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12 results on '"G Pühlhofer"'

1. Very-high-energy γ-Ray Emission from Young Massive Star Clusters in the Large Magellanic Cloud

Author

F. Aharonian, F. Ait Benkhali, J. Aschersleben, H. Ashkar, M. Backes, V. Barbosa Martins, R. Batzofin, Y. Becherini, D. Berge, K. Bernlöhr, M. Böttcher, J. Bolmont, M. de Bony de Lavergne, J. Borowska, R. Brose, A. Brown, F. Brun, B. Bruno, C. Burger-Scheidlin, S. Casanova, J. Celic, M. Cerruti, T. Chand, S. Chandra, A. Chen, J. Chibueze, O. Chibueze, G. Cotter, P. Cristofari, J. Devin, A. Djannati-Ataï, J. Djuvsland, A. Dmytriiev, K. Egberts, S. Einecke, K. Feijen, M. Filipovic, G. Fontaine, S. Funk, S. Gabici, Y. A. Gallant, J. F. Glicenstein, J. Glombitza, G. Grolleron, L. Haerer, B. Heß, J. A. Hinton, W. Hofmann, T. L. Holch, D. Horns, Zhiqiu Huang, M. Jamrozy, F. Jankowsky, I. Jung-Richardt, E. Kasai, K. Katarzyński, R. Khatoon, B. Khélifi, W. Kluźniak, Nu. Komin, K. Kosack, D. Kostunin, A. Kundu, R. G. Lang, S. Le Stum, A. Lemière, M. Lemoine-Goumard, J.-P. Lenain, F. Leuschner, J. Mackey, V. Marandon, G. Martí-Devesa, R. Marx, A. Mehta, A. Mitchell, R. Moderski, M. O. Moghadam, L. Mohrmann, A. Montanari, E. Moulin, M. de Naurois, J. Niemiec, S. Ohm, L. Olivera-Nieto, E. de Ona Wilhelmi, M. Ostrowski, S. Panny, U. Pensec, G. Peron, G. Pühlhofer, A. Quirrenbach, S. Ravikularaman, M. Regeard, A. Reimer, O. Reimer, H. Ren, M. Renaud, B. Reville, F. Rieger, G. Rowell, B. Rudak, E. Ruiz-Velasco, K. Sabri, V. Sahakian, H. Salzmann, A. Santangelo, M. Sasaki, J. Schäfer, F. Schüssler, H. M. Schutte, H. Sol, S. Spencer, Ł. Stawarz, S. Steinmassl, C. Steppa, K. Streil, I. Sushch, A. M. Taylor, R. Terrier, M. Tsirou, N. Tsuji, C. van Eldik, M. Vecchi, C. Venter, J. Vink, S. J. Wagner, R. White, A. Wierzcholska, M. Zacharias, A. A. Zdziarski, A. Zech, N. Żywucka, and H.E.S.S. Collaboration

Subjects
Young star clusters, Massive stars, Large Magellanic Cloud, Gamma-ray astronomy, Astrophysics, QB460-466
Abstract

The Tarantula Nebula in the Large Magellanic Cloud is known for its high star formation activity. At its center lies the young massive star cluster R136, providing a significant amount of the energy that makes the nebula shine so brightly at many wavelengths. Recently, young massive star clusters have been suggested to also efficiently produce very high-energy cosmic rays, potentially beyond PeV energies. Here, we report the detection of very-high-energy γ -ray emission from the direction of R136 with the High Energy Stereoscopic System, achieved through a multicomponent, likelihood-based modeling of the data. This supports the hypothesis that R136 is indeed a very powerful cosmic-ray accelerator. Moreover, from the same analysis, we provide an updated measurement of the γ -ray emission from 30 Dor C, the only superbubble detected at TeV energies presently. The γ -ray luminosity above 0.5 TeV of both sources is (2–3) × 10 ^35 erg s ^−1 . This exceeds by more than a factor of 2 the luminosity of HESS J1646−458, which is associated with the most massive young star cluster in the Milky Way, Westerlund 1. Furthermore, the γ -ray emission from each source is extended with a significance of >3 σ and a Gaussian width of about 30 pc. For 30 Dor C, a connection between the γ -ray emission and the nonthermal X-ray emission appears likely. Different interpretations of the γ -ray signal from R136 are discussed.

Published
2024
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2. H.E.S.S. Follow-up Observations of GRB 221009A

