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  1. Book ; Online: Validating Monte Carlo simulations for an analysis chain in H.E.S.S

    Leuschner, Fabian / Schäfer, Johannes / Steinmassl, Simon / Holch, Tim Lukas / Bernlöhr, Konrad / Funk, Stefan / Hinton, Jim / Ohm, Stefan / Pühlhofer, Gerd

    2023  

    Abstract: Imaging Air Cherenkov Telescopes (IACTs) detect very high energetic (VHE) gamma rays. They observe the Cherenkov light emitted in electromagnetic shower cascades that gamma rays induce in the atmosphere. A precise reconstruction of the primary photon ... ...

    Abstract Imaging Air Cherenkov Telescopes (IACTs) detect very high energetic (VHE) gamma rays. They observe the Cherenkov light emitted in electromagnetic shower cascades that gamma rays induce in the atmosphere. A precise reconstruction of the primary photon energy and the source flux depends heavily on accurate Monte Carlo (MC) simulations of the shower propagation and the detector response, and therefore also on adequate assumptions about the atmosphere at the site and time of a measurement. Here, we present the results of an extensive validation of the MC simulations for an analysis chain of the H.E.S.S. experiment with special focus on the recently installed FlashCam camera on the large 28 m telescope. One goal of this work was to create a flexible and easy-to-use framework to facilitate the detailed validation of MC simulations also for past and future phases of the H.E.S.S. experiment. Guided by the underlying physics, the detector simulation and the atmospheric transmission profiles were gradually improved until low level parameters such as cosmic ray (CR) trigger rates matched within a few percent between simulations and observational data. This led to instrument response functions (IRFs) with which the analysis of current H.E.S.S. data can ultimately be carried out within percent accuracy, substantially improving earlier simulations.

    Comment: 8 pages, 4 figures, 1 table. Accepted as Proceeding of the 7th Heidelberg International Symposium on High-Energy Gamma-Ray Astronomy (Gamma2022)
    Keywords Astrophysics - Instrumentation and Methods for Astrophysics ; Astrophysics - High Energy Astrophysical Phenomena
    Subject code 612
    Publishing date 2023-03-01
    Publishing country us
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  2. Article ; Online: Acceleration and transport of relativistic electrons in the jets of the microquasar SS 433.

    Aharonian, F / Benkhali, F Ait / Aschersleben, J / Ashkar, H / Backes, M / Martins, V Barbosa / Batzofin, R / Becherini, Y / Berge, D / Bernlöhr, K / Bi, B / Böttcher, M / Boisson, C / Bolmont, J / de Lavergne, M de Bony / Borowska, J / Bouyahiaoui, M / Breuhaus, M / Brose, R /
    Brown, A M / Brun, F / Bruno, B / Bulik, T / Burger-Scheidlin, C / Caroff, S / Casanova, S / Cecil, R / Celic, J / Cerruti, M / Chand, T / Chandra, S / Chen, A / Chibueze, J / Chibueze, O / Cotter, G / Dai, S / Mbarubucyeye, J Damascene / Djannati-Ataï, A / Dmytriiev, A / Doroshenko, V / Egberts, K / Einecke, S / Ernenwein, J-P / Filipovic, M / Fontaine, G / Füßling, M / Funk, S / Gabici, S / Ghafourizadeh, S / Giavitto, G / Glawion, D / Glicenstein, J-F / Grolleron, G / Haerer, L / Hinton, J A / Hofmann, W / Holch, T L / Holler, M / Horns, D / Jamrozy, M / Jankowsky, F / Jardin-Blicq, A / Joshi, V / Jung-Richardt, I / Kasai, E / Katarzyński, K / Khatoon, R / Khélifi, B / Klepser, S / Kluźniak, W / Komin, Nu / Kosack, K / Kostunin, D / Kundu, A / Lang, R G / Le Stum, S / Leitl, F / Lemière, A / Lenain, J-P / Leuschner, F / Lohse, T / Luashvili, A / Lypova, I / Mackey, J / Malyshev, D / Marandon, V / Marchegiani, P / Marcowith, A / Martí-Devesa, G / Marx, R / Mehta, A / Mitchell, A / Moderski, R / Mohrmann, L / Montanari, A / Moulin, E / Murach, T / Nakashima, K / de Naurois, M / Niemiec, J / Noel, A Priyana / Ohm, S / Olivera-Nieto, L / de Ona Wilhelmi, E / Ostrowski, M / Panny, S / Panter, M / Parsons, R D / Peron, G / Prokhorov, D A / Pühlhofer, G / Punch, M / Quirrenbach, A / Reichherzer, P / Reimer, A / Reimer, O / Ren, H / Renaud, M / Reville, B / Rieger, F / Rowell, G / Rudak, B / Ricarte, H Rueda / Ruiz-Velasco, E / Sahakian, V / Salzmann, H / Santangelo, A / Sasaki, M / Schäfer, J / Schüssler, F / Schwanke, U / Shapopi, J N S / Sol, H / Specovius, A / Spencer, S / Stawarz, L / Steenkamp, R / Steinmassl, S / Steppa, C / Streil, K / Sushch, I / Suzuki, H / Takahashi, T / Tanaka, T / Taylor, A M / Terrier, R / Tsirou, M / Tsuji, N / Unbehaun, T / van Eldik, C / Vecchi, M / Veh, J / Venter, C / Vink, J / Wach, T / Wagner, S J / Werner, F / White, R / Wierzcholska, A / Wong, Yu Wun / Zacharias, M / Zargaryan, D / Zdziarski, A A / Zech, A / Zouari, S / Żywucka, N

