech, A., Zhu, S., Zorn, J., Zouari, S., Z̀ywucka, N., Acciari, V. A., Ansoldi, S., Antonelli, L. A., Arbet Engels, A., Artero, M., Asano, K., Baack, D., Babić, A., Baquero, A., Barres Almeida, U., Barrio, J. A., Batković, I., Becerra González, J., Bednarek, W., Bellizzi, L., Bernardini, E., Bernardos, M., Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Biland, A., Blanch, O., Bökenkamp, H., Bonnoli, G., Bošnjak, Ž, Busetto, G., Carosi, R., Ceribella, G., Cerruti, M., Chai, Y., Chilingarian, A., Cikota, S., Colak, S. M., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., D’amico, G., D’elia, V., Da Vela, P., Dazzi, F., Angelis, A., Lotto, B., Delfino, M., Delgado, J., Delgado Mendez, C., Depaoli, D., Di Pierro, F., Di Venere, L., Do Souto Espiñeira, E., Do-Minis Prester, D., Donini, A., Dorner, D., Doro, M., Elsaesser, D., Fallah Ramazani, V., Fattorini, A., Fonseca, M. V., Font, L., Fruck, C., Fukami, S., Fukazawa, Y., García López, R. J., Garczarczyk, M., Gasparyan, S., Gaug, M., Giglietto, N., Giordano, F., Gliwny, P., Godinović, N., Green, J. G., Green, D., Hadasch, D., Hahn, A., Heckmann, L., Herrera, J., Hoang, J., Hrupec, D., Hütten, M., Inada, T., Ishio, K., Iwamura, Y., Jiménez Martínez, I., Jormanainen, J., Jouvin, L., Karjalainen, M., Kerszberg, D., Kobayashi, Y., Kubo, H., Kushida, J., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Linhoff, L., Lombardi, S., Longo, F., López-Moya, M., López-Oramas, A., Loporchio, S., Machado Oliveira Fraga, B., Maggio, C., Majumdar, P., Makariev, M., Mallamaci, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martínez, M., Mazin, D., Menchiari, S., Mender, S., Mićanović, S., Miceli, D., Miener, T., Miranda, J. M., Mirzoyan, R., Molina, E., Moralejo, A., Morcuende, D., Moreno, V., Moretti, E., Nakamori, T., Nava, L., Neustroev, V., Nigro, C., Nilsson, K., Nishijima, K., Noda, K., Nozaki, S., Ohtani, Y., Oka, T., Otero-Santos, J., Paiano, S., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Pavletić, L., Peñil, P., Persic, M., Pihet, M., Prada Moroni, P. G., Prandini, E., Priyadarshi, C., Puljak, I., Rhode, W., Ribó, M., Rico, J., Righi, C., Rugliancich, A., Sahakyan, N., Saito, T., Sakurai, S., Satalecka, K., Saturni, F. G., Schleicher, B., Schmidt, K., Schweizer, T., Sitarek, J., Šnidarić, I., Dorota Sobczynska, Spolon, A., Stamerra, A., Strišković, J., Strom, D., Strzys, M., Suda, Y., Surić, T., Takahashi, M., Takeishi, R., Tavecchio, F., Temnikov, P., Terzić, T., Teshima, M., Tosti, L., Truzzi, S., Tutone, A., Ubach, S., Scherpenberg, J., Vanzo, G., Vazquez Acosta, M., Ventura, S., Verguilov, V., Vigorito, C. F., Vitale, V., Vovk, I., Will, M., Wunderlich, C., Yamamoto, T., Zarić, D., Adams, C. B., Archer, A., Benbow, W., Brill, A., Buckley, J. H., Capasso, M., Christiansen, J. L., Chromey, A. J., Errando, M., Falcone, A., Farrell, A., Feng, Q., Foote, G. M., Fortson, L., Furniss, A., Gent, A., Gillanders, G. H., Gueta, O., Hanna, D., Hervet, O., Holder, J., Humensky, T. B., Jin, W., Kaaret, P., Kertzman, M., Kleiner, T. K., Kumar, S., Lang, M. J., Lundy, M., Maier, G., Mcgrath, C. E., Moriarty, P., Mukherjee, R., Nieto, D., Nievas-Rosillo, M., O’brien, S., Ong, R. A., Otte, A. N., Patel, S. R., Patel, S., Pfrang, K., Pohl, M., Prado, R. R., Pueschel, E., Quinn, J., Ragan, K., Reynolds, P. T., Ribeiro, D., Roache, E., Ryan, J. L., Sadeh, I., Santander, M., Sembroski, G. H., Shang, R., Tak, D., Vassiliev, V. V., Weinstein, A., Williams, D. A., Williamson, T. J., 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), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Hess, HAWC, VERITAS, MAGIC, H.E.S.S., Fermi-LAT, Naurois , Mathieu, Ona-Wilhelmi , Emma, and Bony , Mathieu
Subjects: data analysis method, talk: Berlin 2021/07/15, FOS: Physical sciences, dark matter: signature, dark matter: direct detection, WIMP: dark matter, channel cross section: upper limit, annihilation [dark matter], GLAST, High Energy Physics - Experiment, dark matter [WIMP], WIMP: annihilation, High Energy Physics - Experiment (hep-ex), Tellurium compounds, Germanium compounds, HESS, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Dark Matter, ddc:530, annihilation [WIMP], ComputingMilieux_MISCELLANEOUS, direct detection [dark matter], High Energy Astrophysical Phenomena (astro-ph.HE), energy: high, upper limit [channel cross section], background, Gamma rays, dark matter: annihilation, Berlin 2021/07/15 [talk], sensitivity, Galaxies, Maximum likelihood estimation, MAGIC, mass dependence, Dark matter searches, high [energy], VERITAS, galaxy, signature [dark matter], Astrophysics - High Energy Astrophysical Phenomena, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], HAWC, experimental results
Abstract: Cosmological and astrophysical observations suggest that 85% of the total matter of the Universe is made of Dark Matter (DM). However, its nature remains one of the most challenging and fundamental open questions of particle physics. Assuming particle DM, this exotic form of matter cannot consist of Standard Model (SM) particles. Many models have been developed to attempt unraveling the nature of DM such as Weakly Interacting Massive Particles (WIMPs), the most favored particle candidates. WIMP annihilations and decay could produce SM particles which in turn hadronize and decay to give SM secondaries such as high energy γ rays. In the framework of indirect DM search, observations of promising targets are used to search for signatures of DM annihilation. Among these, the dwarf spheroidal galaxies (dSphs) are commonly favored owing to their expected high DM content and negligible astrophysical background. In this work, we present the very first combination of 20 dSph observations, performed by the Fermi-LAT, HAWC, H.E.S.S., MAGIC, and VERITAS collaborations in order to maximize the sensitivity of DM searches and improve the current results. We use a joint maximum likelihood approach combining each experiment’s individual analysis to derive more constraining upper limits on the WIMP DM self-annihilation cross-section as a function of DM particle mass. We present new DM constraints over the widest mass range ever reported, extending from 5 GeV to 100 TeV thanks to the combination of these five different γ-ray instruments., PoS: Proceedings of Science, 395, ISSN:1824-8039, Proceedings of 37th International Cosmic Ray Conference
Published: 2022

2. Searching for TeV Gamma-Ray Emission from SGR 1935+2154 during Its 2020 X-Ray and Radio Bursting Phase

Author: Collaboration, H. E. S. S., Abdalla, H., Aharonian, F., Benkhali, F. Ait, Anguner, E. O., Arcaro, C., Armand, C., Armstrong, T., Ashkar, H., Backes, M., Baghmanyan, V., Martins, V. Barbosa, Barnacka, A., Barnard, M., Becherini, Y., Berge, D., Bernlohr, K., Bi, B., Bottcher, M., Boisson, C., Bolmont, J., de Lavergne, M. de Bony, Breuhaus, M., Brose, R., Brun, F., Brun, P., Bryan, M., Buchele, M., Bulik, T., Bylund, T., Cangemi, F., Caroff, S., Carosi, A., Casanova, S., Chambery, P., Chand, T., Chandra, S., Chen, A., Cotter, G., lo, M. Cury, Mbarubucyeye, J. Damascene, Davids, I. D., Davies, J., Deil, C., Devin, J., Dirson, L., Djannati-Ata��, A., Dmytriiev, A., Donath, A., Doroshenko, V., Dreyer, L., Duffy, C., Plessis, L. Du, Dyks, J., Egberts, K., Eichhorn, F., Einecke, S., Emery, G., Ernenwein, J. -P., Feijen, K., Fegan, S., Fiasson, A., de Clairfontaine, G. Fichet, Fontaine, G., Funk, S., F��ling, M., Gabici, S., Gallant, Y. A., Ghafourizade, S., Giavitto, G., Giunti, L., Glawion, D., Glicenstein, J. F., Grondin, M. -H., Hahn, J., Haupt, M., Hattingh, S., Hermann, G., Hinton, J. A., Hofmann, W., Hoischen, C., Holch, T. L., Holler, M., Horbe, M., Horns, D., Huang, Z., Huber, D., Jamrozy, M., Jankowsky, D., Jankowsky, F., Jardin-Blicq, A., Joshi, V., Jung-Richardt, I., Kasai, E., Kastendieck, M. A., Katarzy��ski, K., Katz, U., Khangulyan, D., Kh��lifi, B., Klepser, S., Klu��niak, W., Komin, Nu., Konno, R., Kosack, K., Kostunin, D., Kreter, M., Mezek, G. Kukec, Kundu, A., Lamanna, G., Lemi��re, A., Lemoine-Goumard, M., Lenain, J. -P., Stum, S. Le, Leuschner, F., Levy, C., Lohse, T., Luashvili, A., Lypova, I., Mackey, J., Majumdar, J., Malyshev, D., Marandon, V., Marchegiani, P., Marcowith, A., Mares, A., Mart��-Devesa, G., Marx, R., Maurin, G., Meintjes, P. J., Meyer, M., Mitchell, A., Moderski, R., Mohrmann, L., Montanari, A., Moore, C., Morris, P., Moulin, E., Muller, J., Murach, T., Nakashima, K., Nayerhoda, A., de Naurois, M., Ndiyavala, H., Niemiec, J., Oakes, L., O'Brien, P., Odaka, H., Ohm, S., Olivera-Nieto, L., Wilhelmi, E. de Ona, Ostrowski, M., Panny, S., Panter, M., Parsons, R. D., Peron, G., Peyaud, B., Piel, Q., Pita, S., Poireau, V., Noel, A. Priyana, Prokhorov, D. A., Prokoph, H., P��hlhofer, G., Punch, M., Quirrenbach, A., Raab, S., Rauth, R., Reichherzer, P., Reimer, A., Reimer, O., Remy, Q., Renaud, M., Reville, B., Rieger, F., Rinchiuso, L., Romoli, C., Rowell, G., Rudak, B., Ricarte, H. Rueda, Ruiz-Velasco, E., Sahakian, V., Sailer, S., Salzmann, H., Sanchez, D. A., Santangelo, A., Sasaki, M., Sch��fer, J., Sch��ssler, F., Schutte, H. M., Schwanke, U., Seglar-Arroyo, M., Senniappan, M., Seyffert, A. S., Shafi, N., Shapopi, J. N. S., Shiningayamwe, K., Simoni, R., Sinha, A., Sol, H., Spackman, H., Specovius, A., Spencer, S., Spir-Jacob, M., Stawarz, L., Sun, L., Steenkamp, R., Stegmann, C., Steinmassl, S., Steppa, C., Takahashi, T., Tanaka, T., Tavernier, T., Taylor, A. M., Terrier, R., Thiersen, J. H. E., Thorpe-Morgan, C., Tiziani, D., Tluczykont, M., Tomankova, L., Trichard, C., Tsirou, M., Tsuji, N., Tuffs, R., Uchiyama, Y., van der Walt, D. J., van Eldik, C., van Rensburg, C., van Soelen, B., Vasileiadis, G., Veh, J., Venter, C., Vincent, P., Vink, J., V��lk, H. J., Wadiasingh, Z., Wagner, S. J., Watson, J., Werner, F., White, R., Wierzcholska, A., deWilt, P., Wong, Yu Wun, Yassin, H., Yusafzai, A., Zacharias, M., Zanin, R., Zargaryan, D., Zdziarski, A. A., Zech, A., Zhu, S. J., Zorn, J., Zouari, S., ��ywucka, N., Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), 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), Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE (UMR_7585)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), 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)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Laboratoire Univers et Particules de Montpellier (LUPM), 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 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), Linnaeus University, North-West University [Potchefstroom] (NWU), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), and 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)
Subjects: Radio transient sources, [PHYS.ASTR.HE]Physics [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], Gamma-ray telescopes, VHE [gamma ray], satellite, brightness, FOS: Physical sciences, GLAST, Burst astrophysics, Gamma-ray transient sources, emission [gamma ray], HESS, TeV, Magnetars, Soft gamma-ray repeaters, ddc:530, High Energy Astrophysical Phenomena (astro-ph.HE), radio wave, Gamma-ray sources, Gamma-ray astronomy, temperature, magnetar, ddc:520, high [energy], galaxy, Gamma-rays, Astrophysics - High Energy Astrophysical Phenomena, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], High energy astrophysics, burst [X-ray]
Abstract: Magnetar hyperflares are the most plausible explanation for fast radio bursts (FRB) -- enigmatic powerful radio pulses with durations of several milliseconds and high brightness temperatures. The first observational evidence for this scenario was obtained in 2020 April when a FRB was detected from the direction of the Galactic magnetar and soft gamma-ray repeater SGR\,1935+2154. The FRB was preceded by two gamma-ray outburst alerts by the BAT instrument aboard the Swift satellite, which triggered follow-up observations by the High Energy Stereoscopic System (H.E.S.S.). H.E.S.S. has observed SGR\,1935+2154 for 2 hr on 2020 April 28. The observations are coincident with X-ray bursts from the magnetar detected by INTEGRAL and Fermi-GBM, thus providing the first very high energy (VHE) gamma-ray observations of a magnetar in a flaring state. High-quality data acquired during these follow-up observations allow us to perform a search for short-time transients. No significant signal at energies $E>0.6$~TeV is found and upper limits on the persistent and transient emission are derived. We here present the analysis of these observations and discuss the obtained results and prospects of the H.E.S.S. follow-up program for soft gamma-ray repeaters., Received 2021 June 13; accepted 2021 June 28; published 2021 September 29
Published: 2021

3. Searching for TeV Gamma-Ray Emission from SGR 1935+2154 during Its 2020 X-Ray and Radio Bursting Phase

Author: Abdalla, H., Aharonian, F., Ait Benkhali, F., Angüner, E. O., Arcaro, C., Armand, C., Armstrong, T., Ashkar, H., Backes, M., Baghmanyan, V., Barbosa Martins, V., Barnacka, A., Barnard, M., Becherini, Y., Berge, D., Bernlöhr, K., Bi, B., Böttcher, M., Boisson, C., Bolmont, J., de Bony de Lavergne, M., Breuhaus, M., Brose, R., Brun, F., Brun, P., Bryan, M., Büchele, M., Bulik, T., Bylund, T., Cangemi, F., Caroff, S., Carosi, A., Casanova, S., Chambery, P., Chand, T., Chandra, S., Chen, A., Cotter, G., Curyło, M., Damascene Mbarubucyeye, J., Davids, I. D., Davies, J., Deil, C., Devin, J., Dirson, L., Djannati-Ataï, A., Dmytriiev, A., Donath, A., Doroshenko, V., Dreyer, L., Duffy, C., Du Plessis, L., Dyks, J., Egberts, K., Eichhorn, F., Einecke, S., Emery, G., Ernenwein, J.-P., Feijen, K., Fegan, S., Fiasson, A., Fichet de Clairfontaine, G., Fontaine, G., Funk, S., Füßling, M., Gabici, S., Gallant, Y. A., Ghafourizade, S., Giavitto, G., Giunti, L., Glawion, D., Glicenstein, J. F., Grondin, M.-H., Hahn, J., Haupt, M., Hattingh, S., Hermann, G., Hinton, J. A., Hofmann, W., Hoischen, C., Holch, T. L., Holler, M., Hörbe, M., Horns, D., Huang, Z., Huber, D., Jamrozy, M., Jankowsky, D., Jankowsky, F., Jardin-Blicq, A., Joshi, V., Jung-Richardt, I., Kasai, E., Kastendieck, M. A., Katarzyński, K., Katz, U., Khangulyan, D., Khélifi, B., Klepser, S., and Kluźniak, W.
Subjects: ddc:520, ddc:530, 520 Astronomie und zugeordnete Wissenschaften, 530 Physik
Abstract: Magnetar hyperflares are the most plausible explanation for fast radio bursts (FRBs)—enigmatic powerful radio pulses with durations of several milliseconds and high brightness temperatures. The first observational evidence for this scenario was obtained in 2020 April when an FRB was detected from the direction of the Galactic magnetar and soft gamma-ray repeater SGR 1935+2154. The FRB was preceded by two gamma-ray outburst alerts by the BAT instrument aboard the Swift satellite, which triggered follow-up observations by the High Energy Stereoscopic System (H.E.S.S.). H.E.S.S. observed SGR 1935+2154 for 2 hr on 2020 April 28. The observations are coincident with X-ray bursts from the magnetar detected by INTEGRAL and Fermi-GBM, thus providing the first very high energy gamma-ray observations of a magnetar in a flaring state. High-quality data acquired during these follow-up observations allow us to perform a search for short-time transients. No significant signal at energies E > 0.6 TeV is found, and upper limits on the persistent and transient emission are derived. We here present the analysis of these observations and discuss the obtained results and prospects of the H.E.S.S. follow-up program for soft gamma-ray repeaters.
Published: 2021

