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1. Chasing Gravitational Waves with the Cherenkov Telescope Array

Author: Green, Jarred Gershon, Carosi, Alessandro, Nava, Lara, Patricelli, Barbara, Schüssler, Fabian, Seglar-Arroyo, Monica, Consortium, Cta, Abe, Kazuki, Abe, Shotaro, Acharyya, Atreya, Adam, Remi, Aguasca-Cabot, Arnau, Agudo, Ivan, Alfaro, Jorge, Alvarez-Crespo, Nuria, Batista, Rafael Alves, Amans, Jean-Philippe, Amato, Elena, Ambrosino, Filippo, Angüner, Ekrem Oguzhan, Antonelli, Lucio Angelo, Aramo, Carla, Arcaro, Cornelia, Arrabito, Luisa, Asano, Katsuaki, Aschersleben, Jann, Ashkar, Halim, Stuani, Luiz Augusto, Baack, Dominik, Backes, Michael, Balazs, Csaba, Balbo, Matteo, Larriva, Andres Baquero, Martins, Victor Barbosa, de Almeida, Ulisses Barres, Barrio, Juan Abel, Bastieri, Denis, Batista, Pedro Ivo, Batković, Ivana, Batzofin, Rowan William, Baxter, Joshua Ryo, Beck, Geoffrey, Tjus, Julia Becker, Beiske, Lukas, Belardinelli, Daniele, Benbow, Wystan, Bernardini, Elisa, Medrano, Juan Bernete, Bernlöhr, Konrad, Berti, Alessio, Beshley, Vasyl, Bhattacharjee, Pooja, Bhattacharyya, Saptashwa, Bi, Baiyang, Biederbeck, Noah, Biland, Adrian, Bissaldi, Elisabetta, Blanch, Oscar, Blazek, Jiri, Boisson, Catherine, Bolmont, Julien, Bonnoli, Giacomo, Bordas, Pol, Bošnjak, Željka, Bradascio, Federica, Braiding, Catherine, Bronzini, Ettore, Brose, Robert, Brown, Anthony M., Brun, Francois, Brunelli, Giulia, Bulgarelli, Andrea, Burelli, Irene, Burmistrov, Leonid, Burton, Michael, Bylund, Tomas, Calisse, Paolo Gherardo, Campoy-Ordaz, Anna, Cantlay, Brandon Khan, Capalbi, Milvia, Caproni, Anderson, Capuzzo-Dolcetta, Roberto, Carlile, Colin, Caroff, Sami, Carosi, Roberto, Carrasco, Marie-Sophie, Cascone, Enrico, Cassol, Franca, Castrejon, Noelia, Catalani, Fernando, Cerasole, Davide, Cerruti, Matteo, Chaty, Sylvain, Chen, Andrew W, Chernyakova, Maria, Chiavassa, Andrea, Chudoba, Jiří, Araujo, Carlos Henrique Coimbra, Conforti, Vito, Conte, Francesco, Contreras, Jose Luis, Cossou, Christophe, Costa, Alessandro, Costantini, Heide, Cristofari, Pierre, Cuevas, Omar, Curtis-Ginsberg, Zachary, D'Amico, Giacomo, D'Ammando, Filippo, Dadina, Mauro, Dalchenko, Mykhailo, David, Ludovic, Davids, Isak Delberth, Dazzi, Francesco, De Angelis, Alessandro, de Lavergne, Mathieu de Bony, De Caprio, Vincenzo, De Cesare, Giovanni, Pino, Elisabete M. de Gouveia Dal, De Lotto, Barbara, de Lucia, Mario, de Menezes, Raniere, de Naurois, Mathieu, Wilhelmi, Emma de Oña, De Simone, Nicola, de Souza, Vitor, Del Peral, Luis, del Valle, Maria Victoria, Delagnes, Eric, Giler, Andres Gabriel Delgado, Delgado, Carlos, Dell'aiera, Michael, Della Ceca, Roberto, Della Valle, Massimo, Della Volpe, Domenico, Depaoli, Davide, Dettlaff, Antonios, Di Girolamo, Tristano, Di Piano, Ambra, Di Pierro, Federico, Di Tria, Riccardo, Di Venere, Leonardo, Díaz-Bahamondes, Christian, Dib, Claudio, Diebold, Sebastian, Dima, Razvan, Dinesh, Adithiya, Djannati-Ataï, Arache, Djuvsland, Julia Isabel, Dominguez, Alberto, Dominik, Rune Michael, Donini, Alice, Dorner, Daniela, Dörner, Julien, Doro, Michele, Anjos, Rita de Cassia dos, Dournaux, Jean-Laurent, Dravins, Dainis, Duangchan, Chaimongkol, Dubos, Coline, Ducci, Lozenzo, Dwarkadas, Vikram V., Ebr, Jan, Eckner, Christopher, Egberts, Kathrin, Einecke, Sabrina, Elsässer, Dominik, Emery, Gabriel, Godoy, Miguel Escobar, Escudero, Juan, Esposito, Paolo, Falceta-Gonçalves, Diego, Ramazani, Vandad Fallah, Faure, Alice, Fedorova, Elena, Fegan, Stephen, Feijen, Kirsty, Feng, Qi, Ferrand, Gilles, Ferrarotto, Fabio, Fiandrini, Emanuele, Fiasson, Armand, Fioretti, Valentina, Foffano, Luca, Guiteras, Lluis Font, Fontaine, Gerard, Fröse, Stefan, Fukami, Satoshi, Fukui, Yasuo, Funk, Stefan, Gaggero, Daniele, Galanti, Giorgio, Galaz, Gaspar, Gallant, Yves A., Gallozzi, Stefano, Gammaldi, Viviana, Gasbarra, Claudio, Gaug, Markus, Ghalumyan, Arsen, Gianotti, Fulvio, Giarrusso, Marina, Giglietto, Nicola, Giordano, Francesco, Giuliani, Andrea, Glicenstein, Jean-Francois, Glombitza, Jonas, Goldoni, Paolo, González, José Mauricio, González, Maria Magdalena, Coelho, Jaziel Goulart, Granot, Jonathan, Grasso, Dario, Haro, Roger Grau, Green, David, Greenshaw, Tim, Grolleron, Guillaume, Grube, Jeff, Gueta, Orel, Gunji, Shuichi, Hadasch, Daniela, Hamal, Petr, Hanlon, William, Hara, Satoshi, Harvey, Violet M., Hashiyama, Kazuaki, Hassan, Tarek, Heller, Matthieu, Cadena, Sergio Hernández, Hie, Jonathan, Hiroshima, Nagisa, Hnatyk, Bohdan, Hnatyk, Roman, Hoffmann, Dirk, Hofmann, Werner, Holler, Markus, Horan, Deirdre, Horvath, Pavel, Hovatta, Talvikki, Hrupec, Dario, Hussain, Saqib, Iarlori, Marco, Inada, Tomohiro, Incardona, Federico, Inome, Yusuke, Inoue, Susumu, Iocco, Fabio, Ishio, Kazuma, Jamrozy, Marek, Janecek, Petr, Jankowsky, Felix, Jarnot, Christian, Jean, Pierre, Martínez, Irene Jiménez, Jin, Weidong, Jocou, Laurent, Juramy-Gilles, Claire, Jurysek, Jakub, KALEKIN, Oleg, Kantzas, Dimitrios, Karas, Vladimir, Kaufmann, Sarah, Kerszberg, Daniel, Khelifi, Bruno, Kieda, David B, Kleiner, Tobias Kai, Kluźniak, Włodzimierz, Kobayashi, Yukiho, Kohri, Kazunori, Komin, Nukri, Kornecki, Paula, Kosack, Karl, Kubo, Hidetoshi, Kushida, Junko, La Barbera, Antonino, La Palombara, Nicola, Lainez, Maria, Lamastra, Alessandra, Lapington, Jon S, Lazarevic, Sanja, Lazendic-Galloway, Jasmina, Leach, Steven, Lemoine-Goumard, Marianne, Lenain, Jean-Philippe, Leto, Giuseppe, Leuschner, Fabian, Lindfors, Elina, Linhoff, Maximilian, Liodakis, Ioannis, Loïc, Lozach, Lombardi, Saverio, Longo, Francesco, López-Coto, Rubén, López-Moya, Marcos, López-Oramas, Alicia, Loporchio, Serena, Bahilo, Julio Lozano, Luque-Escamilla, Pedro L., Macias, Oscar, Maier, Gernot, Majumdar, Pratik, Malyshev, Denys, Malyshev, Dmitry, Mandat, Dusan, Manicò, Giulio, Marinos, Peter David, Markoff, Sera, Márquez, Isabel, Marquez, Patricia, Marsella, Giovanni, Martí, Josep, Martin, Pierrick, Martínez, Gustavo Augusto, Martínez, Manel, Martinez, Oibar, Marty, Christophe, Mas-Aguilar, Alvaro, Mastropietro, Michele, Maurin, Gilles, Max-Moerbeck, Walter, Mazin, Daniel, Melkumyan, David, Menchiari, Stefano, Mestre, Enrique, Meunier, Jean-Luc, Meyer, Dominique M. -A., Miceli, Davide, Michailidis, Miltiadis, Michałowski, Jerzy, Miener, Tjark, Miranda, Jose Miguel, Mitchell, Alison, Mizote, Masaya, Mizuno, Tsunefumi, Moderski, Rafal, Mohrmann, Lars, Molero, Miguel, Molfese, Cesare, Molina, Edgar, Montaruli, Teresa, Moralejo, Abelardo, Morcuende, Daniel, Morik, Katharina, Morselli, Aldo, Moulin, Emmanuel, Zamanillo, Victor Moya, Mukherjee, Reshmi, Munari, Kevin, Muraczewski, Adam, Muraishi, Hiroshi, Nakamori, Takeshi, Nayak, Amrit, Nemmen, Rodrigo, Nickel, Lukas, Niemiec, Jacek, Nieto, Daniel, Rosillo, Mireia Nievas, Nikołajuk, Marek, Nishijima, Kyoshi, Noda, Koji, Nosek, Dalibor, Novosyadlyj, Bohdan, Novotný, Vladimír, Nozaki, Seiya, O'Brien, Paul, Ohishi, Michiko, Ohtani, Yoshiki, Okumura, Akira, Olive, Jean-François, Olmi, Barbara, Ong, Rene A., Orienti, Monica, Orito, Reiko, Orlandini, Mauro, Orlando, Elena, Ostrowski, Michal, Otte, Nepomuk, Oya, Igor, Pagano, Isabella, Pagliaro, Antonio, Palatiello, Michele, Panebianco, Gabriele, Paredes, Josep M., Parmiggiani, Nicolò, Patel, Sonal Ramesh, Pavlović, Dijana, Pe'er, Asaf, Pech, Miroslav, Pecimotika, Mario, Peresano, Michele, Pérez-Romero, Judit, Peron, Giada, Persic, Massimo, Petrucci, Pierre-Olivier, Petruk, Oleh, Pfeifle, Felix, Pintore, Fabio, Pirola, Giorgio, Pittori, Carlotta, Plard, Cyann, Podobnik, Franjo, Pohl, Martin, Pons, Estelle, Prandini, Elisa, Prast, Julie, Principe, Giacomo, Priyadarshi, Chaitanya, Produit, Nicolas, Prokhorov, Dmitry, Pueschel, Elisa, Pühlhofer, Gerd, Pumo, Maria Letizia, Punch, Michael, Quirrenbach, Andreas, Raino, Silvia, Randazzo, Nunzio, Rando, Riccardo, Ravel, Thierry, Razzaque, Soebur, Regeard, Maxime, Reichherzer, Patrick, Reimer, Anita, Reimer, Olaf, Reisenegger, Andreas, Reposeur, Thierry, Reville, Brian, Rhode, Wolfgang, Ribó, Marc, Richtler, Tom, Rieger, Frank, Roache, Emmet, Fernandez, Gonzalo Rodriguez, Frías, Maria Dolores Rodríguez, Rodríguez-Vázquez, Juan José, Romano, Patrizia, Romeo, Giuseppe, Rosado, Jaime, Rowell, Gavin P, Rudak, Bronislaw, Ruiter, Ashley J., Rulten, Cameron Boyd, Russo, Federico, Sadeh, Iftach, Saha, Lab, Saito, Takayuki, Sakurai, Shunsuke, Salzmann, Heiko, Sanchez, David, Sanchez-Conde, Miguel, Sangiorgi, Pierluca, Sano, Hidetoshi, Santander, Marcos, Santangelo, Andrea, Santos-Lima, Reinaldo, Sanuy, Andreu, Šarić, Toni, Sarkar, Arkadipta, Sarkar, Subir, Saturni, Francesco Gabriele, Savchenko, Volodymyr, Scherer, Andres, Schipani, Pietro, Schleicher, Bernd, Schovanek, Petr, Schubert, Jan Lukas, Schwanke, Ullrich, Schwefer, Georg, Scuderi, Salvatore, Arroyo, Monica Seglar, Seitenzahl, Ivo, Sergijenko, Olga, Sguera, Vito, Shang, Ruo-Yu, Sharma, Pooja, Sidibe, Guereguin Der Sylvestre, Sidoli, Lara, Siejkowski, Hubert, Siqueira, Clarissa, Sizun, Patrick, Sliusar, Vitalii, Slowikowska, Agnieszka, Sol, Helene, Specovius, Andreas, Spencer, Samuel Timothy, Spiga, Daniele, Stamerra, Antonio, Stanič, Samo, Starecki, Tomasz, Starling, Rhaana, Steppa, Constantin, Stolarczyk, Thierry, Strišković, Jelena, Strzys, Marcel C., Suda, Yusuke, Suomijarvi, Tiina, Tak, Donggeun, Takahashi, Mitsunari, Takeishi, Ryuji, Tam, Pak-Hin Thomas, Tanaka, Shuta J, Tanaka, Takaaki, Terauchi, Kenta, Testa, Vincenzo, Tibaldo, Luigi, Tibolla, Omar, Torradeflot, Francesc, Torres, Diego F., Torresi, Eleonora, Tothill, Nick, Toussenel, Francois, Touzard, Victoria, Tramacere, Andrea, Travnicek, Petr, Tripodo, Giovanni, Truzzi, Stefano, Tsiahina, Adellain, Tutone, Antonio, Vacula, Martin, Vallage, Bertrand, Vallania, Piero, Vallés, Ramon, van Eldik, Christopher, van Scherpenberg, Juliane, Vandenbroucke, Justin, Vassiliev, Vladimir, Venault, Philippe, Ventura, Sofia, Vercellone, Stefano, Verna, Gaia, Viana, Aion, Viaux, Nicolás, Vigliano, Alessandro, Vignatti, Jonatan, Vigorito, Carlo francesco, Vitale, Vincenzo, Vodeb, Veronika, Voisin, Vincent, Vorobiov, Serguei, Voutsinas, Georgios Gerasimos, Vovk, Ievgen, Waegebaert, Vincent, Wagner, Stefan Joachim, Walter, Roland, Ward, Martin, Wechakama, Maneenate, White, Richard, Wierzcholska, Alicja, Will, Martin, Williams, David A., Wohlleben, Frederik, Wolter, Anna, Yamamoto, Tokonatsu, Yamazaki, Ryo, Yang, Lili, Yoshida, Tatsuo, Yoshikoshi, Takanori, Zacharias, Michael, Sanchez, Ricardo Zanmar, Zavrtanik, Danilo, Zavrtanik, Marko, Zdziarski, Andrzej A., Zech, Andreas, Zhdanov, Valery I., Ziȩtara, Krzysztof, Živec, Miha, and Zuriaga-Puig, Jaume
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: The detection of gravitational waves from a binary neutron star merger by Advanced LIGO and Advanced Virgo (GW170817), along with the discovery of the electromagnetic counterparts of this gravitational wave event, ushered in a new era of multimessenger astronomy, providing the first direct evidence that BNS mergers are progenitors of short gamma-ray bursts (GRBs). Such events may also produce very-high-energy (VHE, > 100GeV) photons which have yet to be detected in coincidence with a gravitational wave signal. The Cherenkov Telescope Array (CTA) is a next-generation VHE observatory which aims to be indispensable in this search, with an unparalleled sensitivity and ability to slew anywhere on the sky within a few tens of seconds. New observing modes and follow-up strategies are being developed for CTA to rapidly cover localization areas of gravitational wave events that are typically larger than the CTA field of view. This work will evaluate and provide estimations on the expected number of of gravitational wave events that will be observable with CTA, considering both on- and off-axis emission. In addition, we will present and discuss the prospects of potential follow-up strategies with CTA., Comment: Presented at the 38th International Cosmic Ray Conference (ICRC 2023), 2023 (arXiv:2309.08219)
Published: 2023

