Autor: Prokhorov, D. - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Even coefficient estimates for bounded univalent functions
Autorzy:: Prokhorov, D.
Tematy:: coefficient estimates
univalent function
Pick function
Koebe function; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Matematyczny PAN
Powiązania:: https://bibliotekanauki.pl/articles/1311781.pdf Link otwiera się w nowym oknie
Opis:: Extremal coefficient properties of Pick functions are proved. Even coefficients of analytic univalent functions f with |f(z)| < M, |z| < 1, are bounded by the corresponding coefficients of the Pick functions for large M. This proves a conjecture of Jakubowski. Moreover, it is shown that the Pick functions are not extremal for a similar problem for odd coefficients.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: TeV flaring activity of the AGN PKS 0625–354 in November 2018
Autorzy:: Schüssler, F.
Holch, T. L.
Batzofin, R.
Mehta, A.
Holler, M.
Niemiec, J.
Barnard, J.
Fontaine, G.
Wierzcholska, A.
Lenain, J.-P.
Aharonian, F.
Kostunin, D.
Lang, R. G.
de Ona Wilhelmi, E.
Ren, H.
Streil, K.
Giavitto, G.
Caroff, S.
Ohm, S.
Glawion, D.
O’Brien, P.
Khatoon, R.
Kasai, E.
Sanchez, D. A.
Takahashi, T.
Sasaki, M.
Leitl, F.
Spencer, S.
Barbosa Martins, V.
Ait Benkhali, F.
Punch, M.
Brose, R.
Reimer, O.
Boisson, C.
Casanova, S.
Bradascio, F.
Katarzyński, K.
Venter, C.
Chibueze, O.
Kluźniak, W.
Bernlöhr, K.
Bulik, T.
Böttcher, M.
Brun, F.
Panny, S.
Cerruti, M.
Veh, J.
van Eldik, C.
Borowska, J.
Schutte, H. M.
Stawarz, Łukasz
Hinton, J. A.
Salzmann, H.
Bylund, T.
Rudak, B.
Bolmont, J.
Reimer, A.
Joshi, V.
Bi, B.
de Naurois, M.
Suzuki, H.
Moulin, E.
Kosack, K.
Wagner, S. J.
Zargaryan, D.
Chand, T.
Mitchell, A.
Gabici, S.
Funk, S.
Chen, A.
Baktash, A.
Steinmassl, S.
Olivera-Nieto, L.
Breuhaus, M.
Dmytriiev, A.
Chandra, S.
Davids, I. D.
Ernenwein, J.-P.
Ostrowski, Michał
Doroshenko, V.
Khélifi, B.
Le Stum, S.
Jamrozy, Marek
Shapopi, J. N. S.
Cotter, G.
Mackey, J.
Moderski, R.
Leuschner, F.
Ghafourizadeh, S.
Einecke, S.
Becherini, Y.
Quirrenbach, A.
Cecil, R.
Aschersleben, J.
Specovius, A.
Tanaka, T.
Damascene Mbarubucyeye, J.
Meyer, M.
Jung-Richardt, I.
Chibueze, J.
Bruno, B.
Haerer, L.
Backes, M.
Prokhorov, D. A.
Djuvsland, J.
Vecchi, M.
Żywucka, N.
Horns, D.
Grolleron, G.
Marx, R.
Glicenstein, J. F.
Reichherzer, P.
Zouari, S.
Goswami, P.
Rieger, F.
Berge, D.
Lemière, A.
Parsons, R. D.
Pühlhofer, G.
Celic, J.
Brown, A.
Ashkar, H.
de Bony de Lavergne, M.
Luashvili, A.
Egberts, K.
Sol, H.
Montanari, A.
Sushch, I.
Jankowsky, F.
Burger-Scheidlin, C.
Glombitza, J.
Füßling, M.
Pita, S.
Sahakian, V.
Zdziarski, A. A.
Zech, A.
Steenkamp, R.
Zacharias, M.
Komin, Nu.
Opis:: Most γ-ray detected active galactic nuclei are blazars with one of their relativistic jets pointing towards the Earth. Only a few objects belong to the class of radio galaxies or misaligned blazars. Here, we investigate the nature of the object PKS 0625−354, its γ-ray flux and spectral variability and its broad-band spectral emission with observations from H.E.S.S., Fermi-LAT, Swift-XRT, and UVOT taken in November 2018. The H.E.S.S. light curve above 200 GeV shows an outburst in the first night of observations followed by a declining flux with a halving time scale of 5.9 h. The γγ-opacity constrains the upper limit of the angle between the jet and the line of sight to ∼10°. The broad-band spectral energy distribution shows two humps and can be well fitted with a single-zone synchrotron self Compton emission model. We conclude that PKS 0625−354, as an object showing clear features of both blazars and radio galaxies, can be classified as an intermediate active galactic nuclei. Multi-wavelength studies of such intermediate objects exhibiting features of both blazars and radio galaxies are sparse but crucial for the understanding of the broad-band emission of γ-ray detected active galactic nuclei in general.
Dostawca treści:: Repozytorium Uniwersytetu Jagiellońskiego

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Skocz do pozycji: 3.