4. Evidence of 100 TeV γ-ray emission from HESS J1702-420

Author: Abdalla, H., Aharonian, F., Barbosa Martins, Victor, Lemoine-Goumard, M., Lenain, J.-P., Leuschner, F., Levy, C., Lohse, T., Lypova, Iryna, Mackey, J., Majumdar, Jhilik, Malyshev, D., Barnacka, A., Marandon, V., Marchegiani, P., Marcowith, A., Mares, A., Martí-Devesa, G., Marx, R., Maurin, G., Meintjes, P. J., Meyer, M., Mitchell, A., Barnard, M., Moderski, R., Mohrmann, L., Montanari, A., Moore, C., Morris, P., Moulin, E., Muller, J., Murach, Thomas, Nakashima, K., Nayerhoda, A., Becherini, Y., de Naurois, M., Ndiyavala, H., Niemiec, J., Oakes, L., O'Brien, P., Odaka, H., Ohm, Stefan, Olivera-Nieto, L., de Ona Wilhelmi, Emma Maria, Ostrowski, M., Berge, D., Panny, S., Panter, M., Parsons, R. D., Peron, G., Peyaud, B., Piel, Q., Pita, S., Poireau, V., Noel, A. Priyana, Prokhorov, D. A., Bernlöhr, K., Prokoph, Heike, Pühlhofer, G., Punch, M., Quirrenbach, A., Raab, S., Rauth, R., Reichherzer, P., Reimer, A., Reimer, O., Remy, Q., Bi, B., Renaud, M., Rieger, F., Rinchiuso, L., Romoli, C., Rowell, G., Rudak, B., Ruiz-Velasco, E., Sahakian, V., Sailer, S., Salzmann, H., Böttcher, M., Sanchez, D. A., Santangelo, A., Sasaki, M., Scalici, M., Schäfer, J., Schüssler, F., Schutte, H. M., Schwanke, U., Seglar-Arroyo, M., Senniappan, M., Boisson, C., Seyffert, A. S., Shafi, N., Shapopi, J. N. S., Shiningayamwe, K., Simoni, R., Sinha, A., Sol, H., Specovius, A., Spencer, S., Spir-Jacob, M., Bolmont, J., Stawarz, L., Sun, L., Steenkamp, R., Stegmann, Christian, Steinmassl, S., Steppa, C., Takahashi, T., Tavernier, T., Taylor, Andrew, Terrier, R., Benkhali, F. Ait, de Bony de Lavergne, M., Thiersen, J. H. E., Tiziani, D., Tluczykont, M., Tomankova, L., Trichard, C., Tsirou, M., Tuffs, R., Uchiyama, Y., van der Walt, D. J., van Eldik, C., Breuhaus, M., van Rensburg, C., van Soelen, B., Vasileiadis, G., Veh, J., Venter, C., Vincent, P., Vink, J., Völk, H. J., Wadiasingh, Z., Wagner, S. J., Brun, F., Watson, J., Werner, F., White, R., Wierzcholska, A., Wong, Yu Wun, Yusafzai, A., Zacharias, M., Zanin, R., Zargaryan, D., Zdziarski, A. A., Brun, P., Zech, A., Zhu, Sylvia Jiechen, Zorn, J., Zouari, S., Żywucka, N., Acero, F., H. E. S. S. Collaboration, Bryan, M., Büchele, M., Bulik, T., Bylund, T., Caroff, S., Carosi, A., Angüner, E. O., Casanova, S., Chand, T., Chandra, S., Chen, A., Cotter, G., Curyło, M., Mbarubucyeye, Jean Damascene, Davids, I. D., Davies, J., Deil, C., Arcaro, C., Devin, J., Dirson, L., Djannati-Ataï, A., Dmytriiev, A., Donath, A., Doroshenko, V., Dreyer, L., Duffy, C., Dyks, J., Egberts, K., Armand, C., Eichhorn, F., Einecke, S., Emery, G., Ernenwein, J.-P., Feijen, K., Fegan, S., Fiasson, A., Fichet de Clairfontaine, G., Fontaine, G., Funk, S., Armstrong, T., Füssling, Matthias, Gabici, S., Gallant, Y. A., Giavitto, Gianluca, Giunti, L., Glawion, D., Glicenstein, J. F., Grondin, M.-H., Hahn, J., Haupt, Maria, Ashkar, H., Hermann, G., Hinton, J. A., Hofmann, W., Hoischen, C., Holch, Tim Lukas, Holler, M., Hörbe, M., Horns, D., Huber, D., Jamrozy, M., Backes, M., Jankowsky, D., Jankowsky, F., Jardin-Blicq, A., Joshi, V., Jung-Richardt, I., Kasai, E., Kastendieck, M. A., Katarzyński, K., Katz, U., Khangulyan, D., Baghmanyan, V., Khélifi, B., Klepser, S., Kluźniak, W., Komin, Nu., Konno, Ruslan, Kosack, K., Kostunin, D., Kreter, M., Lamanna, G., Lemière, A., Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), 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), 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 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)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE (UMR_7585)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), 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)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), 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 Univers et Particules de Montpellier (LUPM), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), H.E.S.S., 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 National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), 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), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2), Gravitation and Astroparticle Physics Amsterdam, and High Energy Astrophys. & Astropart. Phys (API, FNWI)
Subjects: Photon, dimension: 3, Hadron, Astrophysics, GeV, 01 natural sciences, law.invention, law, HESS, Spectral slope, site, High Energy Stereoscopic System, Ultra-high-energy cosmic ray, 010303 astronomy & astrophysics, energy spectrum [gamma ray], Physics, energy: high, cosmic radiation: spectrum, Gamma ray, non-thermal [radiation mechanisms], 3. Good health, curvature, 3 [dimension], high [energy], Astrophysics - High Energy Astrophysical Phenomena, Astrophysics::High Energy Astrophysical Phenomena, UHE [cosmic radiation], Context (language use), Cosmic ray, gamma ray: energy spectrum, GLAST, energy [p], solids, cosmic rays, 5/3, 0103 physical sciences, data analysis [methods], TeV, spectrum [cosmic radiation], cosmic radiation: UHE, 010308 nuclear & particles physics, Astronomy and Astrophysics, Particle accelerator, acceleration, Galaxy, p: energy, Space and Planetary Science, ddc:520, spectral, galaxy, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], general [gamma rays], Energy (signal processing), Fermi Gamma-ray Space Telescope
Abstract: The identification of PeVatrons, hadronic particle accelerators reaching the knee of the cosmic ray spectrum (few $10^{15}$ eV), is crucial to understand the origin of cosmic rays in the Galaxy. We provide an update on the unidentified source HESS J1702-420, a promising PeVatron candidate. We present new observations of HESS J1702-420 made with the High Energy Stereoscopic System (H.E.S.S.), and processed using improved analysis techniques. The analysis configuration was optimized to enhance the collection area at the highest energies. We applied a three-dimensional (3D) likelihood analysis to model the source region and adjust non thermal radiative spectral models to the $\gamma$-ray data. We also analyzed archival data from the Fermi Large Area Telescope (LAT) to constrain the source spectrum at $\gamma$-ray energies >10 GeV. We report the detection of a new source component called HESS J1702-420A, that was separated from the bulk of TeV emission at a $5.4\sigma$ confidence level. The power law $\gamma$-ray spectrum of HESS J1702-420A extends with an index of $\Gamma=1.53\pm0.19_\text{stat}\pm0.20_\text{sys}$ and without curvature up to the energy band 64-113 TeV, in which it was detected by H.E.S.S. at a $4.0\sigma$ confidence level. This brings evidence for the source emission up to $100\,\text{TeV}$, which makes HESS J1702-420A a compelling candidate site for the presence of extremely high energy cosmic rays. Remarkably, in a hadronic scenario, the cut-off energy of the proton distribution powering HESS J1702-420A is found to be higher than 0.5 PeV at a 95% confidence level. HESS J1702-420A becomes therefore one of the most solid PeVatron candidates detected so far in H.E.S.S. data, altough a leptonic origin of its emission could not be ruled out either., Comment: Accepted for publication in the 2. Astrophysical processes section of Astronomy & Astrophysics
Published: 2021

5. Search for dark matter annihilation in the dwarf irregular galaxy WLM with H.E.S.S

Author: Collaboration, H. E. S. S., Abdallah, H., Adam, R., Aharonian, F., Benkhali, F. Ait, Ang��ner, E. O., Arcaro, C., Armand, C., Armstrong, T., Ashkar, H., Backes, M., Baghmanyan, V., Martins, V. Barbosa, Barnacka, A., Barnard, M., Becherini, Y., Berge, D., Bernl��hr, K., Bi, B., B��ttcher, M., Boisson, C., Bolmont, J., de Lavergne, M. de Bony, Breuhaus, M., Brun, F., Brun, P., Bryan, M., B��chele, M., Bulik, T., Bylund, T., Caroff, S., Carosi, A., Casanova, S., Chand, T., Chandra, S., Chen, A., Cotter, G., Curylo, M., Mbarubucyeye, J. Damascene, Davids, I. D., Davies, J., Deil, C., Devin, J., deWilt, P., Dirson, L., Djannati-Ata��, A., Dmytriiev, A., Donath, A., Doroshenko, V., Duffy, C., Dyks, J., Egberts, K., Eichhorn, F., Einecke, S., Emery, G., Ernenwein, J. -P., Feijen, K., Fegan, S., Fiasson, A., de Clairfontaine, G. Fichet, Fontaine, G., Funk, S., F��ling, M., Gabici, S., Gallant, Y. A., Giavitto, G., Giunti, L., Glawion, D., Glicenstein, J. F., Gottschall, D., Grondin, M. -H., Hahn, J., Haupt, M., Hermann, G., Hinton, J. A., Hofmann, W., Hoischen, C., Holch, T. L., Holler, M., H��rbe, M., Horns, D., Huber, D., Jamrozy, M., Jankowsky, D., Jankowsky, F., Jardin-Blicq, A., Joshi, V., Jung-Richardt, I., Kasai, E., Kastendieck, M. A., Katarzy��ski, K., Katz, U., Khangulyan, D., Kh��lifi, B., Klepser, S., Kluzniak, W., Komin, Nu., Konno, R., Kosack, K., Kostunin, D., Kreter, M., Lamanna, G., Lemi��re, A., Lemoine-Goumard, M., Lenain, J. -P., Levy, C., Lohse, T., Lypova, I., Mackey, J., Majumdar, J., Malyshev, D., Marandon, V., Marchegiani, P., Marcowith, A., Mares, A., Mart��-Devesa, G., Marx, R., Maurin, G., Meintjes, P. J., Meyer, M., Moderski, R., Mohamed, M., Mohrmann, L., Montanari, A., Moore, C., Morris, P., Moulin, E., Muller, J., Murach, T., Nakashima, K., Nayerhoda, A., de Naurois, M., Ndiyavala, H., Niederwanger, F., Niemiec, J., Oakes, L., O'Brien, P., Odaka, H., Ohm, S., Olivera-Nieto, L., Wilhelmi, E. de Ona, Ostrowski, M., Panter, M., Panny, S., Parsons, R. D., Peron, G., Peyaud, B., Piel, Q., Pita, S., Poireau, V., Noel, A. Priyana, Prokhorov, D. A., Prokoph, H., P��hlhofer, G., Punch, M., Quirrenbach, A., Raab, S., Rauth, R., Reichherzer, P., Reimer, A., Reimer, O., Remy, Q., Renaud, M., Rieger, F., Rinchiuso, L., Romoli, C., Rowell, G., Rudak, B., Ruiz-Velasco, E., Sahakian, V., Sailer, S., Sanchez, D. A., Santangelo, A., Sasaki, M., Scalici, M., Sch��ssler, F., Schutte, H. M., Schwanke, U., Schwemmer, S., Seglar-Arroyo, M., Senniappan, M., Seyffert, A. S., Shafi, N., Shiningayamwe, K., Simoni, R., Sinha, A., Sol, H., Specovius, A., Spencer, S., Spir-Jacob, M., Stawarz, L., Sun, L., Steenkamp, R., Stegmann, C., Steinmassl, S., Steppa, C., Takahashi, T., Tavernier, T., Taylor, A. M., Terrier, R., Tiziani, D., Tluczykont, M., Tomankova, L., Trichard, C., Tsirou, M., Tuffs, R., Uchiyama, Y., van der Walt, D. J., van Eldik, C., van Rensburg, C., van Soelen, B., Vasileiadis, G., Veh, J., Venter, C., Vincent, P., Vink, J., V��lk, H. J., Vuillaume, T., Wadiasingh, Z., Wagner, S. J., Watson, J., Werner, F., White, R., Wierzcholska, A., Wong, Yu Wun, Yusafzai, A., Zacharias, M., Zanin, R., Zargaryan, D., Zdziarski, A. A., Zech, A., Zhu, S., Zorn, J., Zouari, S., and Zywucka, N.
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), High Energy Physics - Experiment (hep-ex), Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics::Galaxy Astrophysics, High Energy Physics - Experiment
Abstract: We search for an indirect signal of dark matter through very high-energy gamma rays from the Wolf-Lundmark-Melotte (WLM) dwarf irregular galaxy. The pair annihilation of dark matter particles would produce Standard Model particles in the final state such as gamma rays, which might be detected by ground-based Cherenkov telescopes. Dwarf irregular galaxies represent promising targets as they are dark matter dominated objects with well measured kinematics and small uncertainties on their dark matter distribution profiles. In 2018, the H.E.S.S. five-telescope array observed the dwarf irregular galaxy WLM for 18 hours. We present the first analysis based on data obtained from an imaging atmospheric Cherenkov telescope for this subclass of dwarf galaxy. As we do not observe any significant excess in the direction of WLM, we interpret the result in terms of constraints on the velocity-weighted cross section for dark matter pair annihilation as a function of the dark matter particle mass for various continuum channels as well as the prompt gamma-gamma emission. For the $\tau^+\tau^-$ channel the limits reach a $\langle \sigma v \rangle$ value of about $4\times 10^{-22}$ cm3s-1 for a dark matter particle mass of 1 TeV. For the prompt gamma-gamma channel, the upper limit reaches a $\langle \sigma v \rangle$ value of about $5 \times10^{-24}$ cm3s-1 for a mass of 370 GeV. These limits represent an improvement of up to a factor 200 with respect to previous results for the dwarf irregular galaxies for TeV dark matter search., Comment: 13 pages, 5 figures
Published: 2021

6. Evidence of 100 TeV $��$-ray emission from HESS J1702-420: A new PeVatron candidate

Author: Abdalla, H., Aharonian, F., Benkhali, F. Ait, Ang��ner, E. O., Arcaro, C., Armand, C., Armstrong, T., Ashkar, H., Backes, M., Baghmanyan, V., Martins, V. Barbosa, Barnacka, A., Barnard, M., Becherini, Y., Berge, D., Bernl��hr, K., Bi, B., B��ttcher, M., Boisson, C., Bolmont, J., de Lavergne, M. de Bony, Breuhaus, M., Brun, F., Brun, P., Bryan, M., B��chele, M., Bulik, T., Bylund, T., Caroff, S., Carosi, A., Casanova, S., Chand, T., Chandra, S., Chen, A., Cotter, G., Cury��o, M., Mbarubucyeye, J. Damascene, Davids, I. D., Davies, J., Deil, C., Devin, J., Dirson, L., Djannati-Atai, A., Dmytriiev, A., Donath, A., Doroshenko, V., Dreyer, L., Duffy, C., Dyks, J., Egberts, K., Eichhorn, F., Einecke, S., Emery, G., Ernenwein, J. -P., Feijen, K., Fegan, S., Fiasson, A., de Clairfontaine, G. Fichet, Fontaine, G., Funk, S., F��ling, M., Gabici, S., Gallant, Y. A., Giavitto, G., Giunti, L., Glawion, D., Glicenstein, J. F., Grondin, M. -H., Hahn, J., Haupt, M., Hermann, G., Hinton, J. A., Hofmann, W., Hoischen, C., Holch, T. L., Holler, M., H��rbe, M., Horns, D., Huber, D., Jamrozy, M., Jankowsky, D., Jankowsky, F., Jardin-Blicq, A., Joshi, V., Jung-Richardt, I., Kasai, E., Kastendieck, M. A., Katarzynski, K., Katz, U., Khangulyan, D., Kh��lifi, B., Klepser, S., Klu��niak, W., Komin, Nu., Konno, R., Kosack, K., Kostunin, D., Kreter, M., Lamanna, G., Lemi��re, A., Lemoine-Goumard, M., Lenain, J. -P., Leuschner, F., Levy, C., Lohse, T., Lypova, I., Mackey, J., Majumdar, J., Malyshev, D., Marandon, V., Marchegiani, P., Marcowith, A., Mares, A., Mart��-Devesa, G., Marx, R., Maurin, G., Meintjes, P. J., Meyer, M., Mitchell, A., Moderski, R., Mohrmann, L., Montanari, A., Moore, C., Morris, P., Moulin, E., Muller, J., Murach, T., Nakashima, K., Nayerhoda, A., de Naurois, M., Ndiyavala, H., Niemiec, J., Oakes, L., O'Brien, P., Odaka, H., Ohm, S., Olivera-Nieto, L., Wilhelmi, E. de Ona, Ostrowski, M., Panny, S., Panter, M., Parsons, R. D., Peron, G., Peyaud, B., Piel, Q., Pita, S., Poireau, V., Noel, A. Priyana, Prokhorov, D. A., Prokoph, H., P��hlhofer, G., Punch, M., Quirrenbach, A., Raab, S., Rauth, R., Reichherzer, P., Reimer, A., Reimer, O., Remy, Q., Renaud, M., Rieger, F., Rinchiuso, L., Romoli, C., Rowell, G., Rudak, B., Ruiz-Velasco, E., Sahakian, V., Sailer, S., Salzmann, H., Sanchez, D. A., Santangelo, A., Sasaki, M., Scalici, M., Sch��fer, J., Sch��ssler, F., Schutte, H. M., Schwanke, U., Seglar-Arroyo, M., Senniappan, M., Seyffert, A. S., Shafi, N., Shapopi, J. N. S., Shiningayamwe, K., Simoni, R., Sinha, A., Sol, H., Specovius, A., Spencer, S., Spir-Jacob, M., Stawarz, L., Sun, L., Steenkamp, R., Stegmann, C., Steinmassl, S., Steppa, C., Takahashi, T., Tavernier, T., Taylor, A. M., Terrier, R., Thiersen, J. H. E., Tiziani, D., Tluczykont, M., Tomankova, L., Trichard, C., Tsirou, M., Tuffs, R., Uchiyama, Y., van der Walt, D. J., van Eldik, C., van Rensburg, C., van Soelen, B., Vasileiadis, G., Veh, J., Venter, C., Vincent, P., Vink, J., V��lk, H. J., Wadiasingh, Z., Wagner, S. J., Watson, J., Werner, F., White, R., Wierzcholska, A., Wong, Yu Wun, Yusafzai, A., Zacharias, M., Zanin, R., Zargaryan, D., Zdziarski, A. A., Zech, A., Zhu, S. J., Zorn, J., Zouari, S., ��ywucka, N., and Acero, F.
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences
Abstract: The identification of PeVatrons, hadronic particle accelerators reaching the knee of the cosmic ray spectrum (few $10^{15}$ eV), is crucial to understand the origin of cosmic rays in the Galaxy. We provide an update on the unidentified source HESS J1702-420, a promising PeVatron candidate. We present new observations of HESS J1702-420 made with the High Energy Stereoscopic System (H.E.S.S.), and processed using improved analysis techniques. The analysis configuration was optimized to enhance the collection area at the highest energies. We applied a three-dimensional (3D) likelihood analysis to model the source region and adjust non thermal radiative spectral models to the $��$-ray data. We also analyzed archival data from the Fermi Large Area Telescope (LAT) to constrain the source spectrum at $��$-ray energies >10 GeV. We report the detection of a new source component called HESS J1702-420A, that was separated from the bulk of TeV emission at a $5.4��$ confidence level. The power law $��$-ray spectrum of HESS J1702-420A extends with an index of $��=1.53\pm0.19_\text{stat}\pm0.20_\text{sys}$ and without curvature up to the energy band 64-113 TeV, in which it was detected by H.E.S.S. at a $4.0��$ confidence level. This brings evidence for the source emission up to $100\,\text{TeV}$, which makes HESS J1702-420A a compelling candidate site for the presence of extremely high energy cosmic rays. Remarkably, in a hadronic scenario, the cut-off energy of the proton distribution powering HESS J1702-420A is found to be higher than 0.5 PeV at a 95% confidence level. HESS J1702-420A becomes therefore one of the most solid PeVatron candidates detected so far in H.E.S.S. data, altough a leptonic origin of its emission could not be ruled out either., Accepted for publication in the 2. Astrophysical processes section of Astronomy & Astrophysics
Published: 2021
Full Text: View/download PDF