2. H.E.S.S. realtime follow-ups of IceCube high-energy neutrino alerts

Author: Bradascio, Federica, Ashkar, Halim, Borowska, Jowita, Mbarubucyeye, Jean Damascene, Oukacha, Enzo, Schüssler, Fabian, Suzuki, Hiromasa, and Wierzcholska, Alicja
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: The evidence for multi-messenger photon and neutrino emission from the blazar TXS 0506+056 has demonstrated the importance of realtime follow-up of neutrino events by various ground- and space-based facilities. The effort of H.E.S.S. and other experiments in coordinating observations to obtain quasi-simultaneous multiwavelength flux and spectrum measurements has been critical in measuring the chance coincidence with the high-energy neutrino event IC-170922A and constraining theoretical models. For about a decade, the H.E.S.S. transient program has included a search for gamma-ray emission associated with high-energy neutrino alerts, looking for gamma-ray activity from known sources and newly detected emitters consistent with the neutrino location. In this contribution, we present an overview of follow-up activities for realtime neutrino alerts with H.E.S.S. in 2021 and 2022. Our analysis includes both public IceCube neutrino alerts and alerts exchanged as part of a joint H.E.S.S.-IceCube program. We focus on interesting coincidences observed with gamma-ray sources, particularly highlighting the significant detection of PKS 0625-35, an AGN previously detected by H.E.S.S., and three IceCube neutrinos., Comment: Presented at the 38th International Cosmic Ray Conference (ICRC2023). See arXiv:2307.13047 for all IceCube contributions
Published: 2023

3. X-ray intraday variability of the TeV blazar Mrk 421 with {\it XMM-Newton}

Author: Noel, A Priyana, Gaur, Haritma, Gupta, Alok C., Wierzcholska, Alicja, Ostrowski, Michal, Dhiman, Vinit, and Bhatta, Gopal
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: Highly variable Markarian 421 is a bright high synchrotron energy peaked blazar showing wide featureless non-thermal spectrum making it a good candidate for our study of intraday flux and spectral variations over time. We analyse its X-ray observations of over 17 years taken with the EPIC-PN instrument to probe into the intraday variability properties. The photon energy band of 0.3 - 10.0 keV, and its sub-bands, soft 0.3-2.0 keV and hard 2.0-10.0 keV. To examine flux variability, fractional variability amplitude and the minimum variability timescale have been calculated. We also probed into the spectral variability by studying hardness ratio for each observation and the correlation between the two energy bands using discrete correlation function and inspecting the normalized light curves. The parameters obtained from these methods have been studied for any correlation or non-random trends. From this work, we speculate on the constraints for possible particle acceleration and emission processes in the jet, for better understanding of the processes involving a turbulent behaviour except of shocks. A positive discrete correlation function between the two sub-bands indicates the role of the same electron population in the emission of photons in the two bands. The correlation between the parameters of flux variability and parameters of spectral variation and lags in sub-energy bands provide the constraints to be considered for any modelling of emission processes., Comment: Accepted in APJS on 31 May 2022; Online supplementary material of paper placed in ancillary material on arxiv
Published: 2022

4. Is PKS 0625-354 another variable TeV active galactic nucleus?

Author: Glawion, Dorit and Wierzcholska, Alicja
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: The majority of the active galactic nuclei (AGN) detected at very-high-energies above 100 GeV belong to the class of blazars with a small angle between the jet-axis and the line-of-sight. Only about 10 percent of the gamma-ray AGN are objects with a larger viewing angle resulting in a smaller Doppler boosting of the emission. Originally, it was believed that gamma-ray emission can only be observed from blazars and those are variable in its brightness. Instead, the last years have shown that non-blazar active galaxies also show a fascinating variability behaviour which provide important new insights into the physical processes responsible for the gamma-ray production and especially for flaring events. Here, we report on the observation of gamma-ray variability of the active galaxy PKS 0625-354 detected with the H.E.S.S. telescopes in November 2018. The classification of PKS 0625-354 is a still matter of debate. The H.E.S.S. measurements were performed as part of a flux observing program and showed in the first night of the observation a detection of the object with >5sigma. A denser observation campaign followed for the next nine nights resulting in a decrease of the gamma-ray flux. Those observations were accompanied with Swift in the X-ray and UV/optical band allowing for the reconstruction of a multi-band broad-band spectral energy distribution. We will discuss the implications of the gamma-ray variability of the object., Comment: Proceedings of the 37th International Cosmic Ray Conference (ICRC 2021)
Published: 2021

5. The ablation of gas clouds by blazar jets and the long-lasting flare in CTA 102

Author: Zacharias, Michael, Heil, Jonathan, Boettcher, Markus, Jankowsky, Felix, Lenain, Jean-Philippe, Wagner, Stefan, and Wierzcholska, Alicja
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies
Abstract: Long-lasting, very bright multiwavelength flares of blazar jets are a curious phenomenon. The interaction of a large gas cloud with the jet of a blazar may serve as a reservoir of particles entrained by the jet. The size and density structure of the cloud then determine the duration and strength of the particle injection into the jet and the subsequent radiative outburst of the blazar. In this presentation, a comprehensive parameter study is provided showing the rich possibilities that this model offers. Additionally, we use this model to explain the 4-months long, symmetrical flare of the flat spectrum radio quasar CTA 102 in late 2016. During this flare, CTA 102 became one of the brightest blazars in the sky despite its large redshift of $z=1.032$., Comment: Proceedings contribution of the 37th International Cosmic Ray Conference (ICRC 2021)
Published: 2021

6. Constraining X-ray emission in HBL blazars using multiwavelength observations

Author: Wierzcholska, Alicja and Wagner, Stefan
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: The X-ray spectrum of extreme HBL type blazars is located in the synchrotron branch of the broadband spectral energy distribution (SED), at energies below the peak. A joint fit of the extrapolated X-ray spectra together with a host galaxy template allows characterizing the synchrotron branch in the SED. The X-ray spectrum is usually characterized either with a pure or a curved power-law model. In the latter case, however, it is hard to distinguish an intrinsic curvature from excess absorption. In this paper, we focus on five well-observed blazars: 1ES 0229+200, PKS 0548-322, RX J1136+6737, 1ES 1741+196, 1ES 2344+514. We constrain the infrared-to-X-ray emission of these five blazars using a model that is characterized by the host galaxy, spectral curvature, absorption, and ultraviolet excess to separate these spectral features. In the case of four sources: 1ES 0229+200, PKS 0548-322, 1ES 1741+196, 1ES 2344+514 the spectral fit with the atomic neutral hydrogen from the Leiden Argentina Bonn Survey result in a significant UV excess present in the broadband spectral energy distribution. Such excess can be interpreted as an additional component, for example, a blue bump. However, in order to describe spectra of these blazars without such excess, additional absorption to the atomic neutral hydrogen from the Leiden Argentina Bonn Survey is needed., Comment: 12 pages, 6 figures, accepted for publication in MNRAS
Published: 2020
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7. Unraveling The Complex Nature Of The Very High-Energy $\gamma$-Ray Blazar PKS 2155-304

Author: Wierzcholska, Alicja, Zacharias, Michael, Jankowsky, Felix, Wagner, Stefan, and Collaboration, H. E. S. S.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: PKS 2155-304 is a blazar located in the Southern Hemisphere, monitored with the High Energy Stereoscopic System (H.E.S.S.) at very high energy (VHE, E>100 GeV) $\gamma$ rays every year since 2002. Thanks to the large data set collected in the VHE range and simultaneous coverage in optical, ultraviolet (UV), X-ray and high energy $\gamma$-ray ranges, this object is an excellent laboratory to study spectral and temporal variability in blazars. However, despite many years of dense monitoring, the nature of the variability observed in PKS 2155-304 remains puzzling. In this paper, we discuss the complex spectral and temporal variability observed in PKS 2155-304. The data discussed include VHE $\gamma$-ray data collected with H.E.S.S. between 2013 and 2016, complemented with multiwavelength (MWL) observations from Fermi-LAT, Swift-XRT, Swift-UVOT, SMARTS, and the ATOM telescope. During the period of monitoring, PKS 2155-304 was transitioning from its lower state to the flaring states, and exhibiting different flavors of outbursts. For the first time, orphan optical flare lasting a few months was observed. Correlation studies show an indication of correlation between the X-ray and VHE $\gamma$-ray fluxes. Interestingly, a comparison of optical and X-ray or VHE $\gamma$-ray fluxes does not show global correlation. However, two distinct tracks in the diagram were found, which correspond to the different flaring activity states of PKS 2155-304., Comment: Proceedings paper of "High Energy Phenomena in Relativistic Outflows VII - HEPRO VII", held 9-12 July 2019 at Facultat de F\'isica, Universitat de Barcelona, Spain; accepted by PoS
Published: 2019

8. Observations of blazar PKS 2023-07 in flaring state with HESS and Fermi-LAT in 2016-2017 and constraints on an intrinsic cut-off

