51 results on '"Aharonian, Felix A."'
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2. Revisiting the PeVatron candidate MGRO J1908+06 with an updated H.E.S.S. analysis
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Abdalla, Hassan, Aharonian, Felix, Barbosa Martins, Victor, Lohse, Thomas, Luashvili, Anna, Lypova, Iryna, Mackey, Jonathan, Majumdar, Jhilik, Malyshev, Denys, MALYSHEV, Dmitry, Marandon, Vincent, Marchegiani, Paolo, Marcowith, Alexandre, Barnacka, Anna, Mares, Arnaud, Marti'i-Devesa, Guillem, Marx, Ramin, Maurin, Gilles, Meintjes, Pieter, Meyer, Manuel, Moderski, Rafal, Mohrmann, Lars, de Ona Wilhelmi, E., Joshi, Vikas, Barnard, Monica, Mitchell, Alison, Montanari, Alessandro, Moore, Chris, Morris, Paul, Moulin, Emmanuel, Muller, Jacques, Murach, Thomas, Nakashima, Kaori, Naurois , Mathieu, Nayerhoda, Amid, Batzofin, Rowan, Ndiyavala, Hambeleleni, Niemiec, Jacek, Noel, Angel, O'Brien, Paul, Oberholzer, Laenita Lorraine, Ohm, Stefan, Khelifi, Bruno, Giunti, Luca, Olivera-Nieto, Laura, de Ona Wilhelmi, Emma Maria, Becherini, Yvonne, Ostrowski, Michal, Panny, Sebastian, Panter, Michael, Parsons, Dan, Peron, Giada, Pita, Santiago, Poireau, Vincent, Prokhorov, Dmitry, Prokoph, Heike, PUEHLHOFER, Gerd, Berge, David, Punch, Michael, Quirrenbach, Andreas, Reichherzer, Patrick, Reimer, Anita, Reimer, Olaf, Remy, Quentin, Renaud, Matthieu, Reville, Brian, Rieger, Frank, Romoli, Carlo, Bernloehr, Konrad, Rowell, Gavin, Rudak, Bronislaw, Rueda Ricarte, Hector, Ruiz Velasco, Edna, Sahakian, Vardan, Sailer, Simon, Salzmann, Heiko, Sanchez, David, Santangelo, Andrea, Sasaki, Manami, Bi, Baiyang, Schaefer, Johannes, Schutte, Hester, Schwanke, Ullrich, Schüssler, Fabian, Senniappan, Mohanraj, Seyffert, Albert, Shapopi, Jimmy N. S., Shiningayamwe, Kleopas, Simoni, Rachel, Sinha, Atreyee, Boettcher, Markus, Sol, Helene, Spackman, Hugh, Specovius, Andreas, Spencer, Samuel Timothy, Spir-Jacob, Marion, Stawarz, Lukasz, Steenkamp, Riaan, Stegmann, Christian, Steinmassl, Simon, Steppa, Constantin, Boisson, Catherine, Sun, Lei, Takahashi, Tadayuki, Tanaka, Takaaki, Tavernier, Thomas, Taylor, Andrew, Terrier, Regis, Thiersen, Hannes, Thorpe-Morgan, Charles, Tluczykont, Martin, Tomankova, Lenka, Ait-Benkhali, Faical, Bolmont, Julien, Tsirou, Michelle, Tsuji, Naomi, Tuffs, Richard, Uchiyama, Yasunobu, van der Walt, Johann, van Eldik, Christopher, van Rensburg, Carlo, van Soelen, Brian, Vasileiadis, George, Veh, Johannes, Bony , Mathieu, Venter, Christo, Vincent, Pascal, Vink, Jacco, Völk, Heinrich J., Wagner, Stefan, Watson, Jason John, Werner, Felix, White, Richard, Wierzcholska, Alicja, Wong, Yu Wun, Breuhaus, Mischa, Yassin, Hend, Yusafzai, Anke, Zacharias, Michael, Zanin, Roberta, Zargaryan, Davit, Zdziarski, Andrzej, Zech, Andreas, Zhu, Sylvia Jiechen, Zmija, Andreas, Zouari, Samuel, Brose, Robert, Zywucka, Natalia, H. E. S. S. Collaboration, Brun, Francois, Bulik, Tomasz, Bylund, Thomas, Cangemi, Floriane, Caroff, Sami, Casanova, Sabrina, Anguener, Oguzhan, Catalano, Jaqueline, Chambery, Pauline, Chand, Tej Bahadur, Chen, Andrew, Cotter, Garret, Curlo, Malgorzata, Dalgleish, Hannah, Mbarubucyeye, Jean Damascene, Davids, Isak Delberth, Davies, James, Arcaro, Cornelia, Devin, Justine, Djannati-Ataï, Arache, Dmytriiev, Anton, Donath, Axel, Doroshenko, Victor, Dreyer, Lente, Du Plessis, Louis, Duffy, Connor, Egberts, Kathrin, Einecke, Sabrina, Armand, Celine, ERNENWEIN, Jean-Pierre, Fegan, Steven, Feijen, Kirsty, Fiasson, Armand, Fichet de Clairfontaine, Gaëtan, Fontaine, Gerard, Frans, Lott, Füssling, Matthias, Funk, Stefan, Gabici, Stefano, Armstrong, Tom, Gallant, Yves, Giavitto, Gianluca, Glawion, Dorit, Glicenstein, Jean-Francois, Grondin, Marie-Hélène, Hattingh, Sumari, Haupt, Maria, HERMANN, German, Hinton, Jim, Hofmann, Werner, Ashkar, Halim, Hoischen, Clemens, Holch, Tim Lukas, Holler, Markus, Horns, Dieter, Huang, Zhiqiu, Huber, David, Hörbe, Mario, Jamrozy, Marek, Jankowsky, Felix, JUNG, Ira, Backes, Michael, Kasai, Eli, Katarzynski, Krzysztof, Katz, Ulì, Khangulyan, Dmitry, Klepser, Stefan, Kluzniak, Wlodek, Komin, Nukri, Konno, Ruslan, Kosack, Karl, Kostiunin, Dmitriy, Baghmanyan, Vardan, Kreter, Michael, Kukec Mezek, Gašper, Kundu, Anu, Lamanna, Giovanni, Le Stum, Sébastien, Lemiere, Anne, Lemoine-Goumard, Marianne, Lenain, Jean-Philippe, Leuschner, Fabian, Levy, Christelle, 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), 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 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., Naurois , Mathieu, Bony , Mathieu, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), and Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)
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Photon ,Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences ,Cosmic ray ,Astrophysics ,emission [photon] ,Acceleration ,Pulsar ,photon: emission ,emission [gamma ray] ,Angular resolution ,ddc:530 ,galaxy [gamma ray] ,Supernova remnant ,Physics ,High Energy Astrophysical Phenomena (astro-ph.HE) ,gamma ray: galaxy ,energy: high ,cosmic radiation: propagation ,Molecular cloud ,gamma ray: emission ,13. Climate action ,cosmic radiation: galaxy ,Milagro ,HESS - Abteilung Hinton ,high [energy] ,galaxy [cosmic radiation] ,propagation [cosmic radiation] ,Astrophysics - High Energy Astrophysical Phenomena ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] - Abstract
37th International Cosmic Ray Conference, ICRC 2021, Berlin, Germany - Online, 12 Jul 2021 - 23 Jul 2021; Proceedings of Science / International School for Advanced Studies (ICRC2021), 779 (2021). doi:10.22323/1.395.0779, Detecting and studying galactic gamma-ray sources emitting very-high energy photons sheds light on the acceleration and propagation of cosmic rays presumably created in these sources. Currently, there are few sources emitting photons with energies exceeding 100 TeV. In this work we revisit the unidentified source MGRO J1908+06, initially detected by Milagro, using an updated H.E.S.S. dataset and analysis pipeline. The vicinity of the source contains a supernova remnant and pulsars as well as molecular clouds. This makes the identification of the primary source(s) of galactic cosmic rays as well as the nature of the gamma-ray emission challenging, especially in light of the recent HAWC and LHAASO detection of the high energy tail of its spectrum. Exploiting the better angular resolution as compared to particle detectors, we investigate the morphology of the source as well as its spectral properties., Published by SISSA, Trieste
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- 2021
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3. Does the Geminga, Monogem and PSR J0622+3749 $��$-ray halos imply slow diffusion around pulsars?
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Recchia, Sarah, Di Mauro, Mattia, Aharonian, Felix A., Orusa, Luca, Donato, Fiorenza, Gabici, Stefano, and Manconi, Silvia
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High Energy Astrophysical Phenomena (astro-ph.HE) ,Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences - Abstract
The HAWC Collaboration has reported the detection of an extended $��$-ray emission around the Geminga and Monogem pulsars of a few degree extension. Very recently, the LHAASO Collaboration released also the data for an extended $��$-ray emission around the pulsar PSR J0622+3749. This flux can be explained with electrons and positrons injected from these sources and their inverse Compton Scattering on the interstellar radiation fields. So far the size of such $��-$ray halos has been interpreted as the result of the diffusion coefficient around the sources being about two orders of magnitude smaller than the average in the Galaxy. However, this conclusion is driven by the assumption that particles propagate diffusively right away after the injection without taking into account the ballistic propagation. The propagation of cosmic-ray leptons in the proximity of the Geminga, Monogem and PSR J0622+3749 pulsars is examined here considering the transition from the quasi-ballistic, valid for the most recently injected particles, to the diffusive transport regime. For typical interstellar values of the diffusion coefficient, the quasi-ballistic regime dominates the lepton distribution up to distances of a few tens of parsec from the pulsar for particle energies above $\sim 10$ TeV. In this regime the resulting $��-$ray source tends to be rather compact, despite particles travel a long distance. Indeed, for larger values of the diffusion coefficient, particles propagate ballistically up to larger distances with the result of a more point-like $��-$ray source. When such transition is taken into account, a good fit to the HAWC and LHAASO $��-$ray data around Geminga, Monogem and PSR J0622+3749 is obtained without the need to invoke a strong suppression of the diffusion coefficient., 10 pages, 4 figures. This version includes other two sources (Monogem and PSR J0622+3749) with respect to the first version
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- 2021
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4. Probing the galactic cosmic-ray density with current and future $��$-ray instruments
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Peron, Giada and Aharonian, Felix
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High Energy Astrophysical Phenomena (astro-ph.HE) ,Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics::Galaxy Astrophysics - Abstract
Cosmic Rays (CRs) propagating through dense molecular clouds (MCs) produce gamma rays which carry direct information about the CR distribution throughout the Galaxy. Observations of gamma rays in different energy bands allow exploration of the average CR density in the Galactic Disk, the so-called level of the "CR Sea". Fermi-LAT observations have demonstrated the method's feasibility based on two dozen MCs in our Galaxy. However, the potential of Fermi-LAT is limited by the most massive and relatively nearby MCs; thus, the current observations cover only a tiny fraction of the Milky Way. In this paper, we study the prospects of expanding the CR measurements to very and ultra-high energies and remote parts of the Galaxy with the current and next-generation detectors. Based on calculations of fluxes expected from MCs, we formulate the requirements to the sensitivity of the post-Fermi-LAT detectors to map GeV-TeV CRs in the Galactic Disk. We also explore the potential of the current and future air-shower and atmospheric Cherenkov telescope arrays for the extension of CR studies to multi-TeV and PeV energy bands. We demonstrate that the improvement of the Fermi-LAT sensitivity by a factor of a few would allow a dramatic increase in the number of detectable MCs covering almost the entire Galaxy. The recently completed LHAASO should be able to take the first CR probes at PeV energies in the coming five years or so., 9 pages, 8 figures
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- 2021
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5. Observation of burst activity from SGR1935+2154 associated to first galactic FRB with H.E.S.S
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Abdalla, Hassan, Aharonian, Felix, Barbosa Martins, Victor, Lenain, Jean-Philippe, Leuschner, Fabian, Levy, Christelle, Lohse, Thomas, Luashvili, Anna, Lypova, Iryna, Mackey, Jonathan, Majumdar, Jhilik, Malyshev, Denys, Malyshev, Dmitry, Barnacka, Anna, Marandon, Vincent, Marchegiani, Paolo, Marcowith, Alexandre, Mares, Arnaud, Martí-Devesa, Guillem, Marx, Ramin, Maurin, Gilles, Meintjes, Pieter, Meyer, Manuel, Mitchell, Alison, Barnard, Monica, Moderski, Rafal, Mohrmann, Lars, Montanari, Alessandro, Moore, Chris, Morris, Paul, Moulin, Emmanuel, Muller, Jacques, Murach, Thomas, Nakashima, Kaori, Naurois , Mathieu, Batzofin, Rowan, Nayerhoda, Amid, Davids, Hambeleleni, Niemiec, Jacek, Noel, Angel, O'Brien, Paul, Oberholzer, Laenita Lorraine, Ohm, Stefan, Olivera-Nieto, Laura, Ona-Wilhelmi , Emma, Ostrowski, Michal, Becherini, Yvonne, Panny, Sebastian, Panter, Michael, Parsons, Dan, Peron, Giada, Pita, Santiago, Poireau, Vincent, Prokhorov, Dmitry, Prokoph, Heike, PUEHLHOFER, Gerd, Punch, Michael, Berge, David, Quirrenbach, Andreas, Reichherzer, Patrick, Reimer, Anita, Reimer, Olaf, Remy, Quentin, Renaud, Matthieu, Reville, Brian, Rieger, Frank, Romoli, Carlo, Rowell, Gavin, Bernloehr, Konrad, Rudak, Bronislaw, Rueda Ricarte, Hector, Ruiz Velasco, Edna, Sahakian, Vardan, Sailer, Simon, Salzmann, Heiko, Sanchez, David, Santangelo, Andrea, Sasaki, Manami, Schaefer, Johannes, Bi, Baiyang, Schutte, Hester, Schwanke, Ullrich, Schüssler, Fabian, Senniappan, Mohanraj, Seyffert, Albert, Shapopi, Jimmy N. S., Shiningayamwe, Kleopas, Simoni, Rachel, Sinha, Atreyee, Sol, Helene, Böttcher, Markus, Spackman, Hugh, Specovius, Andreas, Spencer, Samuel Timothy, Spir-Jacob, Marion, Stawarz, Lukasz, Steenkamp, Riaan, Stegmann, Christian, Steinmassl, Simon, Steppa, Constantin, Sun, Lei, Boisson, Catherine, Takahashi, Tadayuki, Tanaka, Takaaki, Tavernier, Thomas, Taylor, Andrew, Terrier, Regis, Thiersen, Hannes, Thorpe-Morgan, Charles, Tluczykont, Martin, Tomankova, Lenka, Tsirou, Michelle, Ait-Benkhali, Faical, Bolmont, Julien, Tsuji, Naomi, Tuffs, Richard, Uchiyama, Yasunobu, van der Walt, Johann, van Eldik, Christopher, van Rensburg, Carlo, van Soelen, Brian, Vasileiadis, George, Veh, Johannes, Venter, Christo, Bony , Mathieu, Vincent, Pascal, Vink, Jacco, Völk, Heinrich J., Wagner, Stefan, Watson, Jason John, Werner, Felix, White, Richard, Wierzcholska, Alicja, Wong, Yu Wun, Yassin, Hend Mahmoud, Breuhaus, Mischa, Yusafzai, Anke, Zacharias, Michael, Zanin, Roberta, Zargaryan, Davit, Zdziarski, Andrzej, Zech, Andreas, Zhu, Sylvia, Zmija, Andreas, Zouari, Samuel, Żywucka, Natalia, Brose, Robert, H. E. S. S. Collaboration, Brun, Francois, Bulik, Tomasz, Bylund, Thomas, Cangemi, Floriane, Caroff, Sami, Casanova, Sabrina, Anguener, Oguzhan, Catalano, Jaqueline, Chambery, Pauline, Chand, Tej Bahadur, Chen, Andrew, Cotter, Garret, Curlo, Malgorzata, Dalgleish, Hannah, Damascene Mbarubucyeye, Jean, Davids, Isak Delberth, Davies, James, Arcaro, Cornelia, Devin, Justine, Djannati-Ataï, Arache, Dmytriev, Anton, Donath, Axel, Doroshenko, Victor, Dreyer, Lente, Du Plessis, Louis, Duffy, Connor, Egberts, Kathrin, Einecke, Sabrina, Armand, Celine, ERNENWEIN, Jean-Pierre, Fegan, Steven, Feijen, Kirsty, Fiasson, Armand, Fichet de Clairfontaine, Gaëtan, Fontaine, Gerard, Frans, Lott, Fuessling, Matthias, Funk, Stefan, Gabici, Stefano, Armstrong, Tom, Gallant, Yves, Giavitto, Gianluca, Giunti, Luca, Glawion, Dorit, Glicenstein, Jean-Francois, Grondin, Marie-Hélène, Hattingh, Sumari, Haupt, Maria, HERMANN, German, Hinton, Jim, Ashkar, Halim, Hofmann, Werner, Hoischen, Clemens, Holch, Tim, Holler, Markus, Horns, Dieter, Huang, Zhi-Qiu, Huber, David, Hörbe, Mario, Jamrozy, Marek, Jankowsky, Felix, Backes, Michael, Joshi, Vikas, JUNG, Ira, Kasai, Eli, Katarzynski, Krzysztof, Katz, Ulì, Khangulyan, Dmitry, Khelifi, Bruno, Klepser, Stefan, Kluzniak, Wlodek, Komin, Nukri, Baghmanyan, Vardan, Konno, Ruslan, Kosack, Karl, Kostiunin, Dmitriy, Kreter, Michael, Kukec Mezek, Gašper, Kundu, Anu, Lamanna, Giovanni, Le Stum, Sébastien, Lemiere, Anne, Lemoine-Goumard, Marianne, Naurois , Mathieu, Bony , Mathieu, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, and H.E.S.S.