    Science (New York, N.Y.)

    2024  Volume 383, Issue 6681, Page(s) 402–406

    Abstract: SS 433 is a microquasar, a stellar binary system that launches collimated relativistic jets. We observed SS 433 in gamma rays using the High Energy Stereoscopic System (H.E.S.S.) and found an energy-dependent shift in the apparent position of the gamma- ... ...

    Abstract SS 433 is a microquasar, a stellar binary system that launches collimated relativistic jets. We observed SS 433 in gamma rays using the High Energy Stereoscopic System (H.E.S.S.) and found an energy-dependent shift in the apparent position of the gamma-ray emission from the parsec-scale jets. These observations trace the energetic electron population and indicate that inverse Compton scattering is the emission mechanism of the gamma rays. Our modeling of the energy-dependent gamma-ray morphology constrains the location of particle acceleration and requires an abrupt deceleration of the jet flow. We infer the presence of shocks on either side of the binary system, at distances of 25 to 30 parsecs, and that self-collimation of the precessing jets forms the shocks, which then efficiently accelerate electrons.
    Language English
    Publishing date 2024-01-25
    Publishing country United States
    Document type Journal Article
    ZDB-ID 128410-1
    ISSN 1095-9203 ; 0036-8075
    ISSN (online) 1095-9203
    ISSN 0036-8075
    DOI 10.1126/science.adi2048
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: Search for Dark Matter Annihilation Signals in the H.E.S.S. Inner Galaxy Survey.

    Abdalla, H / Aharonian, F / Benkhali, F Ait / Angüner, E O / Armand, C / Ashkar, H / Backes, M / Baghmanyan, V / Martins, V Barbosa / Batzofin, R / Becherini, Y / Berge, D / Bernlöhr, K / Bi, B / Böttcher, M / Bolmont, J / de Lavergne, M de Bony / Brose, R / Brun, F /
    Cangemi, F / Caroff, S / Cerruti, M / Chand, T / Chen, A / Cotter, G / Mbarubucyeye, J Damascene / Devin, J / Djannati-Ataï, A / Dmytriiev, A / Doroshenko, V / Egberts, K / Fiasson, A / de Clairfontaine, G Fichet / Fontaine, G / Funk, S / Gabici, S / Giavitto, G / Glawion, D / Glicenstein, J F / Grondin, M-H / Hinton, J A / Hofmann, W / Holch, T L / Holler, M / Horns, D / Huang, Zhiqiu / Jamrozy, M / Jankowsky, F / Kasai, E / Katarzyński, K / Katz, U / Khélifi, B / Kluźniak, W / Komin, Nu / Kosack, K / Kostunin, D / Lamanna, G / Lemoine-Goumard, M / Lenain, J-P / Leuschner, F / Lohse, T / Luashvili, A / Lypova, I / Mackey, J / Malyshev, D / Marandon, V / Marchegiani, P / Martí-Devesa, G / Marx, R / Maurin, G / Meyer, M / Mitchell, A / Moderski, R / Montanari, A / Moulin, E / Muller, J / de Naurois, M / Niemiec, J / Noel, A Priyana / Ohm, S / Olivera-Nieto, L / Wilhelmi, E de Ona / Ostrowski, M / Panny, S / Panter, M / Parsons, R D / Peron, G / Poireau, V / Prokoph, H / Pühlhofer, G / Punch, M / Quirrenbach, A / Reichherzer, P / Reimer, A / Reimer, O / Renaud, M / Rieger, F / Rowell, G / Rudak, B / Ricarte, H Rueda / Ruiz-Velasco, E / Sahakian, V / Salzmann, H / Santangelo, A / Sasaki, M / Schüssler, F / Schutte, H M / Schwanke, U / Senniappan, M / Shapopi, J N S / Sol, H / Specovius, A / Spencer, S / Stawarz, Ł / Stegmann, C / Steinmassl, S / Steppa, C / Takahashi, T / Tanaka, T / Terrier, R / Thorpe-Morgan, C / Tluczykont, M / Tsirou, M / Tsuji, N / Uchiyama, Y / van Eldik, C / Veh, J / Vink, J / Wagner, S J / White, R / Wierzcholska, A / Wong, Yu Wun / Zacharias, M / Zargaryan, D / Zdziarski, A A / Zech, A / Zhu, S J / Zouari, S / Żywucka, N