Author: Emery, Gabriel, Jankowsky, Felix, Lenain, Jean-Philippe, Marais, Johannes Petrus, Mbonani, Tekano, Meyer, Manuel, Romoli, Carlo, van Soelen, Brian, Wierzcholska, Alicja, and Zacharias, Michael
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: PKS 2023-07 is a flat spectrum radio quasar located at a redshift $z=1.388$, farther than any source currently detected at very high energies ($E>100$ GeV). At such energies, absorption by the extragalactic background light (EBL) renders the detection of distant sources particularly challenging. The High Energy Stereoscopic System (H.E.S.S.) observed the source following reports from AGILE (April 2016) and Fermi-LAT (April 2016, September and October 2017) on high-flux states in gamma rays. During each of the three flaring periods, near-simultaneous observations were obtained with H.E.S.S., Fermi-LAT and multiple telescopes at other wavelengths. Though the source was not significantly detected by H.E.S.S., upper limits were derived for each observation period. Through constraints given by Fermi-LAT in the MeV--GeV domain and differential upper limits by H.E.S.S., we searched for an intrinsic cutoff in the EBL-corrected gamma ray spectrum of PKS 2023-07., Comment: Proceedings of the 36th International Cosmic Ray Conference, 2019, Madison, WI, USA
Published: 2019

9. H.E.S.S. Monitoring of PKS 2155-304 in 2015 and 2016

Author: Wierzcholska, Alicja, Zacharias, Michael, Jankowsky, Felix, Wagner, Stefan, and Collaboration, H. E. S. S.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: PKS 2155-304 is one of the brightest blazar located in Southern Hemisphere, monitored with H.E.S.S. since the first light of the experiment. Here we report multiwavelength monitoring observations collected during the period of 2015-2016 with H.E.S.S.,Fermi-LAT, Swift-XRT, Swift-UVOT, and ATOM. Two years of multiwavelength data with very good temporal coverage allowed to characterize broadband emission observed from the region of PKS 2155-304 and study potential multifrequency correlations. During the period of monitoring, PKS 2155-304 revealed complex multiwavelength variability with two outbursts characterized by completely different multiband properties. The 2015 activity of the blazar is characterized by a flare observed at all wavelengths studied. The broadband emission observed during the outburst is well correlated without any time lags. Contrary to 2015, in 2016, only orphan outburst in the optical and ultraviolet wavelengths was observed. Such an orphan activity is reported for the first time for the blazar PKS 2155-304., Comment: 10 pages, 2 figures, conference paper for the workshop "Monitoring the non-thermal Universe 2018" held in Cochem in September 2018
Published: 2019
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10. The VHE Gamma-Ray View of the FSRQ PKS~1510-089

Author: Zacharias, Michael, Prester, Dijana Dominis, Jankowsky, Felix, Lindfors, Elina, Meyer, Manuel, Mohamed, Mahmoud, Prokoph, Heike, Sanchez, David, Sitarek, Julian, Terzic, Tomislav, Wagner, Stefan, and Wierzcholska, Alicja
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies
Abstract: The flat spectrum radio quasar PKS 1510-089 is a monitored target in many wavelength bands due to its high variability. It was detected as a very-high-energy (VHE) $\gamma$-ray emitter with H.E.S.S. in 2009, and has since been a regular target of VHE observations by the imaging Cherenkov observatories H.E.S.S. and MAGIC. In this paper, we summarize the current state of results focusing on the monitoring effort with H.E.S.S. and the discovery of a particularly strong VHE flare in 2016 with H.E.S.S. and MAGIC. While the source has now been established as a weak, but regular emitter at VHE, no correlation with other energy bands has been established. This is underlined by the 2016 VHE flare, where the detected optical and high-energy $\gamma$-ray counterparts evolve differently than the VHE flux., Comment: 11 pages, 8 figures, conference paper for the workshop "Monitoring the non-thermal Universe 2018" held in Cochem in September 2018
Published: 2019

11. The Long-Lasting Activity in the Flat Spectrum Radio Quasar (FSRQ) CTA~102

Author: Zacharias, Michael, Böttcher, Markus, Jankowsky, Felix, Lenain, Jean-Philippe, Wagner, Stefan J., and Wierzcholska, Alicja
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies
Abstract: The flat spectrum radio quasar CTA 102 ($z = 1.032$) went through a tremendous phase of variability. Since early 2016 the gamma-ray flux level has been significantly higher than in previous years. It was topped by a four month long giant outburst, where peak fluxes were more than 100 times higher than the quiescence level. Similar trends are observable in optical and X-ray energies. We have explained the giant outburst as the ablation of a gas cloud by the relativistic jet that injects additional matter into the jet and can self-consistently explain the long-term light curve. Here, we argue that the cloud responsible for the giant outburst is part of a larger system that collides with the jet and is responsible for the years-long activity in CTA 102., Comment: 9 pages, 5 figures, accepted by Galaxies as part of the special issue "Monitoring the non-thermal Universe", a conference held in Cochem, Germany, 17th - 21st September 2018
Published: 2019

12. The extended flare in CTA 102 in 2016 and 2017 within a hadronic model through cloud ablation by the relativistic jet

Author: Zacharias, Michael, Böttcher, Markus, Jankowsky, Felix, Lenain, Jean-Philippe, Wagner, Stefan, and Wierzcholska, Alicja
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies
Abstract: The flat spectrum radio quasar CTA 102 (redshift 1.037) exhibited a tremendously bright 4-months long outburst from late 2016 to early 2017. In a previous paper, we interpreted the event as the ablation of a gas cloud by the relativistic jet. The multiwavelength data have been reproduced very well within this model using a leptonic emission scenario. Here we expand that work by using a hadronic scenario, which gives us greater freedom with respect to the location of the emission region within the jet. This is important, since the inferred gas cloud parameters depend on the distance from the black hole. While the hadronic model faces the problem of invoking super-Eddington jet luminosities, it reproduces well the long-term trend and also days-long subflares. While the latter result in inferred cloud parameters that match those expected for clouds of the broad-line region, the long-term trend is not compatible with such an interpretation. We explore the possibilities that the cloud is from the atmosphere of a red giant star or comes from a star-forming region that passes through the jet. The latter could also explain the much longer-lasting activity phase of CTA 102 from late 2015 till early 2018., Comment: 20 pages, 9 figures, 8 tables, accepted for publication in ApJ
Published: 2018
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13. Characterizing long-term optical, ultraviolet and X-ray variability in different activity states of OJ 287

Author: Siejkowski, Hubert and Wierzcholska, Alicja
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: We have studied long-term optical, ultraviolet (UV) and X-ray observations of OJ 287 collected with the UVOT and XRT instruments mounted on board the Swift satellite to quantify spectral and temporal variability patterns observed during different activity states. We characterized the flux variations using the data collected during almost 11 yr of the monitoring of the blazar. Significant variability of the blazar has been detected both in the flux and spectral index from the optical to X-ray regimes. We noted that the variability patterns observed in the optical range are more pronounced than the ones in the X-ray band. There is no clear relation between the optical/UV and X-ray emission, neither during the quiescence state nor during outbursts. The most significant flares in the optical/UV regime were detected in 2015 December-2016 January. The shortest variability time-scale is one day and it is limited by the observation pointing. A low activity state of OJ 287 was observed at the end of 2014, while the beginning of 2015 revealed a flat X-ray spectrum, which has been observed for the first time. On one hand, this can be a spectral upturn where the synchrotron and inverse Compton components meet, but on the other hand, it can be generated by an additional emission component. The spectral studies have not revealed any bluer-when-brighter or redder-when-brighter chromatism in the colour-magnitude diagram for OJ 287 in any state of the source's activity. A harder-when-brighter behaviour was noticed for OJ 287 only in the case of the X-ray observations., Comment: 10 pages, 9 figures
Published: 2018
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14. Signature of Inverse Compton emission from blazars

Author: Gaur, Haritma, Mohan, P., Wierzcholska, Alicja, and Gu, Minfeng
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: Blazars are classified into high, intermediate and low energy peaked sources based on the location of their synchrotron peak. This lies in infra-red/optical to ultra-violet bands for low and intermediate peaked blazars. The transition from synchrotron to inverse Compton emission falls in the X-ray bands for such sources. We present the spectral and timing analysis of 14 low and intermediate energy peaked blazars ob- served with XMMNewton spanning 31 epochs. Parametric fits to X-ray spectra helps constrain the possible location of transition from the high energy end of the syn- chrotron to the low energy end of the inverse Compton emission. In seven sources in our sample, we infer such a transition and constrain the break energy in the range 0.6 10 keV. The Lomb-Scargle periodogram is used to estimate the power spectral density (PSD) shape. It is well described by a power law in a majority of light curves, the index being flatter compared to general expectation from AGN, ranging here between 0.01 and 1.12, possibly due to short observation durations resulting in an absence of long term trends. A toy model involving synchrotron self-Compton (SSC) and exter- nal Compton (EC; disk, broad line region, torus) mechanisms are used to estimate magnetic field strength 6 0.03 - 0.88 G in sources displaying the energy break and infer a prominent EC contribution. The timescale for variability being shorter than synchrotron cooling implies steeper PSD slopes which are inferred in these sources., Comment: 24 pages, 6 Tables, 13 figures, Accepted for MNRAS
Published: 2017
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15. Monitoring of the FSRQ PKS 1510-089 with H.E.S.S

Author: Zacharias, Michael, Jankowsky, Felix, Mohamed, Mahmoud, Prokoph, Heike, Sanchez, David, Wagner, Stefan, and Wierzcholska, Alicja
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: The flat spectrum radio quasar (FSRQ) PKS 1510-089 (z=0.361) is known for its complex multiwavelength behavior. It has been monitored regularly at very high energy (VHE, $E>100\,$GeV) gamma-rays with H.E.S.S. since its discovery in 2009 in order to study the unknown behavior of FSRQs in quiescence at VHE, as well as the flux evolution around flaring events. Given the expected strong cooling of electrons and the absorption of VHE emission within the broad-line region, a detection of PKS 1510-089 at VHE in a quiescent state would be an important result, implying an acceleration and emission region on scales beyond the broad-line region. The H.E.S.S. monitoring has been intensified since 2015 and is complemented by monitoring at high energy ($E>100\,$MeV) gamma-rays with Fermi, at X-rays with Swift-XRT, and at optical frequencies with ATOM. The dense lightcurves allow for the first time detailed comparison studies between these energy bands. The source has been active in several frequency bands for a large fraction of the observation time frames. Yet, we do not find obvious correlations between the VHE and the other bands over the observed time frame indicating a non-trivial interplay of the acceleration, cooling and radiative processes. It also implies a rich variety in flaring behavior, which makes this source difficult to interpret within a unique theoretical framework., Comment: To appear in Proceedings of 35th ICRC, Busan (Korea) 2017
Published: 2017

16. The Exceptional Flare of Mrk 501 in 2014: Combined Observations with H.E.S.S. and FACT

Author: Cologna, Gabriele, Chakraborty, Nachiketa, Jacholkowska, Agnieszka, Lorentz, Matthias, Mohamed, Mahmoud, Perennes, Cedric, Romoli, Carlo, Wagner, Stefan J., Wierzcholska, Alicja, Dorner, Daniela, and Kurtanidze, Omar
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: The BL Lac type object Mrk 501 was observed at very high energies (E > 100 GeV) in 2014 with the upgraded H.E.S.S. (High Energy Stereoscopic System) phase 2 array. The data collected with the central 28m telescope allow for a broader energy range extending to lower energies when compared to the one obtained with the four small telescopes alone. A strong flaring event with a flux level comparable to the 1997 historical maximum has been detected as a consequence of target of opportunity observations triggered by alerts from the FACT collaboration. The First G-APD Cherenkov Telescope (FACT) is continuously monitoring bright blazars at TeV energies providing important pre- and post-flare information. For the first time, the data and lightcurves from H.E.S.S. and FACT are compared. These contemporaneous observations allow for a better characterization of the source emission. In a multiwavelength context, more precise correlation studies between VHE and lower energies are possible thanks to the dense sampling of the FACT observations. The hard intrinsic spectrum detected by H.E.S.S. during the flare allows the derivation of strong constraints on the scale of Lorentz invariance violation via the non-detection of EBL opacity modifications and from time-of-flight studies., Comment: 6 pages, 5 figures, proceeding Gamma 2016
Published: 2016
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17. The Complex VHE And Multiwavelength Flaring Activity Of The FSRQ PKS 1510-089 In May 2015

Author: Zacharias, Michael, Böttcher, Markus, Chakraborty, Nachiketa, Cologna, Gabriele, Jankowsky, Felix, Lenain, Jean-Philippe, Mohamed, Mahmoud, Prokoph, Heike, Wagner, Stefan, Wierzcholska, Alicja, and Zaborov, Dmitry
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: The blazar PKS 1510-089 was the first of the flat spectrum radio quasar type, which had been detected simultaneously by a ground based Cherenkov telescope (H.E.S.S.) and the LAT instrument on board the Fermi satellite. Given the strong broad line region emission defining this blazar class, and the resulting high optical depth for VHE ($E>100\,$GeV) $\gamma$-rays, it was surprising to detect VHE emission from such an object. In May 2015, PKS 1510-089 exhibited high states throughout the electromagnetic spectrum. Target of Opportunity observations with the H.E.S.S. experiment revealed strong and unprecedented variability of this source. Comparison with the lightcurves obtained with the \textit{Fermi}-LAT in HE $\gamma$-rays ($100\,$MeV$
Published: 2016
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18. First hard X-ray observations of the blazar S5 0716+714 with NuSTAR during a multiwavelength campaign