7. Search for dark matter annihilation in the Wolf-Lundmark-Melotte dwarf irregular galaxy with H.E.S.S

Author: Abdallah, H., Adam, R., Baghmanyan, V., Lamanna, G., Lemière, A., Lemoine-Goumard, M., Lenain, J.-P., Levy, C., Lohse, T., Lypova, Iryna, Mackey, J., Majumdar, Jhilik, Malyshev, D., Barbosa Martins, Victor, Marandon, V., Marchegiani, P., Marcowith, A., Mares, A., Martì-Devesa, G., Marx, R., Maurin, G., Meintjes, P. J., Meyer, M., Barnacka, A., Moderski, R., Mohamed, M., Mohrmann, L., Montanari, A., Moore, C., Morris, P., Moulin, Jean-Francois, Muller, J., Murach, Thomas, Nakashima, K., Barnard, M., Nayerhoda, A., de Naurois, M., Ndiyavala, H., Niederwanger, F., Niemiec, J., Oakes, L., O'Brien, P., Odaka, H., Ohm, Stefan, Olivera-Nieto, L., Becherini, Y., de Ona Wilhelmi, Emma Maria, Ostrowski, M., Panter, M., Panny, S., Parsons, R. D., Peron, G., Peyaud, B., Piel, Q., Pita, S., Poireau, V., Berge, D., Noel, A. Priyana, Prokhorov, D. A., Prokoph, Heike, Pühlhofer, G., Punch, M., Quirrenbach, A., Raab, S., Rauth, R., Reichherzer, P., Reimer, A., Bernlöhr, K., Reimer, O., Remy, Q., Renaud, M., Rieger, F., Rinchiuso, L., Romoli, C., Rowell, G., Rudak, B., Ruiz-Velasco, E., Sahakian, V., Bi, B., Sailer, S., Sanchez, D. A., Santangelo, A., Sasaki, M., Scalici, M., Schüssler, F., Schutte, H. M., Schwanke, U., Schwemmer, S., Seglar-Arroyo, M., Böttcher, M., Senniappan, M., Seyffert, A. S., Shafi, N., Shiningayamwe, K., Simoni, R., Sinha, A., Sol, H., Specovius, A., Spencer, S., Spir-Jacob, M., Boisson, C., Stawarz, Ł., Sun, L., Steenkamp, R., Stegmann, Christian, Steinmassl, S., Steppa, C., Takahashi, T., Tavernier, T., Taylor, Andrew, Terrier, R., Aharonian, F., Bolmont, J., Tiziani, D., Tluczykont, M., Tomankova, L., Trichard, C., Tsirou, M., Tuffs, R., Uchiyama, Y., van der Walt, D. J., van Eldik, C., van Rensburg, C., de Bony de Lavergne, M., van Soelen, B., Vasileiadis, G., Veh, J., Venter, C., Vincent, P., Vink, J., Völk, H. J., Vuillaume, T., Wadiasingh, Z., Wagner, S. J., Breuhaus, M., Watson, J., Werner, F., White, R., Wierzcholska, A., Wong, Yu Wun, Yusafzai, A., Zacharias, M., Zanin, R., Zargaryan, D., Zdziarski, A. A., Brun, F., Zech, A., Zhu, Sylvia Jiechen, Zorn, J., Zouari, S., Z̀ywucka, N., H. E. S. S. Collaboration, Brun, P., Bryan, M., Büchele, M., Bulik, T., Bylund, T., Caroff, S., Benkhali, F. Ait, Carosi, A., Casanova, S., Chand, T., Chandra, S., Chen, A., Cotter, G., Curyło, M., Mbarubucyeye, Jean Damascene, Davids, I. D., Davies, J., Angüner, E. O., Deil, C., Devin, J., deWilt, P., Dirson, L., Djannati-Ataï, A., Dmytriiev, A., Donath, A., Doroshenko, V., Duffy, C., Dyks, J., Arcaro, C., Egberts, K., Eichhorn, F., Einecke, S., Emery, G., Ernenwein, J.-P., Feijen, K., Fegan, S., Fiasson, A., de Clairfontaine, G. Fichet, Fontaine, G., Armand, C., Funk, S., Füssling, Matthias, Gabici, S., Gallant, Y. A., Giavitto, Gianluca, Giunti, L., Glawion, D., Glicenstein, J. F., Gottschall, D., Grondin, M.-H., Armstrong, T., Hahn, J., Haupt, Maria, Hermann, G., Hinton, J. A., Hofmann, W., Hoischen, C., Holch, T. L., Holler, M., Hörbe, M., Horns, D., Ashkar, H., Huber, D., Jamrozy, M., Jankowsky, D., Jankowsky, F., Jardin-Blicq, A., Joshi, V., Jung-Richardt, I., Kasai, E., Kastendieck, M. A., Katarzyński, K., Backes, M., Katz, U., Khangulyan, D., Khélifi, B., Klepser, S., Kluźniak, W., Komin, Nu., Konno, Ruslan, Kosack, K., Kostunin, D., Kreter, M., 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), Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), 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), 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 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), Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE (UMR_7585)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), 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)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), 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), H.E.S.S., Collaboration, H.E.S.S., 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), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2), Gravitation and Astroparticle Physics Amsterdam, and High Energy Astrophys. & Astropart. Phys (API, FNWI)
Subjects: atmosphere [Cherenkov counter], Astrophysics::High Energy Astrophysical Phenomena, Dark matter, VHE [gamma ray], Cosmic ray, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, GeV, Cherenkov counter: atmosphere, 01 natural sciences, Cosmology, annihilation [dark matter], S030DMA, cosmic rays, S046PHB, HESS, 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], TeV, Experiments in gravity, ddc:530, photon photon, High Energy Stereoscopic System, high energy physics - experiment, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Dwarf galaxy, Physics, Experiments in gravity, cosmology, cosmic rays, astrophysics - high energy astrophysical phenomena, Annihilation, 010308 nuclear & particles physics, imaging, dark matter: annihilation, Galaxy, gamma ray: VHE, kinematics, galaxy, Irregular galaxy, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], cosmology
Abstract: Physical review / D 103(10), 102002 (2021). doi:10.1103/PhysRevD.103.102002, We search for an indirect signal of dark matter through very high-energy γ rays from the Wolf-Lundmark-Melotte (WLM) dwarf irregular galaxy. The pair annihilation of dark matter particles would produce Standard Model particles in the final state such as γ rays, which might be detected by ground-based Cherenkov telescopes. Dwarf irregular galaxies represent promising targets as they are dark matter dominated objects with well-measured kinematics and small uncertainties on their dark matter distribution profiles. In 2018, the five-telescopes of the high energy stereoscopic system observed the dwarf irregular galaxy WLM for 18 hours. We present the first analysis based on data obtained from an imaging atmospheric Cherenkov telescope for this subclass of dwarf galaxy. As we do not observe any significant excess in the direction of WLM, we interpret the result in terms of constraints on the velocity-weighted cross section for dark matter pair annihilation ⟨σv⟩ as a function of the dark matter particle mass for various continuum channels, as well as the prompt γγ emission. For the τ+τ- channel, the limits reach a ⟨σv⟩ value of about 4×10-22 cm3 s-1 for a dark matter particle mass of 1 TeV. For the prompt γγ channel, the upper limit reaches a ⟨σv⟩ value of about 5×10-24 cm3 s-1 for a mass of 370 GeV. These limits represent an improvement of up to a factor 200, with respect to previous results for the dwarf irregular galaxies for TeV dark matter search., Published by Inst., Melville, NY
Published: 2021

8. Search for dark matter annihilation signals from unidentified Fermi-LAT objects with H.E.S.S

Author: Abdalla, H., Aharonian, F., Benkhali, F. Ait, Angüner, E.O., Arcaro, C., Armand, C., Armstrong, T., Ashkar, H., Backes, M., Baghmanyan, V., Barbosa Martins, V., Barnacka, A., Barnard, M., Becherini, Y., Berge, D., Bernlöhr, K., Bi, B., Böttcher, M., Boisson, C., Bolmont, J., de Bony de Lavergne, M., Breuhaus, M., Brose, R., Brun, F., Brun, P., Bryan, M., Büchele, M., Bulik, T., Bylund, T., Cangemi, F., Caroff, S., Carosi, A., Casanova, S., Chambery, P., Chand, J. Catalano T., Chandra, S., Chen, A., Cotter, G., Curyło, M., Dalgleish, H., Mbarubucyeye, J. Damascene, Davids, I.D., Davies, J., Deil, C., Devin, J., Dirson, L., Djannati-Ataï, A., Dmytriiev, A., Donath, A., Doroshenko, V., Dreyer, L., Plessis, L. Du, Duffy, C., Dyks, J., Egberts, K., Eichhorn, F., Einecke, S., Emery, G., Ernenwein, J.-P., Feijen, K., Fegan, S., Fiasson, A., de Clairfontaine, G. Fichet, Fontaine, G., Funk, S., Füßling, M., Gabici, S., Gallant, Y.A., Giavitto, G., Giunti, L., Glawion, D., Glicenstein, J.F., Gottschall, D., Grondin, M.-H., Hattingh, S., Hahn, J., Haupt, M., Hermann, G., Hinton, J.A., Hofmann, W., Hoischen, C., Holch, T.L., Holler, M., Hörbe, M., Horns, D., Huang, Z., Huber, D., Jamrozy, M., Jankowsky, D., Jankowsky, F., Jardin-Blicq, A., Joshi, V., Jung-Richardt, I., Kasai, E., Katarzyński, K., Katz, U., Khangulyan, D., Khélifi, B., Klepser, S., Kluźniak, W., Komin, Nu., Konno, R., Kosack, K., Kostunin, D., Kreter, M., Mezek, G. Kukec, Kundu, A., Lamanna, G., Lemière, A., Lemoine-Goumard, M., Lenain, J.-P., Leuschner, F., Levy, C., Lohse, T., Luashvili, A., Lypova, I., Mackey, J., Majumdar, J., Malyshev, D., Marandon, V., Marchegiani, P., Marcowith, A., Mares, A., Martí-Devesa, G., Marx, R., Maurin, G., Meintjes, P.J., Meyer, M., Mitchell, A., Moderski, R., Mohrmann, L., Montanari, A., Moore, C., Morris, P., Moulin, E., Muller, J., Murach, T., Nakashima, K., Nayerhoda, A., de Naurois, M., Ndiyavala, H., Niemiec, J., Oakes, L., Odaka, H., Peyaud, B., Piel, Q., Noel, A., Oberholzer, L., O'Brien, P., Ohm, S., Olivera-Nieto, L., de Ona Wilhelmi, E., Ostrowski, M., Panter, M., Panny, S., Parsons, R.D., Peron, G., Pita, S., Poireau, V., Prokhorov, D.A., Prokoph, H., Pühlhofer, G., Punch, M., Quirrenbach, A., Raab, S., Rauth, R., Reichherzer, P., Reimer, A., Reimer, O., Remy, Q., Renaud, M., Rieger, F., Rinchiuso, L., Romoli, C., Rowell, G., Rudak, B., Ricarte, H. Rueda, Ruiz-Velasco, E., Sahakian, V., Sailer, S., Salzmann, H., Sanchez, D.A., Santangelo, A., Sasaki, M., Scalici, M., Schäfer, J., Schüssler, F., Schutte, H.M., Schwanke, U., Seglar-Arroyo, M., Senniappan, M., Seyffert, A.S., Shafi, N., Shapopi, J.N.S., Shiningayamwe, K., Simoni, R., Sinha, A., Sol, H., Spackman, H., Specovius, A., Spencer, S., Spir-Jacob, M., Stawarz, Ł., Sun, L., Steenkamp, R., Stegmann, C., Steinmassl, S., Steppa, C., Takahashi, T., Tanaka, T., Tavernier, T., Taylor, A.M., Terrier, R., Morgan, C. Thorpe, Thiersen, J.H.E., Tiziani, D., Tluczykont, M., Tomankova, L., Trichard, C., Tsirou, M., Tsuji, M., Tuffs, R., Uchiyama, Y., van der Walt, D.J., van Eldik, C., van Rensburg, C., van Soelen, B., Vasileiadis, G., Veh, J., Venter, C., Viana, A., Vincent, P., Vink, J., Völk, H.J., Wadiasingh, Z., Wagner, S.J., Watson, J., Werner, F., White, R., Wierzcholska, A., Wong, Yu Wun, Yassin, H., Yusafzai, A., Zacharias, M., Zanin, R., Zargaryan, D., Zdziarski, A.A., Zech, A., Zhu, S.J., Zmija, A., Zorn, J., Zouari, S., Żywucka, N., Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), 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), 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 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 Cité (UPCité), Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE (UMR_7585)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), 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, 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 Univers et Particules de Montpellier (LUPM), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), H.E.S.S., H.E.S.S. Collaboration, 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 National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), High Energy Astrophys. & Astropart. Phys (API, FNWI), and 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)
Subjects: MATÉRIA ESCURA, scale: TeV, High-energy astronomy, WIMP, Milky Way, Astrophysics::High Energy Astrophysical Phenomena, Dark matter, Population, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, GeV, 01 natural sciences, GLAST, cross section: annihilation, thermal, HESS, 0103 physical sciences, education, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, [PHYS]Physics [physics], education.field_of_study, Annihilation, 010308 nuclear & particles physics, dark matter: mass, Gamma ray, Astronomy and Astrophysics, dark matter: annihilation, Galaxy, Distribution function, gamma ray: emission, gamma ray: VHE, Space and Planetary Science, Product (mathematics), many-body problem, HESS - Abteilung Hinton, High Energy Physics::Experiment, galaxy, Astrophysics - High Energy Astrophysical Phenomena, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Fermi Gamma-ray Space Telescope
Abstract: Cosmological $N$-body simulations show that Milky Way-sized galaxies harbor a population of unmerged dark matter subhalos. These subhalos could shine in gamma-rays and be eventually detected in gamma-ray surveys as unidentified sources. We performed a thorough selection among unidentified Fermi-LAT Objects (UFOs) to identify them as possible TeV-scale dark matter subhalo candidates. We search for very-high-energy (E $\gtrsim$ 100 GeV) gamma-ray emissions using H.E.S.S. observations towards four selected UFOs. Since no significant very-high-energy gamma-ray emission is detected in any dataset of the four observed UFOs nor in the combined UFO dataset, strong constraints are derived on the product of the velocity-weighted annihilation cross section $\langle \sigma v \rangle$ by the $J$-factor for the dark matter models. The 95% C.L. observed upper limits derived from combined H.E.S.S. observations reach $\langle \sigma v \rangle J$ values of 3.7$\times$10$^{-5}$ and 8.1$\times$10$^{-6}$ GeV$^2$cm$^{-2}$s$^{-1}$ in the $W^+W^-$ and $\tau^+\tau^-$ channels, respectively, for a 1 TeV dark matter mass. Focusing on thermal WIMPs, the H.E.S.S. constraints restrict the $J$-factors to lie in the range 6.1$\times$10$^{19}$ - 2.0$\times$10$^{21}$ GeV$^2$cm$^{-5}$, and the masses to lie between 0.2 and 6 TeV in the $W^+W^-$ channel. For the $\tau^+\tau^-$ channel, the $J$-factors lie in the range 7.0$\times$10$^{19}$ - 7.1$\times$10$^{20}$ GeV$^2$cm$^{-5}$ and the masses lie between 0.2 and 0.5 TeV. Assuming model-dependent predictions from cosmological N-body simulations on the $J$-factor distribution for Milky Way-sized galaxies, the dark matter models with masses greater than 0.3 TeV for the UFO emissions can be ruled out at high confidence level., Comment: 11 pages, 7 figures, matches accepted version in The Astrophysical Journal
Published: 2021

9. Broadband Multi-wavelength Properties of M87 during the 2017 Event Horizon Telescope Campaign

Author: Algaba, J.C. Anczarski, J. Asada, K. Baloković, M. Chandra, S. Cui, Y.-Z. Falcone, A.D. Giroletti, M. Goddi, C. Hada, K. Haggard, D. Jorstad, S. Kaur, A. Kawashima, T. Keating, G. Kim, J.-Y. Kino, M. Komossa, S. Kravchenko, E.V. Krichbaum, T.P. Lee, S.-S. Lu, R.-S. Lucchini, M. Markoff, S. Neilsen, J. Nowak, M.A. Park, J. Principe, G. Ramakrishnan, V. Reynolds, M.T. Sasada, M. Savchenko, S.S. Williamson, K.E. Akiyama, K. Alberdi, A. Alef, W. Anantua, R. Azulay, R. Baczko, A.-K. Ball, D. Barrett, J. Bintley, D. Benson, B.A. Blackburn, L. Blundell, R. Boland, W. Bouman, K.L. Bower, G.C. Boyce, H. Bremer, M. Brinkerink, C.D. Brissenden, R. Britzen, S. Broderick, A.E. Broguiere, D. Bronzwaer, T. Byun, D.-Y. Carlstrom, J.E. Chael, A. Chan, C.-K. Chatterjee, S. Chatterjee, K. Chen, M.-T. Chen, Y. Chesler, P.M. Cho, I. Christian, P. Conway, J.E. Cordes, J.M. Crawford, T.M. Crew, G.B. Cruz-Osorio, A. Davelaar, J. De Laurentis, M. Deane, R. Dempsey, J. Desvignes, G. Dexter, J. Doeleman, S.S. Eatough, R.P. Falcke, H. Farah, J. Fish, V.L. Fomalont, E. Ford, H.A. Fraga-Encinas, R. Friberg, P. Fromm, C.M. Fuentes, A. Galison, P. Gammie, C.F. García, R. Gentaz, O. Georgiev, B. Gold, R. Gómez, J.L. Gómez-Ruiz, A.I. Gu, M. Gurwell, M. Hecht, M.H. Hesper, R. Ho, L.C. Ho, P. Honma, M. Huang, C.-W.L. Huang, L. Hughes, D.H. Ikeda, S. Inoue, M. Issaoun, S. James, D.J. Jannuzi, B.T. Janssen, M. Jeter, B. Jiang, W. Jiménez-Rosales, A. Johnson, M.D. Jung, T. Karami, M. Karuppusamy, R. Kettenis, M. Kim, D.-J. Kim, J. Kim, J. Koay, J.Y. Kofuji, Y. Koch, P.M. Koyama, S. Kramer, M. Kramer, C. Kuo, C.-Y. Lauer, T.R. Levis, A. Li, Y.-R. Li, Z. Lindqvist, M. Lico, R. Lindahl, G. Liu, J. Liu, K. Liuzzo, E. Lo, W.-P. Lobanov, A.P. Loinard, L. Lonsdale, C. Macdonald, N.R. Mao, J. Marchili, N. Marrone, D.P. Marscher, A.P. Martí-Vidal, I. Matsushita, S. Matthews, L.D. Medeiros, L. Menten, K.M. Mizuno, I. Mizuno, Y. Moran, J.M. Moriyama, K. Moscibrodzka, M. Müller, C. Musoke, G. Mejías, A.M. Nagai, H. Nagar, N.M. Nakamura, M. Narayan, R. Narayanan, G. Natarajan, I. Nathanail, A. Neri, R. Ni, C. Noutsos, A. Okino, H. Olivares, H. Ortiz-León, G.N. Oyama, T. Ozel, F. Palumbo, D.C.M. Patel, N. Pen, U.-L. Pesce, D.W. Piétu, V. Plambeck, R. Popstefanija, A. Porth, O. Pötzl, F.M. Prather, B. Preciado-López, J.A. Psaltis, D. Pu, H.-Y. Rao, R. Rawlings, M.G. Raymond, A.W. Rezzolla, L. Ricarte, A. Ripperda, B. Roelofs, F. Rogers, A. Ros, E. Rose, M. Roshanineshat, A. Rottmann, H. Roy, A.L. Ruszczyk, C. Rygl, K.L.J. Sánchez, S. Sánchez-Arguelles, D. Savolainen, T. Schloerb, F.P. Schuster, K.-F. Shao, L. Shen, Z. Small, D. Sohn, B.W. Soohoo, J. Sun, H. Tazaki, F. Tetarenko, A.J. Tiede, P. Tilanus, R.P.J. Titus, M. Toma, K. Torne, P. Trent, T. Traianou, E. Trippe, S. Van Bemmel, I. Van Langevelde, H.J. Van Rossum, D.R. Wagner, J. Ward-Thompson, D. Wardle, J. Weintroub, J. Wex, N. Wharton, R. Wielgus, M. Wong, G.N. Wu, Q. Yoon, D. Young, A. Young, K. Younsi, Z. Yuan, F. Yuan, Y.-F. Zensus, J.A. Zhao, G.-Y. Zhao, S.-S. Principe, G. Giroletti, M. D'Ammando, F. Orienti, M. Abdalla, H. Adam, R. Aharonian, F. Benkhali, F.A. Angüner, E.O. Arcaro, C. Armand, C. Armstrong, T. Ashkar, H. Backes, M. Baghmanyan, V. Barbosa Martins, V. Barnacka, A. Barnard, M. Becherini, Y. Berge, D. Bernlöhr, K. Bi, B. Böttcher, M. Boisson, C. Bolmont, J. De Bony De Lavergne, M. Breuhaus, M. Brun, F. Brun, P. Bryan, M. Büchele, M. Bulik, T. Bylund, T. Caroff, S. Carosi, A. Casanova, S. Chand, T. Chen, A. Cotter, G. Curyło, M. Damascene Mbarubucyeye, J. Davids, I.D. Davies, J. Deil, C. Devin, J. Dewilt, P. Dirson, L. Djannati-Ataï, A. Dmytriiev, A. Donath, A. Doroshenko, V. Duffy, C. Dyks, J. Egberts, K. Eichhorn, F. Einecke, S. Emery, G. Ernenwein, J.-P. Feijen, K. Fegan, S. Fiasson, A. De Clairfontaine, G.F. Fontaine, G. Funk, S. Füßling, M. Gabici, S. Gallant, Y.A. Giavitto, G. Giunti, L. Glawion, D. Glicenstein, J.F. Gottschall, D. Grondin, M.-H. Hahn, J. Haupt, M. Hermann, G. Hinton, J.A. Hofmann, W. Hoischen, C. Holch, T.L. Holler, M. Hörbe, M. Horns, D. Huber, D. Jamrozy, M. Jankowsky, D. Jankowsky, F. Jardin-Blicq, A. Joshi, V. Jung-Richardt, I. Kasai, E. Kastendieck, M.A. Katarzyński, K. Katz, U. Khangulyan, D. Khélifi, B. Klepser, S. Kluźniak, W. Komin, N. Konno, R. Kosack, K. Kostunin, D. Kreter, M. Lamanna, G. Lemiere, A. Lemoine-Goumard, M. Lenain, J.-P. Levy, C. Lohse, T. Lypova, I. Mackey, J. Majumdar, J. Malyshev, D. Malyshev, D. Marandon, V. Marchegiani, P. Marcowith, A. Mares, A. Martí-Devesa, G. Marx, R. Maurin, G. Meintjes, P.J. Meyer, M. Moderski, R. Mohamed, M. Mohrmann, L. Montanari, A. Moore, C. Morris, P. Moulin, E. Muller, J. Murach, T. Nakashima, K. Nayerhoda, A. De Naurois, M. Ndiyavala, H. Niederwanger, F. Niemiec, J. Oakes, L. O'Brien, P. Odaka, H. Ohm, S. Olivera-Nieto, L. De Ona Wilhelmi, E. Ostrowski, M. Panter, M. Panny, S. Parsons, R.D. Peron, G. Peyaud, B. Piel, Q. Pita, S. Poireau, V. Noel, A.P. Prokhorov, D.A. Prokoph, H. Pühlhofer, G. Punch, M. Quirrenbach, A. Rauth, R. Reichherzer, P. Reimer, A. Reimer, O. Remy, Q. Renaud, M. Rieger, F. Rinchiuso, L. Romoli, C. Rowell, G. Rudak, B. Ruiz-Velasco, E. Sahakian, V. Sailer, S. Sanchez, D.A. Santangelo, A. Sasaki, M. Scalici, M. Schutte, H.M. Schwanke, U. Schwemmer, S. Seglar-Arroyo, M. Senniappan, M. Seyffert, A.S. Shafi, N. Shiningayamwe, K. Simoni, R. Sinha, A. Sol, H. Specovius, A. Spencer, S. Spir-Jacob, M. Stawarz, Ł. Sun, L. Steenkamp, R. Stegmann, C. Steinmassl, S. Steppa, C. Takahashi, T. Tavernier, T. Taylor, A.M. Terrier, R. Tiziani, D. Tluczykont, M. Tomankova, L. Trichard, C. Tsirou, M. Tuffs, R. Uchiyama, Y. Van Der Walt, D.J. Van Eldik, C. Van Rensburg, C. Van Soelen, B. Vasileiadis, G. Veh, J. Venter, C. Vincent, P. Vink, J. Völk, H.J. Vuillaume, T. Wadiasingh, Z. Wagner, S.J. Watson, J. Werner, F. White, R. Wierzcholska, A. Wong, Y.W. Yusafzai, A. Zacharias, M. Zanin, R. Zargaryan, D. Zdziarski, A.A. Zech, A. Zhu, S.J. Zorn, J. Zouari, S. Żywucka, N. Acciari, V.A. Ansoldi, S. Antonelli, L.A. Engels, A.A. Artero, M. Asano, K. Baack, D. Babić, A. Baquero, A. De Almeida, U.B. Barrio, J.A. Becerra González, J. Bednarek, W. Bellizzi, L. Bernardini, E. Bernardos, M. Berti, A. Besenrieder, J. Bhattacharyya, W. Bigongiari, C. Biland, A. Blanch, O. Bonnoli, G. Bošnjak, Ž. Busetto, G. Carosi, R. Ceribella, G. Cerruti, M. Chai, Y. Chilingarian, A. Cikota, S. Colak, S.M. Colombo, E. Contreras, J.L. Cortina, J. Covino, S. D'Amico, G. D'Elia, V. Da Vela, P. Dazzi, F. De Angelis, A. De Lotto, B. Delfino, M. Delgado, J. Delgado Mendez, C. Depaoli, D. Di Pierro, F. Di Venere, L. Do Souto Espineira, E. Dominis Prester, D. Donini, A. Dorner, D. Doro, M. Elsaesser, D. Fallah Ramazani, V. Fattorini, A. Ferrara, G. Fonseca, M.V. Font, L. Fruck, C. Fukami, S. García López, R.J. Garczarczyk, M. Gasparyan, S. Gaug, M. Giglietto, N. Giordano, F. Gliwny, P. Godinović, N. Green, J.G. Green, D. Hadasch, D. Hahn, A. Heckmann, L. Herrera, J. Hoang, J. Hrupec, D. Hütten, M. Inada, T. Inoue, S. Ishio, K. Iwamura, Y. Jiménez, I. Jormanainen, J. Jouvin, L. Kajiwara, Y. Karjalainen, M. Kerszberg, D. Kobayashi, Y. Kubo, H. Kushida, J. Lamastra, A. Lelas, D. Leone, F. Lindfors, E. Lombardi, S. Longo, F. López-Coto, R. López-Moya, M. López-Oramas, A. Loporchio, S. Machado De Oliveira Fraga, B. Maggio, C. Majumdar, P. Makariev, M. Mallamaci, M. Maneva, G. Manganaro, M. Mannheim, K. Maraschi, L. Mariotti, M. Martínez, M. Mazin, D. Menchiari, S. Mender, S. Mićanović, S. Miceli, D. Miener, T. Minev, M. Miranda, J.M. Mirzoyan, R. Molina, E. Moralejo, A. Morcuende, D. Moreno, V. Moretti, E. Neustroev, V. Nigro, C. Nilsson, K. Nishijima, K. Noda, K. Nozaki, S. Ohtani, Y. Oka, T. Otero-Santos, J. Paiano, S. Palatiello, M. Paneque, D. Paoletti, R. Paredes, J.M. Pavletić, L. Penil, P. Perennes, C. Persic, M. Moroni, P.G.P. Prandini, E. Priyadarshi, C. Puljak, I. Rhode, W. Ribó, M. Rico, J. Righi, C. Rugliancich, A. Saha, L. Sahakyan, N. Saito, T. Sakurai, S. Satalecka, K. Saturni, F.G. Schleicher, B. Schmidt, K. Schweizer, T. Sitarek, J. Šnidarić, I. Sobczynska, D. Spolon, A. Stamerra, A. Strom, D. Strzys, M. Suda, Y. Surić, T. Takahashi, M. Tavecchio, F. Temnikov, P. Terzić, T. Teshima, M. Tosti, L. Truzzi, S. Tutone, A. Ubach, S. Van Scherpenberg, J. Vanzo, G. Vazquez Acosta, M. Ventura, S. Verguilov, V. Vigorito, C.F. Vitale, V. Vovk, I. Will, M. Wunderlich, C. Zarić, D. Adams, C.B. Benbow, W. Brill, A. Capasso, M. Christiansen, J.L. Chromey, A.J. Daniel, M.K. Errando, M. Farrell, K.A. Feng, Q. Finley, J.P. Fortson, L. Furniss, A. Gent, A. Giuri, C. Hassan, T. Hervet, O. Holder, J. Hughes, G. Humensky, T.B. Jin, W. Kaaret, P. Kertzman, M. Kieda, D. Kumar, S. Lang, M.J. Lundy, M. Maier, G. Moriarty, P. Mukherjee, R. Nieto, D. Nievas-Rosillo, M. O'Brien, S. Ong, R.A. Otte, A.N. Patel, S. Pfrang, K. Pohl, M. Prado, R.R. Pueschel, E. Quinn, J. Ragan, K. Reynolds, P.T. Ribeiro, D. Richards, G.T. Roache, E. Rulten, C. Ryan, J.L. Santander, M. Sembroski, G.H. Shang, R. Weinstein, A. Williams, D.A. Williamson, T.J. Hirota, T. Cui, L. Niinuma, K. Ro, H. Sakai, N. Sawada-Satoh, S. Wajima, K. Wang, N. Liu, X. Yonekura, Y.
Subjects: Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Cosmology and Extragalactic Astrophysics
Abstract: In 2017, the Event Horizon Telescope (EHT) Collaboration succeeded in capturing the first direct image of the center of the M87 galaxy. The asymmetric ring morphology and size are consistent with theoretical expectations for a weakly accreting supermassive black hole of mass ∼6.5 × 109 M o˙. The EHTC also partnered with several international facilities in space and on the ground, to arrange an extensive, quasi-simultaneous multi-wavelength campaign. This Letter presents the results and analysis of this campaign, as well as the multi-wavelength data as a legacy data repository. We captured M87 in a historically low state, and the core flux dominates over HST-1 at high energies, making it possible to combine core flux constraints with the more spatially precise very long baseline interferometry data. We present the most complete simultaneous multi-wavelength spectrum of the active nucleus to date, and discuss the complexity and caveats of combining data from different spatial scales into one broadband spectrum. We apply two heuristic, isotropic leptonic single-zone models to provide insight into the basic source properties, but conclude that a structured jet is necessary to explain M87's spectrum. We can exclude that the simultaneous γ-ray emission is produced via inverse Compton emission in the same region producing the EHT mm-band emission, and further conclude that the γ-rays can only be produced in the inner jets (inward of HST-1) if there are strongly particle-dominated regions. Direct synchrotron emission from accelerated protons and secondaries cannot yet be excluded. © 2021. The Author(s). Published by the American Astronomical Society..
Published: 2021