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Physics ,High Energy Astrophysical Phenomena (astro-ph.HE) ,Brightness ,Astrophysics::High Energy Astrophysical Phenomena ,atmosphere [Cherenkov counter] ,Soft gamma repeater ,FOS: Physical sciences ,burst [gamma ray] ,X-ray: burst ,Astrophysics ,gamma ray: burst ,Cherenkov counter: atmosphere ,Magnetar ,Radio spectrum ,Observational evidence ,Pulsar ,ddc:530 ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] ,Astrophysics - High Energy Astrophysical Phenomena ,Cherenkov radiation ,burst [X-ray] - Abstract
37th International Cosmic Ray Conference, ICRC2021, Berlin, Germany - Online, 12 Jul 2021 - 23 Jul 2021; Proceedings of Science / International School for Advanced Studies (ICRC2021), 777 (2021). doi:10.22323/1.395.0777, Fast radio bursts (FRB) are enigmatic powerful single radio pulses with durations of several milliseconds and high brightness temperatures suggesting coherent emission mechanism. For the time being a number of extragalactic FRBs have been detected in the high-frequency radio band including repeating ones. The most plausible explanation for these phenomena is magnetar hyperflares. The first observational evidence of this scenario was obtained in April 2020 when an FRB was detected from the direction of the Galactic magnetar and soft gamma repeater SGR1935+2154. The FRB was preceded with a number of soft gamma-ray bursts observed by Swift-BAT satellite, which triggered the follow-up program of the H.E.S.S. imaging atmospheric Cherenkov telescopes (IACTs). H.E.S.S. has observed SGR1935+2154 over a 2 hour window few hours prior to the FRB detection by STARE2 and CHIME. The observations overlapped with other X-ray bursts from the magnetar detected by INTEGRAL and Swift-BAT, thus providing first observations of a magnetar in a flaring state in the very-high energy domain. We present the analysis of these observations, discuss the obtained results and prospects of the H.E.S.S. follow-up program for soft gamma repeaters and anomalous X-ray pulsars., Published by SISSA, Trieste
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- 2021
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6. Detection of UHE gamma rays from the Crab Nebula: Physical Implications
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Khangulyan, Dmitry, Arakawa, Masanori, and Aharonian, Felix
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High Energy Astrophysical Phenomena (astro-ph.HE) ,Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences ,Physics::Accelerator Physics ,Astrophysics - High Energy Astrophysical Phenomena - Abstract
The Crab Nebula is an extreme particle accelerator boosting the energy of electrons up to a few PeV ($10^{15} \ \rm eV$), close to the maximum energy allowed by theory. The physical conditions in the acceleration site and the nature of the acceleration process itself remain highly uncertain. The key information about the highest energy accelerated particles is contained in the synchrotron and inverse Compton (IC) channels of radiation at energies above 1~MeV and 100~TeV, respectively. The recent report of detection of ultra-high energy gamma-ray signal from the Crab Nebula up to 300~TeV allows one to determine the energy distribution of the highest energy electrons and to derive the magnetic field strength in the acceleration region, $B\leq120\rm\,\mu G$, in a parameter-free way. This estimate brings new constraints on the properties of non-thermal particle distributions and puts important constraints on the MHD models for the Crab Nebula, in particular on the feasible magnetization and anisotropy of the pulsar wind. The calculations of synchrotron and IC emission show that future observations with instruments allowing detection of the Crab Nebula above 300~TeV and above 1~MeV will clarify the conditions allowing acceleration of electrons beyond PeV energies in the Crab Nebula. In particular, one will (1) verify the hypothetical multi-component composition of the electron energy distribution, and (2) determine the magnetic field strength in the regions responsible for the acceleration of PeV electrons., Comment: 8 pages, 5 figures, MNRAS accepted
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- 2019
7. Gamma Ray Astrophysics
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Aharonian, Felix
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neutrino, multimessenger ,Astrophysics::High Energy Astrophysical Phenomena ,High Energy Physics::Phenomenology ,Astrophysics::Instrumentation and Methods for Astrophysics ,High Energy Physics::Experiment ,Astrophysics::Galaxy Astrophysics - Abstract
Invited Talk presented at the “XVIII International Workshop on Neutrino Telescopes&rdquo
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- 2019
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8. The 2014TeV gamma-Ray Flare of Mrk 501 Seen with HESS
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Abdalla, Hassan E., Aharonian, Felix A., Benkhali, F. Ait, Angüner, Ekrem Oǧuzhan, Arakawa, M., Arcaro, C., Armand, C., Arrieta, M., Backes, M., Barnard, M., Becherini, Y., Tjus, J. Becker, Berge, D., Bernhard, S., Bernloehr, K., Blackwell, R., Bottcher, M., Boisson, C., Bolmont, J., Bonnefoy, S., Bordas, Pol, Bregeon, J., Brun, F., Brun, P., Bryan, M., Buechele, M., Bulik, T., Bylund, T., Capasso, M., Caroff, S., Carosi, A., Cerruti, M., Chakraborty, N., Chandra, S., Chaves, R. C. G., Chen, A., Colafrancesco, S., Condon, B., Davids, I. D., Deil, C., Devin, J., deWilt, P., Dirson, L., Djannati-Atai, A., Dmytriiev, A., Donath, A., Doroshenko, V, Dyks, J., Egberts, Kathrin (Dr. rer. n.), Emery, G., Ernenwein, J-P, Eschbach, S., Fegan, S., Fiasson, A., Fontaine, G., Funk, S., Fuessling, M., Gabici, S., Gallant, Y. A., Gate, F., Giavitto, G., Glawion, D., Glicenstein, J. F., Gottschall, D., Grondin, M-H, Hahn, J., Haupt, M., Heinzelmann, G., Henri, G., Hermann, G., Hinton, James Anthony, Hofmann, W., Hoischen, Clemens (Dr.), Holch, Tim Lukas, Holler, M., Horns, D., Huber, D., Iwasaki, H., Jacholkowska, A., Jamrozy, M., Jankowsky, D., Jankowsky, F., Jouvin, L., Jung-Richardt, I, Kastendieck, M. A., Katarzynski, K., Katsuragawa, M., Katz, U., Kerszberg, D., Khangulyan, D., Khelifi, B., King, J., Klepser, S., Kluzniak, W., Komin, Nu, Kosack, K., Krakau, S., Kraus, M., Kruger, P. P., Lamanna, G., Lau, J., Lefaucheur, J., Lemiere, A., Lemoine-Goumard, M., Lenain, J-P, Leser, Eva (Dr.), Lohse, T., Lorentz, M., Lopez-Coto, R., Lypova, I, Malyshev, D., Marandon, V, Marcowith, A., Mariaud, C., Marti-Devesa, G., Marx, R., Maurin, G., Meintjes, P. J., Mitchell, A. M. W., Moderski, R., Mohamed, M., Mohrmann, L., Moulin, E., Murach, T., Nakashima, S., de Naurois, M., Ndiyavala, H., Niederwanger, F., Niemiec, J., Oakes, L., Odaka, H., Ohm, S., Ostrowski, M., Oya, I, Padovani, M., Panter, M., Parsons, R. D., Perennes, C., Petrucci, P-O, Peyaud, B., Piel, Q., Pita, S., Poireau, V, Noel, A. Priyana, Prokhorov, D., Prokoph, H., Puehlhofer, G., Punch, M., Quirrenbach, A., Raab, S., Rauth, R., Reimer, A., Reimer, O., Renaud, M., Rieger, F., Rinchiuso, L., Romoli, C., Rowell, G., Rudak, B., Ruiz-Velasco, E., Sahakian, V, Saito, S., Sanchez, David M., Santangelo, A., Sasaki, M., Schlickeiser, R., Schussler, F., Schulz, A., Schwanke, U., Schwemmer, S., Seglar-Arroyo, M., Senniappan, M., Seyffert, A. S., Shafi, N., Shilon, I, Shiningayamwe, K., Simoni, R., Sinha, A., Sol, H., Spanier, F., Specovius, A., Spir-Jacob, M., Stawarz, L., Steenkamp, R., Stegmann, Christian (Prof. Dr.), Steppa, Constantin Beverly (PhD), Takahashi, T., Tavernet, J-P, Tavernier, T., Taylor, A. M., Terrier, R., Tibaldo, L., Tiziani, D., Tluczykont, M., 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., Voisin, F., Voelk, H. J., Vuillaume, T., Wadiasingh, Z., Wagner, S. J., Wagner, R. M., White, R., Wierzcholska, A., Yang, R., Zaborov, D., Zacharias, M., Zanin, R., Zdziarski, A. A., Zech, A., Zefi, F., Ziegler, A., Zorn, J., and Zywucka, N.
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Astrophysics::High Energy Astrophysical Phenomena ,ddc:520 ,Institut für Physik und Astronomie ,ddc:530 - Abstract
The blazar Mrk 501 (z = 0.034) was observed at very-high-energy (VHE, E greater than or similar to 100 GeV) gamma-ray wavelengths during a bright flare on the night of 2014 June 23-24 (MJD 56832) with the H.E.S.S. phase-II array of Cherenkov telescopes. Data taken that night by H.E.S.S. at large zenith angle reveal an exceptional number of gamma-ray photons at multi-TeV energies, with rapid flux variability and an energy coverage extending significantly up to 20 TeV. This data set is used to constrain Lorentz invariance violation (LIV) using two independent channels: a temporal approach considers the possibility of an energy dependence in the arrival time of gamma-rays, whereas a spectral approach considers the possibility of modifications to the interaction of VHE gamma-rays with extragalactic background light (EBL) photons. The non-detection of energy-dependent time delays and the non-observation of deviations between the measured spectrum and that of a supposed power-law intrinsic spectrum with standard EBL attenuation are used independently to derive strong constraints on the energy scale of LIV (E-QG) in the subluminal scenario for linear and quadratic perturbations in the dispersion relation of photons. For the case of linear perturbations, the 95% confidence level limits obtained are E-QG,E-1 > 3.6 x 10(17) GeV using the temporal approach and E-QG,E-1 > 2.6 x 10(19) GeV using the spectral approach. For the case of quadratic perturbations, the limits obtained are E-QG,E-2 > 8.5 x 10(10) GeV using the temporal approach and E-QG,E-2 > 7.8 x 10(11) GeV using the spectral approach.
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- 2019
9. Deeper HESS observations of Vela Junior (RX J0852.0-4622)
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Abdalla, Hassan E., Abramowski, A., Aharonian, Felix A., Benkhali, F. Ait, Akhperjanian, A. G., Andersson, T., Anguener, E. O., Arakawa, M., Arrieta, M., Aubert, P., Backes, M., Balzer, A., Barnard, M., Becherini, Y., Tjus, J. Becker, Berge, D., Bernhard, S., Bernloehr, K., Blackwell, R., Boettcher, M., Boisson, C., Bolmont, J., Bordas, Pol, Bregeon, J., Brun, F., Brun, P., Bryan, M., Bilchele, M., Bulik, T., Capasso, M., Carr, J., Casanova, Sabrina, Cerruti, M., Chakraborty, N., Chalme-Calvet, R., Chaves, R. C. G., Chen, A., Chevalier, J., Chretien, M., Coffaro, M., Colafrancesco, S., Cologna, G., Condon, B., Conrad, J., Cui, Y., Davids, I. D., Decock, J., Degrange, B., Deil, C., Devin, J., deWilt, P., Dirson, L., Djannati-Atai, A., Domainko, W., Donath, A., Dutson, K., Dyks, J., Edwards, T., Egberts, Kathrin (Dr. rer. n), Eger, P., Ernenwein, J. -P., Eschbach, S., Farnier, C., Fegan, S., Fernandes, M. V., Fiasson, A., Fontaine, G., Foerster, A., Funk, S., Fuessling, M., Gabici, S., Gajdus, M., Gallant, Y. A., Garrigoux, T., Giavitto, G., Giebels, B., Glicenstein, J. F., Gottschall, D., Goya, A., Grondin, M. -H., Hahn, J., Haupt, M., Hawkes, J., Heinzelmann, G., Henri, G., Hermann, G., Hervet, O., Hinton, J. A., Hofmann, W., Hoischen, Clemens (Dr.), Holler, M., Horns, D., Ivascenko, A., Iwasaki, H., Jacholkowska, A., Jamrozy, M., Janiak, M., Jankowsky, D., Jankowsky, F., Jingo, M., Jogler, T., Jouvin, L., Jung-Richardt, I., Kastendieck, M. A., Katarzynski, K., Katsuragawa, M., Katz, U., Kerszberg, D., Khangulyan, D., Khelifi, B., Kieffer, M., King, J., Klepser, S., Klochkov, D., Kluzniak, W., Kolitzus, D., Komin, Nu., Kosack, K., Krakau, S., Kraus, M., Krueger, P. P., Laffon, H., Lamanna, G., Lau, J., Lees, J. -P., Lefaucheur, J., Lefranc, V., Lemiere, A., Lemoine-Goumard, M., Lenain, J. -P., Leser, Eva (Dr.), Lohse, T., Lorentz, M., Liu, R., Lopez-Coto, R., Lypova, I., Marandon, V., Marcowith, A., Mariaud, C., Marx, R., Maurin, G., Maxted, N., Mayer, M., Meintjes, P. J., Meyer, M., Mitche, A. M. W., Moderski, R., Mohamed, M., Mohrmann, L., Mora, K., Moulin, E., Murach, T., Nakashima, S., de Naurois, M., Niederwanger, F., Niemiec, J., Oakes, L., Odaka, H., Oettl, S., Ohm, S., Ostrowski, M., Oya, I., Padovani, M., Panter, M., Parsons, R. D., Arribas, M. Paz, Pekeur, N. W., Pelletier, G., Perennes, C., Petrucci, P. -O., Peyaud, B., Piel, Q., Pita, S., Poon, H., Prokhorov, D., Prokoph, H., Puehlhofer, G., Punch, M., Quirrenbach, A., Raab, S., Reimer, A., Reimer, O., Renaud, M., de los Reyes, R., Richter, S., Rieger, F., Romoli, C., Rowell, G., Rudak, B., Rulten, C. B., Sahakian, V., Saito, S., Salek, D., Sanchez, D. A., Santangelo, A., Sasaki, M., Schlickeiser, R., Schuessler, F., Schulz, A., Schwanke, U., Schwemmer, S., Seglar-Arroyo, M., Settimo, M., Seyffert, A. S., Shafi, N., Shilon, I., Simoni, R., Sol, H., Spanier, F., Spengler, G., Spies, F., Stawarz, L., Steenkamp, R., Stegmann, Christian (Prof. Dr.), Stycz, K., Sushch, I., Takahashi, T., Tavernet, J. -P., Tavernier, T., Taylor, A. M., Terrier, R., Tibaldo, L., Tiziani, D., Tluczykont, M., Trichard, C., 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., Voisin, F., Voelk, H. J., Vuillaume, T., Wadiasingh, Z., Wagner, S. J., Wagner, P., Wagner, R. M., White, R., Wierzcholska, A., Willmann, P., Woernlein, A., Wouters, D., Yang, R., Zabalza, V., Zaborov, D., Zacharias, M., Zanin, R., Zdziarski, A. A., Zech, A., Zefi, F., Ziegler, A., and Zywucka, N.
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Astrophysics::High Energy Astrophysical Phenomena ,ddc:520 ,Institut für Physik und Astronomie ,ddc:530 - Abstract
Aims. We study gamma-ray emission from the shell-type supernova remnant (SNR) RXJ0852.0-4622 to better characterize its spectral properties and its distribution over the SNR. Methods. The analysis of an extended High Energy Spectroscopic System (H.E.S.S.) data set at very high energies (E > 100 GeV) permits detailed studies, as well as spatially resolved spectroscopy, of the morphology and spectrum of the whole RXJ0852.0-4622 region. The H.E.S.S. data are combined with archival data from other wavebands and interpreted in the framework of leptonic and hadronic models. The joint Fermi-LAT-H.E.S.S. spectrum allows the direct determination of the spectral characteristics of the parent particle population in leptonic and hadronic scenarios using only GeV-TeV data. Results. An updated analysis of the H.E.S.S. data shows that the spectrum of the entire SNR connects smoothly to the high-energy spectrum measured by Fermi-LAT. The increased data set makes it possible to demonstrate that the H.E.S.S. spectrum deviates significantly from a power law and is well described by both a curved power law and a power law with an exponential cutoff at an energy of E-cut = (6.7 +/- 1.2(stat) +/- 1.2(syst)) TeV. The joint Fermi-LAT-H.E.S.S. spectrum allows the unambiguous identification of the spectral shape as a power law with an exponential cutoff. No significant evidence is found for a variation of the spectral parameters across the SNR, suggesting similar conditions of particle acceleration across the remnant. A simple modeling using one particle population to model the SNR emission demonstrates that both leptonic and hadronic emission scenarios remain plausible. It is also shown that at least a part of the shell emission is likely due to the presence of a pulsar wind nebula around PSR J0855-4644.