Author: Wierzcholska, Alicja and Siejkowski, Hubert
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: We report the results of a multifrequency campaign targeting S5 0716+714 in the flaring state of the source observed in 2015 January and February. The observations have been performed using the following instruments: Fermi/Large Area Telescope (LAT), Nuclear Spectroscopic Telescope Array, X-ray Telescope and Ultraciolet/Optical Telescope. The elevated flux level was visible in all frequencies and the outburst consists of five sub-flares. In this paper we focus on the analysis of the X-ray observations both in the soft and hard regimes for data collected with NuStar and Swift/XRT. This is the first time, when hard X-ray observations of the source collected with NuStar are reported. The studies reveal both low- and high-energy components clearly visible in the energy band, with the break energy of 8 keV, which is the highest break energy ever reported for S5 0716+714. The second part of this work is concentrated on multifrequency observations collected during the flaring activity period. The variability patterns recorded during the period are characterized using a fractional variability amplitude and description of the flare profiles. The correlation studies reveal strong and significant relation between the optical, ultraviolet and gamma-ray observations, and no time lag is found for any of the studied relations.
Published: 2016
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19. Nine years of multi-frequency monitoring of the blazar PKS 0048-097: spectral and temporal variability

Author: Wierzcholska, Alicja
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: Blazars are highly variable, radio-loud active galactic nuclei with jets oriented at a small angle to the line of sight. The observed emission of these sources covers the whole electromagnetic spectrum from radio frequencies up to the high or even very high energy gamma-ray range. To understand the complex physics of these objects, multi-wavelength observations and studies on the variability and correlations between different wavelengths are therefore essential. The long-term multi-frequency observations of PKS 0048-097 are analysed here to investigate its spectral and temporal features. The studies includes nine years of observations of the blazar, which is well studied in the optical and radio domain, but not in the other frequencies. Multi-wavelength data collected with OVRO, KAIT, Catalina, Swift/UVOT, Swift/XRT and Fermi/LAT were studied. The performed analysis revealed strong variability in all wavelengths that is most clearly manifested in the X-ray range. The correlation studies do not exhibit any relation between different wavelengths, except for the very strong positive correlation between the optical emission in V and R bands., Comment: 11 pages, 7 figures, published in A&A
Published: 2016
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20. Swift/XRT view on S5 0716+714 during a flare

Author: Wierzcholska, Alicja and Siejkowski, Hubert
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: The blazar S5 0716+714 has been monitored in its flaring state between 2015 January 19 and February 22 with Swift/XRT. During this period an exceptional flux level was observed in the X-ray range as well as in the other wavelengths, e.g. optical, near infrared and very high energy $\gamma$ rays. Here, we report X-ray observations of S5 0716+714 carried out during the outburst. The observed X-ray spectra, well described with broken power-law model, disentangle both synchrotron and inverse Compton components. The break energy shifts towards higher energies with increasing flux, revealing the dominance of synchrotron radiation in the X-ray spectrum observed. We also report spectrum softening with increasing flux. During the recent flare, significant temporal intranight variability is observed in the X-ray range., Comment: Published in MNRAS
Published: 2016
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21. X-ray spectral studies of TeV gamma-ray emitting blazars

Author: Wierzcholska, Alicja and Wagner, Stefan
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: This work is a summary of the X-ray spectral studies of 29 TeV $\gamma$-ray emitting blazars observed with Swift/XRT, especially focusing on sources for which X-ray regime allows to study the low and the high energy ends of the particle distributions function. Variability studies require simultaneous coverage, ideally sampling different flux states of each source. This is achieved using X-ray observations by disentangling the high-energy end of the synchrotron emission and the low-energy end of the Compton emission, which are produced by the same electron population. We focused on a sample of 29 TeV gamma-ray emitting blazars with the best signal-to-noise X-ray observations collected with Swift/XRT in the energy range of 0.3-10 keV during 10 years of Swift/XRT operations. We investigate the X-ray spectral shapes and the effects of different corrections for neutral hydrogen absorption and decompose the synchrotron and inverse Compton components. In the case of 5 sources (3C 66A, S5 0716+714, W Comae, 4C +21.35 and BL Lacertae) a superposition of both components is observed in the X-ray band, permitting simultaneous, time resolved studies of both ends of the electron distribution. The analysis of multi-epoch observations revealed that the break energy of X-ray spectrum varies only by a small factor with flux changes. Flux variability is more pronounced in the synchrotron domain (high-energy end of the electron distribution) than in the Compton domain (low energy end of the electron distribution). The spectral shape of the Compton domain is stable, while the flux of the synchrotron domain is variable. These changes cannot be described by simple variations of the cut-off energy, suggesting that the high-energy end of the electron distribution is not generally well-described by cooling only., Comment: Accepted for publications in MNRAS. Version with the online material
Published: 2016
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22. Discovery of VHE gamma-rays from the radio galaxy PKS 0625-354 with H.E.S.S

Author: Dyrda, Michal, Wierzcholska, Alicja, Hervet, Olivier, Moderski, Rafal, Janiak, Mateusz, Ostrowski, Michał, and Stawarz, Łukasz
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: Most of the extragalactic objects detected so far in the very high energy (VHE) regime are blazars, but the discovered nearby radio galaxies: M87, Cen A and NGC 1275 of type FRI seem to constitute a new class of VHE emitters. The radio galaxy PKS 0625-354 was observed and detected ($\sim$6$\sigma$) with the H.E.S.S. phase I telescopes in 2012, above an energy threshold of 250 GeV. The time-averaged VHE energy spectrum is well characterized by a power law model. The broad-band light curve, including the available multiwavelength data, as well as the VHE data gathered with H.E.S.S. will be presented., Comment: In Proceedings of the 34th International Cosmic Ray Conference (ICRC2015), The Hague, The Netherlands
Published: 2015

23. Long term lightcurve of the BL Lac object 1ES 0229+200 at TeV energies

Author: Cologna, Gabriele, Mohamed, Mahmoud, Wagner, Stefan J., Wierzcholska, Alicja, Romoli, Carlo, and Kurtanidze, Omar
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: The high-frequency peaked BL Lac object 1ES 0229+200 (z = 0.14) was first detected in very high energy (VHE, E > 100 GeV) $\gamma$-rays by the H.E.S.S. (High Energy Stereoscopic System) collaboration in 2006. No flux variability was reported in the initial study and its spectral characteristics have been used to derive constraints on the extragalactic background light (EBL) and on the intergalactic magnetic field (IGMF). 1ES 0229+200 has been observed with H.E.S.S. for $\sim$130 hours from 2004 to 2013: the full dataset analysed with a more sensitive method will be presented here. The results indicate that the source is not constant and displays flux variability on yearly and monthly timescales. The existence of flux variability affects the derivation of the constraints on the IGMF. The H.E.S.S. observations cover several simultaneous multi-frequency campaigns and the VHE variations are compared with those reported in different bands., Comment: ICRC 2015 proceeding
Published: 2015

24. Spectral characteristics of Mrk 501 during the 2012 and 2014 flaring states

Author: Cologna, Gabriele, Chakraborty, Nachiketa, Mohamed, Mahmoud, Rieger, Frank, Romoli, Carlo, Taylor, Andrew, Wagner, Stefan J., Wierzcholska, Alicja, and Jacholkowska, Agnieszka
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: Observations at Very High Energies (VHE, E > 100 GeV) of the BL Lac object Mrk 501 taken with the High Energy Stereoscopic System (H.E.S.S.) in four distinct periods between 2004 and 2014 are presented, with focus on the 2012 and 2014 flaring states. The source is detected with high significance above $\sim$ 2 TeV in $\sim$ 13.1 h livetime. The observations comprise low flux states and strong flaring events, which in 2014 show a flux level comparable to the 1997 historical maximum. Such high flux states enable spectral variability and flux variability studies down to a timescale of four minutes in the 2-20 TeV energy range. During the 2014 flare, the source is clearly detected in each of these bins. The intrinsic spectrum is well described by a power law of index $\Gamma=2.15\pm0.06$ and does not show curvature in this energy range. Flux dependent spectral analyses show a clear harder-when-brighter behaviour. The high flux levels and the high sensitivity of H.E.S.S. allow studies in the unprecedented combination of short timescales and an energy coverage that extends significantly above 20 TeV. The high energies allow us to probe the effect of EBL absorption at low redshifts, jet physics and LIV. The multiwavelength context of these VHE observations is presented as well., Comment: ICRC 2015 proceeding
Published: 2015

25. Longterm Optical Monitoring of Bright BL Lacertae Objects with ATOM: Spectral Variability and Multiwavelength Correlations

Author: Wierzcholska, Alicja, Ostrowski, Michał, Stawarz, Łukasz, Wagner, Stefan, and Hauser, Marcus
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: Blazars are the established sources of an intense and variable non-thermal radiation extending from radio wavelengths up to HE and VHE gamma-rays. Understanding the spectral evolution of blazars in selected frequency ranges, as well as multi-frequency correlations in various types of blazar sources, is of a primary importance for constraining the blazar physics. Here we present the results of a long-term optical monitoring of a sample of 30 blazars of the BL Lac type. We study the optical color-magnitude correlation patterns emerging in the analyzed sample, and compare the optical properties of the targets with the high-energy gamma-ray and high-frequency radio data. The optical observations were carried out in R and B filters using ATOM telescope. Each object was observed during at least 20 nights in the period 2007-2012. We find significant global color-magnitude correlations in 40 % of the sample. The sources which do not display any clear chromatism often do exhibit bluer-when-brighter (bwb) behavior but only in isolated shorter time intervals. We also discovered spectral state transitions at optical wavelengths in several sources. Finally, we find that the radio, optical, and gamma-ray luminosities of the sources obey almost linear correlations, which seem however induced, at least partly, by the redshift dependance, and may be also affected by non-simultaneousness of the analyzed dataset. We argue that the observed bwb behavior is intrinsic to the jet emission regions, at least for some of the analyzed blazars, rather than resulting from the contamination of the measured flux by the starlight of host galaxies. We also conclude that the significance of color-magnitude scalings does not correlate with the optical color, but instead seems to depend on the source luminosity, in a sense that these are the lowest-luminosity BL Lac objects which display the strongest correlations., Comment: 16 pages, 9 figures, accepted for publication in Astronomy & Astrophysics
Published: 2014
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26. The Eta Carinae 2020 periastron passage as seen by H.E.S.S.