Tytuł:: Constraints on the Intergalactic Magnetic Field using Fermi-LAT and H.E.S.S. Blazar Observations
Autorzy:: Mitchell, A.
Takahashi, T.
Glicenstein, J. F.
Thorpe-Morgan, C.
de Bony, M.
Chibueze, O.
Marx, R.
Funk, S.
Schwanke, U.
Martí-Devesa, G.
Marcowith, A.
de Ona Wilhelmi, E.
Backes, M.
Aharonian, F.
Quirrenbach, A.
Lenain, J. -P.
Lang, R. G.
Ohm, S.
Steinmassl, S.
Mohrmann, L.
Goswami, P.
Malyshev, D.
Venter, C.
Le Stum, S.
Lemière, A.
Kluźniak, W.
Tanaka, T.
Füssling, M.
Jamrozy, Marek
Panter, M.
Jankowsky, F.
Bylund, T.
Wong, Yu Wun
Reimer, A.
Reichherzer, P.
Egberts, K.
Murach, T.
Burger-Scheidlin, C.
White, R.
Leuschner, F.
Chen, A.
Ghafourizadeh, S.
Leitl, F.
Schüssler, F.
Martins, V. Barbosa
Bulik, T.
Sanchez, D. A.
Marchegiani, P.
Breuhaus, M.
Pühlhofer, G.
Aschersleben, J.
Wagner, S. J.
Joshi, V.
Zdziarski, A. A.
Terrier, R.
Uchiyama, Y.
Sasaki, M.
Jung-Richardt, I.
Ruiz-Velasco, E.
Panny, S.
Niemiec, J.
Peron, G.
Bouyahiaoui, M.
Muller, J.
Grondin, M. -H.
Marandon, V.
Rudak, B.
Taylor, A. M.
Holch, T. L.
Horns, D.
Kosack, K.
Montanari, A.
Katarzyński, K.
Sol, H.
Wierzcholska, Alicja
Glawion, D.
Meyer, M.
Celic, J.
Lohse, T.
Brun, F.
Reville, B.
Fontaine, G.
Chandra, S.
Caroff, S.
Zargaryan, D.
Brose, R.
Gabici, S.
Sahakian, V.
Spencer, S.
Lypova, I.
Kostunin, D.
Berge, D.
Mackey, J.
Khatoon, R.
Kasai, E.
Rowell, G.
Suzuki, H.
Punch, M.
Parsons, R. D.
Tsuji, N.
Veh, J.
Ernenwein, J. -P.
Cotter, G.
Giavitto, G.
Prokhorov, D. A.
Prokoph, H.
Żywucka, N.
Chand, T.
Tsirou, M.
Casanova, S.
Reimer, O.
Haerer, L.
Fichet de Clairfontaine, G.
Nakashima, K.
Rieger, F.
Moulin, E.
Shapopi, J. N. S.
Becherini, Y.
Batzofin, R.
van Eldik, C.
Zacharias, M.
Khélifi, B.
Holler, M.
Bi, B.
Luashvili, A.
Bruno, B.
Cerruti, M.
Filipovic, M.
Zouari, S.
Chibueze, J.
Komin, Nu.
Moderski, R.
Olivera-Nieto, L.
Schutte, H. M.
Opis:: Magnetic fields in galaxies and galaxy clusters are believed to be the result of the amplification of intergalactic seed fields during the formation of large-scale structures in the universe. However, the origin, strength, and morphology of this intergalactic magnetic field (IGMF) remain unknown. Lower limits on (or indirect detection of) the IGMF can be obtained from observations of high-energy gamma rays from distant blazars. Gamma rays interact with the extragalactic background light to produce electron−positron pairs, which can subsequently initiate electromagnetic cascades. The gamma-ray signature of the cascade depends on the IGMF since it deflects the pairs. Here we report on a new search for this cascade emission using a combined data set from the Fermi Large Area Telescope and the High Energy Stereoscopic System. Using state-of-the-art Monte Carlo predictions for the cascade signal, our results place a lower limit on the IGMF of B > 7.1 × 10$^{-16}$ G for a coherence length of 1 Mpc even when blazar duty cycles as short as 10 yr are assumed. This improves on previous lower limits by a factor of 2. For longer duty cycles of 10$^{4}$ (10$^{7}$) yr, IGMF strengths below 1.8 × 10$^{-14}$ G (3.9 × 10$^{-14}$ G) are excluded, which rules out specific models for IGMF generation in the early universe.
Dostawca treści:: Repozytorium Uniwersytetu Jagiellońskiego

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Skocz do pozycji: 4.