    Physical review letters

    2022  Volume 129, Issue 11, Page(s) 111101

    Abstract: The central region of the Milky Way is one of the foremost locations to look for dark matter (DM) signatures. We report the first results on a search for DM particle annihilation signals using new observations from an unprecedented γ-ray survey of the ... ...

    Abstract The central region of the Milky Way is one of the foremost locations to look for dark matter (DM) signatures. We report the first results on a search for DM particle annihilation signals using new observations from an unprecedented γ-ray survey of the Galactic Center (GC) region, i.e., the Inner Galaxy Survey, at very high energies (≳100  GeV) performed with the H.E.S.S. array of five ground-based Cherenkov telescopes. No significant γ-ray excess is found in the search region of the 2014-2020 dataset and a profile likelihood ratio analysis is carried out to set exclusion limits on the annihilation cross section ⟨σv⟩. Assuming Einasto and Navarro-Frenk-White (NFW) DM density profiles at the GC, these constraints are the strongest obtained so far in the TeV DM mass range. For the Einasto profile, the constraints reach ⟨σv⟩ values of 3.7×10^{-26}  cm^{3} s^{-1} for 1.5 TeV DM mass in the W^{+}W^{-} annihilation channel, and 1.2×10^{-26}  cm^{3} s^{-1} for 0.7 TeV DM mass in the τ^{+}τ^{-} annihilation channel. With the H.E.S.S. Inner Galaxy Survey, ground-based γ-ray observations thus probe ⟨σv⟩ values expected from thermal-relic annihilating TeV DM particles.
    Language English
    Publishing date 2022-09-26
    Publishing country United States
    Document type Journal Article
    ZDB-ID 208853-8
    ISSN 1079-7114 ; 0031-9007
    ISSN (online) 1079-7114
    ISSN 0031-9007
    DOI 10.1103/PhysRevLett.129.111101
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: Time-resolved hadronic particle acceleration in the recurrent nova RS Ophiuchi.

    Aharonian, F / Ait Benkhali, F / Angüner, E O / Ashkar, H / Backes, M / Baghmanyan, V / Barbosa Martins, V / Batzofin, R / Becherini, Y / Berge, D / Bernlöhr, K / Bi, B / Böttcher, M / Boisson, C / Bolmont, J / de Bony de Lavergne, M / Breuhaus, M / Brose, R / Brun, F /
    Caroff, S / Casanova, S / Cerruti, M / Chand, T / Chen, A / Cotter, G / Damascene Mbarubucyeye, J / Djannati-Ataï, A / Dmytriiev, A / Doroshenko, V / Duffy, C / Egberts, K / Ernenwein, J-P / Fegan, S / Feijen, K / Fiasson, A / Fichet de Clairfontaine, G / Fontaine, G / Füßling, M / Funk, S / Gabici, S / Gallant, Y A / Ghafourizadeh, S / Giavitto, G / Giunti, L / Glawion, D / Glicenstein, J F / Grondin, M-H / Hermann, G / Hinton, J A / Hörbe, M / Hofmann, W / Hoischen, C / Holch, T L / Holler, M / Horns, D / Huang, Zhiqiu / Jamrozy, M / Jankowsky, F / Jung-Richardt, I / Kasai, E / Katarzyński, K / Katz, U / Khangulyan, D / Khélifi, B / Klepser, S / Kluźniak, W / Komin, Nu / Konno, R / Kosack, K / Kostunin, D / Le Stum, S / Lemière, A / Lemoine-Goumard, M / Lenain, J-P / Leuschner, F / Lohse, T / Luashvili, A / Lypova, I / Mackey, J / Malyshev, D / Marandon, V / Marchegiani, P / Marcowith, A / Martí-Devesa, G / Marx, R / Maurin, G / Meyer, M / Mitchell, A / Moderski, R / Mohrmann, L / Montanari, A / Moulin, E / Muller, J / Murach, T / Nakashima, K / de Naurois, M / Nayerhoda, A / Niemiec, J / Priyana Noel, A / O'Brien, P / Ohm, S / Olivera-Nieto, L / de Ona Wilhelmi, E / Ostrowski, M / Panny, S / Panter, M / Parsons, R D / Peron, G / Pita, S / Poireau, V / Prokhorov, D A / Prokoph, H / Pühlhofer, G / Punch, M / Quirrenbach, A / Reichherzer, P / Reimer, A / Reimer, O / Renaud, M / Reville, B / Rieger, F / Rowell, G / Rudak, B / Rueda Ricarte, H / Ruiz-Velasco, E / Sahakian, V / Sailer, S / Salzmann, H / Sanchez, D A / Santangelo, A / Sasaki, M / Schäfer, J / Schüssler, F / Schutte, H M / Schwanke, U / Senniappan, M / Shapopi, J N S / Simoni, R / Sinha, A / Sol, H / Specovius, A / Spencer, S / Stawarz, Ł / Steinmassl, S / Steppa, C / Takahashi, T / Tanaka, T / Taylor, A M / Terrier, R / Thorpe-Morgan, C / Tsirou, M / Tsuji, N / Tuffs, R / Uchiyama, Y / Unbehaun, T / van Eldik, C / van Soelen, B / Veh, J / Venter, C / Vink, J / Wagner, S J / Werner, F / White, R / Wierzcholska, A / Wong, Yu Wun / Yusafzai, A / Zacharias, M / Zargaryan, D / Zdziarski, A A / Zech, A / Zhu, S J / Zouari, S / Żywucka, N