Author: Steinmassl, Simon, primary, Marandon, Vincent, additional, Remy, Quentin, additional, Hinton, Jim, additional, Collaboration, H.E.S.S., additional, Aharonian, Felix, additional, Ait-Benkhali, Faical, additional, Alkan, Attila, additional, Aschersleben, Jann, additional, Ashkar, Halim, additional, Backes, Michael, additional, Baktash, Ali, additional, Barbosa Martins, Victor, additional, Barnacka, Anna, additional, Barnard, Joleen, additional, Batzofin, Rowan William, additional, Becherini, Yvonne, additional, Beck, Geoffrey, additional, Berge, David, additional, Bernloehr, Konrad, additional, Bi, Baiyang, additional, Boettcher, Markus, additional, Boisson, Catherine, additional, Bolmont, Julien, additional, Bony (de), Mathieu, additional, Borowska, Jowita, additional, Bouyahiaoui, Makarim, additional, Bradascio, Federica, additional, Breuhaus, Mischa, additional, Brose, Robert, additional, Brown, Anthony, additional, Brun, Francois, additional, Bruno, Benedetta, additional, Bulik, Tomasz, additional, Burger-Scheidlin, Christopher, additional, Bylund, Thomas, additional, Cangemi, Floriane, additional, Caroff, Sami, additional, Casanova, Sabrina, additional, Cecil, Rahul, additional, Celic, Jelena, additional, Cerruti, Matteo, additional, Chambéry, Pauline, additional, Chand, Tej Bahadur, additional, Chandra, Sunil, additional, Chen, Andrew, additional, Chibueze, James Okwe, additional, Chibueze, Ogochukwu, additional, Collins, Tiffany, additional, Cotter, Garret, additional, Cristofari, Pierre, additional, Damascene Mbarubucyeye, Jean, additional, Davids, Isak Delberth, additional, Davies, James, additional, de Jonge, Laenita, additional, Devin, Justine, additional, Djannati-Ataï, Arache, additional, Djuvsland, Julia Isabel, additional, Dmytriiev, Anton, additional, Doroshenko, Victor, additional, Dreyer, Lente, additional, Du Plessis, Louis, additional, Egberts, Kathrin, additional, Einecke, Sabrina, additional, ERNENWEIN, Jean-Pierre, additional, Fegan, Steven, additional, Feijen, Kirsty, additional, Fichet de Clairfontaine, Gaëtan, additional, Fontaine, Gerard, additional, Frans, Lott, additional, Fuessling, Matthias, additional, Funk, Stefan, additional, Gabici, Stefano, additional, Gallant, Yves, additional, Ghafourizadeh, Shahede, additional, Giavitto, Gianluca, additional, Giunti, Luca, additional, Glawion, Dorit, additional, Glicenstein, Jean-Francois, additional, Glombitza, Jonas, additional, Goswami, Pranjupriya, additional, Grolleron, Guillaume, additional, Grondin, Marie-Hélène, additional, Haerer, Lucia, additional, Hattingh, Sumari, additional, Haupt, Maria, additional, HERMANN, German, additional, Hofmann, Werner, additional, Holch, Tim, additional, Holler, Markus, additional, Horns, Dieter, additional, Huang, Zhiqiu, additional, Jaitly, Annanay, additional, Jamrozy, Marek, additional, Jankowsky, Felix, additional, Jardin-Blicq, Armelle, additional, Joshi, Vikas, additional, Jung-Richardt, Ira, additional, Kasai, Eli, additional, Katarzynski, Krzysztof, additional, Katjaita, Hiiko, additional, Khangulyan, Dmitry, additional, Khatoon, Rukaiya, additional, Khelifi, Bruno, additional, Klepser, Stefan, additional, Kluzniak, Wlodek, additional, Komin, Nukri, additional, Konno, Ruslan, additional, Kosack, Karl, additional, Kostunin, Dmitriy, additional, Kundu, Anu, additional, Lamanna, Giovanni, additional, Lang, Rodrigo Guedes, additional, Le Stum, Sebastien, additional, Lefranc, Valentin, additional, Leitl, Franziska, additional, Lemiere, Anne, additional, Lemoine-Goumard, Marianne, additional, Lenain, Jean-Philippe, additional, Leuschner, Fabian, additional, Luashvili, Anna, additional, Lypova, Iryna, additional, Mackey, Jonathan, additional, Malyshev, Denys, additional, Malyshev, Dmitry, additional, Marcowith, Alexandre, additional, Marinos, Peter David, additional, Marti'i-Devesa, Guillem, additional, Marx, Ramin, additional, Maurin, Gilles, additional, Mehta, Abhay, additional, Meintjes, Pieter, additional, Meyer, Manuel, additional, Mitchell, Alison, additional, Moderski, Rafal, additional, Mohrmann, Lars, additional, Montanari, Alessandro, additional, Moore, Chris, additional, Moulin, Emmanuel, additional, Murach, Thomas, additional, Nakashima, Kaori, additional, Naurois (de), Mathieu, additional, Ndiyavala, Hambeleleni, additional, Niemiec, Jacek, additional, Noel, Angel, additional, O'Brien, Paul, additional, Ohm, Stefan, additional, Olivera-Nieto, Laura, additional, Ona-Wilhelmi (de), Emma, additional, Ostrowski, Michal, additional, Oukacha, Enzo, additional, Panny, Sebastian, additional, Panter, Michael, additional, Parsons, Dan, additional, Pensec, Ugo, additional, Peron, Giada, additional, Pita, Santiago, additional, Poireau, Vincent, additional, Prokhorov, Dmitry, additional, Prokoph, Heike, additional, PUEHLHOFER, Gerd, additional, Punch, Michael, additional, Quirrenbach, Andreas, additional, Regeard, Maxime, additional, Reichherzer, Patrick, additional, Reimer, Anita, additional, Reimer, Olaf, additional, Reis, Igor, additional, Ren, Helena X., additional, Renaud, Matthieu, additional, Reville, Brian, additional, Rieger, Frank, additional, Roellinghoff, Gerrit, additional, Rol, Evert, additional, Rowell, Gavin P, additional, Rudak, Bronislaw, additional, Rueda Ricarte, Hector, additional, Ruiz Velasco, Edna, additional, Sabri, Karim, additional, Sahakian, Vardan, additional, Sailer, Simon, additional, Salzmann, Heiko, additional, Sanchez, David, additional, Santangelo, Andrea, additional, Sasaki, Manami, additional, Schaefer, Johannes, additional, Schuessler, Fabian, additional, Schutte, Hester, additional, Senniappan, Mohanraj, additional, Shapopi, Jimmy N.S., additional, Shilunga, Sigrid, additional, Shiningayamwe, Kleopas, additional, Sol, Helene, additional, Spackman, Hugh, additional, Specovius, Andreas, additional, Spencer, Samuel, additional, Stawarz, Lukasz, additional, Steenkamp, Riaan, additional, Stegmann, Christian, additional, Steppa, Constantin, additional, Streil, Katrin, additional, Sushch, Iurii, additional, Suzuki, Hiromasa, additional, Takahashi, Tadayuki, additional, Tanaka, Takaaki, additional, Tavernier, Thomas, additional, Taylor, Andrew, additional, Terrier, Regis, additional, Thakur, Adnaan, additional, Thiersen, Hannes, additional, Thorpe-Morgan, Charles, additional, Tluczykont, Martin, additional, Tsirou, Michelle, additional, Tsuji, Naomi, additional, Tuffs, Richard, additional, Uchiyama, Yasunobu, additional, Ullmo, Marion, additional, Unbehaun, Tim, additional, van der Merwe, Pieter, additional, van Eldik, Christopher, additional, van Soelen, Brian, additional, Vasileiadis, George, additional, Vecchi, Manuela, additional, Veh, Johannes, additional, Venter, Christo, additional, Vink, Jacco, additional, Voelk, Heinrich, additional, Vogel, Naomi, additional, Wach, Tina, additional, Wagner, Stefan, additional, Werner, Felix, additional, White, Richard, additional, Wierzcholska, Alicja, additional, Wong, Yu Wun, additional, Yassin, Hend Mahmoud, additional, Zacharias, Michael, additional, Zargaryan, Davit, additional, Zdziarski, Andrzej, additional, Zech, Andreas, additional, Zhu, Sylvia, additional, Zmija, Andreas, additional, Zouari, Samuel, additional, and Żywucka, Natalia, additional
Published: 2023
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27. HESS J1809−193 : a halo of escaped electrons around a pulsar wind nebula?

Author: Aharonian, F., Ait Benkhali, F., Aschersleben, J., Ashkar, H., Backes, M., Barbosa Martins, V., Batzofin, R., Becherini, Y., Berge, D., Böttcher, M., Boisson, C., Bolmont, J., Borowska, J., Bouyahiaoui, M., Bradascio, F., Breuhaus, M., Brose, R., Brun, F., Bruno, B., Bulik, T., Burger-Scheidlin, C., Bylund, T., Caroff, S., Casanova, S., Celic, J., Cerruti, M., Chambery, P., Chand, T., Chen, A., Chibueze, J., Chibueze, O., Damascene Mbarubucyeye, J., Djannati-Ataï, A., Dmytriiev, A., Einecke, S., Ernenwein, J. -P., Feijen, K., Filipovic, M., Fontaine, G., Füßling, M., Funk, S., Gabici, S., Gallant, Y. A., Ghafourizadeh, S., Giavitto, G., Giunti, L., Glawion, D., Goswami, P., Grolleron, G., Grondin, M. -H., Haerer, L., Hinton, J. A., Hofmann, W., Holch, T. L., Holler, M., Horns, D., Huang, Zhiqiu, Jamrozy, Marek, Jankowsky, F., Joshi, V., Jung-Richardt, I., Kasai, E., Katarzyński, K., Khélifi, B., Kluźniak, W., Komin, Nu., Kosack, K., Kostunin, D., Lang, R. G., Le Stum, S., Leitl, F., 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., Marinos, P., Martí-Devesa, G., Marx, R., Mitchell, A., Moderski, R., Mohrmann, L., Montanari, A., Moulin, E., Muller, J., Nakashima, K., de Naurois, M., Niemiec, J., Noel, Angel, Ohm, S., Olivera-Nieto, L., de Ona Wilhelmi, E., Ostrowski, Michał, Panny, S., Panter, M., Parsons, R. D., Prokhorov, D. A., Pühlhofer, G., Punch, M., Quirrenbach, A., Reichherzer, P., Reimer, A., Reimer, O., Renaud, M., Reville, B., Rieger, F., Rowell, G., Rudak, B., Sahakian, V., Santangelo, A., Sasaki, M., Schutte, H. M., Schwanke, U., Shapopi, J. N. S., Sol, H., Specovius, A., Spencer, S., Stawarz, Łukasz, Steenkamp, R., Steinmassl, S., Sushch, I., Suzuki, H., Takahashi, T., Tanaka, T., Terrier, R., Thorpe-Morgan, C., Tsirou, M., Tsuji, N., Uchiyama, Y., van Eldik, C., Vecchi, M., Veh, J., Venter, C., Vink, J., Wach, T., Wagner, S. J., White, R., Wierzcholska, Alicja, Wong, Yu Wun, Zacharias, M., Zargaryan, D., Zdziarski, A. A., Zech, A., Zouari, S., and Żywucka, N.
Subjects: non-thermal [radiation mechanisms], general [gamma rays], acceleration of particles, individual: PSR J1809-1917 [pulsars]
Abstract: Context. HESS J1809−193 is an unassociated very-high-energy γ-ray source located on the Galactic plane. While it has been connected to the nebula of the energetic pulsar PSR J1809−1917, supernova remnants and molecular clouds present in the vicinity also constitute possible associations. Recently, the detection of γ-ray emission up to energies of ∼100 TeV with the HAWC observatory has led to renewed interest in HESS J1809−193. Aims. We aim to understand the origin of the γ-ray emission of HESS J1809−193. Methods. We analysed 93.2 h of data taken on HESS J1809−193 above 0.27 TeV with the High Energy Stereoscopic System (H.E.S.S.), using a multi-component, three-dimensional likelihood analysis. In addition, we provide a new analysis of 12.5 yr of Fermi-LAT data above 1 GeV within the region of HESS J1809−193. The obtained results are interpreted in a time-dependent modelling framework. Results. For the first time, we were able to resolve the emission detected with H.E.S.S. into two components: an extended component (modelled as an elongated Gaussian with a 1-σ semi-major and semi-minor axis of ∼0.62° and ∼0.35°, respectively) that exhibits a spectral cutoff at ∼13 TeV, and a compact component (modelled as a symmetric Gaussian with a 1-σ radius of ∼0.1°) that is located close to PSR J1809−1917 and shows no clear spectral cutoff. The Fermi-LAT analysis also revealed extended γ-ray emission, on scales similar to that of the extended H.E.S.S. component. Conclusions. Our modelling indicates that based on its spectrum and spatial extent, the extended H.E.S.S. component is likely caused by inverse Compton emission from old electrons that form a halo around the pulsar wind nebula. The compact component could be connected to either the pulsar wind nebula or the supernova remnant and molecular clouds. Due to its comparatively steep spectrum, modelling the Fermi-LAT emission together with the H.E.S.S. components is not straightforward.
Published: 2023

28. X-Ray Intraday Variability of the TeV Blazar Markarian 421 with XMM-Newton

Author: Noel, A Priyana, primary, Gaur, Haritma, additional, Gupta, Alok C., additional, Wierzcholska, Alicja, additional, Ostrowski, Michał, additional, Dhiman, Vinit, additional, and Bhatta, Gopal, additional
Published: 2022
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29. Book Review: High Energy Astrophysical Techniques by Rosa Poggiani, UNITEXT for Physics, Springer, 2017; ISBN: 978-3-319-44728-5, DOI: 10.1007/978-3-319-44729-2

Author: Wierzcholska, Alicja
Published: 2018
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30. Revisiting the PeVatron candidate MGRO J1908+06 with an updated H.E.S.S. analysis

Author: 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)
Subjects: 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
Published: 2021
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31. Book Review: “Star Formation in Galaxy Evolution: Connecting Numerical Models to Reality: Saas-Fee-Advanced Course 43, Swiss Society for Astrophysics and Astronomy”, by Nickolay Y. Gnedin, Simon C.O. Glover, Ralf S. Klessen and Volker Springel, Springer, 2015; ISBN: 978-3-662-47889-9, DOI: 10.1007/978-3-662-47889-9, hardcover: 111.96 USD

Author: Siejkowski, Hubert and Wierzcholska, Alicja
Published: 2017
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32. Book Review: “Physics of the Plasma Universe”, Second Edition, by Anthony L. Peratt, Springer, 2015; ISBN: 978-1-4614-7818-8, doi:10.1007/978-1-4614-7819-5

Author: Wierzcholska, Alicja and Siejkowski, Hubert
Published: 2017
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33. Astronomy outreach in Namibia: H.E.S.S. and beyond