10. LMC N132D: A mature supernova remnant with a power-law gamma-ray spectrum extending beyond 8 TeV

Author: Abdalla, H., Aharonian, F., Martins, V. Barbosa, Klepser, S., Kluźniak, W., Komin, Nu., Konno, R., Kosack, K., Kostunin, D., Kreter, M., Mezek, G. Kukec, Kundu, A., Lamanna, G., Barnacka, A., Stum, S. Le, Lemière, A., Lemoine-Goumard, M., Lenain, J.-P., Leuschner, F., Levy, C., Lohse, T., Luashvili, A., Lypova, I., Mackey, J., Barnard, M., Majumdar, J., Malyshev, D., Marandon, V., Marchegiani, P., Marcowith, A., Mares, A., Martí-Devesa, G., Marx, R., Maurin, G., Meintjes, P. J., Batzofin, R., Meyer, M., Mitchell, A., Moderski, R., Mohrmann, L., Montanari, A., Moore, C., Morris, P., Moulin, E., Muller, J., Murach, T., Becherini, Y., Nakashima, K., de Naurois, M., Nayerhoda, A., Ndiyavala, H., Niemiec, J., Oakes, L., Peyaud, B., Piel, Q., Noel, A. Priyana, O'Brien, P., Berge, D., Oberholzer, L., Odaka, H., Ohm, S., Olivera-Nieto, L., Wilhelmi, E. de Ona, Ostrowski, M., Panny, S., Panter, M., Parsons, R. D., Peron, G., Bernlöhr, K., Pita, S., Poireau, V., Prokhorov, D. A., Prokoph, H., Pühlhofer, G., Punch, M., Quirrenbach, A., Raab, S., Rauth, R., Reichherzer, P., Bi, B., Reimer, A., Reimer, O., Remy, Q., Renaud, M., Rinchiuso, L., Reville, B., Rieger, F., Romoli, C., Rowell, G., Rudak, B., Böttcher, M., Ricarte, H. Rueda, Ruiz-Velasco, E., Sahakian, V., Sailer, S., Salzmann, H., Sanchez, D. A., Santangelo, A., Sasaki, M., Scalici, M., Schäfer, J., Boisson, C., Schüssler, F., Schutte, H. M., Schwanke, U., Seglar-Arroyo, M., Senniappan, M., Seyffert, A. S., Shafi, N., Shapopi, J. N. S., Shiningayamwe, K., Simoni, R., Benkhali, F. Ait, Bolmont, J., Sinha, A., Sol, H., Specovius, A., Spencer, S., Spir-Jacob, M., Stawarz, L., Steenkamp, R., Stegmann, C., Steinmassl, S., Steppa, C., de Lavergne, M. de Bony, Sun, L., Takahashi, T., Tanaka, T., Tavernier, T., Taylor, A. M., Terrier, R., Thiersen, J. H. E., Thorpe-Morgan, C., Tiziani, D., Tluczykont, M., Breuhaus, M., Tomankova, L., Trichard, C., Tsirou, M., Tsuji, N., Tuffs, R., Uchiyama, Y., van der Walt, D. J., van Eldik, C., van Rensburg, C., van Soelen, B., Brose, R., Vasileiadis, G., Veh, J., Venter, C., Vincent, P., Vink, J., Völk, H. J., Wadiasingh, Z., Wagner, S. J., Watson, J., Werner, F., Brun, F., White, R., Wierzcholska, A., Wong, Yu Wun, Yassin, H., Yusafzai, A., Zacharias, M., Zanin, R., Zargaryan, D., Zdziarski, A. A., Zech, A., Brun, P., Zhu, S. J., Zmija, A., Zorn, J., Zouari, S., Żywucka, N., H. E. S. S. Collaboration, Bryan, M., Büchele, M., Bulik, T., Bylund, T., Angüner, E. O., Cangemi, F., Caroff, S., Carosi, A., Casanova, S., Catalano, J., Chambery, P., Chand, T., Chandra, S., Chen, A., Cotter, G., Arcaro, C., Curyło, M., Mbarubucyeye, J. Damascene, Davids, I. D., Davies, J., Deil, C., Devin, J., Dirson, L., Djannati-Atai, A., Dmytriiev, A., Donath, A., Armand, C., Doroshenko, V., Dreyer, L., Plessis, L. Du, Duffy, C., Dyks, J., Egberts, K., Eichhorn, F., Einecke, S., Emery, G., Ernenwein, J.-P., Armstrong, T., Fegan, S., Feijen, K., Fiasson, A., de Clairfontaine, G. Fichet, Fontaine, G., Lott, F., Füßling, M., Funk, S., Gabici, S., Gallant, Y. A., Ashkar, H., Giavitto, G., Giunti, L., Glawion, D., Glicenstein, J. F., Grondin, M.-H., Hattingh, S., Hahn, J., Haupt, M., Hermann, G., Hinton, J. A., Backes, M., Hofmann, W., Hoischen, C., Holch, T. L., Holler, M., Hörbe, M., Horns, D., Huang, Zhiqiu, Huber, D., Jamrozy, M., Jankowsky, D., Baghmanyan, V., Jankowsky, F., Jardin-Blicq, A., Joshi, V., Jung-Richardt, I., Kasai, E., Kastendieck, M. A., Katarzynski, K., Katz, U., Khangulyan, D., Khélifi, B., Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE (UMR_7585)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), 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)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Laboratoire Univers et Particules de Montpellier (LUPM), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), H.E.S.S., Collaboration, H.E.S.S., and High Energy Astrophys. & Astropart. Phys (API, FNWI)
Subjects: Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Cosmic ray, Astrophysics, Spectral line, Luminosity, cosmic rays, High Energy Stereoscopic System, Large Magellanic Cloud, Supernova remnant, Astrophysics::Galaxy Astrophysics, ISM: supernova remnants, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Computer Science::Information Retrieval, supernova remnants [ISM], Astronomy and Astrophysics, gamma rays: general, Space and Planetary Science, Spectral energy distribution, ddc:520, Astrophysics - High Energy Astrophysical Phenomena, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], general [gamma rays], Fermi Gamma-ray Space Telescope
Abstract: Astronomy and astrophysics 655, A7 (2021). doi:10.1051/0004-6361/202141486, Context. Supernova remnants (SNRs) are commonly thought to be the dominant sources of Galactic cosmic rays up to the knee of the cosmic-ray spectrum at a few PeV. Imaging Atmospheric Cherenkov Telescopes have revealed young SNRs as very-high-energy (VHE, >100 GeV) gamma-ray sources, but for only a few SNRs the hadronic cosmic-ray origin of their gamma-ray emission is indisputably established. In all these cases, the gamma-ray spectra exhibit a spectral cutoff at energies much below 100 TeV and thus do not reach the PeVatron regime.Aims. The aim of this work was to achieve a firm detection for the oxygen-rich SNR LMC N132D in the VHE gamma-ray domain with an extended set of data, and to clarify the spectral characteristics and the localization of the gamma-ray emission from this exceptionally powerful gamma-ray-emitting SNR.Methods. We analyzed 252 h of High Energy Stereoscopic System (H.E.S.S.) observations towards SNR N132D that were accumulated between December 2004 and March 2016 during a deep survey of the Large Magellanic Cloud, adding 104 h of observations to the previously published data set to ensure a > 5σ detection. To broaden the gamma-ray spectral coverage required for modeling the spectral energy distribution, an analysis of Fermi-LAT Pass 8 data was also included.Results. We unambiguously detect N132D at VHE with a significance of 5.7σ. We report the results of a detailed analysis of its spectrum and localization based on the extended H.E.S.S. data set. The joint analysis of the extended H.E.S.S and Fermi-LAT data results in a spectral energy distribution in the energy range from 1.7 GeV to 14.8 TeV, which suggests a high luminosity of N132D at GeV and TeV energies. We set a lower limit on a gamma-ray cutoff energy of 8 TeV with a confidence level of 95%. The new gamma-ray spectrum as well as multiwavelength observations of N132D when compared to physical models suggests a hadronic origin of the VHE gamma-ray emission.Conclusions. SNR N132D is a VHE gamma-ray source that shows a spectrum extending to the VHE domain without a spectral cutoff at a few TeV, unlike the younger oxygen-rich SNR Cassiopeia A. The gamma-ray emission is best explained by a dominant hadronic component formed by diffusive shock acceleration. The gamma-ray properties of N132D may be affected by an interaction with a nearby molecular cloud that partially lies inside the 95% confidence region of the source position.Key words: gamma rays: general / cosmic rays / ISM: supernova remnants, Published by EDP Sciences, Les Ulis
Published: 2021

11. An extreme particle accelerator in the Galactic plane

Author: Abdalla, H., Adam, R., Aharonian, Felix A., Benkhali, F. Ait, Angüner, Ekrem Oǧuzhan, Arcaro, C., Armand, C., Armstrong, T., Ashkar, H., Backes, M., Baghmanyan, V., Martins, V. Barbosa, Barnacka, A., Barnard, M., Becherini, Y., Berge, D., Bernlohr, K., Bi, B., Bottcher, M., Boisson, C., Bolmont, J., de Lavergne, M. de Bony, Bordas, Pol, Breuhaus, M., Brun, F., Brun, P., Bryan, M., Buchele, M., Bulik, T., Bylund, T., Caroff, S., Carosi, A., Casanova, Sabrina, Chand, T., Chandra, S., Chen, A., Cotter, G., Curylo, M., Mbarubucyeye, J. Damascene, Davids, I. D., Davies, J., Deil, C., Devin, J., deWilt, P., Dirson, L., Djannati-Atai, A., Dmytriiev, A., Donath, A., Doroshenko, V., Duffy, C., Dyks, J., Egberts, Kathrin (Dr. rer. nat.), Eichhorn, F., Einecke, S., Emery, G., Ernenwein, J. -P., Feijen, K., Fegan, S., Fiasson, A., de Clairfontaine, G. Fichet, Fontaine, G., Funk, S., Fussling, Matthias, Gabici, S., Gallant, Y. A., Giavitto, G., Giunti, L., Glawion, D., Glicenstein, J. F., Gottschall, D., Grondin, M. -H., Hahn, J., Haupt, M., Hermann, G., Hinton, J. A., Hofmann, W., Hoischen, Clemens (Dr.), Holch, T. L., Holler, M., Horbe, M., Horns, D., Huber, D., Jamrozy, M., Jankowsky, D., Jankowsky, F., Jardin-Blicq, A., Joshi, V., Jung-Richardt, I., Kasai, E., Kastendieck, M. A., Katarzynski, K., Katz, U., Khangulyan, D., Khelifi, B., Klepser, S., Kluzniak, W., Komin, Nu., Konno, R., Kosack, K., Kostunin, D., Kreter, M., Lamanna, G., Lemiere, A., Lemoine-Goumard, M., Lenain, J. -P., Levy, C., Lohse, T., Lypova, I., Mackey, J., Majumdar, J., Malyshev, D., Marandon, V., Marchegiani, P., Marcowith, A., Mares, A., Marti-Devesa, G., Marx, R., Maurin, G., Meintjes, P. J., Meyer, M., Mitchell, A., Moderski, R., Mohamed, M., Mohrmann, L., Montanari, A., Moore, C., Morris, P., Moulin, E., Muller, J., Murach, T., Nakashima, K., Nayerhoda, A., de Naurois, M., Ndiyavala, H., Niederwanger, F., Niemiec, J., Oakes, L., O'Brien, Patrick (Prof. Dr.), Odaka, H., Ohm, S., Olivera-Nieto, L., Wilhelmi, E. de Ona, Ostrowski, M., Oya, I., Panter, M., Panny, S., Parsons, R. D., Peron, G., Peyaud, B., Piel, Q., Pita, S., Poireau, V., Noel, A. Priyana, Prokhorov, D. A., Prokoph, H., Puhlhofer, G., Punch, M., Quirrenbach, A., Raab, S., Rauth, R., Reichherzer, P., Reimer, A., Reimer, O., Remy, Q., Renaud, M., Rieger, F., Rinchiuso, L., Romoli, C., Rowell, G., Rudak, B., Ruiz-Velasco, E., Sahakian, V., Sailer, S., Sanchez, D. A., Santangelo, A., Sasaki, M., Scalici, M., Schussler, F., Schutte, H. M., Schwanke, U., Schwemmer, S., Seglar-Arroyo, M., Senniappan, M., Seyffert, A. S., Shafi, N., Shiningayamwe, K., Simoni, R., Sinha, A., Sol, H., Specovius, A., Spencer, S., Spir-Jacob, M., Stawarz, L., Sun, L., Steenkamp, R., Stegmann, C., Steinmassl, S., Steppa, C., Takahashi, T., Tavernier, T., Taylor, A. M., Terrier, R., Tiziani, D., Tluczykont, M., Tomankova, L., Trichard, C., Tsirou, M., Tuffs, R., Uchiyama, Y., van der Walt, D. J., van Eldik, C., van Rensburg, C., van Soelen, B., Vasileiadis, G., Veh, J., Venter, C., Vincent, P., Vink, J., Volk, H. J., Vuillaume, T., Wadiasingh, Z., Wagner, S. J., Watson, J., Werner, F., White, R., Wierzcholska, A., Wong, Yu Wun, Yusafzai, A., Zacharias, M., Zanin, R., Zargaryan, D., Zdziarski, A. A., Zech, A., Zhu, S. J., Ziegler, A., Zorn, J., Zouari, S., and Zywucka, N.
Subjects: ddc:520, Institut für Physik und Astronomie, ddc:530
Abstract: The unidentified very-high-energy (VHE; E > 0.1 TeV) gamma -ray source, HESS J1826-130, was discovered with the High Energy Stereoscopic System (HESS) in the Galactic plane. The analysis of 215 h of HESS data has revealed a steady gamma -ray flux from HESS J1826-130, which appears extended with a half-width of 0.21 degrees +/- 0.02 (stat)degrees stat degrees +/- 0.05 (sys)degrees sys degrees . The source spectrum is best fit with either a power-law function with a spectral index Gamma = 1.78 +/- 0.10(stat) +/- 0.20(sys) and an exponential cut-off at 15.2 (+5.5)(-3.2) -3.2+5.5 TeV, or a broken power-law with Gamma (1) = 1.96 +/- 0.06(stat) +/- 0.20(sys), Gamma (2) = 3.59 +/- 0.69(stat) +/- 0.20(sys) for energies below and above E-br = 11.2 +/- 2.7 TeV, respectively. The VHE flux from HESS J1826-130 is contaminated by the extended emission of the bright, nearby pulsar wind nebula, HESS J1825-137, particularly at the low end of the energy spectrum. Leptonic scenarios for the origin of HESS J1826-130 VHE emission related to PSR J1826-1256 are confronted by our spectral and morphological analysis. In a hadronic framework, taking into account the properties of dense gas regions surrounding HESS J1826-130, the source spectrum would imply an astrophysical object capable of accelerating the parent particle population up to greater than or similar to 200 TeV. Our results are also discussed in a multiwavelength context, accounting for both the presence of nearby supernova remnants, molecular clouds, and counterparts detected in radio, X-rays, and TeV energies.
Published: 2020