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- 2018
10. The H.E.S.S. Galactic plane survey
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H.E.S.S, Collaboration, Abdalla, H., Abramowski, A., Aharonian, Felix, Ait Benkhali, F., Angüner, E. O., Arakawa, M., Arrieta, M., Aubert, P., Backes, M., Balzer, A., Barnard, M., Becherini, Y., Becker Tjus, J., Berge, D., Bernhard, S., Bernlöhr, K., Blackwell, R., Böttcher, M., Boisson, Catherine, Bolmont, J., Bonnefoy, S., Bordas, P., Bregeon, J., Brun, F., Brun, P., Bryan, M., Büchele, M., Bulik, Tomasz, Capasso, M., Carrigan, S., Caroff, S., Carosi, A., Casanova, S., Cerruti, Matteo, Chakraborty, N., Chaves, R. C. G., Chen, A., Chevalier, J., Colafrancesco, Sergio, Condon, B., Conrad, J., Davids, I. D., Decock, J., Deil, C., Devin, J., Dewilt, P., Dirson, L., Djannati-Ataï, Arache, Domainko, W., Donath, A., Drury, L. O.'C., Dutson, K., Dyks, J., Edwards, T., Egberts, K., Eger, P., Emery, G., Ernenwein, J.-P., Eschbach, S., Farnier, C., Fegan, S., Fernandes, M. V., Fiasson, A., Fontaine, G., Förster, A., Funk, S., Füßling, M., Gabici, Stefano, Gallant, Y. A., Garrigoux, T., Gast, H., Gate, F., Giavitto, G., Giebels, B., Glawion, D., Glicenstein, J.-F., Gottschall, D., Grondin, M.-H., Hahn, J., Haupt, M., Hawkes, J., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A., Hofmann, W., Hoischen, C., Holch, T. L., Holler, M., Horns, D., Ivascenko, A., Iwasaki, H., Jacholkowska, A., Jamrozy, M., Jankowsky, D., Jankowsky, F., Jingo, M., Jouvin, L., Jung-Richardt, I., Kastendieck, M. A., Katarzynski, K., Katsuragawa, M., Katz, U., Kerszberg, D., Khangulyan, D., Khélifi, Bruno, King, J., Klepser, S., Klochkov, D., Kluzniak, Wlodek, Komin, Nu., Kosack, K., Krakau, S., Kraus, M., Krüger, P. P., Laffon, H., Lamanna, G., Lau, J., Lees, J.-P., Lefaucheur, Julien, Lemière, Anne, Lemoine-Goumard, M., Lenain, J.-P., Leser, E., Lohse, T., Lorentz, M., Liu, R., López-Coto, R., Lypova, I., Marandon, V., Malyshev, D., Marcowith, Alexandre, Mariaud, C., Marx, R., Maurin, G., Maxted, N., Mayer, M., Meintjes, P. J., Meyer, Michael R., Mitchell, A. M. W., Moderski, R., Mohamed, M., Mohrmann, L., Morâ, K., Moulin, E., Murach, T., Nakashima, S., de Naurois, M., Ndiyavala, H., Niederwanger, F., Niemiec, J., Oakes, L., O'Brien, P., Odaka, H., Ohm, S., Ostrowski, M., Oya, I., Padovani, Marco, Panter, M., Parsons, R. D., Paz Arribas, M., Pekeur, N. W., Pelletier, Guy, Perennes, Cédric, Petrucci, Pierre-Olivier, Peyaud, B., Piel, Q., Pita, Santiago, Poireau, V., Poon, H., Prokhorov, D. A., Prokoph, H., Pühlhofer, G., Punch, Michael, Quirrenbach, Andreas, Raab, S., Rauth, R., Reimer, A., Reimer, O., Renaud, M., de los Reyes, R., Rieger, F., Rinchiuso, L., Romoli, C., Rowell, G., Rudak, B., Rulten, Cameron, Safi-Harb, S., Sahakian, V., Saito, S., Sanchez, D. A., Santangelo, Andrea, Sasaki, Misao, Schandri, M., Schlickeiser, R., Schüssler, F., Schulz, A., Schwanke, U., Schwemmer, S., Seglar-Arroyo, M., Settimo, Mariangela, Seyffert, A. S., Shafi, N., Shilon, I., Shiningayamwe, K., Simoni, R., Sol, Hélène, Spanier, Felix, Spir-Jacob, M., Stawarz, L., Steenkamp, R., Stegmann, C., Steppa, C., Sushch, I., Takahashi, Tadayuki, Tavernet, J.-P., Tavernier, Thomas, Taylor, Andrew M., Terrier, R., Tibaldo, L., Tiziani, D., Tluczykont, M., Trichard, C., Tsirou, M., Tsuji, N., Tuffs, Richard J., 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, Jacco, Voisin, F., Völk, H. J., Vuillaume, T., Wadiasingh, Z., Wagner, S. J., Wagner, P., Wagner, R. Mark, White, R., Wierzcholska, A., Willmann, P., Wörnlein, A., Wouters, D., Yang, R., Zaborov, D., Zacharias, M., Zanin, R., Zdziarski, A. A., Zech, Andreas, Zefi, F., Ziegler, A., Zorn, J., Zywucka, N., 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 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)-Université de Paris (UP), 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), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire Leprince-Ringuet (LLR), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), AstroParticule et Cosmologie (APC (UMR_7164)), 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), 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), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA), HESS, 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 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), 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 des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), European Project: 332350,EC:FP7:PEOPLE,FP7-PEOPLE-2012-IEF,PRECISIONGAMMA(2014), Faculty of Science, High Energy Astrophys. & Astropart. Phys (API, FNWI), API Other Research (FNWI), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS), Laboratoire d'Annecy de Physique des Particules (LAPP/Laboratoire d'Annecy-le-Vieux de Physique des Particules), 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), Université de Montpellier (UM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-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)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Aix Marseille Université (AMU), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7), Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Centre for Space Research, North-West University, Institut für Experimentalphysik, Universität Hamburg, Max-Planck-Institut für Kernphysik (MPIK), Instytut Fizyki Jadrowej, PAN (IFJ/PAN), Institute of Space and Astronautical Science (ISAS), University of Namibia, Department of Physics, Private Bag 13301, Windhoek, Namibia, Gravitation AstroParticle Physics Amsterdam (GRAPPA), Department of Physics and Electrical Engineering, Institut für Theoretische Physik and Astrophysik, Universität Würzburg, Institut für Astro- und Teilchenphysik, Leopold-Franzens-Universität Innsbruck, University of Adelaide, Sorbonne Université (SU), Deutsches Elektronen-Synchrotron (DESY), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Physikalisches Institut, Universität Erlangen-Nürnberg, Astronomical Observatory, Eberhard Karls Universität Tübingen = Eberhard Karls University of Tuebingen, School of Physics, University of the Witwatersrand, Department of Physics, Oskar Klein Centre, Stockholm University (OKC), Dublin Institute for Advanced Studies, 31 Fitzwilliam Place, Dublin, 2, Ireland, Department of Physics and Astronomy, Centrum Astronomiczne im. M. Kopernika, Warszawa (CAMK), Institut für Physik und Astronomie, Universität Potsdam, Landessternwarte, Universitat Heidelberg, Konigstuhl, 69117, Heidelberg, Germany, Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France -Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France, Institut für Physik, Humboldt-Universität zu Berlin (IFP-HUB), Obserwatorium Astronomiczne, Uniwersytet Jagiellonski, Centre for Astronomy, Faculty of Physics, Astronomy and Informatics, Now at The School of Physics, The University of New South Wales, Sydney, 2052, Australia, Department of Physics, University of the Free State, PO Box 339, Bloemfontein, 9300, South Africa, and Yerevan Physics Institute
- Subjects
media_common.quotation_subject ,Astrophysics::High Energy Astrophysical Phenomena ,Hochenergie-Astrophysik Theorie - Abteilung Hofmann ,Infrarot-Astrophysik - Abteilung Hofmann ,FOS: Physical sciences ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,01 natural sciences ,Pulsar ,surveys ,HESS ,0103 physical sciences ,supernova ,ddc:530 ,composite ,010303 astronomy & astrophysics ,Galaxy: general ,HESS - Abteilung Hofmann ,Astrophysics::Galaxy Astrophysics ,media_common ,pulsar ,Astroparticle physics ,Physics ,High Energy Astrophysical Phenomena (astro-ph.HE) ,energy: high ,010308 nuclear & particles physics ,general [galaxy] ,Galactic Center ,Institut für Physik und Astronomie ,gamma ray: binary ,Astronomy and Astrophysics ,Radius ,gamma rays: general ,Galactic plane ,sensitivity ,Galaxy ,flux ,Supernova ,Cherenkov counter ,angular resolution ,gamma ray: VHE ,Space and Planetary Science ,Sky ,ddc:520 ,galaxy ,Astrophysics - High Energy Astrophysical Phenomena ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] ,general [gamma rays] - Abstract
著者人数: H.E.S.S. Collaboration 259名 (所属. 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS): 桂川, 美穂; 中島, 真也; 小高, 裕和; 高橋, 忠幸), Number of authors: H.E.S.S. Collaboration 259 (Affiliation. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency(JAXA)(ISAS): Katsuragawa, Miho; Nakashima, Shinya; Odaka, Hirokazu; Takahashi, Tadayuki), Accepted: 2018-01-15, 資料番号: SA1170367000
- Published
- 2018
11. On the shape of the gamma-ray spectrum around the '$\pi^0$-bump'
- Author
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Yang, Rui-zhi, Kafexhiu, Ervin, and Aharonian, Felix
- Subjects
Astrophysics::High Energy Astrophysical Phenomena ,High Energy Physics::Experiment ,Nuclear Experiment ,Astrophysics - High Energy Astrophysical Phenomena - Abstract
The "pion-decay" bump is a distinct signature of the differential energy spectrum of $\gamma$-rays between 100 MeV and 1 GeV produced in hadronic interactions of accelerated particles (cosmic rays) with the ambient gas. We use the recent parametrisations of relevant cross-sections to study the formation of the "pion-decay" bump. The $\gamma$-ray spectrum below the maximum of this spectral feature can be distorted because of contributions of additional radiation components, in particular, due to the bremsstrahlung of secondary electrons and positrons, the products of decays of $\pi^\pm$-mesons, accompanying the $\pi^0$-production. At energies below 100 MeV, a non-negligible fraction of $\gamma$-ray flux could originate from interactions of sub-relativistic heavy ions. We study the impact of these radiation channels on the formation of the overall $\gamma$-ray spectrum based on a time-dependent treatment of evolution of energy distributions of the primary and secondary particles in the $\gamma$-ray production region., Comment: submitted to A&A
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- 2018
12. Glimpse of the highly obscured HMXB IGR J16318−4848 with Hitomi
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Aharonian , Felix, Akamatsu , Hiroki, Akimoto , Fumie, Allen , StevenW., Angelini , Lorella, Audard , Marc, Awaki , Hisamitsu, Axelsson , Magnus, Bamba , Aya, Bautz , MarshallW., Blandford , Roger, Brenneman , LauraW., Brown , GregoryV., Bulbul , Esra, Cackett , EdwardM., Chernyakova , Maria, Chiao , MengP., Coppi , PaoloS., Costantini , Elisa, De Plaa , Jelle, de Vries , CorP., Den Herder , Jan-Willem, Done , Chris, Dotani , Tadayasu, Ebisawa , Ken, Eckart , MeganE., Enoto , Teruaki, Ezoe , Yuichiro, Fabian , AndrewC., Ferrigno , Carlo, Foster , AdamR., Fujimoto , Ryuichi, Fukazawa , Yasushi, Furuzawa , Akihiro, Galeazzi , Massimiliano, Gallo , LuigiC., Gandhi , Poshak, Giustini , Margherita, Goldwurm , Andrea, Gu , Liyi, Guainazzi , Matteo, Haba , Yoshito, Hagino , Kouichi, Hamaguchi , Kenji, Harrus , IlanaM., Hatsukade , Isamu, Hayashi , Katsuhiro, Hayashi , Takayuki, Hayashida , Kiyoshi, Hiraga , JunkoS., Hornschemeier , Ann, Hoshino , Akio, Hughes , JohnP., Ichinohe , Yuto, Iizuka , Ryo, Inoue , Hajime, Inoue , Yoshiyuki, Ishida , Manabu, Ishikawa , Kumi, Ishisaki , Yoshitaka, Iwai , Masachika, Kaastra , Jelle, Kallman , Tim, Kamae , Tsuneyoshi, Kataoka , Jun, Katsuda , Satoru, Kawai , Nobuyuki, Kelley , RichardL., Kilbourne , CarolineA., Kitaguchi , Takao, Kitamoto , Shunji, Kitayama , Tetsu, Kohmura , Takayoshi, Kokubun , Motohide, Koyama , Katsuji, Koyama , Shu, Kretschmar , Peter, Krimm , HansA., Kubota , Aya, Kunieda , Hideyo, Laurent , Philippe, Lee , Shiu-Hang, Leutenegger , MauriceA., Limousin , OlivierO., Loewenstein , Michael, Long , KnoxS., Lumb , David, Madejski , Greg, Maeda , Yoshitomo, Maier , Daniel, Makishima , Kazuo, Markevitch , Maxim, Matsumoto , Hironori, Matsushita , Kyoko, Mccammon , Dan, McNamara , BrianR., Mehdipour , Missagh, Miller , EricD., Miller , JonM., Mineshige , Shin, Mitsuda , Kazuhisa, Mitsuishi , Ikuyuki, Miyazawa , Takuya, Mizuno , Tsunefumi, Mori , Hideyuki, Mori , Koji, Mukai , Koji, Murakami , Hiroshi, Mushotzky , RichardF., Nakagawa , Takao, Nakajima , Hiroshi, Nakamori , Takeshi, Nakashima , Shinya, Nakazawa , Kazuhiro, Nobukawa , KumikoK., Nobukawa , Masayoshi, Noda , Hirofumi, Odaka , Hirokazu, Ohashi , Takaya, Ohno , Masanori, Okajima , Takashi, Ota , Naomi, Ozaki , Masanobu, Paerels , Frits, Paltani , Stéphane, Petre , Robert, Pinto , Ciro, Porter , FrederickS., Pottschmidt , Katja, Reynolds , ChristopherS., Safi-Harb , Samar, Saito , Shinya, Sakai , Kazuhiro, Sasaki , Toru, Sato , Goro, Sato , Kosuke, Sato , Rie, Sawada , Makoto, Schartel , Norbert, Serlemtsos , PeterJ., Seta , Hiromi, Shidatsu , Megumi, Simionescu , Aurora, Smith , RandallK., Soong , Yang, Stawarz , Łukasz, Sugawara , Yasuharu, Sugita , Satoshi, Szymkowiak , Andrew, Tajima , Hiroyasu, Takahashi , Hiromitsu, Takahashi , Tadayuki, Takeda , Shiníchiro, Takei , Yoh, Tamagawa , Toru, Tamura , Takayuki, Tanaka , Takaaki, Tanaka , Yasuo, Tanaka , YasuyukiT., Tashiro , MakotoS., Tawara , Yuzuru, Terada , Yukikatsu, Terashima , Yuichi, Tombesi , Francesco, Tomida , Hiroshi, Tsuboi , Yohko, Tsujimoto , Masahiro, Tsunemi , Hiroshi, Tsuru , Takeshi, Uchida , Hiroyuki, Uchiyama , Hideki, Uchiyama , Yasunobu, Ueda , Shutaro, Ueda , Yoshihiro, Uno , Shiníchiro, Urry , C.Megan, Ursino , Eugenio, Watanabe , Shin, Werner , Norbert, Wilkins , DanR., Williams , BrianJ., Yamada , Shinya, Yamaguchi , Hiroya, Yamaoka , Kazutaka, Yamasaki , NorikoY., Yamauchi , Makoto, Yamauchi , Shigeo, Yaqoob , Tahir, Yatsu , Yoichi, Yonetoku , Daisuke, Zhuravleva , Irina, Zoghbi , Abderahmen, Nakaniwa , Nozomi, AstroParticule et Cosmologie ( APC - UMR 7164 ), Centre National de la Recherche Scientifique ( CNRS ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Observatoire de Paris-Université Paris Diderot - Paris 7 ( UPD7 ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ), and Hitomi
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Astrophysics::High Energy Astrophysical Phenomena ,[ PHYS.ASTR ] Physics [physics]/Astrophysics [astro-ph] - Abstract
International audience; We report on a Hitomi observation of IGR J16318−4848, a high-mass X-ray binary system with an extremely strong absorption of N_H ∼ 10^24 cm^−2. Previous X-ray studies revealed that its spectrum is dominated by strong fluorescence lines of Fe as well as continuum emission lines. For physical and geometrical insight into the nature of the reprocessing material, we utilized the high spectroscopic resolving power of the X-ray microcalorimeter (the soft X-ray spectrometer: SXS) and the wide-band sensitivity by the soft and hard X-ray imagers (SXI and HXI) aboard Hitomi. Even though the photon counts are limited due to unintended off-axis pointing, the SXS spectrum resolves Fe Kα_1 and Kα_2 lines and puts strong constraints on the line centroid and line width. The line width corresponds to a velocity of 160$$^{+300}_{-70}$$ km s^−1. This represents the most accurate, and smallest, width measurement of this line made so far from the any X-ray binary, much less than the Doppler broadening and Doppler shift expected from speeds that are characteristic of similar systems. Combined with the K-shell edge energy measured by the SXI and HXI spectra, the ionization state of Fe is estimated to be in the range of Fe i–iv. Considering the estimated ionization parameter and the distance between the X-ray source and the absorber, the density and thickness of the materials are estimated. The extraordinarily strong absorption and the absence of a Compton shoulder component have been confirmed. These characteristics suggest reprocessing materials that are distributed in a narrow solid angle or scattering, primarily by warm free electrons or neutral hydrogen. This measurement was achieved using the SXS detection of 19 photons. It provides strong motivation for follow-up observations of this and other X-ray binaries using the X-ray Astrophysics Recovery Mission and other comparable future instruments.