Author: Dalgleish, Hannah, primary, Prokoph, Heike, additional, Zhu, Sylvia, additional, Backes, Michael, additional, Cotter, Garret, additional, Catalano, Jacqueline, additional, Ruiz Velasco, Edna, additional, Kasai, Eli, additional, Abdalla, Hassan, additional, Aharonian, Felix, additional, Ait-Benkhali, Faical, additional, Anguener, Oguzhan, additional, Arcaro, Cornelia, additional, Armand, Celine, additional, Armstrong, Tom, additional, Ashkar, Halim, additional, Baghmanyan, Vardan, additional, Barbosa Martins, Victor, additional, Barnacka, Anna, additional, Barnard, Monica, additional, Batzofin, Rowan William, additional, Becherini, Yvonne, additional, Berge, David, additional, Bernloehr, Konrad, additional, Bi, Baiyang, additional, Böttcher, Markus, additional, Boisson, Catherine, additional, Bolmont, Julien, additional, Bony (de), Mathieu, additional, Breuhaus, Mischa, additional, Brose, Robert, additional, Brun, Francois, additional, Bulik, Tomasz, additional, Bylund, Thomas, additional, Cangemi, Floriane, additional, Caroff, Sami, additional, Casanova, Sabrina, additional, Catalano, Jaqueline, additional, Chambery, Pauline, additional, Chand, Tej Bahadur, additional, Chen, Andrew, additional, Curlo, Malgorzata, additional, Damascene Mbarubucyeye, Jean, additional, Davids, Isak Delberth, additional, Davies, James, additional, Devin, Justine, additional, Djannati-Ataï, Arache, additional, Dmytriiev, Anton, additional, Donath, Axel, additional, Doroshenko, Victor, additional, Dreyer, Lente, additional, Du Plessis, Louis, additional, Duffy, Connor, additional, Egberts, Kathrin, additional, Einecke, Sabrina, additional, ERNENWEIN, Jean-Pierre, additional, Fegan, Steven, additional, Feijen, Kirsty, additional, Fiasson, Armand, additional, Fichet de Clairfontaine, Gaëtan, additional, Fontaine, Gerard, additional, Frans, Lott, additional, Fuessling, Matthias, additional, Funk, Stefan, additional, Gabici, Stefano, additional, Gallant, Yves, additional, Giavitto, Gianluca, additional, Giunti, Luca, additional, Glawion, Dorit, additional, Glicenstein, Jean-Francois, additional, Grondin, Marie-Hélène, additional, Hattingh, Sumari, additional, Haupt, Maria, additional, HERMANN, German, additional, Hinton, Jim, additional, Hofmann, Werner, additional, Hoischen, Clemens, additional, Holch, Tim, additional, Holler, Markus, additional, Horns, Dieter, additional, Huang, Zhi-Qiu, additional, Huber, David, additional, Hörbe, Mario, additional, Jamrozy, Marek, additional, Jankowsky, Felix, additional, Joshi, Vikas, additional, JUNG, Ira, additional, Katarzynski, Krzysztof, additional, Katz, Ulì, additional, Khangulyan, Dmitry, additional, Khelifi, Bruno, additional, Klepser, Stefan, additional, Kluzniak, Wlodek, additional, Komin, Nukri, additional, Konno, Ruslan, additional, Kosack, Karl, additional, Kostunin, Dmitriy, additional, Kreter, Michael, additional, Kukec Mezek, Gašper, additional, Kundu, Anu, additional, Lamanna, Giovanni, additional, Le Stum, Sebastien, additional, Lemiere, Anne, additional, Lemoine-Goumard, Marianne, additional, Lenain, Jean-Philippe, additional, Leuschner, Fabian, additional, Levy, Christelle, additional, Lohse, Thomas, additional, Luashvili, Anna, additional, Lypova, Iryna, additional, Mackey, Jonathan, additional, Majumdar, Jhilik, additional, Malyshev, Denys, additional, Malyshev, Dmitry, additional, Marandon, Vincent, additional, Marchegiani, Paolo, additional, Marcowith, Alexandre, additional, Mares, Arnaud, additional, Martí-Devesa, Guillem, additional, Marx, Ramin, additional, Maurin, Gilles, additional, Meintjes, Pieter, additional, Meyer, Manuel, additional, Mitchell, Alison, additional, Moderski, Rafal, additional, Mohrmann, Lars, additional, Montanari, Alessandro, additional, Moore, Chris, additional, Morris, Paul, additional, Moulin, Emmanuel, additional, Muller, Jacques, additional, Murach, Thomas, additional, Nakashima, Kaori, additional, Naurois (de), Mathieu, additional, Nayerhoda, Amid, additional, Davids, Hambeleleni, additional, Niemiec, Jacek, additional, Noel, Angel, additional, O'Brien, Paul, additional, Oberholzer, Laenita Lorraine, additional, Ohm, Stefan, additional, Olivera-Nieto, Laura, additional, Ona-Wilhelmi (de), Emma, additional, Ostrowski, Michal, additional, Panny, Sebastian, additional, Panter, Michael, additional, Parsons, Dan, additional, Peron, Giada, additional, Pita, Santiago, additional, Poireau, Vincent, additional, Prokhorov, Dmitry A, additional, PUEHLHOFER, Gerd, additional, Punch, Michael, additional, Quirrenbach, Andreas, additional, Reichherzer, Patrick, additional, Reimer, Anita, additional, Reimer, Olaf, additional, Remy, Quentin, additional, Renaud, Matthieu, additional, Reville, Brian, additional, Rieger, Frank, additional, Romoli, Carlo, additional, Rowell, Gavin P, additional, Rudak, Bronislaw, additional, Rueda Ricarte, Hector, additional, Sahakian, Vardan, additional, Sailer, Simon, additional, Salzmann, Heiko, additional, Sanchez, David, additional, Santangelo, Andrea, additional, Sasaki, Manami, additional, Schaefer, Johannes, additional, Schutte, Hester, additional, Schwanke, Ullrich, additional, Schüssler, Fabian, additional, Senniappan, Mohanraj, additional, Seyffert, Albert, additional, Shapopi, Jimmy N.S., additional, Shiningayamwe, Kleopas, additional, Simoni, Rachel, additional, Sinha, Atreyee, additional, Sol, Helene, additional, Spackman, Hugh, additional, Specovius, Andreas, additional, Spencer, Samuel Timothy, additional, Spir-Jacob, Marion, additional, Stawarz, Lukasz, additional, Steenkamp, Riaan, additional, Stegmann, Christian, additional, Steinmassl, Simon, additional, Steppa, Constantin, additional, Sun, Lei, additional, Takahashi, Tadayuki, additional, Tanaka, Takaaki, additional, Tavernier, Thomas, additional, Taylor, Andrew, additional, Terrier, Regis, additional, Thiersen, Hannes, additional, Thorpe-Morgan, Charles, additional, Tluczykont, Martin, additional, Tomankova, Lenka, additional, Tsirou, Michelle, additional, Tsuji, Naomi, additional, Tuffs, Richard, additional, Uchiyama, Yasunobu, additional, van der Walt, Johann, additional, van Eldik, Christopher, additional, van Rensburg, Carlo, additional, van Soelen, Brian, additional, Vasileiadis, George, additional, Veh, Johannes, additional, Venter, Christo, additional, Vincent, Pascal, additional, Vink, Jacco, additional, Völk, Heinrich J., additional, Wagner, Stefan, additional, Watson, Jason John, additional, Werner, Felix, additional, White, Richard, additional, Wierzcholska, Alicja, additional, Wong, Yu Wun, additional, Yassin, Hend Mahmoud, additional, Yusafzai, Anke, additional, Zacharias, Michael, additional, Zanin, Roberta, additional, Zargaryan, Davit, additional, Zdziarski, Andrzej, additional, Zech, Andreas, additional, Zmija, Andreas, additional, Zouari, Samuel, additional, and Żywucka, Natalia, additional
Published: 2021
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34. The young massive stellar cluster Westerlund 1 in gamma rays as seen with H.E.S.S.

Author: Mohrmann, Lars, primary, Abdalla, Hassan, additional, Aharonian, Felix, additional, Ait-Benkhali, Faical, additional, Anguener, Oguzhan, additional, Arcaro, Cornelia, additional, Armand, Celine, additional, Armstrong, Tom, additional, Ashkar, Halim, additional, Backes, Michael, additional, Baghmanyan, Vardan, additional, Barbosa Martins, Victor, additional, Barnacka, Anna, additional, Barnard, Monica, additional, Batzofin, Rowan William, additional, Becherini, Yvonne, additional, Berge, David, additional, Bernloehr, Konrad, additional, Bi, Baiyang, additional, Böttcher, Markus, additional, Boisson, Catherine, additional, Bolmont, Julien, additional, Bony (de), Mathieu, additional, Breuhaus, Mischa, additional, Brose, Robert, additional, Brun, Francois, additional, Bulik, Tomasz, additional, Bylund, Thomas, additional, Cangemi, Floriane, additional, Caroff, Sami, additional, Casanova, Sabrina, additional, Catalano, Jaqueline, additional, Chambery, Pauline, additional, Chand, Tej Bahadur, additional, Chen, Andrew, additional, Cotter, Garret, additional, Curlo, Malgorzata, additional, Dalgleish, Hannah, additional, Damascene Mbarubucyeye, Jean, additional, Davids, Isak Delberth, additional, Davies, James, additional, Devin, Justine, additional, Djannati-Ataï, Arache, additional, Dmytriiev, Anton, additional, Donath, Axel, additional, Doroshenko, Victor, additional, Dreyer, Lente, additional, Du Plessis, Louis, additional, Duffy, Connor, additional, Egberts, Kathrin, additional, Einecke, Sabrina, additional, ERNENWEIN, Jean-Pierre, additional, Fegan, Steven, additional, Feijen, Kirsty, additional, Fiasson, Armand, additional, Fichet de Clairfontaine, Gaëtan, additional, Fontaine, Gerard, additional, Frans, Lott, additional, Fuessling, Matthias, additional, Funk, Stefan, additional, Gabici, Stefano, additional, Gallant, Yves, additional, Giavitto, Gianluca, additional, Giunti, Luca, additional, Glawion, Dorit, additional, Glicenstein, Jean-Francois, additional, Grondin, Marie-Hélène, additional, Hattingh, Sumari, additional, Haupt, Maria, additional, HERMANN, German, additional, Hinton, Jim, additional, Hofmann, Werner, additional, Hoischen, Clemens, additional, Holch, Tim, additional, Holler, Markus, additional, Horns, Dieter, additional, Huang, Zhi-Qiu, additional, Huber, David, additional, Hörbe, Mario, additional, Jamrozy, Marek, additional, Jankowsky, Felix, additional, Joshi, Vikas, additional, JUNG, Ira, additional, Kasai, Eli, additional, Katarzynski, Krzysztof, additional, Katz, Ulì, additional, Khangulyan, Dmitry, additional, Khelifi, Bruno, additional, Klepser, Stefan, additional, Kluzniak, Wlodek, additional, Komin, Nukri, additional, Konno, Ruslan, additional, Kosack, Karl, additional, Kostunin, Dmitriy, additional, Kreter, Michael, additional, Kukec Mezek, Gašper, additional, Kundu, Anu, additional, Lamanna, Giovanni, additional, Le Stum, Sebastien, additional, Lemiere, Anne, additional, Lemoine-Goumard, Marianne, additional, Lenain, Jean-Philippe, additional, Leuschner, Fabian, additional, Levy, Christelle, additional, Lohse, Thomas, additional, Luashvili, Anna, additional, Lypova, Iryna, additional, Mackey, Jonathan, additional, Majumdar, Jhilik, additional, Malyshev, Denys, additional, Malyshev, Dmitry, additional, Marandon, Vincent, additional, Marchegiani, Paolo, additional, Marcowith, Alexandre, additional, Mares, Arnaud, additional, Martí-Devesa, Guillem, additional, Marx, Ramin, additional, Maurin, Gilles, additional, Meintjes, Pieter, additional, Meyer, Manuel, additional, Mitchell, Alison, additional, Moderski, Rafal, additional, Montanari, Alessandro, additional, Moore, Chris, additional, Morris, Paul, additional, Moulin, Emmanuel, additional, Muller, Jacques, additional, Murach, Thomas, additional, Nakashima, Kaori, additional, Naurois (de), Mathieu, additional, Nayerhoda, Amid, additional, Davids, Hambeleleni, additional, Niemiec, Jacek, additional, Noel, Angel, additional, O'Brien, Paul, additional, Oberholzer, Laenita Lorraine, additional, Ohm, Stefan, additional, Olivera-Nieto, Laura, additional, Ona-Wilhelmi (de), Emma, additional, Ostrowski, Michal, additional, Panny, Sebastian, additional, Panter, Michael, additional, Parsons, Dan, additional, Peron, Giada, additional, Pita, Santiago, additional, Poireau, Vincent, additional, Prokhorov, Dmitry A, additional, Prokoph, Heike, additional, PUEHLHOFER, Gerd, additional, Punch, Michael, additional, Quirrenbach, Andreas, additional, Rauth, Romed, additional, Reichherzer, Patrick, additional, Reimer, Anita, additional, Reimer, Olaf, additional, Remy, Quentin, additional, Renaud, Matthieu, additional, Reville, Brian, additional, Rieger, Frank, additional, Romoli, Carlo, additional, Rowell, Gavin P, additional, Rudak, Bronislaw, additional, Rueda Ricarte, Hector, additional, Ruiz Velasco, Edna, additional, Sahakian, Vardan, additional, Sailer, Simon, additional, Salzmann, Heiko, additional, Sanchez, David, additional, Santangelo, Andrea, additional, Sasaki, Manami, additional, Schaefer, Johannes, additional, Schutte, Hester, additional, Schwanke, Ullrich, additional, Schüssler, Fabian, additional, Senniappan, Mohanraj, additional, Seyffert, Albert, additional, Shapopi, Jimmy N.S., additional, Shiningayamwe, Kleopas, additional, Simoni, Rachel, additional, Sinha, Atreyee, additional, Sol, Helene, additional, Spackman, Hugh, additional, Specovius, Andreas, additional, Spencer, Samuel Timothy, additional, Spir-Jacob, Marion, additional, Stawarz, Lukasz, additional, Steenkamp, Riaan, additional, Stegmann, Christian, additional, Steinmassl, Simon, additional, Steppa, Constantin, additional, Sun, Lei, additional, Takahashi, Tadayuki, additional, Tanaka, Takaaki, additional, Tavernier, Thomas, additional, Taylor, Andrew, additional, Terrier, Regis, additional, Thiersen, Hannes, additional, Thorpe-Morgan, Charles, additional, Tluczykont, Martin, additional, Tomankova, Lenka, additional, Tsirou, Michelle, additional, Tsuji, Naomi, additional, Tuffs, Richard, additional, Uchiyama, Yasunobu, additional, van der Walt, Johann, additional, van Eldik, Christopher, additional, van Rensburg, Carlo, additional, van Soelen, Brian, additional, Vasileiadis, George, additional, Veh, Johannes, additional, Venter, Christo, additional, Vincent, Pascal, additional, Vink, Jacco, additional, Völk, Heinrich J., additional, Wagner, Stefan, additional, Watson, Jason John, additional, Werner, Felix, additional, White, Richard, additional, Wierzcholska, Alicja, additional, Wong, Yu Wun, additional, Yassin, Hend Mahmoud, additional, Yusafzai, Anke, additional, Zacharias, Michael, additional, Zanin, Roberta, additional, Zargaryan, Davit, additional, Zdziarski, Andrzej, additional, Zech, Andreas, additional, Zhu, Sylvia, additional, Zmija, Andreas, additional, Zouari, Samuel, additional, and Żywucka, Natalia, additional
Published: 2021
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35. Detection of new Extreme BL Lac objects with H.E.S.S. and Swift XRT