    Science (New York, N.Y.)

    2022  Volume 376, Issue 6588, Page(s) 77–80

    Abstract: Recurrent novae are repeating thermonuclear explosions in the outer layers of white dwarfs, due to the accretion of fresh material from a binary companion. The shock generated when ejected material slams into the companion star's wind can accelerate ... ...

    Abstract Recurrent novae are repeating thermonuclear explosions in the outer layers of white dwarfs, due to the accretion of fresh material from a binary companion. The shock generated when ejected material slams into the companion star's wind can accelerate particles. We report very-high-energy (VHE; [Formula: see text]) gamma rays from the recurrent nova RS Ophiuchi, up to 1 month after its 2021 outburst, observed using the High Energy Stereoscopic System (H.E.S.S.). The temporal profile of VHE emission is similar to that of lower-energy giga-electron volt emission, indicating a common origin, with a 2-day delay in peak flux. These observations constrain models of time-dependent particle energization, favoring a hadronic emission scenario over the leptonic alternative. Shocks in dense winds provide favorable environments for efficient acceleration of cosmic rays to very high energies.
    Language English
    Publishing date 2022-03-10
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 128410-1
    ISSN 1095-9203 ; 0036-8075
    ISSN (online) 1095-9203
    ISSN 0036-8075
    DOI 10.1126/science.abn0567
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: Revealing x-ray and gamma ray temporal and spectral similarities in the GRB 190829A afterglow.