Author

F. Aharonian, F. Ait Benkhali, J. Aschersleben, H. Ashkar, M. Backes, A. Baktash, V. Barbosa Martins, R. Batzofin, Y. Becherini, D. Berge, K. Bernlöhr, B. Bi, M. Böttcher, C. Boisson, J. Bolmont, M. de Bony de Lavergne, J. Borowska, M. Bouyahiaoui, F. Bradascio, M. Breuhaus, R. Brose, F. Brun, B. Bruno, T. Bulik, C. Burger-Scheidlin, S. Caroff, S. Casanova, J. Celic, M. Cerruti, T. Chand, S. Chandra, A. Chen, J. Chibueze, O. Chibueze, G. Cotter, S. Dai, J. Damascene Mbarubucyeye, J. Devin, A. Djannati-Ataï, A. Dmytriiev, V. Doroshenko, K. Egberts, S. Einecke, J.-P. Ernenwein, S. Fegan, G. Fichet de Clairfontaine, M. Filipovic, G. Fontaine, M. Füßling, S. Funk, S. Gabici, S. Ghafourizadeh, G. Giavitto, D. Glawion, J. F. Glicenstein, P. Goswami, G. Grolleron, M.-H. Grondin, J. A. Hinton, T. L. Holch, M. Holler, D. Horns, Zhiqiu Huang, M. Jamrozy, F. Jankowsky, V. Joshi, I. Jung-Richardt, E. Kasai, K. Katarzyński, R. Khatoon, B. Khélifi, W. Kluźniak, Nu. Komin, R. Konno, K. Kosack, D. Kostunin, R. G. Lang, S. Le Stum, F. Leitl, A. Lemière, M. Lemoine-Goumard, J.-P. Lenain, F. Leuschner, T. Lohse, I. Lypova, J. Mackey, D. Malyshev, V. Marandon, P. Marchegiani, A. Marcowith, G. Martí-Devesa, R. Marx, M. Meyer, A. Mitchell, L. Mohrmann, A. Montanari, E. Moulin, T. Murach, K. Nakashima, M. de Naurois, J. Niemiec, A. Priyana Noel, P. O’Brien, S. Ohm, L. Olivera-Nieto, E. de Ona Wilhelmi, M. Ostrowski, S. Panny, M. Panter, R. D. Parsons, G. Peron, D. A. Prokhorov, H. Prokoph, G. Pühlhofer, M. Punch, A. Quirrenbach, P. Reichherzer, A. Reimer, O. Reimer, H. Ren, M. Renaud, B. Reville, F. Rieger, G. Rowell, B. Rudak, E. Ruiz-Velasco, V. Sahakian, H. Salzmann, A. Santangelo, M. Sasaki, J. Schäfer, F. Schüssler, H. M. Schutte, U. Schwanke, J. N. S. Shapopi, A. Specovius, S. Spencer, Ł. Stawarz, R. Steenkamp, S. Steinmassl, C. Steppa, I. Sushch, H. Suzuki, T. Takahashi, T. Tanaka, R. Terrier, N. Tsuji, Y. Uchiyama, M. Vecchi, C. Venter, J. Vink, S. J. Wagner, R. White, A. Wierzcholska, Yu Wun Wong, M. Zacharias, D. Zargaryan, A. A. Zdziarski, A. Zech, S. J. Zhu, N. Żywucka, and H.E.S.S. Collaboration

Subjects
Gamma-rays, Gamma-ray bursts, Non-thermal radiation sources, High-energy cosmic radiation, Astrophysics, QB460-466
Abstract

GRB 221009A is the brightest gamma-ray burst (GRB) ever detected. To probe the very-high-energy (VHE; >100 GeV) emission, the High Energy Stereoscopic System (H.E.S.S.) began observations 53 hr after the triggering event, when the brightness of the moonlight no longer precluded observations. We derive differential and integral upper limits using H.E.S.S. data from the third, fourth, and ninth nights after the initial GRB detection, after applying atmospheric corrections. The combined observations yield an integral energy flux upper limit of ${{\rm{\Phi }}}_{\mathrm{UL}}^{95 \% }=9.7\times {10}^{-12}\,\mathrm{erg}\,{\mathrm{cm}}^{-2}\,{{\rm{s}}}^{-1}$ above E _thr = 650 GeV. The constraints derived from the H.E.S.S. observations complement the available multiwavelength data. The radio to X-ray data are consistent with synchrotron emission from a single electron population, with the peak in the spectral energy distribution occurring above the X-ray band. Compared to the VHE-bright GRB 190829A, the upper limits for GRB 221009A imply a smaller gamma-ray to X-ray flux ratio in the afterglow. Even in the absence of a detection, the H.E.S.S. upper limits thus contribute to the multiwavelength picture of GRB 221009A, effectively ruling out an IC-dominated scenario.

Published
2023
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3. The Vanishing of the Primary Emission Region in PKS 1510–089

Author

F. Aharonian, F. Ait Benkhali, J. Aschersleben, H. Ashkar, M. Backes, V. Barbosa Martins, J. Barnard, R. Batzofin, Y. Becherini, D. Berge, K. Bernlöhr, B. Bi, M. de Bony de Lavergne, M. Böttcher, C. Boisson, J. Bolmont, J. Borowska, M. Bouyahiaoui, F. Bradascio, M. Breuhaus, R. Brose, A. M. Brown, F. Brun, B. Bruno, T. Bulik, C. Burger-Scheidlin, S. Caroff, S. Casanova, R. Cecil, J. Celic, M. Cerruti, T. Chand, S. Chandra, A. Chen, J. Chibueze, O. Chibueze, G. Cotter, J. Damascene Mbarubucyeye, I. D. Davids, A. Djannati-Ataï, A. Dmytriiev, V. Doroshenko, K. Egberts, S. Einecke, J.-P. Ernenwein, S. Fegan, G. Fontaine, M. Füßling, S. Funk, S. Gabici, S. Ghafourizadeh, G. Giavitto, D. Glawion, J. F. Glicenstein, P. Goswami, G. Grolleron, L. Haerer, W. Hofmann, T. L. Holch, M. Holler, D. Horns, M. Jamrozy, F. Jankowsky, V. Joshi, I. Jung-Richardt, E. Kasai, K. Katarzyński, R. Khatoon, B. Khélifi, W. Kluźniak, Nu. Komin, K. Kosack, D. Kostunin, R. G. Lang, S. Le Stum, F. Leitl, A. Lemière, J.-P. Lenain, F. Leuschner, A. Luashvili, J. Mackey, V. Marandon, P. Marchegiani, G. Martí-Devesa, R. Marx, A. Mehta, M. Meyer, A. Mitchell, R. Moderski, L. Mohrmann, A. Montanari, E. Moulin, M. de Naurois, J. Niemiec, A. Priyana Noel, P. O’Brien, S. Ohm, L. Olivera-Nieto, E. de Ona Wilhelmi, M. Ostrowski, S. Panny, M. Panter, G. Peron, D. A. Prokhorov, G. Pühlhofer, M. Punch, A. Quirrenbach, P. Reichherzer, A. Reimer, O. Reimer, H. Ren, F. Rieger, G. Rowell, B. Rudak, H. Rueda Ricarte, E. Ruiz-Velasco, V. Sahakian, H. Salzmann, D. A. Sanchez, A. Santangelo, M. Sasaki, F. Schüssler, H. M. Schutte, U. Schwanke, J. N. S. Shapopi, H. Sol, A. Specovius, S. Spencer, Ł. Stawarz, R. Steenkamp, S. Steinmassl, C. Steppa, I. Sushch, H. Suzuki, T. Takahashi, T. Tanaka, R. Terrier, N. Tsuji, C. van Eldik, B. van Soelen, M. Vecchi, J. Veh, J. Vink, T. Wach, S. J. Wagner, A. Wierzcholska, M. Zacharias, D. Zargaryan, A. A. Zdziarski, A. Zech, S. Zouari, N. Żywucka, D. A. H. Buckley, J. Cooper, D. Groenewald, and H.E.S.S. Collaboration