12. Probing the Magnetic Field in the GW170817 Outflow Using H.E.S.S. Observations

Author: Collaboration, H. E. S. S., Abdalla, H., Adam, R., Aharonian, F., Benkhali, F. Ait, Ang��ner, E. O., Arakawa, M., Arcaro, C., Armand, C., Armstrong, T., Ashkar, H., Backes, M., Baghmanyan, V., Barbosa-Martins, V., Barnacka, A., Barnard, M., Becherini, Y., Berge, D., Bernl��hr, K., Blackwell, R., B��ttcher, M., Boisson, C., Bolmont, J., Bonnefoy, S., Bregeon, J., Breuhaus, M., Brun, F., Brun, P., Bryan, M., B��chele, M., Bulik, T., Bylund, T., Caroff, S., Carosi, A., Casanova, S., Cerruti, M., Chand, T., Chandra, S., Chen, A., Cotter, G., Cury��o, M., Davids, I. D., Davies, J., Deil, C., Devin, J., deWilt, P., Dirson, L., Djannati-Ata��, A., Dmytriiev, A., Donath, A., Doroshenko, V., Dyks, J., Egberts, K., Eichhorn, F., Emery, G., Ernenwein, J. -P., Eschbach, S., Feijen, K., Fegan, S., Fiasson, A., Fontaine, G., Funk, S., F��ling, M., Gabici, S., Gallant, Y. A., Giavitto, G., Giunti, L., Glawion, D., Glicenstein, J. F., Gottschall, D., Grondin, M. -H., Hahn, J., Haupt, M., Heinzelmann, G., Hermann, G., Hinton, J. A., Hofmann, W., Hoischen, C., Holch, T. L., Holler, M., H��rbe, M., Horns, D., Huber, D., Iwasaki, H., Jamrozy, M., Jankowsky, D., Jankowsky, F., Jardin-Blicq, A., Joshi, V., Jung-Richardt, I., Kastendieck, M. A., Katarzy��ski, K., Katsuragawa, M., Katz, U., Khangulyan, D., Kh��lifi, B., Klepser, S., Klu��niak, W., Komin, Nu., Konno, R., Kosack, K., Kostunin, D., Kreter, M., Lamanna, G., Lemi��re, A., Lemoine-Goumard, M., Lenain, J. -P., Leser, E., Levy, C., Lohse, T., Lypova, I., Mackey, J., Majumdar, J., Malyshev, D., Marandon, V., Marchegiani, P., Marcowith, A., Mares, A., Mart��-Devesa, G., Marx, R., Maurin, G., Meintjes, P. J., Moderski, R., Mohamed, M., Mohrmann, L., Moore, C., Morris, P., Moulin, E., Muller, J., Murach, T., Nakashima, S., Nakashima, K., de Naurois, M., Ndiyavala, H., Niederwanger, F., Niemiec, J., Oakes, L., O'Brien, P., Odaka, H., Ohm, S., Wilhelmi, E. de Ona, Ostrowski, M., Panter, M., Parsons, R. D., Peyaud, B., Piel, Q., Pita, S., Poireau, V., Noel, A. Priyana, Prokhorov, D. A., Prokoph, H., P��hlhofer, G., Punch, M., Quirrenbach, A., Raab, S., Rauth, R., Reimer, A., Reimer, O., Remy, Q., Renaud, M., Rieger, F., Rinchiuso, L., Romoli, C., Rowell, G., Rudak, B., Ruiz-Velasco, E., Sahakian, V., Sailer, S., Saito, S., Sanchez, D. A., Santangelo, A., Sasaki, M., Scalici, M., Schlickeiser, R., Sch��ssler, F., Schulz, A., Schutte, H., Schwanke, U., Schwemmer, S., Seglar-Arroyo, M., Senniappan, M., Seyffert, A. S., Shafi, N., Shiningayamwe, K., Simoni, R., Sinha, A., Sol, H., Specovius, A., Spencer, S., Spir-Jacob, M., Stawarz, ��., Steenkamp, R., Stegmann, C., Steppa, C., Takahashi, T., Tavernier, T., Taylor, A. M., Terrier, R., Tiziani, D., Tluczykont, M., Tomankova, L., Trichard, C., Tsirou, M., Tsuji, N., Tuffs, R., Uchiyama, Y., van der Walt, D. J., van Eldik, C., van Rensburg, C., van Soelen, B., Vasileiadis, G., Veh, J., Venter, C., Vincent, P., Vink, J., V��lk, H. J., Vuillaume, T., Wadiasingh, Z., Wagner, S. J., Watson, J., Werner, F., White, R., Wierzcholska, A., Yang, R., Yoneda, H., Zacharias, M., Zanin, R., Zdziarski, A. A., Zech, A., Zorn, J., Zywucka, N., Rodrigues, X., North-West University [Potchefstroom] (NWU), 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), Max-Planck-Institut für Kernphysik (MPIK), Max-Planck-Gesellschaft, Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Rikkyo University [Tokyo], 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), University of Oxford [Oxford], 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 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 de Paris (UP), Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE (UMR_7585)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Univers et Particules de Montpellier (LUPM), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), 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, H.E.S.S., 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), 26598973 - Abdalla, Hassan, 30588766 - Arcaro, Cornelia, 28644743 - Backes, Michael, 20574266 - Barnard, Monica, 24420530 - Böttcher, Markus, 30366755 - Chand, Tej B., 31125417 - Chandra, Sunil, 33379009 - Kreter, Michael, 26403366 - Ndiyavala, Hambeleleni, 22799133 - Schutte, Hester M., 20126999 - Seyffert, Albertus Stefanus, 10060499 - Van der Walt, Diederick Johannes, 21106266 - Van Rensburg, Carlo, 12006653 - Venter, Christo, 26594080 - Wadiasingh, Zorawar, 29092086 - Zacharias, Michael, 34208968 - Zywucka-Hejzner, Natalia, 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)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), H. E. S. S. Collaboration, Faculty of Science, High Energy Astrophys. & Astropart. Phys (API, FNWI), Gravitation and Astroparticle Physics Amsterdam, Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)
Subjects: emission [X-ray], electron, neutron star: binary, 010504 meteorology & atmospheric sciences, magnetic field, Astrophysics, binary [neutron star], Kilonova, 01 natural sciences, HESS, 010303 astronomy & astrophysics, Stellar evolution, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), radio wave, nucleosynthesis, r-process, Gamma-ray bursts, Astrophysics - High Energy Astrophysical Phenomena, Radio wave, Ejecta, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, burst [gamma ray], Context (language use), Astrophysics::Cosmology and Extragalactic Astrophysics, gamma ray: burst, Gamma-ray transient sources, 0103 physical sciences, Stellar mergers, X-ray: emission, High Energy Astrophysical Phenomena, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Gamma-ray astronomy, Gravitational wave, gravitational radiation, Astronomy and Astrophysics, Neutron star, electromagnetic, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], HESS - Abteilung Hinton, ddc:520, Gamma-ray burst, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: The astrophysical journal / 1 894(2), 1-5 (2020). doi:10.3847/2041-8213/ab8b59, The detection of the first electromagnetic counterpart to the binary neutron star (BNS) merger remnant GW170817 established the connection between short $γ$-ray bursts and BNS mergers. It also confirmed the forging of heavy elements in the ejecta (a so-called kilonova) via the r-process nucleosynthesis. The appearance of nonthermal radio and X-ray emission, as well as the brightening, which lasted more than 100 days, were somewhat unexpected. Current theoretical models attempt to explain this temporal behavior as either originating from a relativistic off-axis jet or a kilonova-like outflow. In either scenario, there is some ambiguity regarding how much energy is transported in the nonthermal electrons versus the magnetic field of the emission region. Combining the Very Large Array (radio) and Chandra (X-ray) measurements with observations in the GeV–TeV domain can help break this ambiguity, almost independently of the assumed origin of the emission. Here we report for the first time on deep H.E.S.S. observations of GW170817/GRB 170817A between 124 and 272 days after the BNS merger with the full H.E.S.S. array of telescopes, as well as on an updated analysis of the prompt (, Published by Institute of Physics Publ., London
Published: 2020

13. Search for dark matter signals towards a selection of recently-detected DES dwarf galaxy satellites of the Milky Way with H.E.S.S

Author: Collaboration, H. E. S. S., Abdallah, H., Adam, R., Aharonian, F., Benkhali, F. Ait, Ang��ner, E. O., Arakawa, M., Arcaro, C., Armand, C., Armstrong, T., Ashkar, H., Backes, M., Baghmanyan, V., Martins, V. Barbosa, Barnacka, A., Barnard, M., Becherini, Y., Berge, D., Bernl��hr, K., B��ttcher, M., Boisson, C., Bolmont, J., Bonnefoy, S., Breuhaus, M., Bregeon, J., Brun, F., Brun, P., Bryan, M., B��chele, M., Bulik, T., Bylund, T., Caroff, S., Carosi, A., Casanova, S., Chand, T., Chandra, S., Chen, A., Cotter, G., Cury��o, M., Davids, I. D., Davies, J., Deil, C., Devin, J., deWilt, P., Dirson, L., Djannati-Ata��, A., Dmytriiev, A., Donath, A., Doroshenko, V., Dyks, J., Egberts, K., Eichhorn, F., Emery, G., Ernenwein, J. -P., Eschbach, S., Feijen, K., Fegan, S., Fiasson, A., Fontaine, G., Funk, S., F��ling, M., Gabici, S., Gallant, Y. A., Giavitto, G., Giunti, L., Glawion, D., Glicenstein, J. F., Gottschall, D., Grondin, M. -H., Hahn, J., Haupt, M., Hermann, G., Hinton, J. A., Hofmann, W., Hoischen, C., Holch, T. L., Holler, M., H��rbe, M., Horns, D., Huber, D., Iwasaki, H., Jamrozy, M., Jankowsky, D., Jankowsky, F., Jardin-Blicq, A., Joshi, V., Jung-Richardt, I., Kastendieck, M. A., Katarzy��ski, K., Katsuragawa, M., Katz, U., Khangulyan, D., Kh��lifi, B., Klepser, S., Klu��niak, W., Komin, Nu., Konno, R., Kosack, K., Kostunin, D., Kreter, M., Lamanna, G., Lemi��re, A., Lemoine-Goumard, M., Lenain, J. -P., Leser, E., Levy, C., Lohse, T., Lypova, I., Mackey, J., Majumdar, J., Malyshev, D., Marandon, V., Marchegiani, P., Marcowith, A., Mares, A., Mart��-Devesa, G., Marx, R., Maurin, G., Meintjes, P. J., Moderski, R., Mohamed, M., Mohrmann, L., Moore, C., Morris, P., Moulin, E., Muller, J., Murach, T., Nakashima, K., Nakashima, S., de Naurois, M., Ndiyavala, H., Niederwanger, F., Niemiec, J., Oakes, L., O'Brien, P., Odaka, H., Ohm, S., Wilhelmi, E. de Ona, Ostrowski, M., Panter, M., Parsons, R. D., Peyaud, B., Piel, Q., Pita, S., Poireau, V., Noel, A. Priyana, Prokhorov, D. A., Prokoph, H., P��hlhofer, G., Punch, M., Quirrenbach, A., Raab, S., Rauth, R., Reimer, A., Reimer, O., Remy, Q., Renaud, M., Rieger, F., Rinchiuso, L., Romoli, C., Rowell, G., Rudak, B., Ruiz-Velasco, E., Sahakian, V., Sailer, S., Saito, S., Sanchez, D. A., Santangelo, A., Sasaki, M., Scalici, M., Sch��ssler, F., Schutter, H. M., Schwanke, U., Schwemmer, S., Seglar-Arroyo, M., Senniappan, M., Seyffert, A. S., Shafi, N., Shiningayamwe, K., Simoni, R., Sinha, A., Sol, H., Specovius, A., Spencer, S., Spir-Jacob, M., Stawarz, ��., Steenkamp, R., Stegmann, C., Steppa, C., Takahashi, T., Tavernier, T., Taylor, A. M., Terrier, R., Tiziani, D., Tluczykont, M., Tomankova, L., Trichard, C., Tsirou, M., Tsuji, N., Tuffs, R., Uchiyama, Y., van der Walt, D. J., van Eldik, C., van Rensburg, C., van Soelen, B., Vasileiadis, G., Veh, J., Venter, C., Viana, A., Vincent, P., Vink, J., V��lk, H. J., Vuillaume, T., Wadiasingh, Z., Wagner, S. J., Watson, J., Werner, F., White, R., Wierzcholska, A., Yang, R., Yoneda, H., Zacharias, M., Zanin, R., Zargaryan, D., Zdziarski, A. A., Zech, A., Zhu, S., Zorn, J., and ��ywucka, N.
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: Dwarf spheroidal galaxy satellites of the Milky Way are prime targets for indirect detection of dark matter with gamma rays due to their proximity, high dark matter content and absence of non-thermal emission processes. Recently, the Dark Energy Survey (DES) revealed the existence of new ultra-faint dwarf spheroidal galaxies in the southern-hemisphere sky, therefore ideally located for ground-based observations with the imaging atmospheric Cherenkov telescope array H.E.S.S. We present a search for very-high-energy ($E\gtrsim100$ GeV) gamma-ray emission using H.E.S.S. observations carried out recently towards Reticulum II, Tucana II, Tucana III, Tucana IV and Grus II satellites. No significant very-high-energy gamma-ray excess is found from the observations on any individual object nor in the combined analysis of all the datasets. Using the most recent modeling of the dark matter distribution in the dwarf galaxy halo, we compute for the first time on DES satellites individual and combined constraints from Cherenkov telescope observations on the annihilation cross section of dark matter particles in the form of Weakly Interacting Massive Particles. The combined 95% C.L. observed upper limits reach $\langle ��v \rangle \simeq 1 \times 10^{-23}$ cm$^3$s$^{-1}$ in the $W^+W^-$ channel and $4 \times 10^{-26}$ cm$^3$s$^{-1}$ in the $��$ channels for a dark matter mass of 1.5 TeV. The H.E.S.S. constraints well complement the results from Fermi-LAT, HAWC, MAGIC and VERITAS and are currently the most stringent in the $��$ channels in the multi-GeV/multi-TeV mass range., 20 pages, 12 figures
Published: 2020
Full Text: View/download PDF

14. Detection of very-high-energy ��-ray emission from the colliding wind binary �� Car with H.E.S.S

Author: Collaboration, H. E. S. S., Abdalla, H., Adam, R., Aharonian, F., Benkhali, F. Ait, Ang��ner, E. O., Arakawa, M., Arcaro, C., Armand, C., Armstrong, T., Ashkar, H., Backes, M., Martins, V. Barbosa, Barnard, M., Becherini, Y., Berge, D., Bernl��hr, K., Blackwell, R., B��ttcher, M., Boisson, C., Bolmont, J., Bonnefoy, S., Bregeon, J., Breuhaus, M., Brun, F., Brun, P., Bryan, M., B��chele, M., Bulik, T., Bylund, T., Caroff, S., Carosi, A., Casanova, S., Cerruti, M., Chand, T., Chandra, S., Chen, A., Colafrancesco, S., Cotter, G., Cury��o, M., Davids, I. D., Davies, J., Deil, C., Devin, J., deWilt, P., Dirson, L., Djannati-Ata��, A., Dmytriiev, A., Donath, A., Doroshenko, V., Dyks, J., Egberts, K., Eichhorn, F., Emery, G., Ernenwein, J. -P., Eschbach, S., Feijen, K., Fegan, S., Fiasson, A., Fontaine, G., Funk, S., F��ling, M., Gabici, S., Gallant, Y. A., Gat��, F., Giavitto, G., Giunti, L., Glawion, D., Glicenstein, J. F., Gottschall, D., Grondin, M. -H., Hahn, J., Haupt, M., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A., Hofmann, W., Hoischen, C., Holch, T. L., Holler, M., H��rbe, M., Horns, D., Huber, D., Iwasaki, H., Jamrozy, M., Jankowsky, D., Jankowsky, F., Jardin-Blicq, A., Joshi, V., Jung-Richardt, I., Kastendieck, M. A., Katarzy��ski, K., Katsuragawa, M., Katz, U., Khangulyan, D., Kh��lifi, B., King, J., Klepser, S., Klu��niak, W., Komin, Nu., Kosack, K., Kostunin, D., Kreter, M., Lamanna, G., Lemi��re, A., Lemoine-Goumard, M., Lenain, J. -P., Leser, E., Levy, C., Lohse, T., Lypova, I., Mackey, J., Majumdar, J., Malyshev, D., Marandon, V., Marchegiani, P., Marcowith, A., Mares, A., Mart��-Devesa, G., Marx, R., Maurin, G., Meintjes, P. J., Moderski, R., Mohamed, M., Mohrmann, L., Moore, C., Morris, P., Moulin, E., Muller, J., Murach, T., Nakashima, S., Nakashima, K., de Naurois, M., Ndiyavala, H., Niederwanger, F., Niemiec, J., Oakes, L., O'Brien, P., Odaka, H., Ohm, S., Wilhelmi, E. de Ona, Ostrowski, M., Panter, M., Parsons, R. D., Perennes, C., Petrucci, P. -O., Peyaud, B., Piel, Q., Pita, S., Poireau, V., Noel, A. Priyana, Prokhorov, D. A., Prokoph, H., P��hlhofer, G., Punch, M., Quirrenbach, A., Raab, S., Rauth, R., Reimer, A., Reimer, O., Remy, Q., Renaud, M., Rieger, F., Rinchiuso, L., Romoli, C., Rowell, G., Rudak, B., Ruiz-Velasco, E., Sahakian, V., Sailer, S., Saito, S., Sanchez, D. A., Santangelo, A., Sasaki, M., Scalici, M., Schlickeiser, R., Sch��ssler, F., Schulz, A., Schutte, H. M., Schwanke, U., Schwemmer, S., Seglar-Arroyo, M., Senniappan, M., Seyffert, A. S., Shafi, N., Shiningayamwe, K., Simoni, R., Sinha, A., Sol, H., Specovius, A., Spencer, S., Spir-Jacob, M., Stawarz, ��., Steenkamp, R., Stegmann, C., Steppa, C., Takahashi, T., Tavernier, T., Taylor, A. M., Terrier, R., Tiziani, D., Tluczykont, M., Tomankova, L., Trichard, C., Tsirou, M., Tsuji, N., Tuffs, R., Uchiyama, Y., van der Walt, D. J., van Eldik, C., van Rensburg, C., van Soelen, B., Vasileiadis, G., Veh, J., Venter, C., Vincent, P., Vink, J., V��lk, H. J., Vuillaume, T., Wadiasingh, Z., Wagner, S. J., Watson, J., Werner, F., White, R., Wierzcholska, A., Yang, R., Yoneda, H., Zacharias, M., Zanin, R., Zdziarski, A. A., Zech, A., Zorn, J., and Zywucka, N.
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences
Abstract: Aims. Colliding wind binary systems have long been suspected to be high-energy (HE; 100 MeV < E < 100 GeV) ��-ray emitters. �� Car is the most prominent member of this object class and is confirmed to emit phase-locked HE �� rays from hundreds of MeV to ~100 GeV energies. This work aims to search for and characterise the very-high-energy (VHE; E >100 GeV) ��-ray emission from �� Car around the last periastron passage in 2014 with the ground-based High Energy Stereoscopic System (H.E.S.S.). Methods. The region around �� Car was observed with H.E.S.S. between orbital phase p = 0.78 - 1.10, with a closer sampling at p {\approx} 0.95 and p {\approx} 1.10 (assuming a period of 2023 days). Optimised hardware settings as well as adjustments to the data reduction, reconstruction, and signal selection were needed to suppress and take into account the strong, extended, and inhomogeneous night sky background (NSB) in the �� Car field of view. Tailored run-wise Monte-Carlo simulations (RWS) were required to accurately treat the additional noise from NSB photons in the instrument response functions. Results. H.E.S.S. detected VHE ��-ray emission from the direction of �� Car shortly before and after the minimum in the X-ray light-curve close to periastron. Using the point spread function provided by RWS, the reconstructed signal is point-like and the spectrum is best described by a power law. The overall flux and spectral index in VHE �� rays agree within statistical and systematic errors before and after periastron. The ��-ray spectrum extends up to at least ~400 GeV. This implies a maximum magnetic field in a leptonic scenario in the emission region of 0.5 Gauss. No indication for phase-locked flux variations is detected in the H.E.S.S. data., 9 pages, 4 figures, 3 tables, in press with A&A
Published: 2020
Full Text: View/download PDF