Tytuł:: Search for the evaporation of primordial black holes with H.E.S.S.
Autorzy:: Bi, B.
Jamrozy, Marek
Ghafourizadeh, S.
Berge, D.
Fiasson, A.
Steinmassl, S.
Jung-Richardt, I.
Grondin, M. -H.
Spencer, S.
Zdziarski, A. A.
de Naurois, M.
Barbosa Martins, V.
Mitchell, A.
Fichet de Clairfontaine, G.
Borowska, J.
Bulik, T.
O'Brien, P.
Glicenstein, J. F.
Moderski, R.
Füßling, M.
Zargaryan, D.
Malyshev, D.
Zouari, S.
Fontaine, G.
Zech, A.
Reichherzer, P.
Bradascio, F.
Sushch, I.
Leitl, F.
Noel, Angel
Jankowsky, F.
Cerruti, M.
Batzofin, R.
Marinos, P.
Sol, H.
Rudak, B.
Venter, C.
Caroff, S.
de Ona Wilhelmi, E.
Rueda Ricarte, H.
Kosack, K.
Lohse, T.
Schwanke, U.
Brose, R.
Quirrenbach, A.
Tanaka, T.
Leuschner, F.
Horns, D.
Pühlhofer, G.
Burger-Scheidlin, C.
Holler, M.
Kasai, E.
Lypova, I.
Prokhorov, D. A.
Backes, M.
Martí-Devesa, G.
Veh, J.
Sahakian, V.
Becherini, Y.
Kluźniak, W.
Lemière, A.
Ostrowski, Michał
Ait Benkhali, F.
Lenain, J. -P.
Haupt, M.
Suzuki, H.
Kostunin, D.
Haerer, L.
Nakashima, K.
Shapopi, J. N. S.
de Bony de Lavergne, M.
Khélifi, B.
Katarzyński, K.
Żywucka, N.
Aharonian, F.
Glawion, D.
Takahashi, T.
Gabici, S.
Chen, A.
Sanchez, D. A.
Giavitto, G.
Zacharias, M.
Ohm, S.
Mohrmann, L.
Marx, R.
Panter, M.
Wierzcholska, Alicja
Muller, J.
Bolmont, J.
Huang, Z. -Q.
Specovius, A.
White, R.
Prokoph, H.
Hofmann, W.
Mackey, J.
Holch, T. L.
Rieger, F.
Olivera-Nieto, L.
Salzmann, H.
Casanova, S.
Chibueze, O.
Djannati-Ataï, A.
Marandon, V.
Thorpe-Morgan, C.
Brun, F.
Rowell, G.
Hinton, J. A.
Böttcher, M.
van Eldik, C.
Wagner, S. J.
Damascene Mbarubucyeye, J.
Panny, S.
Steppa, C.
Bruno, B.
Ernenwein, J. -P.
Stawarz, Łukasz
Sasaki, M.
Vink, J.
Schutte, H. M.
Luashvili, A.
Moulin, E.
Steenkamp, R.
Punch, M.
Montanari, A.
Niemiec, J.
Wong, Y. W.
Egberts, K.
Chand, T.
Le Stum, S.
Joshi, V.
Komin, N.
Uchiyama, Y.
Cotter, G.
Vecchi, M.
Marchegiani, P.
Aschersleben, J.
Lang, R. G.
Peron, G.
Tsuji, N.
Tavernier, T.
Reimer, O.
Klepser, S.
Santangelo, A.
Celic, J.
Parsons, R. D.
Boisson, C.
Grolleron, G.
Dostawca treści:: Repozytorium Uniwersytetu Jagiellońskiego

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Skocz do pozycji: 5.

Tytuł:: HESS J1809−193 : a halo of escaped electrons around a pulsar wind nebula?
Autorzy:: Holler, M.
Funk, S.
Renaud, M.
Reville, B.
Zargaryan, D.
Komin, Nu.
Bulik, T.
Marcowith, A.
Cerruti, M.
Gallant, Y. A.
Noel, Angel
Reimer, A.
White, R.
Fontaine, G.
Chen, A.
Steenkamp, R.
Gabici, S.
Kluźniak, W.
Kostunin, D.
Montanari, A.
Żywucka, N.
Venter, C.
Lemoine-Goumard, M.
Moulin, E.
de Naurois, M.
Lohse, T.
Leuschner, F.
Wach, T.
Aschersleben, J.
Sushch, I.
Malyshev, D.
Veh, J.
Zech, A.
Steinmassl, S.
Suzuki, H.
Goswami, P.
Böttcher, M.
Chand, T.
Giavitto, G.
Einecke, S.
de Ona Wilhelmi, E.
Joshi, V.
Barbosa Martins, V.
Khélifi, B.
Ghafourizadeh, S.
Batzofin, R.
Damascene Mbarubucyeye, J.
Moderski, R.
Lypova, I.
Santangelo, A.
Schwanke, U.
Brose, R.
Bouyahiaoui, M.
Jamrozy, Marek
Specovius, A.
Tsuji, N.
Thorpe-Morgan, C.
Ohm, S.
Lenain, J. -P.
Huang, Zhiqiu
Becherini, Y.
Leitl, F.
Chibueze, O.
Ernenwein, J. -P.
Le Stum, S.
Kosack, K.
Spencer, S.
Holch, T. L.
Takahashi, T.
Bylund, T.
Berge, D.
Wagner, S. J.
Marchegiani, P.
Marx, R.
Borowska, J.
Ashkar, H.
Tsirou, M.
Parsons, R. D.
Punch, M.
Horns, D.
Uchiyama, Y.
Boisson, C.
Zacharias, M.
Bradascio, F.
Djannati-Ataï, A.
Niemiec, J.
Giunti, L.
Mitchell, A.
Panter, M.
Kasai, E.
Wierzcholska, Alicja
Olivera-Nieto, L.
Rudak, B.
Stawarz, Łukasz
Grondin, M. -H.
Glawion, D.
Hofmann, W.
Marinos, P.
Panny, S.
Füßling, M.
Brun, F.
Filipovic, M.
Marandon, V.
Chambery, P.
Breuhaus, M.
Mackey, J.
Luashvili, A.
Tanaka, T.
Wong, Yu Wun
Katarzyński, K.
Zouari, S.
Dmytriiev, A.
Shapopi, J. N. S.
Aharonian, F.
van Eldik, C.
Chibueze, J.
Burger-Scheidlin, C.
Terrier, R.
Muller, J.
Feijen, K.
Bolmont, J.
Sasaki, M.
Lang, R. G.
Reimer, O.
Nakashima, K.
Lemière, A.
Reichherzer, P.
Bruno, B.
Ait Benkhali, F.
Sahakian, V.
Rowell, G.
Hinton, J. A.
Ostrowski, Michał
Vecchi, M.
Casanova, S.
Jung-Richardt, I.
Pühlhofer, G.
Quirrenbach, A.
Prokhorov, D. A.
Backes, M.
Schutte, H. M.
Zdziarski, A. A.
Grolleron, G.
Jankowsky, F.
Celic, J.
Vink, J.
Caroff, S.
Martí-Devesa, G.
Sol, H.
Rieger, F.
Haerer, L.
Mohrmann, L.
Opis:: 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.
Dostawca treści:: Repozytorium Uniwersytetu Jagiellońskiego