Subjects
Blazars, Relativistic jets, Non-thermal radiation sources, Flat-spectrum radio quasars, Gamma-ray sources, Spectropolarimetry, Astrophysics, QB460-466
Abstract

In 2021 July, PKS 1510−089 exhibited a significant flux drop in the high-energy γ -ray (by a factor 10) and optical (by a factor 5) bands and remained in this low state throughout 2022. Similarly, the optical polarization in the source vanished, resulting in the optical spectrum being fully explained through the steady flux of the accretion disk and the broad-line region. Unlike the aforementioned bands, the very-high-energy γ -ray and X-ray fluxes did not exhibit a significant flux drop from year to year. This suggests that the steady-state very-high-energy γ -ray and X-ray fluxes originate from a different emission region than the vanished parts of the high-energy γ -ray and optical jet fluxes. The latter component has disappeared through either a swing of the jet away from the line of sight or a significant drop in the photon production efficiency of the jet close to the black hole. Either change could become visible in high-resolution radio images.

Published
2023
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4. Constraints on the Intergalactic Magnetic Field Using Fermi-LAT and H.E.S.S. Blazar Observations

Author

F. Aharonian, J. Aschersleben, M. Backes, V. Barbosa Martins, R. Batzofin, Y. Becherini, D. Berge, B. Bi, M. Bouyahiaoui, M. Breuhaus, R. Brose, F. Brun, B. Bruno, T. Bulik, C. Burger-Scheidlin, T. Bylund, S. Caroff, S. Casanova, J. Celic, M. Cerruti, T. Chand, S. Chandra, A. Chen, J. Chibueze, O. Chibueze, G. Cotter, M. de Bony, K. Egberts, J.-P. Ernenwein, G. Fichet de Clairfontaine, M. Filipovic, G. Fontaine, M. Füssling, S. Funk, S. Gabici, S. Ghafourizadeh, G. Giavitto, D. Glawion, J. F. Glicenstein, P. Goswami, M.-H. Grondin, L. Haerer, T. L. Holch, M. Holler, D. Horns, M. Jamrozy, F. Jankowsky, V. Joshi, I. Jung-Richardt, E. Kasai, K. Katarzyński, R. Khatoon, B. Khélifi, W. Kluźniak, Nu. Komin, K. Kosack, D. Kostunin, R. G. Lang, S. Le Stum, F. Leitl, A. Lemière, J.-P. Lenain, F. Leuschner, T. Lohse, A. Luashvili, I. Lypova, J. Mackey, D. Malyshev, V. Marandon, P. Marchegiani, A. Marcowith, G. Martí-Devesa, R. Marx, M. Meyer, A. Mitchell, R. Moderski, L. Mohrmann, A. Montanari, E. Moulin, J. Muller, T. Murach, K. Nakashima, J. Niemiec, S. Ohm, L. Olivera-Nieto, E. de Ona Wilhelmi, S. Panny, M. Panter, R. D. Parsons, G. Peron, D. A. Prokhorov, H. Prokoph, G. Pühlhofer, M. Punch, A. Quirrenbach, P. Reichherzer, A. Reimer, O. Reimer, B. Reville, F. Rieger, G. Rowell, B. Rudak, E. Ruiz-Velasco, V. Sahakian, D. A. Sanchez, M. Sasaki, F. Schüssler, H. M. Schutte, U. Schwanke, J. N. S. Shapopi, H. Sol, S. Spencer, S. Steinmassl, H. Suzuki, T. Takahashi, T. Tanaka, A. M. Taylor, R. Terrier, C. Thorpe-Morgan, M. Tsirou, N. Tsuji, Y. Uchiyama, C. van Eldik, J. Veh, C. Venter, S. J. Wagner, R. White, A. Wierzcholska, Yu Wun Wong, M. Zacharias, D. Zargaryan, A. A. Zdziarski, S. Zouari, N. Żywucka, H.E.S.S. Collaboration, and Fermi-LAT Collaboration

Subjects
Active galaxies, High energy astrophysics, Extragalactic magnetic fields, Astrophysics, QB460-466
Abstract

Magnetic fields in galaxies and galaxy clusters are believed to be the result of the amplification of intergalactic seed fields during the formation of large-scale structures in the universe. However, the origin, strength, and morphology of this intergalactic magnetic field (IGMF) remain unknown. Lower limits on (or indirect detection of) the IGMF can be obtained from observations of high-energy gamma rays from distant blazars. Gamma rays interact with the extragalactic background light to produce electron−positron pairs, which can subsequently initiate electromagnetic cascades. The gamma-ray signature of the cascade depends on the IGMF since it deflects the pairs. Here we report on a new search for this cascade emission using a combined data set from the Fermi Large Area Telescope and the High Energy Stereoscopic System. Using state-of-the-art Monte Carlo predictions for the cascade signal, our results place a lower limit on the IGMF of B > 7.1 × 10 ^−16 G for a coherence length of 1 Mpc even when blazar duty cycles as short as 10 yr are assumed. This improves on previous lower limits by a factor of 2. For longer duty cycles of 10 ^4 (10 ^7 ) yr, IGMF strengths below 1.8 × 10 ^−14 G (3.9 × 10 ^−14 G) are excluded, which rules out specific models for IGMF generation in the early universe.