15. Observation of a sudden cessation of a very-high-energy gamma-ray flare in PKS 1510-089 with H.E.S.S. and MAGIC in May 2016

Author: Collaboration, H. E. S. S., Abdalla, H., Adam, R., Aharonian, F., Benkhali, F. Ait, Angüner, E. O., Arcaro, C., Arm, C., Armstrong, T., Ashkar, H., Backes, M., Baghmanyan, V., Martins, V. Barbosa, Barnacka, A., Barnard, M., Becherini, Y., Berge, D., Bernlöhr, K., Bi, B., Böttcher, M., Boisson, C., Bolmont, J., Bonnefoy, S., de Lavergne, M. de Bony, Bregeon, J., Breuhaus, M., Brun, F., Brun, P., Bryan, M., Büchele, M., Bulik, T., Bylund, T., Caroff, S., Carosi, A., Casanova, S., Ch, T., Ch, S., Chen, A., Cotter, G., Curyło, M., Mbarubucyeye, J. Damascene, Davids, I. D., Davies, J., Deil, C., Devin, J., deWilt, P., Dirson, L., Djannati-Ataï, A., Dmytriiev, A., Donath, A., Doroshenko, V., Dyks, J., Egberts, K., Eichhorn, F., Einecke, S., Emery, G., Ernenwein, J. -P., Feijen, K., Fegan, S., Fiasson, A., de Clairfontaine, G. Fichet, Filipovic, M., Fontaine, G., Funk, S., Füßling, M., Gabici, S., Gallant, Y. A., Giavitto, G., Giunti, L., Glawion, D., Glicenstein, J. F., Gottschall, D., Grondin, M. -H., Hahn, J., Haupt, M., Hermann, G., Hinton, J. A., Hofmann, W., Hoischen, C., Holch, T. L., Holler, M., Hörbe, M., Horns, D., Huber, D., Jamrozy, M., Jankowsky, D., Jankowsky, F., Jardin-Blicq, A., Joshi, V., Jung-Richardt, I., Kastendieck, M. A., Katarzyński, K., Katz, U., Khangulyan, D., Khélifi, B., Klepser, S., Kluźniak, W., Komin, Nu., Konno, R., Kosack, K., Kostunin, D., Kreter, M., Lamanna, G., Lemière, A., Lemoine-Goumard, M., Lenain, J. -P., Levy, C., Lohse, T., Lypova, I., Mackey, J., Majumdar, J., Malyshev, D., Mar, V., Marchegiani, P., Marcowith, A., Mares, A., Martí-Devesa, G., Marx, R., Maurin, G., Meintjes, P. J., Meyer, M., Mitchell, A. M. W., Moderski, R., Mohamed, M., Mohrmann, L., Montanari, A., Moore, C., Morris, P., Moulin, E., Muller, J., Murach, T., Nakashima, K., Nayerhoda, A., de Naurois, M., Ndiyavala, H., Niederwanger, F., Niemiec, J., Oakes, L., O'Brien, P., Odaka, H., Ohm, S., Olivera-Nieto, L., Wilhelmi, E. de Ona, Ostrowski, M., Panter, M., Panny, S., Parsons, R. D., Peron, G., Peyaud, B., Piel, Q., Pita, S., Poireau, V., Noel, A. Priyana, Prokhorov, D. A., Prokoph, H., Pühlhofer, G., Punch, M., Quirrenbach, A., Raab, S., Rauth, R., Reichherzer, P., Reimer, A., Reimer, O., Remy, Q., Renaud, M., Rieger, F., Rinchiuso, L., Romoli, C., Rowell, G., Rudak, B., Ruiz-Velasco, E., Sahakian, V., Sailer, S., Sanchez, D. A., Santangelo, A., Sasaki, M., Scalici, M., Schüssler, F., Schutte, H. M., Schwanke, U., Schwemmer, S., Seglar-Arroyo, M., Senniappan, M., Seyffert, A. S., Shafi, N., Shiningayamwe, K., Simoni, R., Sinha, A., Sol, H., Specovius, A., Spencer, S., Spir-Jacob, M., Stawarz, Ł., Sun, L., Steenkamp, R., Stegmann, C., Steinmassl, S., Steppa, C., Takahashi, T., Tavernier, T., Taylor, A. M., Terrier, R., Tiziani, D., Tluczykont, M., Tomankova, L., Trichard, C., Tsirou, M., Tuffs, R., Uchiyama, Y., van der Walt, D. J., van Eldik, C., van Rensburg, C., van Soelen, B., Vasileiadis, G., Veh, J., Venter, C., Vincent, P., Vink, J., Völk, H. J., Vuillaume, T., Wadiasingh, Z., Wagner, S. J., Watson, J., Werner, F., White, R., Wierzcholska, A., Wong, Yu Wun, Yusafzai, A., Zacharias, M., Zanin, R., Zargaryan, D., Zdziarski, A. A., Zech, A., Zhu, S. J., Zorn, J., Zouari, S., Żywucka, N., Collaboration, MAGIC, Acciari, V. A., Ansoldi, S., Antonelli, L. A., Engels, A. Arbet, Asano, K., Baack, D., Babić, A., Baquero, A., de Almeida, U. Barres, Barrio, J. A., González, J. Becerra, Bednarek, W., Bellizzi, L., Bernardini, E., Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Bil, A., Blanch, O., Bonnoli, G., Bošnjak, Ž., Busetto, G., Carosi, R., Ceribella, G., Cerruti, M., Chai, Y., Chilingarian, A., Cikota, S., Colak, S. M., Colin, U., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., D'Amico, G., D'Elia, V., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., Delfino, M., Delgado, J., Depaoli, D., Di Pierro, F., Di Venere, L., neira, E. Do Souto Espi, Prester, D. Dominis, Donini, A., Dorner, D., Doro, M., Elsaesser, D., Ramazani, V. Fallah, Fattorini, A., Ferrara, G., Foffano, L., Fonseca, M. V., Font, L., Fruck, C., Fukami, S., López, R. J. García, Garczarczyk, M., Gasparyan, S., Gaug, M., Giglietto, N., Giordano, F., Gliwny, P., Godinović, N., Green, D., Hadasch, D., Hahn, A., Heckmann, L., Herrera, J., Hoang, J., Hrupec, D., Hütten, M., Inada, T., Inoue, S., Ishio, K., Iwamura, Y., Jouvin, L., Kajiwara, Y., Karjalainen, M., Kerszberg, D., Kobayashi, Y., Kubo, H., Kushida, J., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Lombardi, S., Longo, F., López, M., López-Coto, R., López-Oramas, A., Loporchio, S., Fraga, B. Machado de Oliveira, Maggio, C., Majumdar, P., Makariev, M., Mallamaci, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martínez, M., Mazin, D., Mender, S., Mićanović, S., Miceli, D., Miener, T., Minev, M., Mir, J. M., Mirzoyan, R., Molina, E., Moralejo, A., Morcuende, D., Moreno, V., Moretti, E., Munar-Adrover, P., Neustroev, V., Nigro, C., Nilsson, K., Ninci, D., Nishijima, K., Noda, K., Nozaki, S., Ohtani, Y., Oka, T., Otero-Santos, J., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Pavletić, L., nil, P. Pe, Perennes, C., Persic, M., Moroni, P. G. Prada, Pr, E., Priyadarshi, C., Puljak, I., Rhode, W., Ribó, M., Rico, J., Righi, C., Rugliancich, A., Saha, L., Sahakyan, N., Saito, T., Sakurai, S., Satalecka, K., Schleicher, B., Schmidt, K., Schweizer, T., Sitarek, J., Šnidarić, I., Sobczynska, D., Spolon, A., Stamerra, A., Strom, D., Strzys, M., Suda, Y., Surić, T., Takahashi, M., Tavecchio, F., Temnikov, P., Terzić, T., Teshima, M., Torres-Albà, N., Tosti, L., Truzzi, S., van Scherpenberg, J., Vanzo, G., Acosta, M. Vazquez, Ventura, S., Verguilov, V., Vigorito, C. F., Vitale, V., Vovk, I., Will, M., Zarić, D., Jorstad, S. G., Marscher, A. P., Boccardi, B., Casadio, C., Hodgson, J., Kim, J. -Y., Krichbaum, T. P., Lähteenmäki, A., Tornikoski, M., Traianou, E., and Weaver, Z. R.
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), Astrophysics::High Energy Astrophysical Phenomena, Astrophysics of Galaxies (astro-ph.GA), FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies
Abstract: The flat spectrum radio quasar (FSRQ) PKS 1510-089 is known for its complex multiwavelength behavior, and is one of only a few FSRQs detected at very high energy (VHE, $E>100\,$GeV) $\gamma$-rays. VHE $\gamma$-ray observations with H.E.S.S. and MAGIC during late May and early June 2016 resulted in the detection of an unprecedented flare, which reveals for the first time VHE $\gamma$-ray intranight variability in this source. While a common variability timescale of $1.5\,$hr is found, there is a significant deviation near the end of the flare with a timescale of $\sim 20\,$min marking the cessation of the event. The peak flux is nearly two orders of magnitude above the low-level emission. For the first time, curvature is detected in the VHE $\gamma$-ray spectrum of PKS 1510-089, which is fully explained through absorption by the extragalactic background light. Optical R-band observations with ATOM reveal a counterpart of the $\gamma$-ray flare, even though the detailed flux evolution differs from the VHE ightcurve. Interestingly, a steep flux decrease is observed at the same time as the cessation of the VHE flare. In the high energy (HE, $E>100\,$MeV) $\gamma$-ray band only a moderate flux increase is observed with Fermi-LAT, while the HE $\gamma$-ray spectrum significantly hardens up to a photon index of 1.6. A search for broad-line region (BLR) absorption features in the $\gamma$-ray spectrum indicates that the emission region is located outside of the BLR. Radio VLBI observations reveal a fast moving knot interacting with a standing jet feature around the time of the flare. As the standing feature is located $\sim 50\,$pc from the black hole, the emission region of the flare may have been located at a significant distance from the black hole. If this correlation is indeed true, VHE $\gamma$ rays have been produced far down the jet where turbulent plasma crosses a standing shock., Comment: 25 pages, 17 figures. Accepted for publication by Astronomy & Astrophysics. Corresponding authors: M. Zacharias, J. Sitarek, D. Sanchez, T. Terzic
Published: 2020
Full Text: View/download PDF

16. Search for dark matter signals towards a selection of recently detected DES dwarf galaxy satellites of the Milky Way with HESS

Author: Collaboration, H. E. S. S., Abdallah, H., Adam, R., Aharonian, F., Benkhali, F. Ait, Angüner, E. O., Arakawa, M., Arcaro, C., Armand, C., Armstrong, T., Ashkar, H., Backes, M., Baghmanyan, V., Martins, V. Barbosa, Barnacka, A., Barnard, M., Becherini, Y., Berge, D., Bernlöhr, K., Böttcher, M., Boisson, C., Bolmont, J., Bonnefoy, S., Breuhaus, M., Bregeon, J., Brun, F., Brun, P., Bryan, M., Büchele, M., Bulik, T., Bylund, T., Caroff, S., Carosi, A., Casanova, S., Chand, T., Chandra, S., Chen, A., Cotter, G., Curyło, M., Davids, I. D., Davies, J., Deil, C., Devin, J., deWilt, P., Dirson, L., Djannati-Ataï, A., Dmytriiev, A., Donath, A., Doroshenko, V., Dyks, J., Egberts, K., Eichhorn, F., Emery, G., Ernenwein, J. -P., Eschbach, S., Feijen, K., Fegan, S., Fiasson, A., Fontaine, G., Funk, S., Füßling, M., Gabici, S., Gallant, Y. A., Giavitto, G., Giunti, L., Glawion, D., Glicenstein, J. F., Gottschall, D., Grondin, M. -H., Hahn, J., Haupt, M., Hermann, G., Hinton, J. A., Hofmann, W., Hoischen, C., Holch, T. L., Holler, M., Hörbe, M., Horns, D., Huber, D., Iwasaki, H., Jamrozy, M., Jankowsky, D., Jankowsky, F., Jardin-Blicq, A., Joshi, V., Jung-Richardt, I., Kastendieck, M. A., Katarzyński, K., Katsuragawa, M., Katz, U., Khangulyan, D., Khélifi, B., Klepser, S., Kluźniak, W., Komin, Nu., Konno, R., Kosack, K., Kostunin, D., Kreter, M., Lamanna, G., Lemière, A., Lemoine-Goumard, M., Lenain, J. -P., Leser, E., Levy, C., Lohse, T., Lypova, I., Mackey, J., Majumdar, J., Malyshev, D., Marandon, V., Marchegiani, P., Marcowith, A., Mares, A., Martì-Devesa, G., Marx, R., Maurin, G., Meintjes, P. J., Moderski, R., Mohamed, M., Mohrmann, L., Moore, C., Morris, P., Moulin, E., Muller, J., Murach, T., Nakashima, K., Nakashima, S., de Naurois, M., Ndiyavala, H., Niederwanger, F., Niemiec, J., Oakes, L., O'Brien, P., Odaka, H., Ohm, S., Wilhelmi, E. de Ona, Ostrowski, M., Panter, M., Parsons, R. D., Peyaud, B., Piel, Q., Pita, S., Poireau, V., Noel, A. Priyana, Prokhorov, D. A., Prokoph, H., Pühlhofer, G., Punch, M., Quirrenbach, A., Raab, S., Rauth, R., Reimer, A., Reimer, O., Remy, Q., Renaud, M., Rieger, F., Rinchiuso, L., Romoli, C., Rowell, G., Rudak, B., Ruiz-Velasco, E., Sahakian, V., Sailer, S., Saito, S., Sanchez, D. A., Santangelo, A., Sasaki, M., Scalici, M., Schüssler, F., Schutter, H. M., Schwanke, U., Schwemmer, S., Seglar-Arroyo, M., Senniappan, M., Seyffert, A. S., Shafi, N., Shiningayamwe, K., Simoni, R., Sinha, A., Sol, H., Specovius, A., Spencer, S., Spir-Jacob, M., Stawarz, Ł., Steenkamp, R., Stegmann, C., Steppa, C., Takahashi, T., Tavernier, T., Taylor, A. M., Terrier, R., Tiziani, D., Tluczykont, M., Tomankova, L., Trichard, C., Tsirou, M., Tsuji, N., Tuffs, R., Uchiyama, Y., van der Walt, D. J., van Eldik, C., van Rensburg, C., van Soelen, B., Vasileiadis, G., Veh, J., Venter, C., Viana, A., Vincent, P., Vink, J., Völk, H. J., Vuillaume, T., Wadiasingh, Z., Wagner, S. J., Watson, J., Werner, F., White, R., Wierzcholska, A., Yang, R., Yoneda, H., Zacharias, M., Zanin, R., Zargaryan, D., Zdziarski, A. A., Zech, A., Zhu, S., Zorn, J., Żywucka, N., 26598973 - Abdalla, Hassan, 30588766 - Arcaro, Cornelia, 28644743 - Backes, Michael, 20574266 - Barnard, Monica, 24420530 - Böttcher, Markus, 30366755 - Chand, Tej B., 31125417 - Chandra, Sunil, 33379009 - Kreter, Michael, 26403366 - Ndiyavala, Hambeleleni, 22799133 - Schutte, Hester M., 20126999 - Seyffert, Albertus Stefanus, 10060499 - Van der Walt, Diederick Johannes, 21106266 - Van Rensburg, Carlo, 12006653 - Venter, Christo, 26594080 - Wadiasingh, Zorawar, 29092086 - Zacharias, Michael, 34208968 - Zywucka-Hejzner, Natalia, 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), Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), 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), 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 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), Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE (UMR_7585)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), 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), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), 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)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), H.E.S.S., 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), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), H. E. S. S. Collaboration, Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2), Faculty of Science, High Energy Astrophys. & Astropart. Phys (API, FNWI), and API Other Research (FNWI)
Subjects: atmosphere [Cherenkov counter], VHE [gamma ray], mass [dark matter], Astrophysics, 01 natural sciences, 7. Clean energy, galaxy: halo, S046PHB, HESS, Gamma ray astronomy, dark energy, Physics, density, OBSERVATÓRIOS, imaging, halo [dark matter], halo [galaxy], gamma ray: emission, Weakly interacting massive particles, VERITAS, Astrophysics - High Energy Astrophysical Phenomena, Particle astrophysics, Cosmology & astrophysics, Gravitation, WIMP, Milky Way, Astrophysics::High Energy Astrophysical Phenomena, satellite, Dark matter, Astrophysics::Cosmology and Extragalactic Astrophysics, Cherenkov counter: atmosphere, GLAST, cross section: annihilation, S030DMA, Galactic halo, statistical analysis, dark matter: halo, cosmic rays, emission [gamma ray], 0103 physical sciences, Experiments in gravity, ddc:530, 14. Life underwater, 010306 general physics, Astrophysics::Galaxy Astrophysics, Dwarf galaxy, background, 010308 nuclear & particles physics, dark matter: mass, sensitivity, MAGIC, Galaxy, Dwarf spheroidal galaxy, Dark matter halo, annihilation [cross section], gamma ray: VHE, 13. Climate action, HESS - Abteilung Hinton, Higgsino, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], HAWC, cosmology, Telescopes
Abstract: Dwarf spheroidal galaxy satellites of the Milky Way are prime targets for indirect detection of dark matter with gamma rays due to their proximity, high dark matter content and absence of non-thermal emission processes. Recently, the Dark Energy Survey (DES) revealed the existence of new ultra-faint dwarf spheroidal galaxies in the southern-hemisphere sky, therefore ideally located for ground-based observations with the imaging atmospheric Cherenkov telescope array H.E.S.S. We present a search for very-high-energy ($E\gtrsim100$ GeV) gamma-ray emission using H.E.S.S. observations carried out recently towards Reticulum II, Tucana II, Tucana III, Tucana IV and Grus II satellites. No significant very-high-energy gamma-ray excess is found from the observations on any individual object nor in the combined analysis of all the datasets. Using the most recent modeling of the dark matter distribution in the dwarf galaxy halo, we compute for the first time on DES satellites individual and combined constraints from Cherenkov telescope observations on the annihilation cross section of dark matter particles in the form of Weakly Interacting Massive Particles. The combined 95% C.L. observed upper limits reach $\langle \sigma v \rangle \simeq 1 \times 10^{-23}$ cm$^3$s$^{-1}$ in the $W^+W^-$ channel and $4 \times 10^{-26}$ cm$^3$s$^{-1}$ in the $\gamma\gamma$ channels for a dark matter mass of 1.5 TeV. The H.E.S.S. constraints well complement the results from Fermi-LAT, HAWC, MAGIC and VERITAS and are currently the most stringent in the $\gamma\gamma$ channels in the multi-GeV/multi-TeV mass range., Comment: 20 pages, 12 figures
Published: 2020