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Skocz do pozycji: 6.

Tytuł:: H.E.S.S. observations of the 2021 periastron passage of PSR B1259-63/LS 2883
Autorzy:: Holler, M.
Funk, S.
Komin, Nu.
Bulik, T.
Ruiz-Velasco, E.
Cerruti, M.
Gallant, Y. A.
Pensec, U.
Reimer, A.
Egberts, K.
Meintjes, P. J.
Fontaine, G.
Chen, A.
Steenkamp, R.
Mehta, A.
Gabici, S.
Kluźniak, W.
Kostunin, D.
Montanari, A.
Żywucka, N.
Khangulyan, D.
Venter, C.
Lenain, J.-P.
Lemoine-Goumard, M.
Moulin, E.
de Naurois, M.
Leuschner, F.
Wach, T.
Aschersleben, J.
Sushch, I.
Malyshev, D.
Zech, A.
Schäfer, J.
Steinmassl, S.
Goswami, P.
Böttcher, M.
Chand, T.
Einecke, S.
de Ona Wilhelmi, E.
Joshi, V.
Barbosa Martins, V.
Khélifi, B.
Wierzcholska, A.
Batzofin, R.
Damascene Mbarubucyeye, J.
Moderski, R.
Santangelo, A.
Brose, R.
Bouyahiaoui, M.
Jamrozy, Marek
Murach, T.
Devin, J.
Thorpe-Morgan, C.
Ohm, S.
Bernlöhr, K.
van Soelen, B.
Huang, Zhiqiu
Werner, F.
Becherini, Y.
Heß, B.
Leitl, F.
Regeard, M.
Chibueze, O.
Chandra, S.
Le Stum, S.
Reis, I.
Kosack, K.
Spencer, S.
Holch, T. L.
Takahashi, T.
Berge, D.
Wagner, S. J.
Ren, H.
Marx, R.
Borowska, J.
Ashkar, H.
Peron, G.
Parsons, R. D.
Punch, M.
Boisson, C.
Kundu, A.
Zacharias, M.
Niemiec, J.
Mitchell, A.
Panter, M.
Salzmann, H.
Kasai, E.
Rudak, B.
Stawarz, Łukasz
Glawion, D.
Hofmann, W.
Panny, S.
Brun, F.
Cotter, G.
Mackey, J.
de Bony de Lavergne, M.
Tanaka, T.
Brown, A.
Katarzyński, K.
Dmytriiev, A.
Shapopi, J. N. S.
Aharonian, F.
van Eldik, C.
Chibueze, J.
Burger-Scheidlin, C.
Glicenstein, J. F.
Terrier, R.
Bolmont, J.
Sasaki, M.
Lang, R. G.
Reimer, O.
Steppa, C.
Lemière, A.
Unbehaun, T.
Bruno, B.
Ait Benkhali, F.
Sahakian, V.
Streil, K.
Ernenwein, J.-P.
Ostrowski, Michał
Taylor, A. M.
Vecchi, M.
Casanova, S.
Jung-Richardt, I.
Pühlhofer, G.
Quirrenbach, A.
Prokhorov, D. A.
Backes, M.
Schüssler, F.
Schutte, H. M.
Zdziarski, A. A.
Tluczykont, M.
Grolleron, G.
Jankowsky, F.
Celic, J.
Vink, J.
Caroff, S.
Martí-Devesa, G.
Rieger, F.
Haerer, L.
Djuvsland, J.
Mohrmann, L.
Khatoon, R.
Opis:: PSR B1259–63/LS 2883 is a gamma-ray binary system that hosts a pulsar in an eccentric orbit, with a 3.4 yr period, around an O9.5Ve star (LS 2883). At orbital phases close to periastron passages, the system radiates bright and variable non-thermal emission, for which the temporal and spectral properties of this emission are, for now, poorly understood. In this regard, very high-energy (VHE) emission is especially useful to study and constrain radiation processes and particle acceleration in the system. We report on an extensive VHE observation campaign conducted with the High Energy Stereoscopic System, comprised of approximately 100 h of data taken over five months, from t$_{p}$ − 24 days to t$_{p}$ + 127 days around the system’s 2021 periastron passage (where t$_{p}$ is the time of periastron). We also present the timing and spectral analyses of the source. The VHE light curve in 2021 is consistent overall with the stacked light curve of all previous observations. Within the light curve, we report a VHE maximum at times coincident with the third X-ray peak first detected in the 2021 X-ray light curve. In the light curve – although sparsely sampled in this time period – we see no VHE enhancement during the second disc crossing. In addition, we see no correspondence to the 2021 GeV flare in the VHE light curve. The VHE spectrum obtained from the analysis of the 2021 dataset is best described by a power law of spectral index Γ = 2.65 ± 0.04$_{stat}$ ± 0.04$_{sys}$, a value consistent with the spectral index obtained from the analysis of data collected with H.E.S.S. during the previous observations of the source. We report spectral variability with a difference of ΔΓ = 0.56 ± 0.18$_{stat}$ ± 0.10$_{sys}$ at 95% confidence intervals, between sub-periods of the 2021 dataset. We also detail our investigation into X-ray/TeV and GeV/TeV flux correlations in the 2021 periastron passage. We find a linear correlation between contemporaneous flux values of X-ray and TeV datasets, detected mainly after t$_{p}$ + 25 days, suggesting a change in the available energy for non-thermal radiation processes. We detect no significant correlation between GeV and TeV flux points, within the uncertainties of the measurements, from ∼t$_{p}$ − 23 days to ∼t$_{p}$ + 126 days. This suggests that the GeV and TeV emission originate from different electron populations.
Dostawca treści:: Repozytorium Uniwersytetu Jagiellońskiego