Published
2023
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5. Multiwavelength Observations of the Blazar PKS 0735+178 in Spatial and Temporal Coincidence with an Astrophysical Neutrino Candidate IceCube-211208A

Author

A. Acharyya, C. B. Adams, A. Archer, P. Bangale, J. T. Bartkoske, P. Batista, W. Benbow, A. Brill, J. H. Buckley, J. L. Christiansen, A. J. Chromey, M. Errando, A. Falcone, Q. Feng, G. M. Foote, L. Fortson, A. Furniss, G. Gallagher, W. Hanlon, D. Hanna, O. Hervet, C. E. Hinrichs, J. Hoang, J. Holder, T. B. Humensky, W. Jin, P. Kaaret, M. Kertzman, M. Kherlakian, D. Kieda, T. K. Kleiner, N. Korzoun, S. Kumar, M. J. Lang, M. Lundy, G. Maier, C. E McGrath, M. J. Millard, J. Millis, C. L. Mooney, P. Moriarty, R. Mukherjee, S. O’Brien, R. A. Ong, M. Pohl, E. Pueschel, J. Quinn, K. Ragan, P. T. Reynolds, D. Ribeiro, E. Roache, I. Sadeh, A. C. Sadun, L. Saha, M. Santander, G. H. Sembroski, R. Shang, M. Splettstoesser, A. Kaushik Talluri, J. V. Tucci, V. V. Vassiliev, A. Weinstein, D. A. Williams, S. L. Wong, J. Woo, F. Aharonian, J. Aschersleben, M. Backes, V. Barbosa Martins, R. Batzofin, Y. Becherini, D. Berge, K. Bernlöhr, B. Bi, M. Böttcher, C. Boisson, J. Bolmont, M. de Bony de Lavergne, J. Borowska, M. Bouyahiaoui, F. Bradascio, M. Breuhaus, R. Brose, F. Brun, B. Bruno, T. Bulik, C. Burger-Scheidlin, S. Caroff, S. Casanova, R. Cecil, J. Celic, M. Cerruti, T. Chand, S. Chandra, A. Chen, J. Chibueze, O. Chibueze, G. Cotter, S. Dai, J. Damascene Mbarubucyeye, A. Djannati-Ataï, A. Dmytriiev, V. Doroshenko, S. Einecke, J.-P. Ernenwein, G. Fichet de Clairfontaine, M. Filipovic, G. Fontaine, M. Füßling, S. Funk, S. Gabici, S. Ghafourizadeh, G. Giavitto, D. Glawion, J. F. Glicenstein, P. Goswami, G. Grolleron, L. Haerer, J. A. Hinton, T. L. Holch, M. Holler, D. Horns, M. Jamrozy, F. Jankowsky, V. Joshi, I. Jung-Richardt, E. Kasai, K. Katarzyński, R. Khatoon, B. Khélifi, S. Klepser, W. Kluźniak, K. Kosack, D. Kostunin, R. G. Lang, S. Le Stum, A. Lemière, J.-P. Lenain, F. Leuschner, T. Lohse, A. Luashvili, I. Lypova, J. Mackey, D. Malyshev, V. Marandon, P. Marchegiani, A. Marcowith, G. Martí-Devesa, R. Marx, A. Mitchell, R. Moderski, L. Mohrmann, A. Montanari, E. Moulin, T. Murach, K. Nakashima, J. Niemiec, A. Priyana Noel, P. O’Brien, L. Olivera-Nieto, E. de Ona Wilhelmi, M. Ostrowski, S. Panny, M. Panter, G. Peron, D. A. Prokhorov, G. Pühlhofer, M. Punch, A. Quirrenbach, P. Reichherzer, A. Reimer, O. Reimer, H. Ren, M. Renaud, F. Rieger, B. Rudak, E. Ruiz-Velasco, V. Sahakian, A. Santangelo, M. Sasaki, J. Schäfer, F. Schüssler, H. M. Schutte, U. Schwanke, J. N. S. Shapopi, A. Specovius, S. Spencer, Ł. Stawarz, R. Steenkamp, S. Steinmassl, I. Sushch, H. Suzuki, T. Takahashi, T. Tanaka, R. Terrier, C. van Eldik, M. Vecchi, J. Veh, C. Venter, J. Vink, R. White, A. Wierzcholska, Yu Wun Wong, M. Zacharias, D. Zargaryan, A. A. Zdziarski, A. Zech, S. Zouari, N. Żywucka, and K. Mori

Published
2023
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6. A MeerKAT, e-MERLIN, HESS, and Swift search for persistent and transient emission associated with three localized FRBs