17. Very high energy $��$-ray emission from two blazars of unknown redshift and upper limits on their distance

Author: Collaboration, H. E. S. S., Abdalla, H., Adam, R., Aharonian, F., Benkhali, F. Ait, Ang��ner, E. O., Arakawa, M., Arcaro, C., Armand, C., Armstrong, T., Ashkar, H., Backes, M., Baghmanyan, V., Martins, V. Barbosa, Barnacka, A., Barnard, M., Becherini, Y., Berge, D., Bernl��hr, K., B��ttcher, M., Boisson, C., Bolmont, J., Bonnefoy, S., Bregeon, J., Breuhaus, M., Brun, F., Brun, P., Bryan, M., B��chele, M., Bulik, T., Bylund, T., Caroff, S., Carosi, A., Casanova, S., Chand, T., Chandra, S., Chen, A., Cotter, G., Cury��o, M., Davids, I. D., Davies, J., Deil, C., Devin, J., deWilt, P., Dirson, L., Djannati-Ata��, A., Dmytriiev, A., Donath, A., Doroshenko, V., Dyks, J., Egberts, K., Eichhorn, F., Emery, G., Ernenwein, J. -P., Feijen, K., Fegan, S., Fiasson, A., Fontaine, G., Funk, S., F��ling, M., Gabici, S., Gallant, Y. A., Giavitto, G., Giunti, L., Glawion, D., Glicenstein, J. F., Gottschall, D., Grondin, M. -H., Hahn, J., Haupt, M., Hermann, G., Hinton, J. A., Hofmann, W., Hoischen, C., Holch, T. L., Holler, M., H{\\\'}orbe, M., Horns, D., Huber, D., Iwasaki, H., Jamrozy, M., Jankowsky, D., Jankowsky, F., Jardin-Blicq, A., Joshi, V., Jung-Richardt, I., Kastendieck, M. A., Katarzynski, K., Katsuragawa, M., Katz, U., Khangulyan, D., Kh��lifi, B., Klepser, S., Kluzniak, W., Komin, Nu., Konno, R., Kosack, K., Kostunin, D., Kreter, M., Lamanna, G., Lemi��re, A., Lemoine-Goumard, M., Lenain, J. -P., Leser, E., Levy, C., Lohse, T., Lypova, I., Mackey, J., Majumdar, J., Malyshev, D., Marandon, V., Marchegiani, P., Marcowith, A., Mares, A., Mart��-Devesa, G., Marx, R., Maurin, G., Meintjes, P. J., Moderski, R., Mohamed, M., Mohrmann, L., Moore, C., Morris, P., Moulin, E., Muller, J., Murach, T., Nakashima, S., Nakashima, K., de Naurois, M., Ndiyavala, H., Niederwanger, F., Niemiec, J., Oakes, L., O'Brien, P., Odaka, H., Ohm, S., Wilhelmi, E. de Ona, Ostrowski, M., Panter, M., Parsons, R. D., Peyaud, B., Piel, Q., Pita, S., Poireau, V., Noel, A. Priyana, Prokhorov, D. A., Prokoph, H., P��hlhofer, G., Punch, M., Quirrenbach, A., Raab, S., Rauth, R., Reimer, A., Reimer, O., Remy, Q., Renaud, M., Rieger, F., Rinchiuso, L., Romoli, C., Rowell, G., Rudak, B., Ruiz-Velasco, E., Sahakian, V., Sailer, S., Saito, S., Sanchez, D. A., Santangelo, A., Sasaki, M., Scalici, M., Sch��ssler, F., Schutte, H. M., Schwanke, U., Schwemmer, S., Seglar-Arroyo, M., Senniappan, M., Seyffert, A. S., Shafi, N., Shiningayamwe, K., Simoni, R., Sinha, A., Sol, H., Specovius, A., Spencer, S., Spir-Jacob, M., Stawarz, ��., Steenkamp, R., Stegmann, C., Steppa, C., Takahashi, T., Tavernier, T., Taylor, A. M., Terrier, R., Tiziani, D., Tluczykont, M., Tomankova, L., Trichard, C., Tsirou, M., Tsuji, N., Tuffs, R., Uchiyama, Y., van der Walt, D. J., van Eldik, C., van Rensburg, C., van Soelen, B., Vasileiadis, G., Veh, J., Venter, C., Vincent, P., Vink, J., V��lk, H. J., Vuillaume, T., Wadiasingh, Z., Wagner, S. J., Watson, J., Werner, F., White, R., Wierzcholska, A., Yang, R., Yoneda, H., Zacharias, M., Zanin, R., Zargaryan, D., Zdziarski, A. A., Zech, A., Zhu, S. J., Zorn, J., ��ywucka, N., and Cerruti, M.
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), FOS: Physical sciences
Abstract: We report on the detection of very-high-energy (VHE; $E > 100$ GeV) $��$-ray emission from the BL Lac objects KUV 00311-1938 and PKS 1440-389 with the High Energy Stereoscopic System (H.E.S.S.). H.E.S.S. observations were accompanied or preceded by multi-wavelength observations with Fermi/LAT, XRT and UVOT on board the Swift satellite, and ATOM. Based on an extrapolation of the Fermi/LAT spectrum towards the VHE $��$-ray regime, we deduce a 95% confidence level upper limit on the unknown redshift of KUV 00311-1938 of z < 0.98, and of PKS 1440-389 of z < 0.53. When combined with previous spectroscopy results the redshift of KUV 00311-1938 is constrained to $0.51 \leq z < 0.98$ and for PKS 1440-389 to $0.14 \lessapprox z < 0.53$., Accepted for publication in MNRAS. 13 pages, 4 figures
Published: 2020
Full Text: View/download PDF

18. Reconstructive carinal surgery – Indication and perioperative management

Author: Eichhorn, F, Dienemann, H, Männle, C, and Hoffmann, H
Subjects: ddc: 610, respiratory system, 610 Medical sciences, Medicine
Abstract: Background: Carinal resection of the trachea is a challenging procedure in pulmonary and central airway surgery. There is only a few number of resectable cases with locally advanced malignoma and careful selection of surgical patients is inevitable. Aim of the study was to illustrate common surgical[for full text, please go to the a.m. URL], 133. Kongress der Deutschen Gesellschaft für Chirurgie
Published: 2016
Full Text: View/download PDF

19. Kombinationseingriffe in der Herz- und Thoraxchirurgie

Author: Eichhorn, F, Arif, R, Karck, M, and Dienemann, H
Subjects: ddc: 610, 610 Medical sciences, Medicine
Abstract: Einleitung: Kardiochirurgisch-thoraxchirurgische Kombinationseingriffe bei Tumorerkrankungen sind vergleichsweise selten. In der Regel handelt es sich um Grenzindikationen sowohl in technischer als auch onkologischer Hinsicht. Dargestellt werden die institutsinternen Kombinationseingriffe zwischen Thorax-[for full text, please go to the a.m. URL], 132. Kongress der Deutschen Gesellschaft für Chirurgie
Published: 2015
Full Text: View/download PDF

20. Langzeitergebnisse der operativen Therapie bei der juvenilen Knochenzyste

Author: Hagmann, S, Eichhorn, F, and Zeifang, F
Subjects: ddc: 610, 610 Medical sciences, Medicine
Abstract: Fragestellung: Die juvenile Knochenzyste stellt aufgrund ihrer Rezidivneigung häufig eine therapeutische Herausforderung dar. Die mittel- und langfristigen Ergebnisse verschiedener operativer Verfahren zur Behandlung der juvenilen Knochenzyste sollten ermittelt werden. Methodik: Retrospektiv[for full text, please go to the a.m. URL], Deutscher Kongress für Orthopädie und Unfallchirurgie; 73. Jahrestagung der Deutschen Gesellschaft für Unfallchirurgie, 95. Tagung der Deutschen Gesellschaft für Orthopädie und Orthopädische Chirurgie, 50. Tagung des Berufsverbandes der Fachärzte für Orthopädie
Published: 2009
Full Text: View/download PDF

21. Structural and magnetic properties of Mn-implanted Si

Author: Zhou, S., Potzger, K., Mücklich, A., Eichhorn, F., Schell, N., Grötzschel, R., Schmidt, B., Skorupa, W., Helm, M., Fassbender, J., and Geiger, D.
Subjects: Ion implantation, Diluted magnetic semiconductor, Si
Abstract: Structural and magnetic properties in Mn-implanted, p-type Si were investigated. High resolution structural analysis techniques such as synchrotron x-ray diffraction revealed the formation of MnSi1.7 nanoparticles already in the as-implanted samples. Depending on the Mn fluence, the size increases from 5 nm to 20 nm upon rapid thermal annealing. No significant evidence is found for Mn substituting Si sites either in the as-implanted or annealed samples. The observed ferromagnetism yields a saturation moment of 0.21µB per implanted Mn at 10 K, which could be assigned to MnSi1.7 nanoparticles as revealed by a temperature-dependent magnetization measurement.
Published: 2007

22. Diffraction measurements with synchrotron radiation on superimposed deformed composite of quartzite and dunite

Author: Walther, K., Frischbutter, A., Scheffzük, C., Kenkmann, T., and Eichhorn, F.
Subjects: superimposed deformation, quartzite, dunite, residual strain, synchrotron diffraction, texture
Abstract: A composite specimen (cylinder) consisting one half each of dunite and quartzite was superimposed (shock) deformed (16-34 GPa). Intracrystalline residual strain was determined from diffraction pattern, obtained using synchrotron radiation at beamline ROBL (ESRF Grenoble). Considerable differences in residual microstrain were determined as the interface is approached. Moreover, the tendencies in size evolution of scattering crystallites were evaluated by diffraction peak shape analysis. The superimposed deformation produced a new microsize structure in dunite, but was only modifying the macrostructure in quartzite, which already exists before the superimposed deformation. Otherwise, the size of scattering crystallites (related to foliation) of quartzite was reduced about six times more than that of dunite (in relation to the newly formed structure).
Published: 2007

23. Structural properties of thin HfSiO films

Author: Teichert, S., Muehle, U., Fachmann, J., Steinhoff, J., Kudelka, S., Wilde, L., Borany, J., and Eichhorn, F.
Abstract: Kein Abstract vorhanden.
Published: 2007

24. Phase Transition and Internal Stresses in Tungsten Coatings

Author: Benayoun, S., Grynszpan, R. I., Hantzpergue, J. J., Anwand, W., Eichhorn, F., and Brauer, G.
Published: 2007

25. Study of anomalous behaviour of LiTaO3 during the annealed proton exchange process of optical waveguide´s formation - comparison with LiNbO3

Author: Salavcova, L., Spirkova, J., Ondracek, F., Mackova, A., Vacik, J., Kreissig, U., Eichhorn, F., and Groetzschel, R.
Subjects: APE, Lithium tantalate, Lithium niobate, Ion exchange
Abstract: This paper deals with detailed study of changes that lithium tantalate (LT) and lithium niobate (LN) single crystals undergo during the APE (Annealed Proton Exchange) process of optical waveguides´ formation. It is a well-known fact that several cases of anomalous behaviour are connected to the APE:LT samples, bringing thus serious limitations for the practical utilization of the APE:LT waveguides. As the LT crystal posseses even better optical properties than the LN (e.g., it is less susceptible to optical damage), it is highly desirable to provide research focused on its behaviour during the APE in order to get a control over fabrication of the APE:LT devices. Neutron Depth Profiling (NDP), Elastic Recoil Detection Analysis (ERDA) and High Ion Energy ERDA (HIERDA) were performed to study changes in the surface of the LT and LN Z-cut wafers caused by the APE treatment and to determine the concentration depth profiles of the exchanged ions (lithium and hydrogen). Information on modifications of the crystals during the APE were obtained using X-Ray Diffraction (XRD) analysis. Optical/waveguiding properties of the samples were obtained by means of the standard mode spectroscopy at 633 nm. The experiments proved that the LT is significantly less affected by the APE process compared to the LN and that most characteristics of the APE:LT layers are relatively easily restored back towards that of the virgin crystal by the annealing process.
Published: 2007

26. A new casting technique for the restoration of lead pipes in old organs

Author: Skorupa, W., Rossner, M., Neelmeijer, C., Eichhorn, F., Borany, J., Werner, H., Eule, A.-C., Schucknecht, T., Klemm, V., and Rafaja, D.
Subjects: metallography, lead casting, PIXE, x-ray diffraction analysis, organ pipes, scanning electron microscopy
Abstract: We have developed a new casting technique basing on old recipes from the 17. and 18. century to restaurate old lead pipes as well as to produce new pipes approaching the quality of the old ones. Materials studies of old and new metal probes were performed by metallography, scanning electron microscopy, and x-ray diffraction analysis. Different casting variants as well as the influence of hammering the casted metal plates onto the microstructure were investigated. Moreover we investigated by PIXE (Proton induced X-ray Emission) the residuals of old glue on the old pipes which remaining from tin foil adornment. In this manner we positioned the pipe directly in front of an external ion beam and analysed it without cutting pieces away from the metal pipe.
Published: 2007

27. Diluted magnetic semiconductors created by non-equilibrium processing -new challenges for ion beams

Author: Potzger, K., Zhou, S., Zhang, G., Reuther, H., Talut, G., Mücklich, A., Eichhorn, F., Schell, N., Grötzschel, R., Skorupa, W., Helm, M., Anwand, W., Brauer, G., and Fassbender, J.
Subjects: diluted magnetic semiconductors, ZnO, ion implantation
Abstract: Diluted magnetic semiconductors (DMS) are based on common semiconducting material like GaAs, Si, Ge, InP, GaN or ZnO doped with a few percent of a transition or rare earth metal. While early work has been performed mainly by polish groups in the 1970ies and 80ies, DMS have attracted worldwide scientific attention during the last 5 years due to their application potential in spintronics. This was triggered by the discovery of ferromagnetic GaMnAs and the theoretical prediction of room temperature ferromagnetism for ZnO:Mn and GaN:Mn by T. Dietl and H. Ohno [1]. One of the main obstacles while creating a DMS is secondary phase formation. Since solubility limits are rather low, non-equilibrium doping techniques like low temperature film growth are commonly used. On the other hand, ion implantation offers superb possibilities for low temperature doping but is always connected with lattice damage of the target material. Combining ion implantation with another non-equilibrium technique, i.e. rapid thermal annealing, leads to a diluted state while the crystallinity of the target material is restored. This has been shown for Si:Mn [2]. Recently, we investigated the secondary phase formation for Fe,Co and Ni as well as Gd, Tb implanted in ZnO single crystals. We found, that at an implantation temperature of 623 K tiny superparamagnetic nanoparticles are formed in all transition metal (TM) doped samples. These phases can hardly be identified using lab X-ray diffraction (XRD), e.g. in the case of Fe. Only application of high resolution methods like synchrotron XRD, susceptometry, Mössbauer spectroscopy and transmission electron microscopy allows their identification [3]. On the other hand, rare earth implanted samples show a diluted state up to annealing temperatures of 823 K. For both ZnO:Tb and ZnO:Gd a ferromagnetic order was found. Low temperature TM implantation (253 K) leads to a 100% diluted state. The TM-ions however do not couple magnetically that can be caused by the lattice damage introduced due to the implantation. Very rapid thermal processing using flash lamps with 20 ms pulse width leads to a significant recovery of the lattice order, while only a small amount of nanoparticles is created. Reference [1] T. Dietl, et al., Science 287, 1019 (2000). [2] M. Bolduc, et al., Phys. Rev. B 71, 033302 (2005). [3] K. Potzger, et al., Appl. Phys. Lett. 88, 052508 (2006).
Published: 2006

28. Mn-silicide nanoparticles: the origin of ferromagnetism in Mn-implanted Si?

Author: Zhou, S., Potzger, K., Zhang, G., Mücklich, A., Eichhorn, F., Grötzschel, R., Schmidt, B., Skorupa, W., Helm, M., and Fassbender, J.
Abstract: Recently Si and Ge semiconductors doped with Mn are reported to be ferromagnetic [1, 2]. The ferromagnetism is attributed to the coupling between Mn ions and carriers. However some MnxSiy and MnxGey compounds are ferromagnetic. A careful structural analysis is crucial to clarify the ferromagnetism in Mn doped Si or Ge. In this work, Mn ions were introduced to p-Si by ion implantation. Structural and ferromagnetic properties of Mn-implanted Si were investigated by Rutherford backscattering, x-ray diffraction (XRD), transmission electron microscopy (TEM) and superconducting quantum interference device magnetometer (SQUID). Synchrotron irradiation XRD and TEM revealed the formation of Mn4Si7 nanoparticles already in the as implanted samples (Fig. 1). Depending on the Mn-fluence they grew up from 5 nm to 20 nm upon rapid thermal annealing. No significant evidence is found for Mn substituting Si sites either in the as-implanted or annealed samples. By SQUID, hysteretic loops were observed, while the coecivity and remanence are drastically decreased with increasing temperature. The magnetization upon zero-field cooled and field cooled procedure shows a characteristic of a magnetic nanoparticle system. Together with structural analysis, we attributed the observed ferromagnetism to Mn-silicides nanoparticles. Reference (1) Y. D. Park, et al., Science 295, 651 (2002). (2) M. Bolduc, et al., Phys. Rev. B 71, 033302 (2005).
Published: 2006

29. Ferromagnetic ZnFe2O4 synthesized by Fe implantation into ZnO

Author: Zhou, S., Potzger, K., Reuther, H., Mücklich, A., Eichhorn, F., Schell, N., Skorupa, W., Helm, M., and Fassbender, J.
Subjects: Ion implantation, Ferromagnetism, ZnO, Zinc ferrite
Abstract: Bulk Zinc ferrite (ZnFe2O4) is known to possess a normal spinel structure and is an antiferromagnetic material. However, ferri- or ferro- magnetism has been observed in nanosized ZnFe2O4, which raised the current interest of ZnFe2O4 nanoparticles [1-3]. In this work, crystalline ZnFe2O4 was synthesized by Fe implantation into ZnO at 623 K, following a post thermal annealing. In the as-implanted ZnO sample, a fraction of Fe is in metallic state, and is responsible for the magnetic property. An annealing at 823 K enhanced the Fe particle formation, but Fe nanoparticles were oxidized after an annealing at 1070 K. A further annealing at 1070 K for 3.5 h induced the formation of ZnFe2O4. ZnFe2O4 was identified by x-ray diffraction, transmission electron microscopy and indirectly by room temperature conversion electron Mössbauer spectroscopy. The magnetic property was investigated by superconducting quantum interference device (SQUID) magnetometry (Fig. 1). At 5 K, the sample shows a hysteric loop upon magnetization reversal with a high coecivity of around 400 Oe. The magnetization also was measured as a function of temperature with zero field cooling and field cooling protocol. The zero field cooling curve exhibits a maximum magnetization at a temperature of around 26 K, indicating a nanoparticle magnetic characteristic. The ferromagnetism of ZnFe2O4 can be explained by a partially inverted spinel structure, where Fe ions migrate from octahedral B sites (Fe3+) to tetrahedral A sites (Fe2+), and a strong A-B superexchange interaction produces the ferromagnetic coupling [1-3]. [1] Z. H. Zhou, et al, Appl. Phys. Lett. 79, 3167 (2001). [2] G. F. Goya, et al, J. Phys.: Condens. Matter 15, 641 (2003). [3] J. H. Shim, et al, Appl. Phys. Lett. 86, 082503 (2005).
Published: 2006

30. Magnetic, structural and electronic properties of Fe implanted GaN

Author: Talut, G., Reuther, H., Eichhorn, F., Mücklich, A., and Potzger, K.
Subjects: Mössbauer, Spintronics, clusters, ferromagnetism, (Ga, Fe)N
Abstract: The request for room-temperature diluted magnetic semiconductors resulted in a large interest in GaN containing transition metals. In contrast to the (Ga,Mn)N-system, the origin of the ferromagnetism in Fe implanted GaN is still not sufficiently investigated. The formation of secondary phases and valence states of Fe play an important role in the discussion of the source of the ferromagnetism. In this study, the electronic, structural and magnetic properties of p-GaN implanted with Fe+ (1 - 16 · 1016 cm^-2) at 350° C and subsequently annealed at 650° - 1000° C were examined by conversion electron Mössbauer spectroscopy, x-ray diffraction, transmission electron microscopy and magnetometry. First experiments show ferromagnetic behaviour above room temperature in samples implanted with the highest amount of Fe. First x-ray diffraction and conversion electron M¨ossbauer spectroscopy measurements reveal the creation of alpha-Fe-clusters which are most likely responsible for the ferromagnetism.
Published: 2006

31. Magnetic nanoparticle formation in Fe implanted ZnO

Author: Zhou, S., Potzger, K., Mücklich, A., Reuther, H., Eichhorn, F., Schell, N., Skorupa, W., Helm, M., and Fassbender, J.
Subjects: nanostructured materials, II-VI semiconductors, superparamagnetism, magnetic semiconductors
Abstract: Low temperature doping with transition metals is currently accepted as the silver bullet for the creation of diluted magnetic semiconductors (DMS). Among them, ion implantation offers the possibility for doping at almost any temperature. However, tiny, hardly detectable ferromagnetic nanoparticles created due to phase separation already during implantation can wrongly give the impression of a DMS by means of a pronounced integral magnetization. In this work we would like to present systematic investigations on the formation of ferromagnetic nanoparticles due to 57Fe implantation into ZnO single crystals applying several sensitive analysis techniques. At an implantation temperature of 623 K and implantation energy of 180 keV, a distinct dependence of the nanoparticle formation on the Fe ion fluence was observed. Below a fluence of 2x1016 cm-2, all Fe is found in nonmagnetic charged states indicating no -Fe-nanoparticle formation as was confirmed using X-ray diffraction. From a fluence of 2x1016 cm-2, superparamagnetic -Fe-nanoparticles are present. They were evidenced by zero-field cooled (ZFC) and field cooled (FC) magnetization curves, x-ray diffraction and transmission electron microscopy. The superparamagnetic blocking temperatures increase with the implanted fluence. An annealing at 823 K for 15 min enhanced the Fe particle formation, but Fe nanoparticles were oxidized after an annealing at 1073 K for 15 min. A further annealing at 1073 K for 3.5 h induced the formed of ZnFe2O4. In a conclusion, we definitely rule out the formation of a diluted magnetic semiconductor in Fe-implanted ZnO at process temperature above 623 K.
Published: 2006