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- 2018
13. Nuclear $��$-ray emission from very hot accretion flows
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Kafexhiu, Ervin, Aharonian, Felix, and Barkov, Maxim
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High Energy Astrophysical Phenomena (astro-ph.HE) ,Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics::Solar and Stellar Astrophysics ,FOS: Physical sciences ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Nuclear Experiment ,Astrophysics::Galaxy Astrophysics - Abstract
Optically thin accretion plasmas can reach ion temperatures $T_{\rm i} \geq 10^{10}$K and thus trigger nuclear reactions. Using a large nuclear interactions network, we studied the radial evolution of the chemical composition of the accretion flow toward the black hole and computed the emissivity in nuclear $��$-ray lines. In the advection dominated accretion flow (ADAF) regime, CNO and heavier nuclei are destroyed before reaching the last stable orbit. The overall luminosity in the de-excitation lines for a solar composition of plasma can be as high as few times $10^{-5}$ the accretion luminosity ($\dot{M}c^2$) and can be increased for heavier compositions up to $10^{-3}$. The efficiency of transformation of the kinetic energy of the outflow into high energy ($\geq 100$~MeV) $��$-rays through the production and decay of $��^0$-mesons can be higher, up to $10^{-2}$ of the accretion luminosity. We show that in the ADAF model up to 15 percent of the mass of accretion matter can `evaporate' in the form of neutrons., 7 pages, 7 figures
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- 2018
- Full Text
- View/download PDF
14. NuSTAR Detection of Nonthermal Bremsstrahlung from the Supernova Remnant W49B
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Wik, Daniel R., Aharonian, Felix A., Castro, Daniel, Foster, Adam R., Petre, Robert, Rho, Jeonghee, Smith, Randall K., Williams, Brian J., Tanaka, Takaaki, Yamaguchi, Hiroya, Bamba, Aya, Uchida, Hiroyuki, and Uchiyama, Yasunobu
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Photon ,ISM: individual objects (W49B) ,Astrophysics::High Energy Astrophysical Phenomena ,Flux ,Energy flux ,FOS: Physical sciences ,Electron ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,01 natural sciences ,0103 physical sciences ,Sensitivity (control systems) ,010306 general physics ,Supernova remnant ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics ,acceleration of particles ,ISM: supernova remnants ,Physics ,High Energy Astrophysical Phenomena (astro-ph.HE) ,Bremsstrahlung ,Astronomy and Astrophysics ,X-rays: ISM ,Particle acceleration ,Space and Planetary Science ,Astrophysics - High Energy Astrophysical Phenomena - Abstract
著者人数: 13名, Accepted: 2018-10-08, 資料番号: SA1180306000
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- 2018
- Full Text
- View/download PDF
15. On the shape of the gamma-ray spectrum around the '$��^0$-bump'
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Yang, Rui-zhi, Kafexhiu, Ervin, and Aharonian, Felix
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High Energy Astrophysical Phenomena (astro-ph.HE) ,Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences ,High Energy Physics::Experiment ,Nuclear Experiment - Abstract
The "pion-decay" bump is a distinct signature of the differential energy spectrum of $��$-rays between 100 MeV and 1 GeV produced in hadronic interactions of accelerated particles (cosmic rays) with the ambient gas. We use the recent parametrisations of relevant cross-sections to study the formation of the "pion-decay" bump. The $��$-ray spectrum below the maximum of this spectral feature can be distorted because of contributions of additional radiation components, in particular, due to the bremsstrahlung of secondary electrons and positrons, the products of decays of $��^\pm$-mesons, accompanying the $��^0$-production. At energies below 100 MeV, a non-negligible fraction of $��$-ray flux could originate from interactions of sub-relativistic heavy ions. We study the impact of these radiation channels on the formation of the overall $��$-ray spectrum based on a time-dependent treatment of evolution of energy distributions of the primary and secondary particles in the $��$-ray production region., submitted to A&A
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- 2018
- Full Text
- View/download PDF
16. Search for thermal X-ray features from the Crab nebula with Hitomi Soft X-ray Spectrometer
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Aharonian, Felix, Akamatsu, Hiroki, Akimoto, Fumie, Allen, Steven W., Angelini, Lorella, Audard, Marc, Awaki, Hisamitsu, Axelsson, Magnus, Bamba, Aya, Bautz, Marshall W., Blandford, Roger, Brenneman, Laura W., Brown, Greg V., Bulbul, Esra, Cackett, Edward M., Chernyakova, Maria, Chiao, Meng P., Coppi, Paolo S., Costantini, Elisa, de Plaa, Jelle, de Vries, Cor P., den Herder, Jan-Willem, Done, Chris, Dotani, Tadayasu, Ebisawa, Ken, Eckart, Megan E., Enoto, Teruaki, Ezoe, Yuichiro, Fabian, Andrew C., Ferrigno, Carlo, Foster, Adam R., Fujimoto, Ryuichi, Fukazawa, Yasushi, Furuzawa, Akihiro, Galeazzi, Massimiliano, Gallo, Luigi C., Gandhi, Poshak, Giustini, Margherita, Goldwurm, Andrea, Gu, Liyi, Guainazzi, Matteo, Haba, Yoshito, Hagino, Kouichi, Hamaguchi, Kenji, Harrus, Ilana M., Hatsukade, Isamu, Hayashi, Katsuhiro, Hayashi, Takayuki, Hayashida, Kiyoshi, Hiraga, Junko S., Hornschemeier, Ann, Hoshino, Akio, Hughes, John P., Ichinohe, Yuto, Iizuka, Ryo, Inoue, Hajime, Inoue, Yoshiyuki, Ishida, Manabu, Ishikawa, Kumi, Ishisaki, Yoshitaka, Kaastra, Jelle, Kallman, Tim, Kamae, Tsuneyoshi, Kataoka, Jun, Katsuda, Satoru, Kawai, Nobuyuki, Kelley, Richard L., Kilbourne, Caroline A., Kitaguchi, Takao, Kitamoto, Shunji, Kitayama, Tetsu, Kohmura, Takayoshi, Kokubun, Motohide, Koyama, Katsuji, Koyama, Shu, Kretschmar, Peter, Krimm, Hans A., Kubota, Aya, Kunieda, Hideyo, Laurent, Philippe, Lee, Shiu-Hang, Leutenegger, Maurice A., Limousin, Olivier O., Loewenstein, Michael, Long, Knox S., Lumb, David, Madejski, Greg, Maeda, Yoshitomo, Maier, Daniel, Makishima, Kazuo, Markevitch, Maxim, Matsumoto, Hironori, Matsushita, Kyoko, McCammon, Dan, McNamara, Brian R., Mehdipour, Missagh, Miller, Eric D., Miller, Jon M., Mineshige, Shin, Mitsuda, Kazuhisa, Mitsuishi, Ikuyuki, Miyazawa, Takuya, Mizuno, Tsunefumi, Mori, Hideyuki, Mori, Koji, Mukai, Koji, Murakami, Hiroshi, Mushotzky, Richard F., Nakagawa, Takao, Nakajima, Hiroshi, Nakamori, Takeshi, Nakashima, Shinya, Nakazawa, Kazuhiro, Nobukawa, Kumiko K., Nobukawa, Masayoshi, Noda, Hirofumi, Odaka, Hirokazu, Ohashi, Takaya, Ohno, Masanori, Okajima, Takashi, Ota, Naomi, Ozaki, Masanobu, Paerels, Frits, Paltani, Stephane, Petre, Robert, Pinto, Ciro, Porter, Frederick S., Pottschmidt, Katja, Reynolds, Christopher S., Safi-Harb, Samar, Saito, Shinya, Sakai, Kazuhiro, Sasaki, Toru, Sato, Goro, Sato, Kosuke, Sato, Rie, Sato, Toshiki, Sawada, Makoto, Schartel, Norbert, Serlemtsos, Peter J., Seta, Hiromi, Shidatsu, Megumi, Simionescu, Aurora, Smith, Randall K., Soong, Yang, Stawarz, Lukasz, Sugawara, Yasuharu, Sugita, Satoshi, Szymkowiak, Andrew, Tajima, Hiroyasu, Takahashi, Hiromitsu, Takahashi, Tadayuki, Takeda, Shinichiro, Takei, Yoh, Tamagawa, Toru, Tamura, Takayuki, Tanaka, Takaaki, Tanaka, Yasuo, Tanaka, Yasuyuki T., Tashiro, Makoto S., Tawara, Yuzuru, Terada, Yukikatsu, Terashima, Yuichi, Tombesi, Francesco, Tomida, Hiroshi, Tsuboi, Yohko, Tsujimoto, Masahiro, Tsunemi, Hiroshi, Tsuru, Takeshi Go, Uchida, Hiroyuki, Uchiyama, Hideki, Uchiyama, Yasunobu, Ueda, Shutaro, Ueda, Yoshihiro, Uno, Shinichiro, Urry, C. Megan, Ursino, Eugenio, Watanabe, Shin, Werner, Norbert, Wilkins, Dan R., Williams, Brian J., Yamada, Shinya, Yamaguchi, Hiroya, Yamaoka, Kazutaka, Yamasaki, Noriko Y., Yamauchi, Makoto, Yamauchi, Shigeo, Yaqoob, Tahir, Yatsu, Yoichi, Yonetoku, Daisuke, Zhuravleva, Irina, Zoghbi, Abderahmen, Tominaga, Nozomu, and Moriya, Takashi J.
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Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics::Galaxy Astrophysics - Abstract
The Crab nebula originated from a core-collapse supernova (SN) explosion observed in 1054 A.D. When viewed as a supernova remnant (SNR), it has an anomalously low observed ejecta mass and kinetic energy for an Fe-core collapse SN. Intensive searches were made for a massive shell that solves this discrepancy, but none has been detected. An alternative idea is that the SN1054 is an electron-capture (EC) explosion with a lower explosion energy by an order of magnitude than Fe-core collapse SNe. In the X-rays, imaging searches were performed for the plasma emission from the shell in the Crab outskirts to set a stringent upper limit to the X-ray emitting mass. However, the extreme brightness of the source hampers access to its vicinity. We thus employed spectroscopic technique using the X-ray micro-calorimeter onboard the Hitomi satellite. By exploiting its superb energy resolution, we set an upper limit for emission or absorption features from yet undetected thermal plasma in the 2-12 keV range. We also re-evaluated the existing Chandra and XMM-Newton data. By assembling these results, a new upper limit was obtained for the X-ray plasma mass of
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- 2017
17. Hitomi Observation of Radio Galaxy NGC 1275: The First X-ray Microcalorimeter Spectroscopy of Fe-K�� Line Emission from an Active Galactic Nucleus
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Hitomi Collaboration, Aharonian, Felix, Akamatsu, Hiroki, Akimoto, Fumie, Allen, Steven W., Angelini, Lorella, Audard, Marc, Awaki, Hisamitsu, Axelsson, Magnus, Bamba, Aya, Bautz, Marshall W., Blandford, Roger, Brenneman, Laura W., Brown, Gregory V., Bulbul, Esra, Cackett, Edward M., Chernyakova, Maria, Chiao, Meng P., Coppi, Paolo S., Costantini, Elisa, de Plaa, Jelle, de Vries, Cor P., Herder, Jan-Willem den, Done, Chris, Dotani, Tadayasu, Ebisawa, Ken, Eckart, Megan E., Enoto, Teruaki, Ezoe, Yuichiro, Fabian, Andrew C., Ferrigno, Carlo, Foster, Adam R., Fujimoto, Ryuichi, Fukazawa, Yasushi, Furuzawa, Akihiro, Galeazzi, Massimiliano, Gallo, Luigi C., Gandhi, Poshak, Giustini, Margherita, Goldwurm, Andrea, Gu, Liyi, Guainazzi, Matteo, Haba, Yoshito, Hagino, Kouichi, Hamaguchi, Kenji, Harrus, Ilana M., Hatsukade, Isamu, Hayashi, Katsuhiro, Hayashi, Takayuki, Hayashida, Kiyoshi, Hiraga, Junko S., Hornschemeier, Ann, Hoshino, Akio, Hughes, John P., Ichinohe, Yuto, Iizuka, Ryo, Inoue, Hajime, Inoue, Yoshiyuki, Ishida, Manabu, Ishikawa, Kumi, Ishisaki, Yoshitaka, Iwai, Masachika, Kaastra, Jelle, Kallman, Tim, Kamae, Tsuneyoshi, Kataoka, Jun, Katsuda, Satoru, Kawai, Nobuyuki, Kelley, Richard L., Kilbourne, Caroline A., Kitaguchi, Takao, Kitamoto, Shunji, Kitayama, Tetsu, Kohmura, Takayoshi, Kokubun, Motohide, Koyama, Katsuji, Koyama, Shu, Kretschmar, Peter, Krimm, Hans A., Kubota, Aya, Kunieda, Hideyo, Laurent, Philippe, Lee, Shiu-Hang, Leutenegger, Maurice A., Limousin, Olivier O., Loewenstein, Michael, Long, Knox S., Lumb, David, Madejski, Greg, Maeda, Yoshitomo, Maier, Daniel, Makishima, Kazuo, Markevitch, Maxim, Matsumoto, Hironori, Matsushita, Kyoko, McCammon, Dan, McNamara, Brian R., Mehdipour, Missagh, Miller, Eric D., Miller, Jon M., Mineshige, Shin, Mitsuda, Kazuhisa, Mitsuishi, Ikuyuki, Miyazawa, Takuya, Mizuno, Tsunefumi, Mori, Hideyuki, Mori, Koji, Mukai, Koji, Murakami, Hiroshi, Mushotzky, Richard F., Nakagawa, Takao, Nakajima, Hiroshi, Nakamori, Takeshi, Nakashima, Shinya, Nakazawa, Kazuhiro, Nobukawa, Kumiko K., Nobukawa, Masayoshi, Noda, Hirofumi, Odaka, Hirokazu, Ohashi, Takaya, Ohno, Masanori, Okajima, Takashi, Ota, Naomi, Ozaki, Masanobu, Paerels, Frits, Paltani, St��phane, Petre, Robert, Pinto, Ciro, Porter, Frederick S., Pottschmidt, Katja, Reynolds, Christopher S., Safi-Harb, Samar, Saito, Shinya, Sakai, Kazuhiro, Sasaki, Toru, Sato, Goro, Sato, Kosuke, Sato, Rie, Sawada, Makoto, Schartel, Norbert, Serlemitsos, Peter J., Seta, Hiromi, Shidatsu, Megumi, Simionescu, Aurora, Smith, Randall K., Soong, Yang, Stawarz, ��ukasz, Sugawara, Yasuharu, Sugita, Satoshi, Szymkowiak, Andrew, Tajima, Hiroyasu, Takahashi, Hiromitsu, Takahashi, Tadayuki, Takeda, Shin'ichiro, Takei, Yoh, Tamagawa, Toru, Tamura, Takayuki, Tanaka, Takaaki, Tanaka, Yasuo, Tanaka, Yasuyuki T., Tashiro, Makoto S., Tawara, Yuzuru, Terada, Yukikatsu, Terashima, Yuichi, Tombesi, Francesco, Tomida, Hiroshi, Tsuboi, Yohko, Tsujimoto, Masahiro, Tsunemi, Hiroshi, Tsuru, Takeshi Go, Uchida, Hiroyuki, Uchiyama, Hideki, Uchiyama, Yasunobu, Ueda, Shutaro, Ueda, Yoshihiro, Uno, Shin'ichiro, Urry, C. Megan, Ursino, Eugenio, Watanabe, Shin, Werner, Norbert, Wilkins, Dan R., Williams, Brian J., Yamada, Shinya, Yamaguchi, Hiroya, Yamaoka, Kazutaka, Yamasaki, Noriko Y., Yamauchi, Makoto, Yamauchi, Shigeo, Yaqoob, Tahir, Yatsu, Yoichi, Yonetoku, Daisuke, Zhuravleva, Irina, Zoghbi, Abderahmen, and Kawamuro, Taiki
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High Energy Astrophysical Phenomena (astro-ph.HE) ,Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics::Galaxy Astrophysics - Abstract
The origin of the narrow Fe-K�� fluorescence line at 6.4 keV from active galactic nuclei has long been under debate; some of the possible sites are the outer accretion disk, the broad line region, a molecular torus, or interstellar/intracluster media. In February-March 2016, we performed the first X-ray microcalorimeter spectroscopy with the Soft X-ray Spectrometer (SXS) onboard the Hitomi satellite of the Fanaroff-Riley type I radio galaxy NGC 1275 at the center of the Perseus cluster of galaxies. With the high energy resolution of ~5 eV at 6 keV achieved by Hitomi/SXS, we detected the Fe-K�� line with ~5.4 �� significance. The velocity width is constrained to be 500-1600 km s$^{-1}$ (FWHM for Gaussian models) at 90% confidence. The SXS also constrains the continuum level from the NGC 1275 nucleus up to ~20 keV, giving an equivalent width ~20 eV of the 6.4 keV line. Because the velocity width is narrower than that of broad H�� line of ~2750 km s$^{-1}$, we can exclude a large contribution to the line flux from the accretion disk and the broad line region. Furthermore, we performed pixel map analyses on the Hitomi/SXS data and image analyses on the Chandra archival data, and revealed that the Fe-K�� line comes from a region within ~1.6 kpc from the NGC 1275 core, where an active galactic nucleus emission dominates, rather than that from intracluster media. Therefore, we suggest that the source of the Fe-K�� line from NGC 1275 is likely a low-covering fraction molecular torus or a rotating molecular disk which probably extends from a pc to hundreds pc scale in the active galactic nucleus system., 20 pages, 8 figures, 6 tables, accepted for publication in PASJ
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- 2017
- Full Text
- View/download PDF
18. $Hitomi$ constraints on the 3.5 keV line in the Perseus galaxy cluster
- Author
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Hitomi Collaboration, Aharonian, Felix A., Akamatsu, Hiroki, Akimoto, Fumie, Allen, Steven W., Angelini, Lorella, Arnaud, Keith A., Audard, Marc, Awaki, Hisamitsu, Axelsson, Magnus, Bamba, Aya, Bautz, Marshall W., Blandford, Roger D., Brenneman, Laura W., Brown, Gregory V., Bulbul, Esra, Cackett, Edward M., Chernyakova, Maria, Chiao, Meng P., Coppi, Paolo, Costantini, Elisa, de Plaa, Jelle, Herder, Jan-Willem den, Done, Chris, Dotani, Tadayasu, Ebisawa, Ken, Eckart, Megan E., Enoto, Teruaki, Ezoe, Yuichiro, Fabian, Andrew C., Ferrigno, Carlo, Foster, Adam R., Fujimoto, Ryuichi, Fukazawa, Yasushi, Furuzawa, Akihiro, Galeazzi, Massimiliano, Gallo, Luigi C., Gandhi, Poshak, Giustini, Margherita, Goldwurm, Andrea, Gu, Liyi, Guainazzi, Matteo, Haba, Yoshito, Hagino, Kouichi, Hamaguchi, Kenji, Harrus, Ilana, Hatsukade, Isamu, Hayashi, Katsuhiro, Hayashi, Takayuki, Hayashida, Kiyoshi, Hiraga, Junko, Hornschemeier, Ann E., Hoshino, Akio, Hughes, John P., Ichinohe, Yuto, Iizuka, Ryo, Inoue, Hajime, Inoue, Shota, Inoue, Yoshiyuki, Ishibashi, Kazunori, Ishida, Manabu, Ishikawa, Kumi, Ishisaki, Yoshitaka, Itoh, Masayuki, Iwai, Masachika, Iyomoto, Naoko, Kaastra, Jelle S., Kallman, Timothy, Kamae, Tuneyoshi, Kara, Erin, Kataoka, Jun, Katsuda, Satoru, Katsuta, Junichiro, Kawaharada, Madoka, Kawai, Nobuyuki, Kelley, Richard L., Khangulyan, Dmitry, Kilbourne, Caroline A., King, Ashley L., Kitaguchi, Takao, Kitamoto, Shunji, Kitayama, Tetsu, Kohmura, Takayoshi, Kokubun, Motohide, Koyama, Shu, Koyama, Katsuji, Kretschmar, Peter, Krimm, Hans A., Kubota, Aya, Kunieda, Hideyo, Laurent, Philippe, Lebrun, Francois, Lee, Shiu-Hang, Leutenegger, Maurice, Limousin, Olivier, Loewenstein, Michael, Long, Knox S., Lumb, David, Madejski, Grzegorz M., Maeda, Yoshitomo, Maier, Daniel, Makishima, Kazuo, Markevitch, Maxim, Matsumoto, Hironori, Matsushita, Kyoko, McCammon, Dan, McNamara, Brian R., Mehdipour, Missagh, Miller, Eric D., Miller, Jon M., Mineshige, Shin, Mitsuda, Kazuhisa, Mitsuishi, Ikuyuki, Miyazawa, Takuya, Mizuno, Tsunefumi, Mori, Hideyuki, Mori, Koji, Moseley, Harvey, Mukai, Koji, Murakami, Hiroshi, Murakami, Toshio, Mushotzky, Richard F., Nakagawa, Takao, Nakajima, Hiroshi, Nakamori, Takeshi, Nakano, Toshio, Nakashima, Shinya, Nakazawa, Kazuhiro, Nobukawa, Kumiko, Nobukawa, Masayoshi, Noda, Hirofumi, Nomachi, Masaharu, O'Dell, Steve L., Odaka, Hirokazu, Ohashi, Takaya, Ohno, Masanori, Okajima, Takashi, Ota, Naomi, Ozaki, Masanobu, Paerels, Frits, Paltani, Stephane, Parmar, Arvind, Petre, Robert, Pinto, Ciro, Pohl, Martin, Porter, F. Scott, Pottschmidt, Katja, Ramsey, Brian D., Reynolds, Christopher S., Russell, Helen R., Safi-Harb, Samar, Saito, Shinya, Sakai, Kazuhiro, Sameshima, Hiroaki, Sasaki, Toru, Sato, Goro, Sato, Kosuke, Sato, Rie, Sawada, Makoto, Schartel, Norbert, Serlemitsos, Peter J., Seta, Hiromi, Shidatsu, Megumi, Simionescu, Aurora, Smith, Randall K., Soong, Yang, Stawarz, Lukasz, Sugawara, Yasuharu, Sugita, Satoshi, Szymkowiak, Andrew E., Tajima, Hiroyasu, Takahashi, Hiromitsu, Takahashi, Tadayuki, Takeda, Shin'ichiro, Takei, Yoh, Tamagawa, Toru, Tamura, Keisuke, Tamura, Takayuki, Tanaka, Takaaki, Tanaka, Yasuo, Tanaka, Yasuyuki, Tashiro, Makoto, Tawara, Yuzuru, Terada, Yukikatsu, Terashima, Yuichi, Tombesi, Francesco, Tomida, Hiroshi, Tsuboi, Yohko, Tsujimoto, Masahiro, Tsunemi, Hiroshi, Tsuru, Takeshi, Uchida, Hiroyuki, Uchiyama, Hideki, Uchiyama, Yasunobu, Ueda, Shutaro, Ueda, Yoshihiro, Ueno, Shiro, Uno, Shin'ichiro, Urry, C. Meg, Ursino, Eugenio, de Vries, Cor P., Watanabe, Shin, Werner, Norbert, Wik, Daniel R., Wilkins, Dan R., Williams, Brian J., Yamada, Shinya, Yamaguchi, Hiroya, Yamaoka, Kazutaka, Yamasaki, Noriko Y., Yamauchi, Makoto, Yamauchi, Shigeo, Yaqoob, Tahir, Yatsu, Yoichi, Yonetoku, Daisuke, Yoshida, Atsumasa, Zhuravleva, Irina, Zoghbi, Abderahmen, Laboratoire AIM, Université Paris Diderot - Paris 7 ( UPD7 ) -Centre d'Etudes de Saclay, Hitomi, Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)