Author

J O Chibueze, M Caleb, L Spitler, H Ashkar, F Schüssler, B W Stappers, C Venter, I Heywood, A M S Richards, D R A Williams, M Kramer, R Beswick, M C Bezuidenhout, R P Breton, L N Driessen, F Jankowski, E F Keane, M Malenta, M Mickaliger, V Morello, H Qiu, K Rajwade, S Sanidas, M Surnis, T W Scragg, C R H Walker, N Wrigley, H E S S Collaboration: F Aharonian, F Ait Benkhali, E O Angüner, M Backes, V Baghmanyan, V Barbosa Martins, R Batzofin, Y Becherini, D Berge, M Böttcher, C Boisson, J Bolmont, M de Bony de Lavergne, M Breuhaus, R Brose, F Brun, T Bulik, F Cangemi, S Caroff, S Casanova, J Catalano, M Cerruti, T Chand, A Chen, O U Chibueze, G Cotter, P Cristofari, J Damascene Mbarubucyeye, J Devin, A Djannati-Ataï, A Dmytriiev, K Egberts, J-P Ernenwein, A Fiasson, G Fichet de Clairfontaine, G Fontaine, S Funk, S Gabici, S Ghafourizadeh, G Giavitto, D Glawion, M-H Grondin, M Hörbe, C Hoischen, T L Holch, Zhiqiu Huang, M Jamrozy, F Jankowsky, V Joshi, I Jung-Richardt, E Kasai, K Katarzyński, U Katz, B Khélifi, W Kluźniak, Nu Komin, K Kosack, D Kostunin, A Lemière, J-P Lenain, F Leuschner, T Lohse, A Luashvili, I Lypova, J Mackey, D Malyshev, V Marandon, P Marchegiani, A Marcowith, G Martí-Devesa, R Marx, A Mitchell, R Moderski, L Mohrmann, E Moulin, J Muller, K Nakashima, M de Naurois, A Nayerhoda, J Niemiec, A Priyana Noel, P O’Brien, S Ohm, L Olivera-Nieto, E de Ona Wilhelmi, M Ostrowski, S Panny, R D Parsons, S Pita, V Poireau, D A Prokhorov, H Prokoph, G Pühlhofer, A Quirrenbach, P Reichherzer, A Reimer, O Reimer, G Rowell, B Rudak, E Ruiz-Velasco, V Sahakian, S Sailer, H Salzmann, D A Sanchez, A Santangelo, M Sasaki, H M Schutte, U Schwanke, J N S Shapopi, A Specovius, S Spencer, R Steenkamp, S Steinmassl, T Takahashi, T Tanaka, C Thorpe-Morgan, N Tsuji, C van Eldik, J Veh, J Vink, S J Wagner, A Wierzcholska, Yu Wun Wong, A Yusafzai, M Zacharias, D Zargaryan, A A Zdziarski, A Zech, S J Zhu, S Zouari, N Żywucka, High Energy Astrophys. & Astropart. Phys (API, FNWI), 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), AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Laboratoire Univers et Théories (LUTH (UMR_8102)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, 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), 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), Université de Bordeaux (UB), Laboratoire Univers et Particules de Montpellier (LUPM), and Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)

Subjects
radio continuum: galaxies, High Energy Astrophysical Phenomena (astro-ph.HE), ) fast radio burst [(transients], FOS: Physical sciences, Astronomy and Astrophysics, radiation mechanisms: non-thermal, non-thermal [radiation mechanisms], Astrophysics - Astrophysics of Galaxies, galaxies [radio continuum], fast radio bursts, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Astrophysics of Galaxies (astro-ph.GA), (transients:) fast radio burst, ddc:520, Astrophysics - High Energy Astrophysical Phenomena
Abstract

Monthly notices of the Royal Astronomical Society 515(1), 1365 - 1379 (2022). doi:10.1093/mnras/stac1601, We report on a search for persistent radio emission from the one-off fast radio burst (FRB) 20190714A, as well as from two repeating FRBs, 20190711A and 20171019A, using the MeerKAT radio telescope. For FRB 20171019A, we also conducted simultaneous observations with the High-Energy Stereoscopic System (H.E.S.S.) in very high-energy gamma rays and searched for signals in the ultraviolet, optical, and X-ray bands. For this FRB, we obtain a UV flux upper limit of |$1.39 \times 10^{-16}~{\rm erg\, cm^{-2}\, s^{-1}}$|Å^−1, X-ray limit of |$\sim 6.6 \times 10^{-14}~{\rm erg\, cm^{-2}\, s^{-1}}$| and a limit on the very high energy gamma-ray flux |$\Phi (E\gt 120\, {\rm GeV}) \lt 1.7\times 10^{-12}\, \mathrm{erg\, cm^{-2}\, s^{-1}}$|⁠. We obtain a radio upper limit of ∼15 |$\mu$|Jy beam^−1 for persistent emission at the locations of both FRBs 20190711A and 20171019A with MeerKAT. However, we detected an almost unresolved (ratio of integrated flux to peak flux is ∼1.7 beam) radio emission, where the synthesized beam size was ∼ 8 arcsec size with a peak brightness of |$\sim 53\, \mu$|Jy beam^−1 at MeerKAT and |$\sim 86\, \mu$|Jy beam^−1 at e-MERLIN, possibly associated with FRB 20190714A at z = 0.2365. This represents the first detection of persistent continuum radio emission potentially associated with a (as-yet) non-repeating FRB. If the association is confirmed, one of the strongest remaining distinction between repeaters and non-repeaters would no longer be applicable. A parallel search for repeat bursts from these FRBs revealed no new detections down to a fluence of 0.08 Jy ms for a 1 ms duration burst., Published by Oxford Univ. Press, Oxford

Published
2023
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7. Sensitivity of the Cherenkov Telescope Array to TeV photon emission from the Large Magellanic Cloud