Author: Noel, Angel Priyana, primary, Abdalla, Hassan, additional, Aharonian, Felix, additional, Ait-Benkhali, Faical, additional, Anguener, Oguzhan, additional, Arcaro, Cornelia, additional, Armand, Celine, additional, Armstrong, Tom, additional, Ashkar, Halim, additional, Backes, Michael, additional, Baghmanyan, Vardan, additional, Barbosa Martins, Victor, additional, Barnacka, Anna, additional, Barnard, Monica, additional, Batzofin, Rowan William, additional, Becherini, Yvonne, additional, Berge, David, additional, Bernloehr, Konrad, additional, Bi, Baiyang, additional, Böttcher, Markus, additional, Boisson, Catherine, additional, Bolmont, Julien, additional, Bony (de), Mathieu, additional, Breuhaus, Mischa, additional, Brose, Robert, additional, Brun, Francois, additional, Bulik, Tomasz, additional, Bylund, Thomas, additional, Cangemi, Floriane, additional, Caroff, Sami, additional, Casanova, Sabrina, additional, Catalano, Jaqueline, additional, Chambery, Pauline, additional, Chand, Tej Bahadur, additional, Chen, Andrew, additional, Cotter, Garret, additional, Curlo, Malgorzata, additional, Dalgleish, Hannah, additional, Damascene Mbarubucyeye, Jean, additional, Davids, Isak Delberth, additional, Davies, James, additional, Devin, Justine, additional, Djannati-Ataï, Arache, additional, Dmytriiev, Anton, additional, Donath, Axel, additional, Doroshenko, Victor, additional, Dreyer, Lente, additional, Du Plessis, Louis, additional, Duffy, Connor, additional, Egberts, Kathrin, additional, Einecke, Sabrina, additional, ERNENWEIN, Jean-Pierre, additional, Fegan, Steven, additional, Feijen, Kirsty, additional, Fiasson, Armand, additional, Fichet de Clairfontaine, Gaëtan, additional, Fontaine, Gerard, additional, Frans, Lott, additional, Fuessling, Matthias, additional, Funk, Stefan, additional, Gabici, Stefano, additional, Gallant, Yves, additional, Giavitto, Gianluca, additional, Giunti, Luca, additional, Glawion, Dorit, additional, Glicenstein, Jean-Francois, additional, Grondin, Marie-Hélène, additional, Hattingh, Sumari, additional, Haupt, Maria, additional, HERMANN, German, additional, Hinton, Jim, additional, Hofmann, Werner, additional, Hoischen, Clemens, additional, Holch, Tim, additional, Holler, Markus, additional, Horns, Dieter, additional, Huang, Zhi-Qiu, additional, Huber, David, additional, Hörbe, Mario, additional, Jamrozy, Marek, additional, Jankowsky, Felix, additional, Joshi, Vikas, additional, JUNG, Ira, additional, Kasai, Eli, additional, Katarzynski, Krzysztof, additional, Katz, Ulì, additional, Khangulyan, Dmitry, additional, Khelifi, Bruno, additional, Klepser, Stefan, additional, Kluzniak, Wlodek, additional, Komin, Nukri, additional, Konno, Ruslan, additional, Kosack, Karl, additional, Kostunin, Dmitriy, additional, Kreter, Michael, additional, Kukec Mezek, Gašper, additional, Kundu, Anu, additional, Lamanna, Giovanni, additional, Le Stum, Sebastien, additional, Lemiere, Anne, additional, Lemoine-Goumard, Marianne, additional, Lenain, Jean-Philippe, additional, Leuschner, Fabian, additional, Levy, Christelle, additional, Lohse, Thomas, additional, Luashvili, Anna, additional, Lypova, Iryna, additional, Mackey, Jonathan, additional, Majumdar, Jhilik, additional, Malyshev, Denys, additional, Malyshev, Dmitry, additional, Marandon, Vincent, additional, Marchegiani, Paolo, additional, Marcowith, Alexandre, additional, Mares, Arnaud, additional, Martí-Devesa, Guillem, additional, Marx, Ramin, additional, Maurin, Gilles, additional, Meintjes, Pieter, additional, Meyer, Manuel, additional, Mitchell, Alison, additional, Moderski, Rafal, additional, Mohrmann, Lars, additional, Montanari, Alessandro, additional, Moore, Chris, additional, Morris, Paul, additional, Moulin, Emmanuel, additional, Muller, Jacques, additional, Murach, Thomas, additional, Nakashima, Kaori, additional, Naurois (de), Mathieu, additional, Nayerhoda, Amid, additional, Davids, Hambeleleni, additional, Niemiec, Jacek, additional, O'Brien, Paul, additional, Oberholzer, Laenita Lorraine, additional, Ohm, Stefan, additional, Olivera-Nieto, Laura, additional, Ona-Wilhelmi (de), Emma, additional, Ostrowski, Michal, additional, Panny, Sebastian, additional, Panter, Michael, additional, Parsons, Dan, additional, Peron, Giada, additional, Pita, Santiago, additional, Poireau, Vincent, additional, Prokhorov, Dmitry A, additional, Prokoph, Heike, additional, PUEHLHOFER, Gerd, additional, Punch, Michael, additional, Quirrenbach, Andreas, additional, Reichherzer, Patrick, additional, Reimer, Anita, additional, Reimer, Olaf, additional, Remy, Quentin, additional, Renaud, Matthieu, additional, Reville, Brian, additional, Rieger, Frank, additional, Romoli, Carlo, additional, Rowell, Gavin P, additional, Rudak, Bronislaw, additional, Rueda Ricarte, Hector, additional, Ruiz Velasco, Edna, additional, Sahakian, Vardan, additional, Sailer, Simon, additional, Salzmann, Heiko, additional, Sanchez, David, additional, Santangelo, Andrea, additional, Sasaki, Manami, additional, Schaefer, Johannes, additional, Schutte, Hester, additional, Schwanke, Ullrich, additional, Schüssler, Fabian, additional, Senniappan, Mohanraj, additional, Seyffert, Albert, additional, Shapopi, Jimmy N.S., additional, Shiningayamwe, Kleopas, additional, Simoni, Rachel, additional, Sinha, Atreyee, additional, Sol, Helene, additional, Spackman, Hugh, additional, Specovius, Andreas, additional, Spencer, Samuel Timothy, additional, Spir-Jacob, Marion, additional, Stawarz, Lukasz, additional, Steenkamp, Riaan, additional, Stegmann, Christian, additional, Steinmassl, Simon, additional, Steppa, Constantin, additional, Sun, Lei, additional, Takahashi, Tadayuki, additional, Tanaka, Takaaki, additional, Tavernier, Thomas, additional, Taylor, Andrew, additional, Terrier, Regis, additional, Thiersen, Hannes, additional, Thorpe-Morgan, Charles, additional, Tluczykont, Martin, additional, Tomankova, Lenka, additional, Tsirou, Michelle, additional, Tsuji, Naomi, additional, Tuffs, Richard, additional, Uchiyama, Yasunobu, additional, van der Walt, Johann, additional, van Eldik, Christopher, additional, van Rensburg, Carlo, additional, van Soelen, Brian, additional, Vasileiadis, George, additional, Veh, Johannes, additional, Venter, Christo, additional, Vincent, Pascal, additional, Vink, Jacco, additional, Völk, Heinrich J., additional, Wagner, Stefan, additional, Watson, Jason John, additional, Werner, Felix, additional, White, Richard, additional, Wierzcholska, Alicja, additional, Wong, Yu Wun, additional, Yassin, Hend Mahmoud, additional, Yusafzai, Anke, additional, Zacharias, Michael, additional, Zanin, Roberta, additional, Zargaryan, Davit, additional, Zdziarski, Andrzej, additional, Zech, Andreas, additional, Zhu, Sylvia, additional, Zmija, Andreas, additional, Zouari, Samuel, additional, and Żywucka, Natalia, additional
Published: 2021
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36. Science verification of the new FlashCam-based camera in the 28m telescope of H.E.S.S.