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galaxies: clusters: individual ,Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,galaxies: clusters: intracluster medium ,clusters: individual: A426 [galaxies] ,Astrophysics::High Energy Astrophysical Phenomena ,[ PHYS.ASTR ] Physics [physics]/Astrophysics [astro-ph] ,Dark matter ,FOS: Physical sciences ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,galaxies: clusters: individual (A426) ,01 natural sciences ,dark matter ,X-ray ,Settore FIS/05 - Astronomia e Astrofisica ,gas ,0103 physical sciences ,calorimeter ,Emission spectrum ,Spectroscopy ,010303 astronomy & astrophysics ,Galaxy cluster ,Astrophysics::Galaxy Astrophysics ,Line (formation) ,High Energy Astrophysical Phenomena (astro-ph.HE) ,Physics ,Nebula ,010308 nuclear & particles physics ,dark matter: decay ,Astronomy and Astrophysics ,charge exchange ,Astrophysics - Astrophysics of Galaxies ,K-line ,Galaxy ,flux ,Space and Planetary Science ,clusters: intracluster medium [galaxies] ,Astrophysics of Galaxies (astro-ph.GA) ,X-rays: galaxies: clusters ,galaxy: cluster ,galaxies: clusters [X-rays] ,Astrophysics - High Energy Astrophysical Phenomena ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] ,signature ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
High-resolution X-ray spectroscopy with Hitomi was expected to resolve the origin of the faint unidentified E=3.5 keV emission line reported in several low-resolution studies of various massive systems, such as galaxies and clusters, including the Perseus cluster. We have analyzed the Hitomi first-light observation of the Perseus cluster. The emission line expected for Perseus based on the XMM-Newton signal from the large cluster sample under the dark matter decay scenario is too faint to be detectable in the Hitomi data. However, the previously reported 3.5 keV flux from Perseus was anomalously high compared to the sample-based prediction. We find no unidentified line at the reported high flux level. Taking into account the XMM measurement uncertainties for this region, the inconsistency with Hitomi is at a 99% significance for a broad dark-matter line and at 99.7% for a narrow line from the gas. We do not find anomalously high fluxes of the nearby faint K line or the Ar satellite line that were proposed as explanations for the earlier 3.5 keV detections. We do find a hint of a broad excess near the energies of high-n transitions of Sxvi (E=3.44 keV rest-frame) -- a possible signature of charge exchange in the molecular nebula and another proposed explanation for the unidentified line. While its energy is consistent with XMM pn detections, it is unlikely to explain the MOS signal. A confirmation of this interesting feature has to wait for a more sensitive observation with a future calorimeter experiment., Discussion of systematics significantly expanded. 9 pages, 5 figures; ApJ Lett. in press
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- 2017
19. Detection of gamma rays of likely jet origin in Cygnus X-1
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Zanin, Roberta, Fernández-Barral, Alba, de Oña-Wilhelmi, Emma, Aharonian, Felix, Blanch, Oscar, Bosch-Ramon, Valentí, and Galindo, Daniel
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High Energy Astrophysical Phenomena (astro-ph.HE) ,Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences ,Astrophysics - High Energy Astrophysical Phenomena - Abstract
Aims: Probe the high-energy ($>$60 MeV) emission from the black hole X-ray binary system, Cygnus X-1, and investigate its origin. Methods: We analysed 7.5 yr of data by Fermi/LAT with the latest PASS8 software version. Results: We report the detection of a signal at $\sim$8 $\sigma$ statistical significance spatially coincident with Cygnus X-1 and a luminosity above 60 MeV of 5.5$\times$10$^{33}$ erg s$^{-1}$. The signal is correlated with the hard X-ray flux: the source is observed at high energies only during the hard X-ray spectral state, when the source is known to display persistent, relativistic radio emitting jets. The energy spectrum, extending up to $\sim$20 GeV without any sign of spectral break, is well fitted by a power-law function with a photon index of 2.3$\pm$0.2. There is a hint of orbital flux variability, with high-energy emission mostly coming around the superior conjunction. Conclusions: We detected GeV emission from Cygnus X-1 and probed that the emission is most likely associated with the relativistic jets. The evidence of flux orbital variability points to the anisotropic inverse Compton on stellar photons as the mechanism at work, thus constraining the emission region to a distance $10^{11}-10^{13}$ cm from the black hole., Comment: accepted A\&A (9 pages and 7 figures)
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- 2016
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20. On the GeV excess in the diffuse ��-ray emission towards the Galactic Center
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Yang, Rui-zhi and Aharonian, Felix
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High Energy Astrophysical Phenomena (astro-ph.HE) ,Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences - Abstract
The Fermi-LAT ��-ray data have been used to study the morphological and spectral features of the so-called GeV excess - a diffuse radiation component recently discovered towards the Galactic centre. We used the likelihood method to analyze Fermi-LAT data. Our study does confirm the existence of such an extra component in the diffuse ��-ray emission at GeV energies. Based on a detailed morphological analysis, a spatial template that fits the data best was generated and adopted. Using this template, the energy distribution of ��-rays was derived in the 0.3-30 GeV energy interval. The spectrum appeared to have less distinct ('bump'-like) structure than previous reported. We argue that the morphology of this radiation component has a bipolar rather than a spherically symmetric structure as has been assumed a priori in previous studies. This finding excludes the associations of the GeV excess with Dark Matter. We briefly discuss the radiation mechanisms and possible source populations that could be responsible for this new component of diffuse gamma radiation., 7 pages, 6 figures, to match the version published in A&A
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- 2016
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21. Detection of diffuse gamma-ray emission near the young massive cluster NGC 3603
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Yang, Rui-zhi and Aharonian, Felix
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High Energy Astrophysical Phenomena (astro-ph.HE) ,Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics::Solar and Stellar Astrophysics ,FOS: Physical sciences ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics - High Energy Astrophysical Phenomena ,Astrophysics::Galaxy Astrophysics - Abstract
We report the Fermi Large Area Telescope's detection of extended gamma-ray emission towards the direction of the young massive star cluster NGC 3603. The emission shows a hard spectrum with a photon index of 2.3 from 1 GeV to 250 GeV. The large size and high luminosity of this structure make it unlikely a pulsar wind nebular. On the other hand the spatial correlation with the ionised gas indicate a hadronic origin. The total cosmic ray (CR) protons energy are estimated to be of the order $10^{50} ~\rm erg$ assuming the gamma-ray are produced in the interaction of CRs with ambient gas . The environment and spectral features show significant similarity with the Cygnus cocoon. It reveals that the young star clusters may be a gamma-ray source population and they can potentially accelerate a significant fraction of the Galactic cosmic rays., Comment: 6 pages, 5 figures, submitted to A&A
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- 2016
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22. Indication of a Local 'Fog' of Sub-Ankle UHECR
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Liu, Ruo-Yu, Taylor, Andrew M., Wang, Xiang-Yu, and Aharonian, Felix A.
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High Energy Astrophysical Phenomena (astro-ph.HE) ,Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics::Instrumentation and Methods for Astrophysics ,FOS: Physical sciences ,Astrophysics - High Energy Astrophysical Phenomena - Abstract
During their propagation through intergalactic space, ultrahigh energy cosmic rays (UHECRs) interact with the background radiation fields. These interactions give rise to energetic electron/positron pairs and photons which in turn feed electromagnetic cascades, contributing to the isotropic gamma-ray background (IGRB). The gamma-ray flux level generated in this way highly depends upon the UHECR propagation distance, as well as the evolution of their sources with redshift. Recently, the Fermi-LAT collaboration reported that the majority of the total extragalactic gamma-ray flux originates from extragalactic point sources. This posits a stringent upper limit on the IGRB generated via UHECR propagation, and subsequently constrains their abundance in the distant Universe. Focusing on the contribution of UHECR at energies below the ankle within a narrow energy band ($(1-4)\times 10^{18}$eV), we calculate the diffuse gamma-ray flux generated through UHECR propagation, normalizing the total cosmic ray energy budget in this band to that measured. We find that in order to not over-produce the new IGRB limit, a local "fog" of UHECR produced by nearby sources may exist, with a possible non-negligible contribution from our Galaxy. Following the assumption that a given fraction of the observed IGRB at 820GeV originates from UHECR, we obtain a constraint on the maximum distance for the majority of their sources. With other unresolved source populations still contaminating the new IGRB limit, and UHECR above the ankle invariably contributing also to this background, the results presented here are rather conservative., Comment: 6 pages, 2 figures, comments are welcome; accepted by PRD
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- 2016
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23. Fast Variability of Nonthermal X-ray Emission in Cassiopeia A: Probing Electron Acceleration in Reverse-Shocked Ejecta
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Aharonian, Felix A. and Uchiyama, Yasunobu
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Physics ,Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics (astro-ph) ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics ,Synchrotron ,Spectral line ,law.invention ,Cassiopeia A ,Particle acceleration ,Supernova ,Space and Planetary Science ,law ,Ejecta ,Supernova remnant ,Equivalent width ,Astrophysics::Galaxy Astrophysics - Abstract
Recent discovery of the year-scale variability in the synchrotron X-ray emission of the supernova remnant (SNR) RX J1713.7-3946 has initiated our study of multi-epoch X-ray images and spectra of the young SNR Cassiopeia A based on the Chandra archive data taken in 2000, 2002, and 2004. We have found year-scale time variations in the X-ray intensity for a number of X-ray filaments or knots associated with the reverse-shocked regions. The X-ray spectra of the variable filaments are characterized by a featureless continuum, and described by a power law with a photon index within 1.9-2.3. The upper limits on the iron K-line equivalent width are 110 eV, which favors a synchrotron origin of the X-ray emission. The characteristic variability timescale of 4 yr can be explained by the effects of fast synchrotron cooling and diffusive shock acceleration with a plausible magnetic field of 1 mG. The X-ray variability provides a new effective way of studying particle acceleration at supernova shocks., 4 pages, 4 figures, accepted for publication in ApJ Letter
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- 2008
24. HESS reveals a lack of TeV emission from the supernova remnant Puppis A (Research Note)
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Abramowski, Attila, Aharonian, Felix A., Benkhali, Faical Ait, Akhperjanian, A. G., Angüner, Ekrem Oǧuzhan, Backes, Michael, Balenderan, Shangkari, Balzer, Arnim, Barnacka, Anna, Becherini, Yvonne, Tjus, J. Becker, Berge, David, Bernhard, Sabrina, Bernlöhr, K., Birsin, E., Biteau, Jonathan, Boettcher, Markus, Boisson, Catherine, Bolmont, J., Bordas, Pol, Bregeon, Johan, Brun, Francois, Brun, Pierre, Bryan, Mark, Bulik, Tomasz, Carrigan, Svenja, Casanova, Sabrina, Chadwick, Paula M., Chakraborty, N., Chalme-Calvet, R., Chaves, Ryan C. G., Chretien, M., Colafrancesco, Sergio, Cologna, Gabriele, Conrad, Jan, Couturier, C., Cui, Y., Davids, I. D., Degrange, B., Deil, C., deWilt, P., Djannati-Ataï, A., Domainko, W., Donath, A., Dubus, G., Dutson, K., Dyks, J., Dyrda, M., Edwards, T., Egberts, Kathrin, Eger, P., Espigat, P., Farnier, C., Fegan, S., Feinstein, F., Fernandes, M. V., Fernandez, D., Fiasson, A., Fontaine, G., Foerster, A., Füssling, Matthias, Gabici, S., Gajdus, M., Gallant, Y. A., Garrigoux, T., Giavitto, G., Giebels, B., Glicenstein, J. F., Gottschall, D., Grondin, M. -H., Grudzinska, M., Hadasch, D., Haeffner, S., Hahn, J., Harris, J., Heinzelmann, G., Henri, G., Hermann, G., Hervet, O., Hillert, A., Hinton, James Anthony, Hofmann, W., Hofverberg, P., Holler, Maraike, Horns, D., Ivascenko, A., Jacholkowska, A., Jahn, C., Jamrozy, M., Janiak, M., Jankowsky, F., Jung-Richardt, I., Kastendieck, M. A., Katarzynski, K., Katz, U., Kaufmann, S., Khelifi, B., Kieffer, M., Klepser, S., Klochkov, D., Kluzniak, W., Kolitzus, D., Komin, Nu., Kosack, K., Krakau, S., Krayzel, F., Krueger, P. P., Laffon, H., Lamanna, G., Lefaucheur, J., Lefranc, V., Lemiere, A., Lemoine-Goumard, M., Lenain, J. -P., Lohse, T., Lopatin, A., Lu, C. -C., Marandon, V., Marcowith, A., Marx, R., Maurin, G., Maxted, N., Mayer, Michael, McComb, T. J. L., Mehault, J., Meintjes, P. J., Menzler, U., Meyer, M., Mitchell, A. M. W., Moderski, R., Mohamed, M., Mora, K., Moulin, E., Murach, T., de Naurois, M., Niemiec, J., Nolan, S. J., Oakes, L., Odaka, H., Ohm, S., Opitz, B., Ostrowski, M., Oya, I., Panter, M., Parsons, R. D., Arribas, M. Paz, Pekeur, N. W., Pelletier, G., Petrucci, P. -O, Peyaud, B., Pita, S., Poon, H., Puehlhofer, G., Punch, M., Quirrenbach, A., Raab, S., Reichardt, I., Reimer, A., Reimer, O., Renaud, M., de los Reyes, R., Rieger, F., Romoli, C., Rosier-Lees, S., Rowell, G., Rudak, B., Rulten, C. B., Sahakian, V., Salek, D., Sanchez, David M., Santangelo, A., Schlickeiser, R., Schuessler, F., Schulz, A., Schwanke, U., Schwarzburg, S., Schwemmer, S., Sol, H., Spanier, F., Spengler, G., Spies, F., Stawarz, L., Steenkamp, R., Stegmann, Christian, Stinzing, F., Stycz, K., Sushch, Iurii, Tavernet, J. -P., Tavernier, T., Taylor, A. M., Terrier, R., Tluczykont, M., Trichard, C., Valerius, K., van Eldik, C., van Soelen, B., Vasileiadis, G., Veh, J., Venter, C., Viana, A., Vincent, P., Vink, J., Voelk, H. J., Volpe, F., Vorster, M., Vuillaume, T., Wagner, S. J., Wagner, P., Wagner, R. M., Ward, M., Weidinger, M., Weitzel, Q., White, R., Wierzcholska, A., Willmann, P., Woernlein, A., Wouters, D., Yang, R., Zabalza, V., Zaborov, D., Zacharias, M., Zdziarski, A. A., Zech, A., and Zechlin, H. -S.
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Astrophysics::High Energy Astrophysical Phenomena ,Institut für Physik und Astronomie - Abstract
Context. Puppis A is an interesting similar to 4 kyr-old supernova remnant (SNR) that shows strong evidence of interaction between the forward shock and a molecular cloud. It has been studied in detail from radio frequencies to high-energy (HE, 0.1-100 GeV) gamma-rays. An analysis of the Fermi-LAT data has shown extended HE gamma-ray emission with a 0.2-100 GeV spectrum exhibiting no significant deviation from a power law, unlike most of the GeV-emitting SNRs known to be interacting with molecular clouds. This makes it a promising target for imaging atmospheric Cherenkov telescopes (IACTs) to probe the gamma-ray emission above 100 GeV. Aims. Very-high-energy (VHE, E >= 0.1 TeV) gamma-ray emission from Puppis A has been, for the first time, searched for with the High Energy Stereoscopic System (HESS.). Methods. Stereoscopic imaging of Cherenkov radiation from extensive air showers is used to reconstruct the direction and energy of the incident gamma-rays in order to produce sky images and source spectra. The profile likelihood method is applied to find constraints on the existence of a potential break or cutoff in the photon spectrum. Results. The analysis of the HESS. data does not reveal any significant emission towards Puppis A. The derived upper limits on the differential photon flux imply that its broadband gamma-ray spectrum must exhibit a spectral break or cutoff. By combining Fermi-LAT and HESS. measurements, the 99% confidence-level upper limits on such a cutoff are found to be 450 and 280 GeV, assuming a power law with a simple exponential and a sub-exponential cutoff, respectively. It is concluded that none of the standard limitations (age, size, radiative losses) on the particle acceleration mechanism, assumed to be continuing at present, can explain the lack of VHE signal. The scenario in which particle acceleration has ceased some time ago is considered as an alternative explanation. The HE/VHE spectrum of Puppis A could then exhibit a break of non-radiative origin (as observed in several other interacting SNRs, albeit at somewhat higher energies), owing to the interaction with dense and neutral material, in particular towards the NE region.