Author

A Acharyya, R Adam, A Aguasca-Cabot, I Agudo, A Aguirre-Santaella, J Alfaro, R Aloisio, R Alves Batista, E Amato, E O Angüner, C Aramo, C Arcaro, K Asano, J Aschersleben, H Ashkar, M Backes, A Baktash, C Balazs, M Balbo, J Ballet, A Bamba, A Baquero Larriva, V Barbosa Martins, U Barres de Almeida, J A Barrio, D Bastieri, P Batista, I Batkovic, J R Baxter, J Becerra González, J Becker Tjus, W Benbow, E Bernardini, M I Bernardos Martín, J Bernete Medrano, A Berti, B Bertucci, V Beshley, P Bhattacharjee, S Bhattacharyya, C Bigongiari, A Biland, E Bissaldi, F Bocchino, P Bordas, J Borkowski, E Bottacini, M Böttcher, F Bradascio, A M Brown, A Bulgarelli, L Burmistrov, S Caroff, A Carosi, E Carquín, S Casanova, E Cascone, F Cassol, M Cerruti, P Chadwick, S Chaty, A Chen, A Chiavassa, L Chytka, V Conforti, J Cortina, A Costa, H Costantini, G Cotter, S Crestan, P Cristofari, F D’Ammando, M Dalchenko, F Dazzi, A De Angelis, V De Caprio, E M de Gouveia Dal Pino, D De Martino, M de Naurois, V de Souza, M V del Valle, A G Delgado Giler, C Delgado, D della Volpe, D Depaoli, T Di Girolamo, A Di Piano, F Di Pierro, R Di Tria, L Di Venere, S Diebold, M Doro, D Dumora, V V Dwarkadas, C Eckner, K Egberts, G Emery, J Escudero, D Falceta-Goncalves, E Fedorova, S Fegan, Q Feng, D Ferenc, G Ferrand, E Fiandrini, M Filipovic, V Fioretti, L Foffano, G Fontaine, Y Fukui, D Gaggero, G Galanti, G Galaz, S Gallozzi, V Gammaldi, M Garczarczyk, C Gasbarra, D Gasparrini, A Ghalumyan, M Giarrusso, G Giavitto, N Giglietto, F Giordano, A Giuliani, J-F Glicenstein, P Goldoni, J Goulart Coelho, J Granot, D Green, J G Green, M-H Grondin, O Gueta, D Hadasch, P Hamal, T Hassan, K Hayashi, M Heller, S Hernández Cadena, N Hiroshima, B Hnatyk, R Hnatyk, W Hofmann, J Holder, M Holler, D Horan, P Horvath, M Hrabovsky, M Hütten, M Iarlori, T Inada, F Incardona, S Inoue, F Iocco, M Jamrozy, W Jin, I Jung-Richardt, J Juryšek, D Kantzas, V Karas, H Katagiri, D Kerszberg, J Knödlseder, N Komin, P Kornecki, K Kosack, G Kowal, H Kubo, A Lamastra, J Lapington, M Lemoine-Goumard, J-P Lenain, F Leone, G Leto, F Leuschner, E Lindfors, T Lohse, S Lombardi, F Longo, R López-Coto, A López-Oramas, S Loporchio, P L Luque-Escamilla, O Macias, P Majumdar, D Mandat, S Mangano, G Manicò, M Mariotti, P Marquez, G Marsella, J Martí, P Martin, M Martínez, D Mazin, S Menchiari, D M-A Meyer, D Miceli, M Miceli, J Michałowski, A Mitchell, R Moderski, L Mohrmann, M Molero, E Molina, T Montaruli, A Moralejo, D Morcuende, A Morselli, E Moulin, V Moya, R Mukherjee, K Munari, A Muraczewski, S Nagataki, T Nakamori, A Nayak, J Niemiec, M Nievas, M Nikołajuk, K Nishijima, K Noda, D Nosek, B Novosyadlyj, S Nozaki, M Ohishi, S Ohm, A Okumura, B Olmi, R A Ong, M Orienti, R Orito, M Orlandini, E Orlando, S Orlando, M Ostrowski, I Oya, A Pagliaro, M Palatka, F R Pantaleo, R Paoletti, J M Paredes, N Parmiggiani, B Patricelli, M Pech, M Pecimotika, M Persic, O Petruk, E Pierre, E Pietropaolo, G Pirola, M Pohl, E Prandini, C Priyadarshi, G Pühlhofer, M L Pumo, M Punch, F S Queiroz, A Quirrenbach, S Rainò, R Rando, S Razzaque, A Reimer, O Reimer, T Reposeur, M Ribó, T Richtler, J Rico, F Rieger, M Rigoselli, V Rizi, E Roache, G Rodriguez Fernandez, P Romano, G Romeo, J Rosado, A Rosales de Leon, B Rudak, C Rulten, I Sadeh, T Saito, M Sánchez-Conde, H Sano, A Santangelo, R Santos-Lima, S Sarkar, F G Saturni, A Scherer, P Schovanek, F Schussler, U Schwanke, O Sergijenko, M Servillat, H Siejkowski, C Siqueira, S Spencer, A Stamerra, S Stanič, C Steppa, T Stolarczyk, Y Suda, T Tavernier, M Teshima, L Tibaldo, D F Torres, N Tothill, M Vacula, B Vallage, P Vallania, C van Eldik, M Vázquez Acosta, M Vecchi, S Ventura, S Vercellone, A Viana, C F Vigorito, J Vink, V Vitale, V Vodeb, S Vorobiov, T Vuillaume, S J Wagner, R Walter, M White, A Wierzcholska, M Will, R Yamazaki, L Yang, T Yoshikoshi, M Zacharias, G Zaharijas, D Zavrtanik, M Zavrtanik, A A Zdziarski, V I Zhdanov, K Ziętara, M Živec, Joseph Louis LAGRANGE (LAGRANGE), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Leprince-Ringuet (LLR), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), 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), Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, 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), AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Galaxies, Etoiles, Physique, Instrumentation (GEPI), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Annecy-le-Vieux de Physique Théorique (LAPTH), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), 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), and Cherenkov Telescope Array

Subjects
High Energy Astrophysical Phenomena (astro-ph.HE), photon, emission, acceleration, efficiency, Cherenkov Telescope Array, WIMP, diffusion, FOS: Physical sciences, Astronomy and Astrophysics, suppression, sensitivity, Navarro-Frenk-White profile, dark matter, photon, energy, flux, cosmic radiation, spectrum, energy, high, Space and Planetary Science, cloud, TeV, spectral, galaxy, Astrophysics - High Energy Astrophysical Phenomena, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], nucleus, cosmic radiation
Abstract