    Abdalla, H / Aharonian, F / Ait Benkhali, F / Angüner, E O / Arcaro, C / Armand, C / Armstrong, T / Ashkar, H / Backes, M / Baghmanyan, V / Barbosa Martins, V / Barnacka, A / Barnard, M / Becherini, Y / Berge, D / Bernlöhr, K / Bi, B / Bissaldi, E / Böttcher, M /
    Boisson, C / Bolmont, J / de Bony de Lavergne, M / Breuhaus, M / Brun, F / Brun, P / Bryan, M / Büchele, M / Bulik, T / Bylund, T / Caroff, S / Carosi, A / Casanova, S / Chand, T / Chandra, S / Chen, A / Cotter, G / Curyło, M / Damascene Mbarubucyeye, J / Davids, I D / Davies, J / Deil, C / Devin, J / Dirson, L / Djannati-Ataï, A / Dmytriiev, A / Donath, A / Doroshenko, V / Dreyer, L / Duffy, C / Dyks, J / Egberts, K / Eichhorn, F / Einecke, S / Emery, G / Ernenwein, J-P / Feijen, K / Fegan, S / Fiasson, A / Fichet de Clairfontaine, G / Fontaine, G / Funk, S / Füßling, M / Gabici, S / Gallant, Y A / Giavitto, G / Giunti, L / Glawion, D / Glicenstein, J F / Grondin, M-H / Hahn, J / Haupt, M / Hermann, G / Hinton, J A / Hofmann, W / Hoischen, C / Holch, T L / Holler, M / Hörbe, M / Horns, D / Huber, D / Jamrozy, M / Jankowsky, D / Jankowsky, F / Jardin-Blicq, A / Joshi, V / Jung-Richardt, I / Kasai, E / Kastendieck, M A / Katarzyński, K / Katz, U / Khangulyan, D / Khélifi, B / Klepser, S / Kluźniak, W / Komin, Nu / Konno, R / Kosack, K / Kostunin, D / Kreter, M / Lamanna, G / Lemière, A / Lemoine-Goumard, M / Lenain, J-P / Leuschner, F / Levy, C / Lohse, T / Lypova, I / Mackey, J / Majumdar, J / Malyshev, D / Marandon, V / Marchegiani, P / Marcowith, A / Mares, A / Martí-Devesa, G / Marx, R / Maurin, G / Meintjes, P J / Meyer, M / Mitchell, A / Moderski, R / Mohrmann, L / Montanari, A / Moore, C / Morris, P / Moulin, E / Muller, J / Murach, T / Nakashima, K / Nayerhoda, A / de Naurois, M / Ndiyavala, H / Niemiec, J / Oakes, L / O'Brien, P / Odaka, H / Ohm, S / Olivera-Nieto, L / de Ona Wilhelmi, E / Ostrowski, M / Panny, S / Panter, M / Parsons, R D / Peron, G / Peyaud, B / Piel, Q / Pita, S / Poireau, V / Priyana Noel, A / Prokhorov, D A / Prokoph, H / Pühlhofer, G / Punch, M / Quirrenbach, A / Raab, S / Rauth, R / Reichherzer, P / Reimer, A / Reimer, O / Remy, Q / Renaud, M / Rieger, F / Rinchiuso, L / Romoli, C / Rowell, G / Rudak, B / Ruiz-Velasco, E / Sahakian, V / Sailer, S / Salzmann, H / Sanchez, D A / Santangelo, A / Sasaki, M / Scalici, M / Schäfer, J / Schüssler, F / Schutte, H M / Schwanke, U / Seglar-Arroyo, M / Senniappan, M / Seyffert, A S / Shafi, N / Shapopi, J N S / Shiningayamwe, K / Simoni, R / Sinha, A / Sol, H / Specovius, A / Spencer, S / Spir-Jacob, M / Stawarz, Ł / Sun, L / Steenkamp, R / Stegmann, C / Steinmassl, S / Steppa, C / Takahashi, T / Tam, T / Tavernier, T / Taylor, A M / Terrier, R / Thiersen, J H E / Tiziani, D / Tluczykont, M / Tomankova, L / Tsirou, M / Tuffs, R / Uchiyama, Y / van der Walt, D J / van Eldik, C / van Rensburg, C / van Soelen, B / Vasileiadis, G / Veh, J / Venter, C / Vincent, P / Vink, J / Völk, H J / Wadiasingh, Z / Wagner, S J / Watson, J / Werner, F / White, R / Wierzcholska, A / Wong, Yu Wun / Yusafzai, A / Zacharias, M / Zanin, R / Zargaryan, D / Zdziarski, A A / Zech, A / Zhu, S J / Zorn, J / Zouari, S / Żywucka, N / Evans, P / Page, K

    Science (New York, N.Y.)

    2021  Volume 372, Issue 6546, Page(s) 1081–1085

    Abstract: Gamma-ray bursts (GRBs), which are bright flashes of gamma rays from extragalactic sources followed by fading afterglow emission, are associated with stellar core collapse events. We report the detection of very-high-energy (VHE) gamma rays from the ... ...

    Abstract Gamma-ray bursts (GRBs), which are bright flashes of gamma rays from extragalactic sources followed by fading afterglow emission, are associated with stellar core collapse events. We report the detection of very-high-energy (VHE) gamma rays from the afterglow of GRB 190829A, between 4 and 56 hours after the trigger, using the High Energy Stereoscopic System (H.E.S.S.). The low luminosity and redshift of GRB 190829A reduce both internal and external absorption, allowing determination of its intrinsic energy spectrum. Between energies of 0.18 and 3.3 tera-electron volts, this spectrum is described by a power law with photon index of 2.07 ± 0.09, similar to the x-ray spectrum. The x-ray and VHE gamma-ray light curves also show similar decay profiles. These similar characteristics in the x-ray and gamma-ray bands challenge GRB afterglow emission scenarios.
    Language English
    Publishing date 2021-05-25
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 128410-1
    ISSN 1095-9203 ; 0036-8075
    ISSN (online) 1095-9203
    ISSN 0036-8075
    DOI 10.1126/science.abe8560
    Database MEDical Literature Analysis and Retrieval System OnLINE

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