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- 2015
25. A dense gas survey of the gamma-ray sources HESS J1731-347 and HESS J1729-345
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Maxted, Nigel, Rowell, Gavin, de Wilt, Phoebe, Burton, Michael, Renaud, Matthieu, Fukui, Yasuo, Hawkes, Jarryd, Blackwell, Rebecca, Voisin, Fabien, Lowe, Vicki, and Aharonian, Felix
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High Energy Astrophysical Phenomena (astro-ph.HE) ,Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics - High Energy Astrophysical Phenomena ,Astrophysics::Galaxy Astrophysics - Abstract
The results of Mopra molecular spectral line observations towards the supernova remnant HESSJ1731-347 (G353.6-0.7) and the unidentified gamma-ray source HESSJ1729-345 are presented. Dense molecular gas in three different velocity-bands (corresponding to three Galactic arms) are investigated using the CS(1-0) line. The CS-traced component provides information about the dense target material in a hadronic scenario for gamma-ray production (cosmic rays interacting with gas) and an understanding of the dynamics. Furthermore, the effects of cosmic ray diffusion into dense gas may alter the gamma-ray spectrum to cause a flattening of spectra towards such regions. Dense molecular gas mass at a level of ~10^5 Mo was revealed in this survey, with mass of the order of ~10^3 Mo towards HESSJ1729-345 in each coincident Galactic arm, but no significant detection of dense molecular gas towards HESSJ1731-347 at the currently-preferred distance of ~5.2-6.2 kpc was discovered., Comment: Accepted for the Proceedings of Science (PoS). Cosmic Rays and the Interstellar Medium (CRISM) Conference 2014. 6 pages and 1 figure
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- 2015
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26. Search for extended gamma-ray emission around AGN with HESS and Fermi-LAT
- Author
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Abramowski, Attila, Aharonian, Felix A., Benkhali, Faical Ait, Akhperjanian, A. G., Angüner, Ekrem Oǧuzhan, Anton, Gisela, Backes, Michael, Balenderan, Shangkari, Balzer, Arnim, Barnacka, Anna, Becherini, Yvonne, Tjus, J. Becker, Bernlöhr, K., Birsin, E., Bissaldi, E., Biteau, Jonathan, Boettcher, Markus, Boisson, Catherine, Bolmont, J., Bordas, Pol, Brucker, J., Brun, Francois, Brun, Pierre, Bulik, Tomasz, Carrigan, Svenja, Casanova, Sabrina, Chadwick, Paula M., Chalme-Calvet, R., Chaves, Ryan C. G., Cheesebrough, A., Chretien, M., Colafrancesco, Sergio, Cologna, Gabriele, Conrad, Jan, Couturier, C., Cui, Y., Djannati-Ataï, A., Domainko, W., Dubus, G., Dutson, K., Dyks, J., Dyrda, M., Edwards, T., Egberts, Kathrin, Eger, P., Espigat, P., Farnier, C., Fegan, S., Feinstein, F., Fernandes, M. V., Fernandez, D., Fiasson, A., Fontaine, G., Foerster, A., Fussling, Matthias, Gajdus, M., Gallant, Y. A., Garrigoux, T., Giavitto, G., Giebels, B., Glicenstein, J. F., Grondin, M. -H., Grudzinska, M., Haeffner, S., Hahn, J., Harris, J., Heinzelmann, G., Henri, G., Hermann, G., Hervet, O., Hillert, A., Hinton, James Anthony, Hofmann, W., Hofverberg, P., Holler, M., Horns, D., Jacholkowska, A., Jahn, C., Jamrozy, M., Janiak, M., Jankowsky, F., Jung, I., Kastendieck, M. A., Katarzynski, K., Katz, U., Kaufmann, S., Khelifi, B., Kieffer, M., Klepser, S., Klochkov, D., Kluzniak, W., Kneiske, T., Kolitzus, D., Komin, Nu., Kosack, K., Krakau, S., Krayzel, F., Krueger, P. P., Laffon, H., Lamanna, G., Lefaucheur, J., Lemiere, A., Lemoine-Goumard, M., Lenain, J. -P., Lohse, T., Lopatin, A., Lu, C. -C., Marandon, V., Marcowith, A., Marx, R., Maurin, G., Maxted, N., Mayer, M., McComb, T. J. L., Mehault, J., Meintjes, P. J., Menzler, U., Meyer, M., Moderski, R., Mohamed, M., Moulin, E., Murach, T., Naumann, C. L., de Naurois, M., Niemiec, J., Nolan, S. J., Oakes, L., Odaka, H., Ohm, S., Wilhelmi, E. de Ona, Opitz, B., Ostrowski, M., Oya, I., Panter, M., Parsons, R. D., Arribas, M. Paz, Pekeur, N. W., Pelletier, G., Perez, J., Petrucci, P. -O., Peyaud, B., Pita, S., Poon, H., Puehlhofer, G., Punch, M., Quirrenbach, A., Raab, S., Raue, M., Reichardt, I., Reimer, A., Reimer, O., Renaud, M., Reyes, R. de los, Rieger, F., Rob, L., Romoli, C., Rosier-Lees, S., Rowell, G., Rudak, B., Rulten, C. B., Sahakian, V., Sanchez, David M., Santangelo, A., Schlickeiser, R., Schuessler, F., Schulz, A., Schwanke, U., Schwarzburg, S., Schwemmer, S., Sol, H., Spengler, G., Spies, F., Stawarz, L., Steenkamp, R., Stegmann, Christian, Stinzing, F., Stycz, K., Sushch, Iurii, Tavernet, J. -P., Tavernier, T., Taylor, A. M., Terrier, R., Tluczykont, M., Trichard, C., Valerius, K., van Eldik, C., van Soelen, B., Vasileiadis, G., Venter, C., Viana, A., Vincent, P., Voelk, H. J., Volpe, F., Vorster, M., Vuillaume, T., Wagner, S. J., Wagner, P., Wagner, R. M., Ward, M., Weidinger, M., Weitzel, Q., White, R., Wierzcholska, A., Willmann, P., Woernlein, A., Wouters, D., Yang, R., Zabalza, V., Zacharias, M., Zdziarski, A. A., Zech, A., Zechlin, H. -S., and Malyshev, D.
- Subjects
Astrophysics::High Energy Astrophysical Phenomena ,Institut für Physik und Astronomie ,Astrophysics::Cosmology and Extragalactic Astrophysics - Abstract
Context. Very-high-energy (VHE; E > 100 GeV) gamma-ray emission from blazars inevitably gives rise to electron-positron pair production through the interaction of these gamma-rays with the extragalactic background light (EBL). Depending on the magnetic fields in the proximity of the source, the cascade initiated from pair production can result in either an isotropic halo around an initially- beamed source or a magnetically- broadened cascade :aux. Aims. Both extended pair-halo (PH) and magnetically broadened cascade (MBC) emission from regions surrounding the blazars 1ES 1101-232, IRS 0229+200, and PKS 2155-304 were searched for using VHE y-ray data taken with the High Energy Stereoscopic System (HESS.) and high-energy (HE; 100 MeV < E < 100 GeV) gamma-ray data with the Fermi Large Area Telescope (LAT). Methods. By comparing the angular distributions of the reconstructed gamma-ray events to the angular profiles calculated from detailed theoretical models, the presence of PH and MBC was investigated. Results. Upper limits on the extended emission around lES 1101-232, lES 0229+200, and PKS 2155-304 are found to be at a level of a few per cent of the Crab nebula flux above 1 TeV, depending on the assumed photon index of the cascade emission. Assuming strong extra-Galactic magnetic field (EGME) values, >10(-12) G, this limits the production of pair haloes developing from electromagnetic cascades. For weaker magnetic fields, in which electromagnetic cascades would result in MBCs. EGMF strengths in the range (0.3-3) x 10(-15) G were excluded for PKS 2155-304 at the 99% confidence level, under the assumption of a 1 Mpc coherence length.
- Published
- 2014
27. TeV Astronomy
- Author
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Rieger, Frank M., de Ona-Wilhelmi, Emma, and Aharonian, Felix A.
- Subjects
Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics::Instrumentation and Methods for Astrophysics ,Astrophysics - High Energy Astrophysical Phenomena - Abstract
With the successful realization of the current-generation of ground-based detectors, TeV Astronomy has entered into a new era. We review recent advances in VHE astronomy, focusing on the potential of Imaging Atmospheric Cherenkov Telescopes (IACTs), and highlight astrophysical implications of the results obtained within recent years., Comment: Invited review article to appear in the special issue of "Frontiers of Physics" on "High Energy Astrophysics" (eds. B. Zhang & P. Meszaros); review, 33 pages, 23 figures, 305 references
- Published
- 2013
28. TeV Astronomy
- Author
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Rieger, Frank M., de Ona-Wilhelmi, Emma, and Aharonian, Felix A.
- Subjects
High Energy Astrophysical Phenomena (astro-ph.HE) ,Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics::Instrumentation and Methods for Astrophysics ,FOS: Physical sciences - Abstract
With the successful realization of the current-generation of ground-based detectors, TeV Astronomy has entered into a new era. We review recent advances in VHE astronomy, focusing on the potential of Imaging Atmospheric Cherenkov Telescopes (IACTs), and highlight astrophysical implications of the results obtained within recent years., Invited review article to appear in the special issue of "Frontiers of Physics" on "High Energy Astrophysics" (eds. B. Zhang & P. Meszaros); review, 33 pages, 23 figures, 305 references
- Published
- 2013
- Full Text
- View/download PDF
29. Discovery of very high energy γ -ray emission from the BL Lacertae object PKS 0301−243 with H.E.S.S
- Author
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Abramowski, Attila, Acero, F., Aharonian, Felix A., Benkhali, Faical Ait, Akhperjanian, A. G., Angüner, Ekrem Oǧuzhan, Anton, Gisela, Balenderan, Shangkari, Balzer, Arnim, Barnacka, Anna, Becherini, Yvonne, Tjus, J. Becker, Bernlöhr, K., Birsin, E., Bissaldi, E., Biteau, Jonathan, Boettcher, Markus, Boisson, Catherine, Bolmont, J., Bordas, Pol, Brucker, J., Brun, Francois, Brun, Pierre, Bulik, Tomasz, Carrigan, Svenja, Casanova, Sabrina, Cerruti, M., Chadwick, Paula M., Chalme-Calvet, R., Chaves, Ryan C. G., Cheesebrough, A., Chretien, M., Colafrancesco, Sergio, Cologna, Gabriele, Conrad, Jan, Couturier, C., Dalton, M., Daniel, M. K., Davids, I. D., Degrange, B., Deil, C., deWilt, P., Dickinson, H. J., Djannati-Ataï, A., Domainko, W., Drury, L. O&rsquo, Dubus, G., Dutson, K., Dyks, J., Dyrda, M., Edwards, T., Egberts, Kathrin, Eger, P., Espigat, P., Farnier, C., Fegan, S., Feinstein, F., Fernandes, M. V., Fernandez, D., Fiasson, A., Fontaine, G., Foerster, A., Fuessling, M., Gajdus, M., Gallant, Y. A., Garrigoux, T., Giebels, B., Glicenstein, J. F., Grondin, M. -H., Grudzinska, M., Haeffner, S., Hague, J. D., Hahn, J., Harris, J., Heinzelmann, G., Henri, G., Hermann, G., Hervet, O., Hillert, A., Hinton, James Anthony, Hofmann, W., Hofverberg, P., Holler, M., Horns, D., Jacholkowska, A., Jahn, C., Jamrozy, M., Janiak, M., Jankowsky, F., Jung, I., Kastendieck, M. A., Katarzynski, K., Katz, U., Kaufmann, S., Khelifi, B., Kieffer, M., Klepser, S., Klochkov, D., Kluzniak, W., Kneiske, T., Kolitzus, D., Komin, Nu., Kosack, K., Krakau, S., Krayzel, F., Krueger, P. P., Laffon, H., Lamanna, G., Lefaucheur, J., Lemoine-Goumard, M., Lenain, J. -P., Lennarz, D., Lohse, T., Lopatin, A., Lu, C. -C., Marandon, V., Marcowith, A., Marx, R., Maurin, G., Maxted, N., Mayer, M., McComb, T. J. L., Medina, M. C., Mehault, J., Menzler, U., Meyer, M., Moderski, R., Mohamed, M., Moulin, E., Murach, T., Naumann, C. L., de Naurois, M., Nedbal, D., Niemiec, J., Nolan, S. J., Oakes, L., Ohm, S., Wilhelmi, E. de Ona, Opitz, B., Ostrowski, M., Oya, I., Panter, M., Parsons, R. D., Arribas, M. Paz, Pekeur, N. W., Pelletier, G., Perez, J., Petrucci, P. -O., Peyaud, B., Pita, S., Poon, H., Puehlhofer, G., Punch, M., Quirrenbach, A., Raab, S., Raue, M., Reimer, A., Reimer, O., Renaud, M., de los Reyes, R., Rieger, F., Rob, L., Rosier-Lees, S., Rowell, G., Rudak, B., Rulten, C. B., Sahakian, V., Sanchez, David M., Santangelo, A., Schlickeiser, R., Schuessler, F., Schulz, A., Schwanke, U., Schwarzburg, S., Schwemmer, S., Sol, H., Spengler, G., Spies, F., Stawarz, L., Steenkamp, R., Stegmann, Christian, Stinzing, F., Stycz, K., Sushch, Iurii, Szostek, A., Tavernet, J. -P., Terrier, R., Tluczykont, M., Trichard, C., Valerius, K., van Eldik, C., Vasileiadis, G., Venter, C., Viana, A., Vincent, P., Voelk, H. J., Volpe, F., Vorster, M., Wagner, S. J., Wagner, P., Ward, M., Weidinger, M., Weitzel, Q., White, R., Wierzcholska, A., Willmann, P., Woernlein, A., Wouters, D., Zacharias, M., Zajczyk, A., Zdziarski, A. A., Zech, A., Zechlin, H. -S., 12006653 - Venter, Christo, 11005394 - Krüger, Petrus Paulus, 22050574 - Pekeur, Nicolette Whilna, 24420530 - Böttcher, Markus, 23909196 - Casanova, Sabrina, 24922986 - Sushch, Iurii, 12792322 - Vorster, Michael Johannes, A., Abramowski, F., Acero, F., Aharonian, F. A., Benkhali, A. G., Akhperjanian, E., Anguener, G., Anton, S., Balenderan, A., Balzer, A., Barnacka, Y., Becherini, J. B., Tju, K., Bernloehr, E., Birsin, Bissaldi, Elisabetta, J., Biteau, M., Boettcher, C., Boisson, J., Bolmont, P., Borda, J., Brucker, F., Brun, P., Brun, T., Bulik, S., Carrigan, S., Casanova, M., Cerruti, P. M., Chadwick, R., Chalme Calvet, R. C., G., A., Cheesebrough, M., Chretien, S., Colafrancesco, G., Cologna, J., Conrad, C., Couturier, M., Dalton, M. K., Daniel, I. D., David, B., Degrange, C., Deil, P., Dewilt, H. J., Dickinson, A., Djannati Atai, W., Domainko, L. O., '., G., Dubu, K., Dutson, J., Dyk, M., Dyrda, T., Edward, K., Egbert, P., Eger, P., Espigat, C., Farnier, S., Fegan, F., Feinstein, M. V., Fernande, D., Fernandez, A., Fiasson, G., Fontaine, A., Foerster, M., Fuessling, M., Gajdu, Y. A., Gallant, T., Garrigoux, B., Giebel, J. F., Glicenstein, M. . ., H., M., Grudzinska, S., Haeffner, J. D., Hague, J., Hahn, J., Harri, G., Heinzelmann, G., Henri, G., Hermann, O., Hervet, A., Hillert, J. A., Hinton, W., Hofmann, P., Hofverberg, M., Holler, D., Horn, A., Jacholkowska, C., Jahn, M., Jamrozy, M., Janiak, F., Jankowsky, I., Jung, M. A., Kastendieck, K., Katarzynski, U., Katz, S., Kaufmann, B., Khelifi, M., Kieffer, S., Klepser, D., Klochkov, W., Kluzniak, T., Kneiske, D., Kolitzu, N., Komin, K., Kosack, S., Krakau, F., Krayzel, P. P., Krueger, H., Laffon, G., Lamanna, J., Lefaucheur, M., Lemoine Goumard, J. . ., P., D., Lennarz, T., Lohse, A., Lopatin, C. . ., C., V., Marandon, A., Marcowith, R., Marx, G., Maurin, N., Maxted, M., Mayer, T. J., L., M. C., Medina, J., Mehault, U., Menzler, M., Meyer, R., Moderski, M., Mohamed, E., Moulin, T., Murach, C. L., Naumann, M. d., Nauroi, D., Nedbal, J., Niemiec, S. J., Nolan, L., Oake, S., Ohm, E. d., Ona, B., Opitz, M., Ostrowski, I., Oya, M., Panter, R. D., Parson, M. P., Arriba, N. W., Pekeur, G., Pelletier, J., Perez, P. . ., O., B., Peyaud, S., Pita, H., Poon, G., Puehlhofer, M., Punch, A., Quirrenbach, S., Raab, M., Raue, A., Reimer, O., Reimer, M., Renaud, R. d., Lo, F., Rieger, L., Rob, S., Rosier Lee, G., Rowell, B., Rudak, C. B., Rulten, V., Sahakian, D. A., Sanchez, A., Santangelo, R., Schlickeiser, F., Schuessler, A., Schulz, U., Schwanke, S., Schwarzburg, S., Schwemmer, H., Sol, G., Spengler, F., Spie, L., Stawarz, R., Steenkamp, C., Stegmann, F., Stinzing, K., Stycz, I., Sushch, A., Szostek, R., Terrier, M., Tluczykont, C., Trichard, K., Valeriu, C. v., Eldik, G., Vasileiadi, C., Venter, A., Viana, P., Vincent, H. J., Voelk, F., Volpe, M., Vorster, S. J., Wagner, P., Wagner, M., Ward, M., Weidinger, Q., Weitzel, R., White, A., Wierzcholska, P., Willmann, A., Woernlein, D., Wouter, M., Zacharia, A., Zajczyk, A. A., Zdziarski, A., Zech, H. . ., S., AstroParticule et Cosmologie (APC (UMR_7164)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7), 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 de Physique Nucléaire et de Hautes Énergies (LPNHE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), H.E.S.S. Collaboration, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Univers et Théories (LUTH (UMR_8102)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), 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), and Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Pierre et Marie Curie - Paris 6 (UPMC)
- Subjects
Active galactic nucleus ,active [Galaxies] ,Opacity ,Ciencias Físicas ,Astrophysics::High Energy Astrophysical Phenomena ,galaxies: active ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics ,7. Clean energy ,01 natural sciences ,non-thermal. [Radiation mechanisms] ,purl.org/becyt/ford/1 [https] ,Gamma ray galaxies ,BL Lacertae objects: individual: PKS 0301-243 ,gamma rays: galaxies ,0103 physical sciences ,Radiation mechanisms ,galaxie [gamma rays] ,individual: PKS 0301-243 [BL Lacertae objects] ,High Energy Stereoscopic System ,010303 astronomy & astrophysics ,BL Lacertae objects: general ,Galaxies: active ,Gamma rays: galaxies ,Radiation mechanisms: non-thermal ,PKS 0301-243 (objeto BL Lacertae) ,Non thermal mechanisms ,Physics ,general [BL Lacertae objects] ,010308 nuclear & particles physics ,Gamma ray ,Astronomy and Astrophysics ,purl.org/becyt/ford/1.3 [https] ,radiation mechanisms: non-thermal ,non-thermal [radiation mechanisms] ,Light curve ,Redshift ,Astronomía ,Extragalactic background light ,13. Climate action ,Space and Planetary Science ,galaxies [gamma rays] ,Active galaxies ,BL Lacertae objects ,ddc:520 ,High Energy Physics::Experiment ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] ,CIENCIAS NATURALES Y EXACTAS ,BL Lac object - Abstract