A deep survey of the Large Magellanic Cloud at ~0.1-100TeV photon energies with the Cherenkov Telescope Array is planned. We assess the detection prospects based on a model for the emission of the galaxy, comprising the four known TeV emitters, mock populations of sources, and interstellar emission on galactic scales. We also assess the detectability of 30 Doradus and SN 1987A, and the constraints that can be derived on the nature of dark matter. The survey will allow for fine spectral studies of N157B, N132D, LMC P3, and 30 Doradus C, and half a dozen other sources should be revealed, mainly pulsar-powered objects. The remnant from SN 1987A could be detected if it produces cosmic-ray nuclei with a flat power-law spectrum at high energies, or with a steeper index 2.3-2.4 pending a flux increase by a factor >3-4 over ~2015-2035. Large-scale interstellar emission remains mostly out of reach of the survey if its >10GeV spectrum has a soft photon index ~2.7, but degree-scale 0.1-10TeV pion-decay emission could be detected if the cosmic-ray spectrum hardens above >100GeV. The 30 Doradus star-forming region is detectable if acceleration efficiency is on the order of 1-10% of the mechanical luminosity and diffusion is suppressed by two orders of magnitude within, Accepted for publication in MNRAS. Corresponding authors: Pierrick Martin, Maria Isabel Bernardos Martin, Fabio Iocco

Published
2023
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8. Dust scattering halo around the CCO in HESS J1731–347: A detailed analysis

Author

A. Landstorfer, V. Doroshenko, and G. Pühlhofer

Subjects
Space and Planetary Science, Astrophysics::High Energy Astrophysical Phenomena, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

The supernova remnant (SNR) HESS J1731−347 is one of the few objects exhibiting emission up to the TeV energy band and it stands as a prime target for the study of cosmic ray acceleration in SNRs. It also hosts a central compact object (CCO), which is of interest in the context of the ultra-dense matter equation of state in neutron stars. For both types of studies, however, the parameters of the respective models depend crucially on the assumed distance to the object and are affected to a certain extent by the assumed interstellar medium (ISM) properties around the SNR. Here, we report on the first quantitative analysis of the properties of the compact X-ray dust scattering halo that is assumed to be present around the CCO based on Chandra observations of the source. Our findings unambiguously confirm the presence of a compact halo around the CCO, and we show that the observed halo properties are consistent with expectations from independent measurements of the dust distribution along the line of sight and the distance to the source. Although we were not able to significantly improve those constraints, our results are important for future studies of the CCO itself. Indeed, the halo contribution is expected to affect the X-ray spectrum and the derived parameters of the neutron star when observed with moderate angular resolutions. Our results, which offer a quantitative characterization of the halo properties, will be useful in accounting for this effect.

Published
2022
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9. High-Statistics Measurement of the Cosmic-Ray Electron Spectrum with H.E.S.S.

Author

Aharonian F, Benkhali FA, Aschersleben J, Ashkar H, Backes M, Martins VB, Batzofin R, Becherini Y, Berge D, Bernlöhr K, Bi B, Böttcher M, Boisson C, Bolmont J, de Lavergne MB, Borowska J, Bouyahiaoui M, Brose R, Brown A, Brun F, Bruno B, Bulik T, Burger-Scheidlin C, Bylund T, Casanova S, Celic J, Cerruti M, Chand T, Chandra S, Chen A, Chibueze J, Chibueze O, Collins T, Cotter G, Mbarubucyeye JD, Devin J, Djuvsland J, Dmytriiev A, Egberts K, Einecke S, Ernenwein JP, Fegan S, Feijen K, Fontaine G, Funk S, Gabici S, Gallant YA, Glicenstein JF, Glombitza J, Grolleron G, Heß B, Hofmann W, Holch TL, Holler M, Horns D, Huang Z, Jamrozy M, Jankowsky F, Joshi V, Jung-Richardt I, Kasai E, Katarzyński K, Kerszberg D, Khatoon R, Khélifi B, Kluźniak W, Komin N, Kosack K, Kostunin D, Kundu A, Lang RG, Le Stum S, Leitl F, Lemière A, Lemoine-Goumard M, Lenain JP, Leuschner F, Luashvili A, Mackey J, Malyshev D, Malyshev D, Marandon V, Marinos P, Martí-Devesa G, Marx R, Meyer M, Mitchell A, Moderski R, Moghadam MO, Mohrmann L, Montanari A, Moulin E, de Naurois M, Niemiec J, Ohm S, Olivera-Nieto L, Wilhelmi EO, Ostrowski M, Panny S, Panter M, Parsons D, Pensec U, Peron G, Pühlhofer G, Punch M, Quirrenbach A, Ravikularaman S, Regeard M, Reimer A, Reimer O, Reis I, Ren H, Reville B, Rieger F, Rowell G, Rudak B, Ruiz-Velasco E, Sahakian V, Salzmann H, Santangelo A, Sasaki M, Schäfer J, Schüssler F, Schutte HM, Shapopi JNS, Sharma A, Sol H, Spencer S, Stawarz Ł, Steinmassl S, Steppa C, Suzuki H, Takahashi T, Tanaka T, Taylor AM, Terrier R, Tsirou M, van Eldik C, Vecchi M, Venter C, Vink J, Wach T, Wagner SJ, Wierzcholska A, Zacharias M, Zdziarski AA, Zech A, and Żywucka N

Abstract

Owing to their rapid cooling rate and hence loss-limited propagation distance, cosmic-ray electrons and positrons (CRe) at very high energies probe local cosmic-ray accelerators and provide constraints on exotic production mechanisms such as annihilation of dark matter particles. We present a high-statistics measurement of the spectrum of CRe candidate events from 0.3 to 40 TeV with the High Energy Stereoscopic System, covering 2 orders of magnitude in energy and reaching a proton rejection power of better than 10^{4}. The measured spectrum is well described by a broken power law, with a break around 1 TeV, where the spectral index increases from Γ_{1}=3.25±0.02(stat)±0.2(sys) to Γ_{2}=4.49±0.04(stat)±0.2(sys). Apart from the break, the spectrum is featureless. The absence of distinct signatures at multi-TeV energies imposes constraints on the presence of nearby CRe accelerators and the local CRe propagation mechanisms.