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Skocz do pozycji: 7.

Tytuł:: Unveiling extended gamma-ray emission around HESS J1813-178
Autorzy:: Holler, M.
Funk, S.
Renaud, M.
Cecil, R.
Reville, B.
Barnard, J.
Zargaryan, D.
Komin, Nu.
Bulik, T.
Cerruti, M.
Gallant, Y. A.
Noel, Angel
Reimer, A.
Fontaine, G.
Chen, A.
Steenkamp, R.
Mehta, A.
Gabici, S.
Kluźniak, W.
Kostunin, D.
Montanari, A.
Żywucka, N.
Venter, C.
Bi, B.
Lenain, J.-P.
Lemoine-Goumard, M.
Moulin, E.
de Naurois, M.
Leuschner, F.
Wach, T.
Aschersleben, J.
Sushch, I.
Malyshev, D.
Veh, J.
Steinmassl, S.
Suzuki, H.
Goswami, P.
Böttcher, M.
Chand, T.
Giavitto, G.
Einecke, S.
de Ona Wilhelmi, E.
Joshi, V.
Barbosa Martins, V.
Khélifi, B.
Wierzcholska, A.
Ghafourizadeh, S.
Batzofin, R.
Damascene Mbarubucyeye, J.
Moderski, R.
O’Brien, P.
Brose, R.
Bouyahiaoui, M.
Baktash, A.
Jamrozy, Marek
Murach, T.
Specovius, A.
Tsuji, N.
Ohm, S.
Bernlöhr, K.
Becherini, Y.
Leitl, F.
Regeard, M.
Doroshenko, V.
Chibueze, O.
Le Stum, S.
Kosack, K.
Spencer, S.
Holch, T. L.
Takahashi, T.
Berge, D.
Wagner, S. J.
Ren, H.
Marx, R.
Borowska, J.
Ashkar, H.
Parsons, R. D.
Punch, M.
Boisson, C.
Kundu, A.
Roellinghoff, G.
Zacharias, M.
Djannati-Ataï, A.
Niemiec, J.
Mitchell, A.
Panter, M.
Salzmann, H.
Olivera-Nieto, L.
Rudak, B.
Glawion, D.
Hofmann, W.
Marinos, P.
Panny, S.
Füßling, M.
Brun, F.
Cotter, G.
Filipovic, M.
Marandon, V.
Chambery, P.
Breuhaus, M.
Mackey, J.
de Bony de Lavergne, M.
Tanaka, T.
Katarzyński, K.
Zouari, S.
Dmytriiev, A.
Shapopi, J. N. S.
Aharonian, F.
van Eldik, C.
Chibueze, J.
Burger-Scheidlin, C.
Glicenstein, J. F.
Terrier, R.
Feijen, K.
Bolmont, J.
Sasaki, M.
Lang, R. G.
Reimer, O.
Steppa, C.
Lemière, A.
Unbehaun, T.
Reichherzer, P.
Bruno, B.
Ait Benkhali, F.
Sahakian, V.
Ernenwein, J.-P.
Hinton, J. A.
Grondin, M.-H.
Ostrowski, Michał
Vecchi, M.
Casanova, S.
Jung-Richardt, I.
Pühlhofer, G.
Quirrenbach, A.
Prokhorov, D. A.
Backes, M.
Schüssler, F.
Schutte, H. M.
Zdziarski, A. A.
Tluczykont, M.
Grolleron, G.
Jankowsky, F.
Celic, J.
Vink, J.
Klepser, S.
Caroff, S.
Martí-Devesa, G.
Rieger, F.
Mohrmann, L.
Khatoon, R.
Opis:: Context. HESS J1813–178 is a very-high-energy γ-ray source spatially coincident with the young and energetic pulsar PSR J1813–1749 and thought to be associated with its pulsar wind nebula (PWN). Recently, evidence for extended high-energy emission in the vicinity of the pulsar has been revealed in the Fermi Large Area Telescope (LAT) data. This motivates revisiting the HESS J1813–178 region, taking advantage of improved analysis methods and an extended dataset. Aims. Using data taken by the High Energy Stereoscopic System (H.E.S.S.) experiment and the Fermi-LAT, we aim to describe the γ-ray emission in the region with a consistent model, to provide insights into its origin. Methods. We performed a likelihood-based analysis on 32 hours of H.E.S.S. data and 12 yr of Fermi-LAT data and we fitted a spectro-morphological model to the combined datasets. These results allowed us to develop a physical model for the origin of the observed γ-ray emission in the region. Results. In addition to the compact very-high-energy γ-ray emission centred on the pulsar, we find a significant yet previously undetected component along the Galactic plane. With Fermi-LAT data, we confirm extended high-energy emission consistent with the position and elongation of the extended emission observed with H.E.S.S. These results establish a consistent description of the emission in the region from GeV energies to several tens of TeV. Conclusions. This study suggests that HESS J1813–178 is associated with a γ-ray PWN powered by PSR J1813–1749. A possible origin of the extended emission component is inverse Compton emission from electrons and positrons that have escaped the confines of the pulsar and form a halo around the PWN.
Dostawca treści:: Repozytorium Uniwersytetu Jagiellońskiego