32. Magnetic and structural properties of Fe implanted GaN

Author: Talut, G., Reuther, H., Eichhorn, F., Mücklich, A., Potzger, K., Stromberg, F., and Zhou, S.
Subjects: Mößbauer, Cluster, DMS, Fe, GaN
Abstract: In order to investigate the possibility to create and stabilize a DMS behavior in the (Ga,Fe)N-system, p-doped GaN was implanted with 200 keV 57Fe+ ions at 350°C, RT and -30°C with fluences Φ = 1*10^16 cm^-2 - 1.6*10^17 cm^-2. Magnetic electronic and structural properties of as implanted as well as subcequently annealed samples were investigated by AES, CEMS, TEM, SQUID and XRD techniques.
Published: 2006

33. Surface modification of Si(111) substrate by iron ion implantation: Growth of a thin beta-FeSi2 layer

Author: Ayache, R., Bouabellou, A., Eichhorn, F., Richter, E., and Mücklich, A.
Subjects: Si111, XRD, TEM, beta-FeSi2, ion beam synthesis, RBS
Abstract: The processes in the synthesis of a thin layer of the semiconducting iron silicide (beta-FeSi2) on the surface of a single-crystal Si(111) substrate by implantation of 195 keV Fe ions with a dose of 8×1017 cm2 are investigated. Using Rutherford backscattering spectrometry, x-ray diffraction and cross-sectional transmission electron microscopy, the structure and the phase composition of the synthesized layers are studied. The infrared transmittance spectra show the absorption at 310 cm1 as an indication of the initial nucleation of beta-FeSi2 precipitates during the implantation of iron into silicon substrate.
Published: 2006

34. Ion beam synthesis of Fe nanoparticles in MgO and Y:ZrO2

Author: Potzger, K., Reuther, H., Zhou, S., Mücklich, A., Grötzschel, R., Eichhorn, F., Liedke, M. O., and Fassbender, J.
Subjects: magnetism, nanoparticles, ion beam synthesis
Abstract: In order to prepare epitaxially oriented Fe nanoparticles near the surface of a single crystalline host material the method of ion beam synthesis has been explored. Two different host matrices, i. e., MgO(001) and Y:ZrO2(001), were employed to study the influence of the lattice misfit, the solubility and the host oxidizing/reducing properties on the formation of the Fe nanoparticles. The Fe ions were implanted at a primary energy of 100 110 keV (mean projected range: 50 nm) with a constant fluence of 6x1016 cm-2 at implantation temperatures varying between 25 °C and 1000°C. Structural and magnetic characterization was performed by means of CEMS (conversion electron Mössbauer spectroscopy), XRD (X-ray diffraction), RBS (Rutherford back scattering), TEM (transmission electron microscopy) and MOKE (magneto-optical Kerr effect). For MgO substrates the fraction of metallic Fe increases from 28% (25°C) to 60% (800°C) as a function of implantation temperature, whilst the Fe depth profile remains the same. For an implantation temperature of 800°C fcc Fe nanoparticles with a mean diameter of 5 nm and an exclusive orientation relationship of -Fe(111)//MgO(111) and -Fe[220]//MgO[220] have been found. However, for an implantation temperature of 1000°C, the amount of Fe incorporated in the calculated depth profile is strongly reduced due to an enhanced mobility and diffusion of the Fe ions in the matrix material. The remaining Fe is found to be in the 3+ oxidation state. Also in Y:ZrO2 the fraction of metallic Fe increases with increasing implantation temperature reaching 96% at 1000 °C. However, the nanoparticles formed are mainly bcc with a mean diameter of 13 nm. The dominant epitaxial relation is Fe(110)//Y:ZrO2(001) and Fe[001]//Y:ZrO2[100]. The ferromagnetic behavior is reflected by a magnetic hyperfine field of 330 kOe and a hysteretic magnetization reversal. No in-plane anisotropy could be detected.
Published: 2006

35. Ion beam synthesis of Fe nanoparticles in MgO and YSZ

Author: Potzger, K., Reuther, H., Zhou, S., Mücklich, A., Grötzschel, R., Eichhorn, F., Liedke, M., Fassbender, J., Lichte, H., and Lenk, A.
Subjects: magnetic nanoparticles, YSZ, MgO, mossbauer spectroscopy, ion beam synthesis
Abstract: In order to prepare epitaxially oriented Fe nanoparticles embedded below the surface of an oxide single crystalline host material the method of ion beam synthesis has been explored for MgO(001) and YSZ(001). At a fixed implantation energy and fluence the implantation temperature has been varied between *room temperature* and 1273 K. It was found, that for MgO substrates the fraction of metallic Fe increases up to a maximum of 60% (at 1073 K) as a function of implantation temperature, whilst the Fe depth profile remains the same. The Fe nanoparticles are nonmagnetic at room temperature exhibiting fcc structure. They show a mean diameter of 5 nm and an exclusive orientation relationship to the host. In YSZ the fraction of metallic Fe increases with increasing implantation temperature reaching 100% at 1273 K. However, the nanoparticles formed are of bcc structure with a mean diameter of 13 nm located mainly close to the sample surface. The ferromagnetic behavior is reflected by a magnetic hyperfine field of 330 kOe and a hysteretic magnetization reversal. Electron holography measurements have been carried out in order to visualize the stray field of the particles.
Published: 2006

36. Fe doped ZnO a diluted magnetic semiconductor?

Author: Potzger, K., Zhou, S., Reuther, H., Mücklich, A., Eichhorn, F., Talut, G., Herrmannsdörfer, T., Bianchi, A., and Fassbender, J.
Subjects: Ion beam doping, ZnO, Diluted magnetic semiconductors
Abstract: The fabrication of diluted magnetic semiconductors (DMS) by transition-metal (TM) doping of ZnO has attracted tremendous interest within the last 3 years. However, there are still vivid discussions if the ferromagnetic state stems from Zener-interaction between diluted TM ions or from magnetic secondary phases. In order to prove or exclude the possible formation of TM-secondary phases in ZnO we have investigated iron doping, since Fe-ZnO (n-type) DMS are theoretically predicted to exhibit ferromagnetism [1]. For these investigations Fe-ions have been implanted with an ion energy of 180 keV (projected range Rp=80 nm) at 250 K and 620 K into ZnO single crystals. Two fluences of either 0.4 or 4x1016 ions per cm2 were chosen which correspond to 0.5 and 5 at%, respectively. The samples were characterized by CEMS (conversion electron Mössbauer spectroscopy), XRD (X-ray diffraction) using synchrotron radiation, RBS (Rutherford back scattering), TEM (transmission electron microscopy) and SQUID (superconducting quantum interference device) magnetometry. For the as implanted sample a high solubility of Fe was found. The ionic states are 2+ and 3+ but none of the ionic fractions could be clearly determined to occupy substitutional lattice sites. The sample implanted at high fluence and 620 K exhibits ferromagnetic behavior at room temperature as was observed by CEMS and SQUID. However, CEMS and XRD measurements confirm that the origin of the ferromagnetic behavior is due to Fe-nanocluster formation. These nanoclusters show the magnetic moment and hyperfine field of metallic bcc-Fe. For samples implanted at 250 K and a low fluence also a ferromagnetic behavior could be detected at room temperature. No secondary phase formation occurs suggesting the formation of a diluted magnetic semiconductor (DMS) [1] K. Sato, H. Katayama-Yoshida, Jpn. J. Appl. Phys. 40, L334 (2001)
Published: 2006

37. Mn-silicide nanoparticles formed inside Si using ion implantation

Author: Zhou, S., Potzger, K., Zhang, G., Mücklich, A., Eichhorn, F., Grötzschel, R., Schmidt, B., Skorupa, W., Helm, M., and Fassbender, J.
Abstract: 300 keV Mn was implanted into p-Si with a fluence of 1*1015/cm2, 1*1016/cm2 and 5*1016/cm2, respectively, at 620 K. The samples were annealed at 1070 K in N2 ambient for 5 min by rapid thermal annealing. Rutherford backscattering/channeling, transmission electron microscopy and X-ray diraction were applied for structural characterization. Mnsilicide nanoparticles were formed with the size of 5 nm already in the asimplanted samples and grew up to around 30 nm after annealing. Moreover no significant evidence is found for Mn substituting Si sites either in as-implanted or annealed samples. The virgin samples already show a ferromagnetic like behavior, and the moment is slightly increased after implantation (1*1016/cm2) and annealing by around 0.5 Bohr magneton per Mn. Therefore, the majority of Mn ions formed Mn-silicides, and some are diluted in Si matrix and develop into ferromagnetic coupling. These effects have to be properly considered for the design of Si-based diluted magnetic semiconductors. [1] M. Bolduc, C. Awo-Aouda, A. Stollenwerk, M. B. Huang, F. G. Ramos, G. Agnello, and V. P. LaBella Phys. Rev. B 71, 033302 (2005).
Published: 2006

38. RBS-channeling, ERDA and XRD study of lithium tantalate modified by annealed proton echange (APE)

Author: Mackova, A., Salavkova, L., Spirkova, J., Grötzschel, R., and Eichhorn, F.
Subjects: ERDA, LiTaO3 [APE], XRD, RBS-channeling
Abstract: Lithium tantalate (LT) single crystals are very promising substrates for constructing highly sophisticated photonics devices. The used procedure for fabricating optical waveguides in them was annealed proton exchange (APE). Here we have used Rutherford backscattering spectrometry (RBS) channeling analysis, X-ray diffraction (XRD) and elastic recoil detection analysis (ERDA) to study changes in the surface of the LT wafers caused by the APE treatment and to determine the concentration depth profiles of hydrogen atoms. The measurements were taken for both virgin (untreated) and APE:LT samples fabricated using various experimental conditions. We have found that the incorporation of hydrogen during the first step, i.e. the PE procedure (proton exchange), leads to modifications of the structure of the LT single crystal, which gradually relaxed towards the structure of the original LT during the post-proton-exchange annealing (A). This study also revealed a substantial dependence of sample behaviour on the crystallographic orientation of the pertinent substrate wafers (commonly used X-(h1120i) and Z-(h0001i) cuts).
Published: 2006

39. Effects of implantation of magnetic ions into ZnO

Author: Potzger, K., Zhou, S., Reuther, H., Brauer, G., Anwand, W., Eichhorn, F., Bischoff, L., Herrmann, F., Grambole, D., Groetzschel, R., and Fassbender, J.
Subjects: diluted magnetic semiconductors, magnetism, ZnO, ion implantation
Abstract: Recent achievements in the field of diluted magnetic semiconductors are summarized. Then, effects of the implantation of magnetic ions into ZnO single crystals are studied by various highly sensitive analysis methods. It is found that the implantation of Fe ions at elevated temperatures (620 K) yields the formation of small ferromagnetic Fe particles. Moreover, the host lattice exhibits open-volume type damage confined at the near surface region. Both effects strongly depend on the ion fluence. On the other hand, after 25 keV focused ion beam implantation of Co+ no magnetic domains could be detected on a ZnO single crystal surface. However, unscreened electric charges are locally introduced effectuating a contrast within a lift mode-operated atomic force microscope that can easily be confused with magnetic field gradients.
Published: 2005

40. TEM-Investigation of Si(001) Modified by Pr Implantation

Author: Mücklich, A., Kögler, R., and Eichhorn, F.
Subjects: Pr silicate, Pr oxide, Pr silicide, high-K dielectrics
Abstract: TEM-Investigation of Si(001) Modified by Pr Implantation
Published: 2005

41. Technical development at the Materials Research end-station

Author: Oehme, W., Dienel, S., Strauch, U., Eichhorn, F., and Schell, N.
Abstract: The report summarizes the most important technical developments realized in 2003/2004 at the Materials Research end-station. There are described new programs which simplify the visualisation and analysis of a large amount of data. These data are collected by a linear position sensitive detector (PSD) and a multi-channel analyzer. Additionally, an electronic stepperrmotor controller switch had been developed. It allows to use two different types of stepper motor controllers to control four of the axes of a 6-circle HUBER-diffractometrer by two different instrumentation systems.
Published: 2005

42. Formation of Au nanocrystals in TiO2, SrTiO3 and MgO by ion implantation

Author: Fromknecht, R., Linker, G., Sun, K., Zhu, S., Wang, L. M., Veen, A., Huis, M. A., Weimann, T., Wang, J., Niemeyer, J., Eichhorn, F., and Wang, T.
Abstract: Kein Abstract vorhanden.
Published: 2005

43. Facility for simultaneous dual beam ion implantation

Author: Kaschny, J. R., Kögler, R., Tyrrof, H., Bürger, W., Eichhorn, F., Mücklich, A., Serre, C., and Skorupa, W.
Subjects: Ion implantation [KEYWORDS], SiC, Ion beam synthesis, Radiation effects, Simultaneous implantation, Si
Abstract: The dual implantation chamber (DIC) at Rossendorf Center for Application of Ion Beams in Materials Research allows materials to be implanted using two ion beams simultaneously. This facility is located at the 45o cross point of two beam lines, one from a single ended HVEE 500 kV ion implanter and the other from a HVEE 3 MV Tandetron accelerator. Each beam line is equipped with independent ion fluence and current control. The special design of the beam sweeping system, enables both ion beams to scan the target surface simultaneously in synchronous mode, i.e. both ion spots are kept at coincident positions over the target. Experiments, concerning the formation of SiC nanoclusters in Si by high dose C and simultaneous Si implantation, are reported.
Published: 2005

44. Ion beam synthesis of Fe nanoparticles in MgO

Author: Potzger, K., Reuther, H., Zhou, S., Mücklich, A., Eichhorn, F., Grötzschel, R., and Fassbender, J.
Subjects: magnetism, ion beam synthesis, embedded nanoparticles
Abstract: MgO(001) single crystals were irradiated with 57Fe at an energy of 100 keV and an ion fluence of 6x1016cm-2 at implantation temperatures between 25°C(RT) and 1000°C. Analysis was carried out by means of CEMS, XRD, RBS and TEM. We found that the implantation temperature plays the important role for the formation of Fe nanoparticles. The fraction of metallic Fe (CEMS Fe0 signal) increases from 28% for RT implantation to 60% for 800°C implantation, while the Fe profile remains unchanged (Rp ¡Ö 50 nm). The nanoparticles formed after 800°C implantation are about 5 nm in size and exhibit fcc-structure with an orientation relationship of Fe(111)/MgO(111) and Fe(220)/MgO(220). The nanoparticles exhibit paramagnetism at room temperature. At an implantation temperature of 1000°C the Fe implantation profile smears out completely and 92% of the Fe atoms are found in the Fe3+ oxidation state.
Published: 2005

45. Defect engineering in ion beam synthesis of SiC and SiO2 in Si

Author: Kögler, R., Mücklich, A., Kaschny, J. R., Reuther, H., Eichhorn, F., Hutter, H., and Skorupa, W.
Subjects: SiC, Ion Implantation, SiO2, Cavities, Excess Vacancies, Ion Beam Synthesis
Abstract: Different methods of defect engineering are applied in this study for ion beam synthesis of a buried layer of SiC and SiO2 in Si. The initial state of phase formation is investigated by implantation of relatively low ion fluences. He-induced cavities and Si ion implantation generated excess vacancies are intentionally introduced in the Si substrate in order to act as trapping centers for C and O atoms and to accommodate volume expansion due to SiC and SiO2 phase formation. Especially the simultaneous dual implantation is shown to be an effective method to achieve better results from ion beam synthesis at implantation temperatures above 400oC. For SiC synthesis it is the only successful way to introduce vacancy defects. The in situ generation of vacancies during implantation increases the amount of SiC nanoclusters and improves crystal quality of Si in the case of SiO2 synthesis. Also the pre-deposition of He-induced cavities is clearly advantageous for the formation of a narrow SiO2 layer. Moreover, in-diffusion of O by surface oxidation can substitute a certain fraction of the O ion fluence necessary to obtain a buried homogeneous SiO2 layer. The results show that defect engineering for SiC and SiO2 synthesis is working. However, the implementation of a single action is not sufficient to achieve a significant improvement of ion beam synthesis. Only an optimized combination of the different versions of defect engineering can bring about pronounced better results.
Published: 2005

46. Surface studies of SiC

Author: Brauer, G., Anwand, W., Eichhorn, F., Skorupa, W., Hofer, C., Brandstetter, S., Teichert, C., Kuriplach, J., Cizek, J., Prochazka, I., Coleman, P. G., Nozawa, T., and Kohyama, A.
Abstract: not available
Published: 2005

47. Structural and optical properties of iron silicide formed by ion beam mixing

Author: Ayache, R., Boubelleou, A., Eichhorn, F., and Richter, E.
Published: 2005

48. The investigation of the chemical composition profile and the lateral homogeneity of AIIIBV quantum wells

Author: Gaca, J., Wojcik, M., Turos, A., Strupinski, W., Jasik, A., Zynek, J., Kosiel, K., Eichhorn, F., and Prokert, F.
Subjects: high resolution x-ray diffractometry, Rutherford backscattering, highly strained heterostructures, x-ray reflectometry, AIIIBV
Abstract: The chemical composition and interplanar spacing profiles as well the lateral homogeneity of AIIIBV heterostructures containing a highly strained In(x)Ga(1-x)As layer were investigated. The heterostructures grown by metallorganic chemical vapor deposition were chracterized by means of high resolution x-ray diffractometry, x-ray reflectometry and Rutherford backscattering. In order to analyze the experimental results an algorithm for calculating the x-ray profiles based on the Darwin diffraction theory has been worked out. The developed method was applied to find out: the dependence of the growth rate and the interface profiles of the highly strained In(x)Ga(1-x)As layer on the deposition time to supervise the growth process of a resonant cavity enhanced photodiode heterostructure for which a highly strained In(x)Ga(1-x)As layer is an essential part.
Published: 2005

49. Investigation of the creation of Fe nanoparticles in MgO by ion beam synthesis

Author: Reuther, H., Potzger, K., Zhou, S., Mücklich, A., and Eichhorn, F.
Abstract: Recently, the investigation of metallic nanoparticles embedded in dielectric oxides has become a topic in magnetic data storage development. Especially the creation of high density data storage devices due to ion beam synthesis of magnetically, highly anisotropic FePt nanoparticles in sapphire yielded promising results. On the other hand, pure Fe-nanoparticles have been created in sapphire, Y-stabilized ZrO2 or MgO. The motivation for the latter includes the search for magneto-optically active surfaces as well as pronounced magnetoresistance. For doping MgO single crystals with Fe, ion implantation is a promising technique. First extensive studies were performed by Perez et al. who investigated the annealing behaviour of samples implanted with different doses of 57Fe at different energies with conversion electron Mössbauer spectroscopy (CEMS) [1]. They obtained up to 20 % of the implanted iron atoms in a-Fe precipitates while the remaining Fe-atoms were found to be in different Fe2+ and Fe3+ charge states. In this paper, we propose a method for the creation of large fractions of a-Fe nanoparticles (up to 60%). MgO(001) single crystals were implanted with of 6x1016 cm-2 ions of the Mössbauer isotope 57Fe at 100 keV. The implantation temperature was varied from room temperature up to 800 °C. Moreover, post annealing was investigated. Samples were characterized by CEMS, RBS, TEM and XRD. We found that the temperature during the implantation plays the important role for the formation of the Fe0 state while post annealing results in the preferential formation of Fe oxidation states, mainly Fe3+ states. The largest fraction of iron with Fe0 state was obtained at implantation temperatures between 600 and 800 °C. [1] A. Perez, G. Marest, B.D. Sawicka, J.A. Sawicki, T. Tyliszczak, Phys. Rev. B, 28, 1227 (1983)
Published: 2005

50. Excess vacancies induced by ion beam implantation into silicon

Author: Kögler, R., Eichhorn, F., Peeva, A., Voelskow, M., Mücklich, A., Serre, C., and Skorupa, W.
Subjects: Excess vacancies, Positron annihilation spectrometry, Silicon, Ion implantation, Electron microscopy
Abstract: The process of formation of excess vacancies by ion implantation is explained. Moreover, the simulation of the process, the experimental detection of excess vacancies and their application for defect engineering is described.
Published: 2004

Catalog

Books, media, physical & digital resources

See catalog results

Searchworks

Select search scope, currently: Articles Catalog books, media & more in Jio Institute collections Articles journal articles & other e-resources

Search

Search Constraints

Refine your results

Search Limiters

Topic

Publication Year Range

Language

Journal

Database

Publisher

115 results on '"Eichhorn, F."'

Search Results

Catalog

Select search scope, currently: Articles

Catalog

books, media & more in Jio Institute collections

Articles

journal articles & other e-resources