Published
2024
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10. Acceleration and transport of relativistic electrons in the jets of the microquasar SS 433.

Author

Aharonian F, Benkhali FA, Aschersleben J, Ashkar H, Backes M, Martins VB, Batzofin R, Becherini Y, Berge D, Bernlöhr K, Bi B, Böttcher M, Boisson C, Bolmont J, de Lavergne MB, Borowska J, Bouyahiaoui M, Breuhaus M, Brose R, Brown AM, 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 JD, Djannati-Ataï A, Dmytriiev A, Doroshenko V, Egberts K, Einecke S, Ernenwein JP, Filipovic M, Fontaine G, Füßling M, Funk S, Gabici S, Ghafourizadeh S, Giavitto G, Glawion D, Glicenstein JF, Grolleron G, Haerer L, Hinton JA, Hofmann W, Holch TL, 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 N, Kosack K, Kostunin D, Kundu A, Lang RG, Le Stum S, Leitl F, Lemière A, Lenain JP, Leuschner F, Lohse T, Luashvili A, Lypova I, Mackey J, Malyshev D, 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 AP, Ohm S, Olivera-Nieto L, de Ona Wilhelmi E, Ostrowski M, Panny S, Panter M, Parsons RD, Peron G, Prokhorov DA, 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 HR, Ruiz-Velasco E, Sahakian V, Salzmann H, Santangelo A, Sasaki M, Schäfer J, Schüssler F, Schwanke U, Shapopi JNS, 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 AM, Terrier R, Tsirou M, Tsuji N, Unbehaun T, van Eldik C, Vecchi M, Veh J, Venter C, Vink J, Wach T, Wagner SJ, Werner F, White R, Wierzcholska A, Wong YW, Zacharias M, Zargaryan D, Zdziarski AA, Zech A, Zouari S, and Żywucka N

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.

Published
2024
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11. Search for Dark Matter Annihilation Signals in the H.E.S.S. Inner Galaxy Survey.

Author

Abdalla H, Aharonian F, Benkhali FA, Angüner EO, Armand C, Ashkar H, Backes M, Baghmanyan V, Martins VB, Batzofin R, Becherini Y, Berge D, Bernlöhr K, Bi B, Böttcher M, Bolmont J, de Lavergne MB, Brose R, Brun F, Cangemi F, Caroff S, Cerruti M, Chand T, Chen A, Cotter G, Mbarubucyeye JD, Devin J, Djannati-Ataï A, Dmytriiev A, Doroshenko V, Egberts K, Fiasson A, de Clairfontaine GF, Fontaine G, Funk S, Gabici S, Giavitto G, Glawion D, Glicenstein JF, Grondin MH, Hinton JA, Hofmann W, Holch TL, Holler M, Horns D, Huang Z, Jamrozy M, Jankowsky F, Kasai E, Katarzyński K, Katz U, Khélifi B, Kluźniak W, Komin N, Kosack K, Kostunin D, Lamanna G, Lemoine-Goumard M, Lenain JP, Leuschner F, Lohse T, Luashvili A, Lypova I, Mackey J, Malyshev D, 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 AP, Ohm S, Olivera-Nieto L, Wilhelmi EO, Ostrowski M, Panny S, Panter M, Parsons RD, 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 HR, Ruiz-Velasco E, Sahakian V, Salzmann H, Santangelo A, Sasaki M, Schüssler F, Schutte HM, Schwanke U, Senniappan M, Shapopi JNS, 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 SJ, White R, Wierzcholska A, Wong YW, Zacharias M, Zargaryan D, Zdziarski AA, Zech A, Zhu SJ, Zouari S, and Żywucka N

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.

Published
2022
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12. Time-resolved hadronic particle acceleration in the recurrent nova RS Ophiuchi.

Author

Aharonian F, Ait Benkhali F, Angüner EO, 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 JP, Fegan S, Feijen K, Fiasson A, Fichet de Clairfontaine G, Fontaine G, Füßling M, Funk S, Gabici S, Gallant YA, Ghafourizadeh S, Giavitto G, Giunti L, Glawion D, Glicenstein JF, Grondin MH, Hermann G, Hinton JA, Hörbe M, Hofmann W, Hoischen C, Holch TL, Holler M, Horns D, Huang Z, Jamrozy M, Jankowsky F, Jung-Richardt I, Kasai E, Katarzyński K, Katz U, Khangulyan D, Khélifi B, Klepser S, Kluźniak W, Komin N, Konno R, Kosack K, Kostunin D, Le Stum S, Lemière A, Lemoine-Goumard M, Lenain JP, Leuschner F, Lohse T, Luashvili A, Lypova I, Mackey J, Malyshev D, 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 RD, Peron G, Pita S, Poireau V, Prokhorov DA, 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 DA, Santangelo A, Sasaki M, Schäfer J, Schüssler F, Schutte HM, Schwanke U, Senniappan M, Shapopi JNS, Simoni R, Sinha A, Sol H, Specovius A, Spencer S, Stawarz Ł, Steinmassl S, Steppa C, Takahashi T, Tanaka T, Taylor AM, 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 SJ, Werner F, White R, Wierzcholska A, Wong YW, Yusafzai A, Zacharias M, Zargaryan D, Zdziarski AA, Zech A, Zhu SJ, Zouari S, and Żywucka N

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.

Published
2022
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