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Skocz do pozycji: 8.

Tytuł:: The vanishing of the primary emission region in PKS 1510-089
Autorzy:: Schüssler, F.
Holch, T. L.
Batzofin, R.
Mehta, A.
Holler, M.
Fegan, S.
Barnard, J.
Niemiec, J.
Fontaine, G.
Ruiz-Velasco, E.
Santangelo, A.
Aharonian, F.
Kostunin, D.
Lang, R. G.
de Ona Wilhelmi, E.
Ren, H.
Buckley, D. A. H.
Giavitto, G.
Caroff, S.
Ohm, S.
Glawion, D.
Khatoon, R.
Kasai, E.
Sanchez, D. A.
Wierzcholska, Alicja
Takahashi, T.
Sasaki, M.
Leitl, F.
Spencer, S.
Steppa, C.
Ernenwein, J. -P.
Punch, M.
Vink, J.
Brose, R.
Reimer, O.
Boisson, C.
Casanova, S.
Wach, T.
Bradascio, F.
Katarzyński, K.
Mohrmann, L.
Chibueze, O.
Kluźniak, W.
Marchegiani, P.
Bernlöhr, K.
Bulik, T.
Böttcher, M.
Brun, F.
Panny, S.
Cerruti, M.
Veh, J.
Marandon, V.
van Eldik, C.
Borowska, J.
Schutte, H. M.
Bouyahiaoui, M.
Stawarz, Łukasz
Groenewald, D.
Salzmann, H.
Benkhali, F. Ait
Martí-Devesa, G.
Rudak, B.
Bolmont, J.
Reimer, A.
Joshi, V.
Bi, B.
Martins, V. Barbosa
de Naurois, M.
Suzuki, H.
Moulin, E.
Kosack, K.
Wagner, S. J.
Zargaryan, D.
Chand, T.
Mitchell, A.
Cooper, J.
Gabici, S.
Funk, S.
Chen, A.
Peron, G.
Steinmassl, S.
Olivera-Nieto, L.
Breuhaus, M.
Dmytriiev, A.
Chandra, S.
Davids, I. D.
Ostrowski, Michał
Noel, Angel
Doroshenko, V.
Djannati-Ataï, A.
Khélifi, B.
Le Stum, S.
Jamrozy, Marek
Shapopi, J. N. S.
Brown, A. M.
Schwanke, U.
Cotter, G.
Mackey, J.
Moderski, R.
Leuschner, F.
Ghafourizadeh, S.
Einecke, S.
O'Brien, P.
Becherini, Y.
Quirrenbach, A.
Cecil, R.
Aschersleben, J.
Specovius, A.
Tanaka, T.
van Soelen, B.
Rowell, G.
Damascene Mbarubucyeye, J.
Meyer, M.
Jung-Richardt, I.
Chibueze, J.
Bruno, B.
Haerer, L.
Backes, M.
Prokhorov, D. A.
Vecchi, M.
Żywucka, N.
Horns, D.
Grolleron, G.
Marx, R.
Glicenstein, J. F.
Reichherzer, P.
Zouari, S.
Goswami, P.
Rieger, F.
Berge, D.
Lemière, A.
Ricarte, H. Rueda
Terrier, R.
Pühlhofer, G.
Celic, J.
Hofmann, W.
Ashkar, H.
de Bony de Lavergne, M.
Luashvili, A.
Tsuji, N.
Egberts, K.
Sol, H.
Montanari, A.
Lenain, J. -P.
Sushch, I.
Panter, M.
Jankowsky, F.
Burger-Scheidlin, C.
Füßling, M.
Sahakian, V.
Zdziarski, A. A.
Zech, A.
Steenkamp, R.
Zacharias, M.
Komin, Nu.
Opis:: In 2021 July, PKS 1510−089 exhibited a significant flux drop in the high-energy γ-ray (by a factor 10) and optical (by a factor 5) bands and remained in this low state throughout 2022. Similarly, the optical polarization in the source vanished, resulting in the optical spectrum being fully explained through the steady flux of the accretion disk and the broad-line region. Unlike the aforementioned bands, the very-high-energy γ-ray and X-ray fluxes did not exhibit a significant flux drop from year to year. This suggests that the steady-state very-high-energy γ-ray and X-ray fluxes originate from a different emission region than the vanished parts of the high-energy γ-ray and optical jet fluxes. The latter component has disappeared through either a swing of the jet away from the line of sight or a significant drop in the photon production efficiency of the jet close to the black hole. Either change could become visible in high-resolution radio images.
Dostawca treści:: Repozytorium Uniwersytetu Jagiellońskiego

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Skocz do pozycji: 9.