The active galactic nucleus PKS 0301−243 (z = 0.266) is a high-synchrotron-peaked BL Lac object that is detected at high energies (HE, 100 MeV 100 GeV) by the High Energy Stereoscopic System (H.E.S.S.) from observations between September 2009 and December 2011 for a total live time of 34.9 h. Gamma rays above 200 GeV are detected at a significance of 9.4σ. A hint of variability at the 2.5σ level is found. An integral flux I(E > 200 GeV) = (3.3 ± 1.1stat ± 0.7syst) × 10-12 ph cm-2 s-1 and a photon index Γ = 4.6 ± 0.7stat ± 0.2syst are measured. Multi-wavelength light curves in HE, X-ray and optical bands show strong variability, and a minimal variability timescale of eight days is estimated from the optical light curve. A single-zone leptonic synchrotron self-Compton scenario satisfactorily reproduces the multi-wavelength data. In this model, the emitting region is out of equipartition and the jet is particle dominated. Because of its high redshift compared to other sources observed at TeV energies, the very high energy emission from PKS 0301−243 is attenuated by the extragalactic background light (EBL) and the measured spectrum is used to derive an upper limit on the opacity of the EBL. Fil: Abramowski, A.. Universitat Hamburg; Alemania Fil: Acero, F.. Universite Montpellier II; Francia Fil: Aharonian, F.. Max Planck Institut für Kernphysik; Alemania Fil: Benkhali, F. Ait. Max Planck Institut für Kernphysik; Alemania Fil: Akhperjanian, A. G.. National Academy of Sciences of the Republic of Armenia; Armenia Fil: Medina, Maria Clementina. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomia; Argentina Fil: Valerius, K.. Universität Erlangen Nürnberg; Alemania Fil: van Eldik, C.. Universität Erlangen Nürnberg; Alemania Fil: Vasileiadis, G.. Universite Montpellier II; Francia Fil: Venter, C.. North West University; Sudáfrica Fil: Viana, A.. Max Planck Institut für Kernphysik; Alemania Fil: Vincent, P.. Université Paris Diderot - Paris 7; Francia Fil: Völk, H. J.. Max Planck Institut für Kernphysik; Alemania Fil: Volpe, F.. Max Planck Institut für Kernphysik; Alemania Fil: Vorster, M.. North West University; Sudáfrica Fil: Wagner, S. J.. Universität Heidelberg; Alemania Fil: Wagner, P.. Humboldt Universität zu Berlin; Alemania Fil: Ward, M.. University Of Durham; Reino Unido Fil: Weidinger, M.. Ruhr-universität Bochum; Alemania Fil: Weitzel, Q.. Max Planck Institut für Kernphysik; Alemania Fil: White, R.. The University of Leicester; Reino Unido Fil: Wierzcholska, A.. Uniwersytet Jagiellonski; Polonia Fil: Willmann, P.. Universität Erlangen Nürnberg; Alemania Fil: Wörnlein, A.. Universität Erlangen Nürnberg; Alemania Fil: Wouters, D.. CEA Saclay; Francia Fil: Zacharias, M.. Ruhr-universität Bochum; Alemania Fil: Zajczyk, A.. Universite Montpellier II; Francia Fil: Zdziarski, A. A.. Nicolaus Copernicus Astronomical Center; Polonia Fil: Zech, A.. Université Paris Diderot - Paris 7; Francia Fil: Zechlin, H. S.. Universitat Hamburg; Alemania
- Published
- 2013
30. Nuclear reactions in hot astrophysical plasmas with $T>10^{10}$ K
- Author
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Kafexhiu, Ervin, Aharonian, Felix, and Vila, Gabriela
- Subjects
Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences ,Solar and Stellar Astrophysics (astro-ph.SR) - Abstract
The importance of nuclear reactions in low-density astrophysical plasmas with ion temperatures $T \geq 10^{10}$ K has been recognized for more than thirty years. However, the lack of comprehensive data banks of relevant nuclear reactions and the limited computational power have not previously allowed detailed theoretical studies. Recent developments in these areas make it timely to conduct comprehensive studies on the nuclear properties of very hot plasmas formed around compact relativistic objects such as black holes and neutron stars. Such studies are of great interest in the context of scientific programs of future low-energy cosmic $��$-ray spectrometry. In this work, using the publicly available code TALYS, we have built a large nuclear network relevant for temperatures exceeding $10^{10}$ K. We have studied the evolution of the chemical composition and accompanying prompt gamma-ray emission of such high temperature plasmas. We present the results on the abundances of light elements D, T, $^3$He, $^4$He, $^{6}$Li, $^{7}$Li $^{9}$Be, $^{10}$B, $^{11}$B, and briefly discuss their implications on the astrophysical abundances of these elements., 39 pages, 26 figures
- Published
- 2012
- Full Text
- View/download PDF
31. X-Ray Diagnostics of Giant Molecular Clouds in the Galactic Center Region and Past Activity of Sgr A*
- Author
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Aharonian, Felix, Khangulyan, Dmitry, Odaka, Hirokazu, Watanabe, Shin, Tanaka, Yasuyuki, and Takahashi, Tadayuki
- Subjects
High Energy Astrophysical Phenomena (astro-ph.HE) ,Physics ,Supermassive black hole ,Photon ,Astrophysics::High Energy Astrophysical Phenomena ,Molecular cloud ,Galactic Center ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics ,Astrophysics - Astrophysics of Galaxies ,Galaxy ,Spectral line ,Luminosity ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,Astrophysics - High Energy Astrophysical Phenomena ,Astrophysics::Galaxy Astrophysics ,Line (formation) - Abstract
Strong iron fluorescence at 6.4 keV and hard-X-ray emissions from giant molecular clouds in the Galactic center region have been interpreted as reflections of a past outburst of the Sgr A* supermassive black hole. Careful treatment of multiple interactions of photons in a complicated geometry is essential to modeling the reprocessed emissions from the dense clouds. We develop a new calculation framework of X-ray reflection from molecular clouds based on Monte Carlo simulations for accurate interpretation of high-quality observational data. By utilizing this simulation framework, we present the first calculations of morphologies and spectra of the reflected X-ray emission for several realistic models of Sgr B2, which is the most massive molecular cloud in our Galaxy. The morphology of scattered hard X-rays above 20 keV is significantly different from that of iron fluorescence due to their large penetrating power into dense regions of the cloud, probing the structure of the cloud. High-resolution spectra provide quantitative evaluation of the iron line including its Compton shoulder to constrain the mass and the chemical composition of the cloud as well as the luminosity of the illuminating source. These predictions can be checked in the near future with future X-ray missions such as NuStar (hard X-rays) and ASTRO-H (both iron lines and hard X-rays)., 28 pages, 15 figures, accepted for publications in ApJ
- Published
- 2011
32. Post-Periastron Gamma Ray Flare from PSR B1259-63/LS 2883 as a Result of Comptonization of the Cold Pulsar Wind
- Author
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Khangulyan, Dmitry, Aharonian, Felix A., Bogovalov, Sergey V., and Ribo, Marc
- Subjects
Physics ,High Energy Astrophysical Phenomena (astro-ph.HE) ,Astrophysics::High Energy Astrophysical Phenomena ,Gamma ray ,Flux ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics ,Binary pulsar ,Luminosity ,law.invention ,Lorentz factor ,symbols.namesake ,Pulsar ,Space and Planetary Science ,law ,symbols ,Astrophysics::Solar and Stellar Astrophysics ,Astrophysics - High Energy Astrophysical Phenomena ,Astrophysics::Galaxy Astrophysics ,Fermi Gamma-ray Space Telescope ,Flare - Abstract
We argue that the bright flare of the binary pulsar \object{PSR B1259$-$63/LS2883} detected by the {\it Fermi} Large Area Telescope (LAT), is due to the inverse Compton (IC) scattering of the unshocked electron-positron pulsar wind with a Lorentz factor $\Gamma_0 \approx 10^4$. The combination of two effects both linked to the circumstellar disk (CD), is a key element in the proposed model. The first effect is related to the impact of the surrounding medium on the termination of the pulsar wind. Inside the disk, the "early" termination of the wind results in suppression of its gamma-ray luminosity. When the pulsar escapes the disk, the conditions for termination of the wind undergo significant changes. This would lead to a dramatic increase of the pulsar wind zone, and thus to the proportional increase of the gamma-ray flux. On the other hand, if the parts of the CD disturbed by the pulsar can supply infrared photons of density high enough for efficient Comptonization of the wind, almost the entire kinetic energy of the pulsar wind would be converted to radiation, thus the gamma-ray luminosity of the wind could approach to the level of the pulsar's spin-down luminosity as reported by the {\it Fermi} collaboration., Comment: 14 pages, 4 figures
- Published
- 2011
33. The need for a local source of UHE CR nuclei
- Author
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Taylor, Andrew M., Ahlers, Markus, and Aharonian, Felix A.
- Subjects
High Energy Astrophysical Phenomena (astro-ph.HE) ,Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics::Instrumentation and Methods for Astrophysics ,FOS: Physical sciences ,Astrophysics - High Energy Astrophysical Phenomena - Abstract
Recent results of the Pierre Auger (Auger) fluorescence detectors indicate an increasingly heavy composition of ultra-high energy (UHE) cosmic rays (CRs). Assuming that this trend continues up to the highest energies observed by the Auger surface detectors we derive the constraints this places on the local source distribution of UHE CR nuclei. Utilizing an analytic description of UHE CR propagation we derive the expected spectra and composition for a wide range of source emission spectra. We find that sources of intermediate-to-heavy nuclei are consistent with the observed spectra and composition data above the ankle. This consistency requires the presence of nearby sources within 60 Mpc and 80 Mpc for silicon and iron only sources, respectively. The necessity of these local sources becomes even more compelling in the presence nano-Gauss local extragalactic magnetic fields., 10 pages, 8 figures
- Published
- 2011
34. Astrophysical Parameters of LS 2883 and Implications for the PSR B1259-63 Gamma-Ray Binary
- Author
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Negueruela, Ignacio, Ribo, Marc, Herrero, Artemio, Lorenzo, Javier, Khangulyan, Dmitry, Aharonian, Felix A., Universidad de Alicante. Departamento de Física, Ingeniería de Sistemas y Teoría de la Señal, and Astrofísica Estelar (AE)
- Subjects
Be star ,Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences ,Binary number ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics ,Luminosity ,Pulsar ,Astrophysics::Solar and Stellar Astrophysics ,Binary system ,Astrophysics::Galaxy Astrophysics ,individual (PSR B1259-63) [Pulsars] ,individual (LS 2883) [Stars] ,Astronomía y Astrofísica ,High Energy Astrophysical Phenomena (astro-ph.HE) ,Physics ,Gamma ray ,stars [Gamma rays] ,Astronomy and Astrophysics ,Particle acceleration ,Stars ,Space and Planetary Science ,emission-line, Be [Stars] ,binaries [X-rays] ,Astrophysics::Earth and Planetary Astrophysics ,Astrophysics - High Energy Astrophysical Phenomena ,close [Binaries] - Abstract
Only a few binary systems with compact objects display TeV emission. The physical properties of the companion stars represent basic input to understand the physical mechanisms behind the particle acceleration, emission, and absorption processes in these so-called gamma-ray binaries. Here we present high-resolution and high signal-to-noise optical spectra of LS2883, the Be star forming a gamma-ray binary with the young non-accreting pulsar PSR B1259-63, showing it to rotate faster and be significantly earlier and more luminous than previously thought. Analysis of the interstellar lines suggest that the system is located at the same distance as (and thus is likely a member of) CenOB1. Taking the distance to the association, d=2.3kpc, and a color excess of E(B-V)=0.85 for LS2883, results in Mv=-4.4. Because of fast rotation, LS2883 is oblate (R_eq=9.7R_sun and R_pole=8.1R_sun) and presents a temperature gradient (T_eq=27500K, log g_eq=3.7; T_pole=34000K, log g_pole=4.1). If the star did not rotate, it would have parameters corresponding to a late O-type star. We estimate its luminosity at log(L*/L_sun)=4.79, and its mass at M=30M_sun. The mass function then implies an inclination of the binary system i_orb=23deg,slightly smaller than previous estimates. We discuss the implications of these new astrophysical parameters of LS2883 for the production of high energy and very high energy gamma rays in the PSR B1259-63/LS2883 gamma-ray binary system. In particular, the stellar properties are very important for prediction of the line-like bulk Comptonization component from the unshocked ultra-relativistic pulsar wind., Accepted for publication in ApJL
- Published
- 2011
35. Wild at Heart: The Particle Astrophysics of the Galactic Centre
- Author
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Crocker, Roland M., Jones, David I., Aharonian, Felix, Law, Casey J., Melia, Fulvio, Oka, Tomoharu, and Ott, Juergen
- Subjects
High Energy Astrophysical Phenomena (astro-ph.HE) ,Astrophysics of Galaxies (astro-ph.GA) ,Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics - High Energy Astrophysical Phenomena ,Astrophysics - Astrophysics of Galaxies ,Astrophysics::Galaxy Astrophysics - Abstract
We treat of the high-energy astrophysics of the inner ~200 pc of the Galaxy. Our modelling of this region shows that the supernovae exploding here every few thousand years inject enough power to i) sustain the steady-state, in situ population of cosmic rays (CRs) required to generate the region's non-thermal radio and TeV ��-ray emis-sion; ii) drive a powerful wind that advects non-thermal particles out of the inner GC; iii) supply the low-energy CRs whose Coulombic collisions sustain the temperature and ionization rate of the anomalously warm, envelope H2 detected throughout the Cen-tral Molecular Zone; iv) accelerate the primary electrons which provide the extended, non-thermal radio emission seen over ~150 pc scales above and below the plane (the Galactic centre lobe); and v) accelerate the primary protons and heavier ions which, advected to very large scales (up to ~10 kpc), generate the recently-identified WMAP haze and corresponding Fermi haze/bubbles. Our modelling bounds the average magnetic field amplitude in the inner few degrees of the Galaxy to the range 60 < B/microG < 400 (at 2 sigma confidence) and shows that even TeV CRs likely do not have time to penetrate into the cores of the region's dense molecular clouds before the wind removes them from the region. This latter finding apparently disfavours scenarios in which CRs - in this star-burst-like environment - act to substantially modify the conditions of star-formation. We speculate that the wind we identify plays a crucial role in advecting low-energy positrons from the Galactic nucleus into the bulge, thereby explaining the extended morphology of the 511 keV line emission. (abridged), One figure corrected. Accepted for publication in MNRAS. 29 pages, 14 figures
- Published
- 2011
36. Gamma-Rays and the Far-Infrared-Radio Continuum Correlation Reveal a Powerful Galactic Centre Wind
- Author
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Crocker, Roland M., Jones, David I., Aharonian, Felix, Law, Casey J., Melia, Fulvio, and Ott, Juergen
- Subjects
High Energy Astrophysical Phenomena (astro-ph.HE) ,Astrophysics of Galaxies (astro-ph.GA) ,Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics - High Energy Astrophysical Phenomena ,Astrophysics - Astrophysics of Galaxies ,Astrophysics::Galaxy Astrophysics - Abstract
We consider the thermal and non-thermal emission from the inner 200 pc of the Galaxy. The radiation from this almost star-burst-like region is ultimately driven dominantly by on-going massive star formation. We show that this region's radio continuum (RC) emission is in relative deficit with respect to the expectation afforded by the Far- infrared-Radio Continuum Correlation (FRC). Likewise we show that the region's gamma-ray emission falls short of that expected given its star formation and resultant supernova rates. These facts are compellingly explained by positing that a powerful (400-1200 km/s) wind is launched from the region. This wind probably plays a number of important roles including advecting positrons into the Galactic bulge thus explaining the observed ~kpc extension of the 511 keV positron annihilation signal around the GC. We also show that the large-scale GC magnetic field falls in the range ~100-300 microG and that - in the time they remain in the region - GC cosmic rays do not penetrate into the region's densest molecular material., Comment: Version accepted for publication in MNRAS Letters. Discussion extended and references added
- Published
- 2011
37. Gamma-ray flares from red giant/jet interactions in AGN
- Author
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Barkov, Maxim V., Aharonian, Felix A., and Bosch-Ramon, Valenti
- Subjects
High Energy Astrophysical Phenomena (astro-ph.HE) ,Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences ,Astrophysics::Solar and Stellar Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics - High Energy Astrophysical Phenomena ,Astrophysics::Galaxy Astrophysics - Abstract
Non-blazar AGN have been recently established as a class of gamma-ray sources. M87, a nearby representative of this class, show fast TeV variability on timescales of a few days. We suggest a scenario of flare gamma-ray emission in non-blazar AGN based on a red giant interacting with the jet at the base. We solve the hydrodynamical equations that describe the evolution of the envelope of a red giant blown by the impact of the jet. If the red giant is at least slightly tidally disrupted by the supermassive black hole, enough stellar material will be blown by the jet, expanding quickly until a significant part of the jet is shocked. This process can render suitable conditions for energy dissipation and proton acceleration, which could explain the detected day-scale TeV flares from M87 via proton-proton collisions. Since the produced radiation would be unbeamed, such an events should be mostly detected from non-blazar AGN. They may be frequent phenomena, detectable in the GeV-TeV range even up to distances of $\sim 1$ Gpc for the most powerful jets. The counterparts at lower energies are expected to be not too bright.} {M87, and nearby non-blazar AGN in general, can be fast variable sources of gamma-rays through red giant/jet interactions., 8 pages, 4 figures
- Published
- 2010
38. The Spectral Shape and Photon Fraction as Signatures of the GZK-Cutoff
- Author
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Taylor, Andrew M. and Aharonian, Felix A.