Author: Puehlhofer, Gerd, primary, Bernlöhr, Konrad, additional, Bi, Baiyang, additional, HERMANN, German, additional, Hinton, Jim, additional, Jung-Richardt, Ira, additional, Leuschner, Fabian, additional, Marandon, Vincent, additional, Mitchell, Alison, additional, Mohrmann, Lars, additional, Parsons, Robert Daniel, additional, Sailer, Simon, additional, Salzmann, Heiko, additional, Steinmassl, Simon, additional, Werner, Felix, additional, Abdalla, Hassan, additional, Aharonian, Felix, additional, Ait-Benkhali, Faical, additional, Anguener, Oguzhan, additional, Arcaro, Cornelia, additional, Armand, Celine, additional, Armstrong, Tom, additional, Ashkar, Halim, additional, Backes, Michael, additional, Baghmanyan, Vardan, additional, Barbosa Martins, Victor, additional, Barnacka, Anna, additional, Barnard, Monica, additional, Batzofin, Rowan, additional, Becherini, Yvonne, additional, Berge, David, additional, Bernloehr, Konrad, additional, Böttcher, Markus, additional, Boisson, Catherine, additional, Bolmont, Julien, additional, Bony (de), Mathieu, additional, Breuhaus, Mischa, additional, Brose, Robert, additional, Brun, Francois, additional, Bulik, Tomasz, additional, Bylund, Thomas, additional, Cangemi, Floriane, additional, Caroff, Sami, additional, Casanova, Sabrina, additional, Catalano, Jaqueline, additional, Chambery, Pauline, additional, Chand, Tej Bahadur, additional, Chen, Andrew, additional, Cotter, Garret, additional, Curlo, Malgorzata, additional, Dalgleish, Hannah, additional, Damascene Mbarubucyeye, Jean, additional, Davids, Isak Delberth, additional, Davies, James, additional, Devin, Justine, additional, Djannati-Ataï, Arache, additional, Dmytriev, Anton, additional, Donath, Axel, additional, Doroshenko, Victor, additional, Dreyer, Lente, additional, Du Plessis, Louis, additional, Duffy, Connor, additional, Egberts, Kathrin, additional, Einecke, Sabrina, additional, ERNENWEIN, Jean-Pierre, additional, Fegan, Steven, additional, Feijen, Kirsty, additional, Fiasson, Armand, additional, Fichet de Clairfontaine, Gaëtan, additional, Fontaine, Gerard, additional, Frans, Lott, additional, Fuessling, Matthias, additional, Funk, Stefan, additional, Gabici, Stefano, additional, Gallant, Yves, additional, Giavitto, Gianluca, additional, Giunti, Luca, additional, Glawion, Dorit, additional, Glicenstein, Jean-Francois, additional, Grondin, Marie-Hélène, additional, Hattingh, Sumari, additional, Haupt, Maria, additional, Hörbe, Mario, additional, Hofmann, Werner, additional, Hoischen, Clemens, additional, Holch, Tim, additional, Holler, Markus, additional, Horns, Dieter, additional, Huang, Zhi-Qiu, additional, Huber, David, additional, Jamrozy, Marek, additional, Jankowsky, Felix, additional, Joshi, Vikas, additional, Kasai, Eli, additional, Katarzynski, Krzysztof, additional, Katz, Ulì, additional, Khangulyan, Dmitry, additional, Khelifi, Bruno, additional, Klepser, Stefan, additional, Kluzniak, Wlodek, additional, Komin, Nukri, additional, Konno, Ruslan, additional, Kosack, Karl, additional, Kostunin, Dmitriy, additional, Kreter, Michael, additional, Kukec Mezek, Gašper, additional, Kundu, Anu, additional, Lamanna, Giovanni, additional, Le Stum, Sébastien, additional, Lemiere, Anne, additional, Lemoine-Goumard, Marianne, additional, Lenain, Jean-Philippe, additional, Levy, Christelle, additional, Lohse, Thomas, additional, Luashvili, Anna, additional, Lypova, Iryna, additional, Mackey, Jonathan, additional, Majumdar, Jhilik, additional, Malyshev, Denys, additional, Malyshev, Dmitry, additional, Marchegiani, Paolo, additional, Marcowith, Alexandre, additional, Mares, Arnaud, additional, Martí-Devesa, Guillem, additional, Marx, Ramin, additional, Maurin, Gilles, additional, Meintjes, Pieter, additional, Meyer, Manuel, additional, Moderski, Rafal, additional, Montanari, Alessandro, additional, Moore, Chris, additional, Morris, Paul, additional, Moulin, Emmanuel, additional, Muller, Jacques, additional, Murach, Thomas, additional, Nakashima, Kaori, additional, Naurois (de), Mathieu, additional, Nayerhoda, Amid, additional, Davids, Hambeleleni, additional, Niemiec, Jacek, additional, Noel, Angel, additional, O'Brien, Paul, additional, Oberholzer, Laenita Lorraine, additional, Ohm, Stefan, additional, Olivera-Nieto, Laura, additional, Ona-Wilhelmi (de), Emma, additional, Ostrowski, Michal, additional, Panny, Sebastian, additional, Panter, Michael, additional, Parsons, Dan, additional, Peron, Giada, additional, Pita, Santiago, additional, Poireau, Vincent, additional, Prokhorov, Dmitry, additional, Prokoph, Heike, additional, Punch, Michael, additional, Quirrenbach, Andreas, additional, Reichherzer, Patrick, additional, Reimer, Anita, additional, Reimer, Olaf, additional, Remy, Quentin, additional, Renaud, Matthieu, additional, Reville, Brian, additional, Rieger, Frank, additional, Romoli, Carlo, additional, Rowell, Gavin, additional, Rudak, Bronislaw, additional, Rueda Ricarte, Hector, additional, Ruiz Velasco, Edna, additional, Sahakian, Vardan, additional, Sanchez, David, additional, Santangelo, Andrea, additional, Sasaki, Manami, additional, Schaefer, Johannes, additional, Schüssler, Fabian, additional, Schutte, Hester, additional, Schwanke, Ullrich, additional, Senniappan, Mohanraj, additional, Seyffert, Albert, additional, Shapopi, Jimmy N.S., additional, Shiningayamwe, Kleopas, additional, Simoni, Rachel, additional, Sinha, Atreyee, additional, Sol, Helene, additional, Spackman, Hugh, additional, Specovius, Andreas, additional, Spencer, Samuel Timothy, additional, Spir-Jacob, Marion, additional, Stawarz, Lukasz, additional, Steenkamp, Riaan, additional, Stegmann, Christian, additional, Steppa, Constantin, additional, Sun, Lei, additional, Takahashi, Tadayuki, additional, Tanaka, Takaaki, additional, Tavernier, Thomas, additional, Taylor, Andrew, additional, Terrier, Regis, additional, Thiersen, Hannes, additional, Thorpe-Morgan, Charles, additional, Tluczykont, Martin, additional, Tomankova, Lenka, additional, Tsirou, Michelle, additional, Tsuji, Naomi, additional, Tuffs, Richard, additional, Uchiyama, Yasunobu, additional, van der Walt, Johann, additional, van Eldik, Christopher, additional, van Rensburg, Carlo, additional, van Soelen, Brian, additional, Vasileiadis, George, additional, Veh, Johannes, additional, Venter, Christo, additional, Vincent, Pascal, additional, Vink, Jacco, additional, Völk, Heinrich J., additional, Wagner, Stefan, additional, Watson, Jason John, additional, White, Richard, additional, Wierzcholska, Alicja, additional, Wong, Yu Wun, additional, Yassin, Hend Mahmoud, additional, Yusafzai, Anke, additional, Zacharias, Michael, additional, Zanin, Roberta, additional, Zargaryan, Davit, additional, Zdziarski, Andrzej, additional, Zech, Andreas, additional, Zhu, Sylvia, additional, Zmija, Andreas, additional, Zouari, Samuel, additional, and Żywucka, Natalia, additional
Published: 2021
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37. The ablation of gas clouds by blazar jets and the long-lasting flare in CTA 102

Author: Zacharias, Michael, primary, Heil, Jonathan, additional, Boettcher, Markus, additional, Jankowsky, Felix, additional, Lenain, Jean-Philippe, additional, Wagner, Stefan, additional, and Wierzcholska, Alicja, additional
Published: 2021
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38. Observation of burst activity from SGR1935+2154 associated to first galactic FRB with H.E.S.S

Author: 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.
Subjects: 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
Published: 2021
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39. Book Review: “Planetary Sciences”, updated edition, by Imke de Pater and Jack J. Lissauer, Cambridge University Press, 2015; ISBN-10: 1107091616, ISBN-13: 978-1107091610, USD 90.88

Author: Siejkowski, Hubert and Wierzcholska, Alicja
Published: 2016
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40. Constraining X-ray emission in HBL blazars using multiwavelength observations

Author: Wierzcholska, Alicja, primary and Wagner, Stefan J, primary
Published: 2020
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41. Unraveling The Complex Nature Of The Very High-Energy $\gamma$-Ray Blazar PKS 2155-304

Author: Wierzcholska, Alicja, primary, Zacharias, Michael, additional, Jankowsky, Felix, additional, and Wagner, Stefan, additional
Published: 2020
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42. CTA 102 -- Year Over Year Receiving You

Author: Zacharias, Michael, primary, Böttcher, Markus, additional, Jankowsky, Felix, additional, Lenain, Jean-Philippe, additional, Wagner, Stefan, additional, and Wierzcholska, Alicja, additional
Published: 2020
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43. The VHE $\gamma$-Ray View of the FSRQ PKS 1510-089

Author: Zacharias, Michael, Dominis Prester, Dijana, Jankowsky, Felix, Lindfors, Elina, Meyer, Manuel, Mohamed, Mahmoud, Prokoph, Heike, Sanchez, David, Sitarek, Julian, Terzic, Tomislav, Wagner, Stefan, Wierzcholska, Alicja, HESS Collaboration, MAGIC Collaboration, 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), H.E.S.S., MAGIC, Laboratoire d'Annecy de Physique des Particules (LAPP/Laboratoire d'Annecy-le-Vieux de Physique des Particules), and 29092086 - Zacharias, Michael
Subjects: High variability, Multi wavelength, 02 engineering and technology, Astrophysics, blazar variability, 01 natural sciences, law.invention, lcsh:QB1-991, law, HESS, optical, 0202 electrical engineering, electronic engineering, information engineering, active galactic nuclei, multi-wavelength, correlation, MAGIC (telescope), 010303 astronomy & astrophysics, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Multi-wavelength, radio wave, imaging, Correlation, observatory, Computer Science::Programming Languages, Astrophysics - High Energy Astrophysical Phenomena, Flare, Active galactic nucleus, lcsh:Astronomy, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, 0103 physical sciences, quasar, Cherenkov radiation, Active galactic nuclei, 020206 networking & telecommunications, Astronomy and Astrophysics, Quasar, Astrophysics - Astrophysics of Galaxies, MAGIC, flux, monitoring, Cherenkov counter, gamma ray: VHE, Astrophysics of Galaxies (astro-ph.GA), Blazar variability, ddc:520, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: Monitoring the Non-Thermal Universe Workshop, Cochem, Germany, 18 Sep 2018 - 21 Sep 2018; Galaxies 7(1), 41 (2019). doi:10.3390/galaxies7010041, The flat spectrum radio quasar PKS 1510-089 is a monitored target in many wavelength bands due to its high variability. It was detected as a very-high-energy (VHE) γ-ray emitter with H.E.S.S. in 2009, and has since been a regular target of VHE observations by the imaging Cherenkov observatories H.E.S.S. and MAGIC. In this paper, we summarize the current state of results focusing on the monitoring effort with H.E.S.S. and the discovery of a particularly strong VHE flare in 2016 with H.E.S.S. and MAGIC. While the source has now been established as a weak, but regular emitter at VHE, no correlation with other energy bands has been established. This is underlined by the 2016 VHE flare, where the detected optical and high-energy γ-ray counterparts evolve differently than the VHE flux., Published by MDPI, Basel
Published: 2019
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44. Book review: Planetary Science: The Science of Planets around Stars, by George H. A. Cole and Michael M. Woolfson, Second edition, CRC Press/Taylor & Francis Group, 2013; ISBN: 978-1-4665-6315-5 (paperback)

Author: Wierzcholska, Alicja and Siejkowski, Hubert
Published: 2014
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45. The Long-Lasting Activity in the Flat Spectrum Radio Quasar (FSRQ) CTA 102

Author: Zacharias, Michael, primary, Böttcher, Markus, additional, Jankowsky, Felix, additional, Lenain, Jean-Philippe, additional, Wagner, Stefan, additional, and Wierzcholska, Alicja, additional
Published: 2019
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46. H.E.S.S. Monitoring of PKS 2155-304 in 2015 and 2016

Author: Wierzcholska, Alicja, primary, Zacharias, Michael, additional, Jankowsky, Felix, additional, Wagner, Stefan, additional, and for the H.E.S.S. Collaboration, for, additional
Published: 2019
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47. The exceptional flare of Mrk 501 in 2014 combined observations with H.E.S.S. and FACT

Author: Cologna, Gabriele, Chakraborty, Nachiketa, Jacholkowska, Agnieszka, Lorentz, Matthias, Mohamed, Mahmoud, Perennes, Cedric, Romoli, Carlo, Wagner, Stefan J., Wierzcholska, Alicja, Dorner, Daniela, Kurtanidze, Omar, 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), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire Univers et Théories (LUTH (UMR_8102)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), H.E.S.S., FACT, 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), 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), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-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), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Nucléaire et de Hautes Énergies ( LPNHE ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Université Paris Diderot - Paris 7 ( UPD7 ) -Centre National de la Recherche Scientifique ( CNRS ), Institut de Recherches sur les lois Fondamentales de l'Univers ( IRFU ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay, Laboratoire Univers et Théories ( LUTH ), and Institut national des sciences de l'Univers ( INSU - CNRS ) -Observatoire de Paris-Université Paris Diderot - Paris 7 ( UPD7 ) -Centre National de la Recherche Scientifique ( CNRS )
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Opacity, 010308 nuclear & particles physics, [ PHYS.ASTR ] Physics [physics]/Astrophysics [astro-ph], Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Context (language use), Astrophysics, 01 natural sciences, law.invention, Telescope, law, Target of opportunity, 0103 physical sciences, High Energy Stereoscopic System, Astrophysics - High Energy Astrophysical Phenomena, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Blazar, 010303 astronomy & astrophysics, Cherenkov radiation, Flare
Abstract: The BL Lac type object Mrk 501 was observed at very high energies (E > 100 GeV) in 2014 with the upgraded H.E.S.S. (High Energy Stereoscopic System) phase 2 array. The data collected with the central 28m telescope allow for a broader energy range extending to lower energies when compared to the one obtained with the four small telescopes alone. A strong flaring event with a flux level comparable to the 1997 historical maximum has been detected as a consequence of target of opportunity observations triggered by alerts from the FACT collaboration. The First G-APD Cherenkov Telescope (FACT) is continuously monitoring bright blazars at TeV energies providing important pre- and post-flare information. For the first time, the data and lightcurves from H.E.S.S. and FACT are compared. These contemporaneous observations allow for a better characterization of the source emission. In a multiwavelength context, more precise correlation studies between VHE and lower energies are possible thanks to the dense sampling of the FACT observations. The hard intrinsic spectrum detected by H.E.S.S. during the flare allows the derivation of strong constraints on the scale of Lorentz invariance violation via the non-detection of EBL opacity modifications and from time-of-flight studies., 6 pages, 5 figures, proceeding Gamma 2016
Published: 2017

48. Book Review

Author: Wierzcholska, Alicja, primary
Published: 2018
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49. Multi-wavelength observations of flaring blazars with ATOM and Fermi-LAT

Author: Jankowsky, Felix, primary, Wagner, Stefan, additional, Böttcher, Markus, additional, Zacharias, Michael, additional, Kurtanidze, Omar, additional, Lenain, Jean-Philippe, additional, and Wierzcholska, Alicja, additional
Published: 2017
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50. Book Review

Author: Siejkowski, Hubert, primary and Wierzcholska, Alicja, additional
Published: 2017
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