Tytuł:: A deep spectromorphological study of the $\gamma$-ray emission surrounding the young massive stellar cluster Westerlund 1
Autorzy:: Panter, M.
Tsuji, N.
Blackwell, R.
Ohm, S.
Vecchi, M.
Holler, M.
Tothill, N.
Mezek, G. Kukec
Prokhorov, D. A.
Zacharias, M.
Murach, T.
Venter, C.
Zargaryan, D.
Goswami, P.
Peron, G.
Reichherzer, P.
Malyshev, D.
Martins, V. Barbosa
Cangemi, F.
Jung-Richardt, I.
Żywucka, N.
Fontaine, G.
Joshi, V.
Djannati-Ataï, A.
Grondin, M.-H.
Lavergne, M. de Bony de
Rauth, R.
Thorpe-Morgan, C.
Reville, B.
Martí-Devesa, G.
Kostunin, D.
Backes, M.
Montanari, A.
Lemoine-Goumard, M.
Marchegiani, P.
Ostrowski, Michał
Brun, F.
Marx, R.
Gabici, S.
Hinton, J. A.
Lenain, J.-P.
Sushch, I.
Tuffs, R.
Katarzyński, K.
Lypova, I.
Jamrozy, Marek
Zhu, S. J.
Braiding, C.
Marcowith, A.
Kosack, K.
Ghafourizadeh, S.
Vink, J.
Feijen, K.
Komin, Nu
Meyer, M.
Stawarz, Łukasz
Muller, J.
Reimer, A.
Haupt, M.
Rowell, G.
Härer, L. K.
Reimer, O.
Glawion, D.
Sahakian, V.
Zouari, S.
Salzmann, H.
Rieger, F.
Mbarubucyeye, J. Damascene
Zdziarski, A. A.
Ruiz-Velasco, E.
Funk, S.
Unbehaun, T.
Hofmann, W.
Becherini, Y.
Quirrenbach, A.
Bradascio, F.
Holch, T. L.
Steinmassl, S.
Chibueze, O.
Veh, J.
Cristofari, P.
Ernenwein, J.-P.
Mohrmann, L.
Panny, S.
Cerruti, M.
Maurin, G.
Tanaka, T.
Nakashima, K.
Specovius, A.
Schüssler, F.
Burton, M.
Lemière, A.
Wagner, S. J.
Glicenstein, J. F.
Niemiec, J.
Moulin, E.
Mitchell, A.
Clairfontaine, G. Fichet de
Stum, S. Le
Kasai, E.
Eldik, C. van
Mackey, J.
Steppa, C.
Wong, G.
Burger-Scheidlin, C.
Spencer, S.
Chand, T.
Berge, D.
Lohse, T.
Naurois, M. de
Parsons, R. D.
Giavitto, G.
Giunti, L.
Pühlhofer, G.
Soelen, B. van
Cubuk, K.
Sasaki, M.
Chen, A.
Renaud, M.
Santangelo, A.
White, R.
Marandon, V.
Schwanke, U.
Wong, Y. Wun
Brose, R.
Takahashi, T.
Schutte, H. M.
Horns, D.
Leuschner, F.
Olivera-Nieto, L.
Khélifi, B.
Nayerhoda, A.
Wierzcholska, Alicja
Majumdar, J.
Suzuki, H.
Filipović, M.
Shapopi, J. N. S.
Aharonian, F.
Gallant, Y. A.
Punch, M.
Casanova, S.
Chandra, S.
Ashkar, H.
Luashvili, A.
Hörbe, M.
Rudak, B.
Tsirou, M.
Caroff, S.
Lang, R. G.
Bulik, T.
Kluźniak, W.
Wilhelmi, E. de Ona
Sanchez, D. A.
Bi, B.
Moderski, R.
Böttcher, M.
Terrier, R.
Katz, U.
Steenkamp, R.
Opis:: Context. Young massive stellar clusters are extreme environments and potentially provide the means for efficient particle acceleration. Indeed, they are increasingly considered as being responsible for a significant fraction of cosmic rays (CRs) that are accelerated within the Milky Way. Westerlund 1, the most massive known young stellar cluster in our Galaxy, is a prime candidate for studying this hypothesis. While the very-high-energy γ-ray source HESS J1646−458 has been detected in the vicinity of Westerlund 1 in the past, its association could not be firmly identified. Aims. We aim to identify the physical processes responsible for the γ-ray emission around Westerlund 1 and thus to understand the role of massive stellar clusters in the acceleration of Galactic CRs better. Methods. Using 164 h of data recorded with the High Energy Stereoscopic System (H.E.S.S.), we carried out a deep spectromorphological study of the γ-ray emission of HESS J1646−458. We furthermore employed H I and CO observations of the region to infer the presence of gas that could serve as target material for interactions of accelerated CRs. Results. We detected large-scale (∼2° diameter) γ-ray emission with a complex morphology, exhibiting a shell-like structure and showing no significant variation with γ-ray energy. The combined energy spectrum of the emission extends to several tens of TeV, and it is uniform across the entire source region. We did not find a clear correlation of the γ-ray emission with gas clouds as identified through H I and CO observations. Conclusions. We conclude that, of the known objects within the region, only Westerlund 1 can explain the majority of the γ-ray emission. Several CR acceleration sites and mechanisms are conceivable and discussed in detail. While it seems clear that Westerlund 1 acts as a powerful particle accelerator, no firm conclusions on the contribution of massive stellar clusters to the flux of Galactic CRs in general can be drawn at this point.
Dostawca treści:: Repozytorium Uniwersytetu Jagiellońskiego

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Skocz do pozycji: 10.