- Subjects
Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics (astro-ph) ,FOS: Physical sciences ,Astrophysics - Abstract
With the prospect of measuring the fraction of arriving secondary photons, produced through photo-pion energy loss interactions of ultra high energy cosmic ray (UHECR) protons with the microwave background during propagation, we investigate how information about the local UHECR source distribution can be inferred from the primary (proton) to secondary (photon) ratio. As an aid to achieve this, we develop an analytic description for both particle populations as a function of propagation time. Through a consideration of the shape of the GZK cut-off and the corresponding photon fraction curve, we investigate the different results expected for both different maximum proton energies injected by the sources, as well as a change in the local source distribution following a perturbative deformation away from a homogeneous description. At the end of the paper, consideration is made as to how these results are modified through extra-galactic magnetic field effects on proton propagation. The paper aims to demonstrate how the shape of the cosmic ray flux in the cut-off region, along with the photon fraction, are useful indicators of the cutoff origin as well as the local UHECR source distribution., Comment: Accepted for publication in PRD, 12 pages, 9 figures
- Published
- 2008
- Full Text
- View/download PDF
39. On the formation of TeV radiation in LS 5039
- Author
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Khangulyan, Dmitry, Aharonian, Felix, and Bosch-Ramon, Valenti
- Subjects
Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics - Abstract
The recent detections of TeV gamma-rays from compact binary systems show that relativistic outflows (jets or winds) are sites of effective acceleration of particles up to multi-TeV energies. In this paper, we discuss the conditions of acceleration and radiation of ultra-relativistic electrons in LS 5039, the gamma-ray emitting binary system for which the highest quality TeV data are available. Assuming that the gamma-ray emitter is a jet-like structure, we performed detailed numerical calculations of the energy spectrum and lightcurves accounting for the acceleration efficiency, the location of the accelerator, the speed of the emitting flow, the inclination angle of the system, as well as specific features related to anisotropic inverse Compton scattering and pair production. We conclude that the accelerator should not be deep inside the binary system unless we assume a very efficient acceleration rate. We show that within the IC scenario both the gamma-ray spectrum and flux are strongly orbital phase dependent. Formally, our model can reproduce, for specific sets of parameter values, the energy spectrum of gamma-rays reported by HESS for wide orbital phase intervals. However, the physical properties of the source can be constrained only by observations capable of providing detailed energy spectra for narrow orbital phase intervals ($\Delta\phi\ll 0.1$)., Comment: 14 pages, 26 figures, accepted for publication in MNRAS, submitted on July 11, 2007
- Published
- 2007
40. On the formation of TeV radiation in LS 5039
- Author
-
Khangulyan, Dmitry, Aharonian, Felix, and Bosch-Ramon, Valenti
- Subjects
Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics (astro-ph) ,FOS: Physical sciences - Abstract
The recent detections of TeV gamma-rays from compact binary systems show that relativistic outflows (jets or winds) are sites of effective acceleration of particles up to multi-TeV energies. In this paper, we discuss the conditions of acceleration and radiation of ultra-relativistic electrons in LS 5039, the gamma-ray emitting binary system for which the highest quality TeV data are available. Assuming that the gamma-ray emitter is a jet-like structure, we performed detailed numerical calculations of the energy spectrum and lightcurves accounting for the acceleration efficiency, the location of the accelerator, the speed of the emitting flow, the inclination angle of the system, as well as specific features related to anisotropic inverse Compton scattering and pair production. We conclude that the accelerator should not be deep inside the binary system unless we assume a very efficient acceleration rate. We show that within the IC scenario both the gamma-ray spectrum and flux are strongly orbital phase dependent. Formally, our model can reproduce, for specific sets of parameter values, the energy spectrum of gamma-rays reported by HESS for wide orbital phase intervals. However, the physical properties of the source can be constrained only by observations capable of providing detailed energy spectra for narrow orbital phase intervals ($����\ll 0.1$)., 14 pages, 26 figures, accepted for publication in MNRAS, submitted on July 11, 2007
- Published
- 2007
- Full Text
- View/download PDF
41. TeV lightcurve of PSR B1259-63/SS2883
- Author
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Khangulyan, Dmitry, Hnatic, Slavomir, Aharonian, Felix, and Bogovalov, Sergey
- Subjects
Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics - Abstract
The inverse Compton scattering of ultrarelativistic electrons accelerated at the pulsar wind termination shock is believed to be responsible for TeV gamma-ray signal recently reported from the binary system PSR B1259-63/SS2883. While this process can explain the energy spectrum of the observed TeV emission, the detected gamma-ray fluxes do not agree with the published theoretical predictions of the TeV lightcurve. The main objective of this paper is to show that the HESS results can be explained, under certain reasonable assumptions, by inverse Compton scenarios of gamma-ray production in the system. In this paper we study evolution of the energy spectra of relativistic electrons under different assumptions about the acceleration and energy-loss rates of electrons, and the impact of these processes on the lightcurve of IC gamma-rays. We demonstrate that the observed TeV lightcurve can be explained (i) by adiabatic losses which dominate over the entire trajectory of the pulsar with a significant increase towards the periastron, or (ii) by the sub-TeV cutoffs in the energy spectra of electrons due to the enhanced rate of Compton losses close to the periastron. The Compton deceleration of the pulsar wind contributes to the decrease of the nonthermal power released in the accelerated electrons, and thus to the reduction of the IC and synchrotron components of radiation close to the periastron. Although this effect alone cannot explain the observed lightcurves, the Comptonization of the pulsar wind leads to the formation of gamma-radiation with a line-type energy spectrum. While the HESS data already constrain the Lorentz factor of the wind, $\Gamma \le 10^6$, future observations of this object with GLAST should allow a deep probe of the wind Lorentz factor in the range between $10^4$ and $10^6$., Comment: 13 pages, 19 figures, accepted for publication in MNRAS
- Published
- 2006
42. TeV lightcurve of PSR B1259-63/SS2883
- Author
-
Khangulyan, Dmitry, Hnatic, Slavomir, Aharonian, Felix, and Bogovalov, Sergey
- Subjects
Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics (astro-ph) ,FOS: Physical sciences - Abstract
The inverse Compton scattering of ultrarelativistic electrons accelerated at the pulsar wind termination shock is believed to be responsible for TeV gamma-ray signal recently reported from the binary system PSR B1259-63/SS2883. While this process can explain the energy spectrum of the observed TeV emission, the detected gamma-ray fluxes do not agree with the published theoretical predictions of the TeV lightcurve. The main objective of this paper is to show that the HESS results can be explained, under certain reasonable assumptions, by inverse Compton scenarios of gamma-ray production in the system. In this paper we study evolution of the energy spectra of relativistic electrons under different assumptions about the acceleration and energy-loss rates of electrons, and the impact of these processes on the lightcurve of IC gamma-rays. We demonstrate that the observed TeV lightcurve can be explained (i) by adiabatic losses which dominate over the entire trajectory of the pulsar with a significant increase towards the periastron, or (ii) by the sub-TeV cutoffs in the energy spectra of electrons due to the enhanced rate of Compton losses close to the periastron. The Compton deceleration of the pulsar wind contributes to the decrease of the nonthermal power released in the accelerated electrons, and thus to the reduction of the IC and synchrotron components of radiation close to the periastron. Although this effect alone cannot explain the observed lightcurves, the Comptonization of the pulsar wind leads to the formation of gamma-radiation with a line-type energy spectrum. While the HESS data already constrain the Lorentz factor of the wind, $��\le 10^6$, future observations of this object with GLAST should allow a deep probe of the wind Lorentz factor in the range between $10^4$ and $10^6$., 13 pages, 19 figures, accepted for publication in MNRAS
- Published
- 2006
- Full Text
- View/download PDF
43. Hard X-ray and Gamma-ray Emission Induced by Ultra-High Energy Protons in Cluster Accretion Shocks and their Detectability
- Author
-
Inoue, Susumu, Aharonian, Felix A., and Sugiyama, Naoshi
- Subjects
Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics (astro-ph) ,FOS: Physical sciences ,Physics::Accelerator Physics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics ,Astrophysics::Galaxy Astrophysics - Abstract
Protons can be plausibly accelerated to $\sim 10^{18}$-$10^{19}$ eV in strong accretion shocks surrounding massive clusters of galaxies. Such protons efficiently produce very high energy pairs through interactions with the CMB, which then radiate synchrotron and inverse Compton emission with hard spectra, peaking respectively in hard X-rays and TeV gamma-rays. We discuss the prospects for detecting this emission from nearby clusters with current and future facilities such as HESS and NeXT, which should provide a clear signature of ultra-high energy proton acceleration and an important probe of magnetic fields in the outermost regions of clusters., To appear in the proceedings of "Rencontres de Moriond: Very High Energy Phenomena in the Universe", La Thuile, Italy (March 12-19, 2005)
- Published
- 2005
44. Next generation of IACT arrays: scientific objectives versus energy domains
- Author
-
Aharonian, Felix
- Subjects
Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics (astro-ph) ,FOS: Physical sciences ,High Energy Physics::Experiment ,Astrophysics ,Nuclear Experiment - Abstract
Several key motivations and perspectives of ground based gamma-ray astronomy are discussed in the context of the specifics of detection techniques and scientific topics/objectives relevant to four major energy domains -- very-low or \textit{multi-GeV} ($E \leq$ 30 GeV), low or \textit{sub-TeV} (30 GeV - 300 GeV), high or \textit{TeV} (300 GeV - 30 TeV), and very-high or \textit{sub-PeV} ($E \geq$ 30 TeV) intervals -- to be covered by the next generation of IACT arrays., Comment: 14 pages, Invited talk at the Conference "Towards a Network of Atmospheric Cherenkov Detectors VII", 2005, Palaiseau, France
- Published
- 2005
- Full Text
- View/download PDF
45. Time Dependent Modeling of the Markarian 501 X-ray and TeV Gamma-Ray Data Taken During March and April, 1997
- Author
-
Krawczynski, Henric, Coppi, Paolo S., and Aharonian, Felix
- Subjects
Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics (astro-ph) ,FOS: Physical sciences ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics - Abstract
If the high-energy emission from TeV blazars is produced by the Synchrotron Self-Compton (SSC) mechanism, then simultaneous X-ray and Gamma-ray observations of these objects are a powerful probe of the electron (and/or positron) populations responsible for this emission. Understanding the emitting particle distributions and their evolution in turn allow us to probe physical conditions in the inner blazar jet and test, for example, various acceleration scenarios. By constraining the SSC emission model parameters, such observations also allow us to predict the intrinsic (unabsorbed) Gamma-ray spectra of these sources, a major uncertainty in current attempts to use the observed Gamma-ray spectra to constrain the intensity of the extragalactic background at optical/infrared wavelengths. As a next step in testing the SSC model and as a demonstration of the potential power of coordinated X-ray and Gamma-ray observations, we attempt to model in detail the X-ray and Gamma-ray light curves of the TeV Blazar Mrk 501 during its April-May 1997 outburst using a time dependent SSC emission model. Extensive, quasi-simultaneous X-ray and gamma-ray coverage exists for this period. We discuss and explore quantitatively several of the flare scenarios presented in the literature. We show that simple two-component models (with a soft, steady X-ray component plus a variable SSC component) involving substantial pre-acceleration of electrons to Lorentz factors on the order of 1E+5 describe the data train surprisingly well. All considered models imply an emission region that is strongly out of equipartition and low radiative efficiencies (ratio between kinetic jet luminosity and comoving radiative luminosity) of 1 per-mill and less., 16 pages, Refereed Manuscript. Minor changes to previous version
- Published
- 2002
46. Flat Spectrum X-ray Emission from the Direction of a Molecular Cloud Associated with SNR RX J1713.7-3946
- Author
-
Aharonian, Felix A., Uchiyama, Yasunobu, and Takahashi, Tadayuki
- Subjects
Physics ,Photon ,Turbulence ,Molecular cloud ,Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics (astro-ph) ,Bremsstrahlung ,FOS: Physical sciences ,Astronomy and Astrophysics ,Plasma ,Astrophysics ,Electron ,Kinetic energy ,Space and Planetary Science ,Mechanical energy ,Astrophysics::Galaxy Astrophysics - Abstract
We report on the discovery of a hard X-ray source with ASCA from a molecular cloud in the vicinity of the SNR RX J1713.7-3946. The energy spectrum (1--10 keV) shows a flat continuum which is described by a power-law with photon index 1.0 +-0.4. We argue that this unusually flat spectrum can be best interpreted in terms of characteristic bremsstrahlung emission from the ionization-loss-flattened distribution of either sub-relativistic protons or mildly-relativistic electrons. The strong shock of the SNR RX J1713.7-3946, which presumably interacts with the molecular cloud, as evidenced by observations of CO-lines, seems to be a natural site of acceleration of such sub- or mildly-relativistic nonthermal particles. However, the observed X-ray luminosity of 1.7 10^35 erg/s (for 6 kpc distance) requires that a huge kinetic energy of about 10^50 erg be released in the form of nonthermal particles to illuminate the cloud. The shock-acceleration at RX J1713.7-3946 can barely satisfy this energetic requirement, unless (i) the source is located much closer than 6 kpc and/or (ii) the mechanical energy of the explosion essentially exceeds 10^51 erg. Another possibility would be that an essential part of the "lost" energy is somehow converted to plasma waves, which return this energy to nonthermal particles through their turbulent reacceleration on plasma waves. Irrespective of mechanisms responsible for production of high-energy particles, the flat X-ray emission seems to be a signature of a new striking energetic phenomenon in molecular clouds., Comment: 6 pages, 2 figures, Accepted for publication in PASJ
- Published
- 2002
- Full Text
- View/download PDF
47. Transient phenomena in the high energy sky
- Author
-
Romoli, Carlo, Aharonian, Felix, Taylor, Andrew M., and Chernyakova, Masha
- Subjects
Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics ,Astrophysics::Galaxy Astrophysics - Abstract
In this thesis I explore some of the brightest transient phenomena we observe in the highnenergy sky. I consider some of the observational difficulties we encounter in studying these highly variable sources, in particular the importance of the level of photon statistics, especially in the difficult region that sits between 10 and 100 GeV, where we have the overlap between the energy domain of space telescopes and the energy range more suited to ground-based Cherenkov telescopes. The specific sources I study here belong to various classes of gamma-ray emitters: Active Galactic Nuclei (AGN), compact binaries, and powerful flare events in the Sun's magnetosphere. The first chapter provides an introduction to the field of high energy gamma-ray astronomy. There, I cover the basic gamma-ray emission mechanisms and give an overview of the sources that I have investigated as well as a description of the telescopes and instruments involved in my gamma-ray observations of these sources. The second and third chapters discuss the work I have done together with colleagues in the H.E.S.S. Collaboration to enable the delivery of the first results from phase II of H.E.S.S. for two bright AGNs and the gamma-ray binary PSR B1259-63. The fourth chapter covers my work on analysing the gamma-ray emission from solar flares in order to put constraints on hadronic models of the are emission. The fifth chapter discusses the evidence for multiple components in the high energy spectrum of the blazar AGN called Mrk 501. The sixth chapter highlights the importance of the study of the cut-off region in bright gamma-ray sources detected by the Fermi- LAT, investigating also the possible improvements that will be brought about by the next generation of ground-based gamma-ray telescopes. Finally, the conclusions summarise my findings and explore future perspectives in the field.
- Published
- 2018
48. X-ray/γ-ray correlation in Seyfert 2 galaxy NGC 4945
- Author
-
Andrzej Niedźwiecki, Rafal Wojaczynski, Aharonian, Felix A., Hofmann, Werner, Rieger, Frank M., Uniwersytet Łódzki, and rafal.wojaczynski@wp.pl
- Subjects
Physics ,Luminous infrared galaxy ,Spectral index ,Astrophysics::High Energy Astrophysical Phenomena ,Astronomy ,Cosmic ray ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics ,non-thermal [radiation mechanisms] ,Galaxy ,individual (NGC 4945) ,Hubble sequence ,Interstellar medium ,symbols.namesake ,Seyfert [galaxies] ,starburst galaxies ,galaxies [gamma rays] ,symbols ,Circinus ,Astrophysics::Galaxy Astrophysics ,Dwarf galaxy - Abstract
We report the correlation between the X-ray and γ-ray emission found in our analysis of the Fermi/LAT and Swift/BAT data from 8 years of observations of the nearby Seyfert 2 galaxy NGC 4945. Using the BAT light-curves we determined summed periods of low and high X-ray flux and we found that the average γ-ray spectrum is harder in the latter (higher X-ray flux level), with the difference of the γ-ray spectral index of ~0.4. The correlation indicates that the γ-rays are produced in the active nucleus of this Seyfert galaxy rather than by cosmic rays interacting with the interstellar medium (as assumed in the alternative starburst model). We compare NGC 4945 with two other γ-ray loud galaxies showing both starburst and AGN activities, NGC 1068 and Circinus. ETIUDA doctoral grant DEC-2016/20/T/ST9/00386, OPUS grant DEC-2016/21/B/ST9/02388
- Published
- 2017
49. High energy radiation from jets and accretion disks near rotating black holes
- Author
-
Asaf Pe'er, Jonathan C. McKinney, Michael O'Riordan, Aharonian, Felix A., Hofmann, Werner, and Rieger, Frank M.
- Subjects
Physics ,Radiation ,Black hole ,Astrophysics::High Energy Astrophysical Phenomena ,Science and engineering ,Astronomy ,Astrophysics ,Emission ,Computing center ,Computational astrophysics ,Spin ,Accretion disc ,Research council ,Pleiades ,Radiofrequency radiation - Abstract
We model the low/hard state in X-ray binaries as a magnetically arrested accretion flow, and calculate the resulting radiation using a general-relativistic radiative transport code. Firstly, we investigate the origin of the high-energy emission. We find the following indications of a significant jet contribution at high energies: (i) a pronounced γ-ray peak at ∼ 1023 Hz, (ii) a break in the optical/UV band where the spectrum changes from disk to jet dominated, and (iii) a low-frequency synchrotron peak ≲ 1014 Hz implies that a significant fraction of any observed X-ray and γ-ray emission originates in the jet. Secondly, we investigate the effects of black hole spin on the high-energy emission. We find that the X-ray and γ-ray power depend strongly on spin and inclination angle. Surprisingly, this dependence is not a result of the Blandford-Znajek mechanism, but instead can be understood as a redshift effect. For rapidly rotating black holes, observers with large inclinations see deeper into the hot, dense, highly-magnetized inner regions of the accretion flow. Since the lower frequency emission originates at larger radii, it is not significantly affected by the spin. Therefore, the ratio of the X-ray to near-infrared power is an observational probe of black hole spin.
- Published
- 2017
50. The most distant cosmological explosion
- Author
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Poonam Chandra, Dale A. Frail, Derek Fox, S. R. Kulkarni, Edo Berger, S. Bradley Cenko, Douglas C.-J. Bock, Fiona Harrison, Mansi Kasliwal, Felix A. Aharonian, Werner Hofmann, Frank M. Rieger, Aharonian, Felix A., Hofmann, Werner, and Rieger, Frank M.
- Subjects
Physics ,Brightness ,education.field_of_study ,Infrared ,Astrophysics::High Energy Astrophysical Phenomena ,Population ,Astronomy ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Redshift survey ,Redshift ,Afterglow ,GRB 090423 ,education ,Stellar evolution ,Astrophysics::Galaxy Astrophysics - Abstract
At a redshift of 8.3 GRB 090423 marks the highest known redshift object in the Universe. By combining our radio measurements with existing X‐ray and infrared observations, we estimated the kinetic energy of the afterglow, the geometry of the outflow and the density of the circumburst medium. Our best fit model is a quasi‐spherical, high‐energy explosion in a low, constant‐density medium. We compare the properties of GRB 090423 with a sample of GRBs at moderate redshifts. We find that the high energy and afterglow properties of GRB 090423 are not sufficiently different from other GRBs to suggest a different kind of progenitor, such as a Population III star. However, we argue that it is not clear that the afterglow properties alone can provide convincing identification of Population III progenitors. We suggest that the millimeter and centimeter radio detections of GRB 090423 at early times contained emission from a reverse shock component. This has important implications for the detection of high redshift GRBs by the next generation of radio facilities.
- Published
- 2011
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