Tytuł:: Constraining the cosmic-ray pressure in the inner Virgo Cluster using H.E.S.S. observations of M 87
Autorzy:: Funk, S.
Renaud, M.
Cecil, R.
Fichet de Clairfontaine, G.
Zargaryan, D.
Komin, Nu.
Bulik, T.
Ruiz-Velasco, E.
Marcowith, A.
Cerruti, M.
Noel, Angel
Reimer, A.
Egberts, K.
White, R.
Fontaine, G.
Chen, A.
Steenkamp, R.
O'Brien, P.
Gabici, S.
Kluźniak, W.
Kostunin, D.
Montanari, A.
Żywucka, N.
Venter, C.
Bi, B.
Lemoine-Goumard, M.
Moulin, E.
de Naurois, M.
Lohse, T.
Leuschner, F.
Wach, T.
Aschersleben, J.
Sushch, I.
Malyshev, D.
Veh, J.
Schäfer, J.
Zech, A.
Steinmassl, S.
Suzuki, H.
Goswami, P.
Böttcher, M.
Chand, T.
Giavitto, G.
de Ona Wilhelmi, E.
Joshi, V.
Barbosa Martins, V.
Khélifi, B.
Ghafourizadeh, S.
Batzofin, R.
Meyer, M.
Damascene Mbarubucyeye, J.
Moderski, R.
Lypova, I.
Santangelo, A.
Schwanke, U.
Brose, R.
Specovius, A.
Jamrozy, Marek
Tsuji, N.
Hermann, G.
Ohm, S.
Bernlöhr, K.
van Soelen, B.
Lenain, J. -P.
Sanchez, D. A.
Becherini, Y.
Leitl, F.
Chibueze, O.
Chandra, S.
Ernenwein, J. -P.
Le Stum, S.
Kosack, K.
Spencer, S.
Holch, T. L.
Takahashi, T.
Bylund, T.
Berge, D.
Wagner, S. J.
Marchegiani, P.
Marx, R.
Borowska, J.
Pita, S.
Peron, G.
Prokoph, H.
Tsirou, M.
Parsons, R. D.
Punch, M.
Horns, D.
Uchiyama, Y.
Boisson, C.
Wong, Y. W.
Zacharias, M.
Bradascio, F.
Djannati-Ataï, A.
Niemiec, J.
Mitchell, A.
Panter, M.
Salzmann, H.
Kasai, E.
Wierzcholska, Alicja
Olivera-Nieto, L.
Rudak, B.
Stawarz, Łukasz
Grondin, M. -H.
Glawion, D.
Marinos, P.
Panny, S.
Füßling, M.
Brun, F.
Cotter, G.
Filipovic, M.
Marandon, V.
Breuhaus, M.
Mackey, J.
Luashvili, A.
Tanaka, T.
Katarzyński, K.
Zouari, S.
Shapopi, J. N. S.
van Eldik, C.
Aharonian, F.
Chibueze, J.
Burger-Scheidlin, C.
Glicenstein, J. F.
Terrier, R.
Muller, J.
Bolmont, J.
Sasaki, M.
Lang, R. G.
Reimer, O.
Nakashima, K.
Steppa, C.
Lemière, A.
Reichherzer, P.
Bruno, B.
Ait Benkhali, F.
Sahakian, V.
Rowell, G.
Hinton, J. A.
Taylor, A. M.
Vecchi, M.
Casanova, S.
Jung-Richardt, I.
Pühlhofer, G.
Quirrenbach, A.
Prokhorov, D. A.
Backes, M.
Schüssler, F.
Zdziarski, A. A.
Arcaro, C.
Grolleron, G.
Jankowsky, F.
Celic, J.
Vink, J.
Caroff, S.
Martí-Devesa, G.
Sol, H.
Rieger, F.
Haupt, M.
Haerer, L.
Mohrmann, L.
Khatoon, R.
Opis:: The origin of the gamma-ray emission from M 87 is currently a matter of debate. This work aims to localize the very high-energy (VHE; 100 GeV – 100 TeV) gamma-ray emission from M 87 and probe a potential extended hadronic emission component in the inner Virgo Cluster. The search for a steady and extended gamma-ray signal around M 87 can constrain the cosmic-ray energy density and the pressure exerted by the cosmic rays onto the intracluster medium and allow us to investigate the role of cosmic rays in the active galactic nucleus feedback as a heating mechanism in the Virgo Cluster. The High Energy Stereoscopic System (H.E.S.S.) telescopes are sensitive to VHE gamma rays and have been used to observe M 87 since 2004. We utilized a Bayesian block analysis to identify M 87 emission states with H.E.S.S. observations from 2004 to 2021, dividing them into low, intermediate, and high states. Because of the causality argument, an extended (≳1 kpc) signal is allowed only in steady emission states. Hence, we fitted the morphology of the 120 h low-state data and find no significant gamma-ray extension. Therefore, we derive for the low state an upper limit of 58″(corresponding to ≈4.6 kpc) in the extension of a single-component morphological model described by a rotationally symmetric 2D Gaussian model at the 99.7% confidence level. Our results exclude the radio lobes (≈30 kpc) as the principal component of the VHE gamma-ray emission from the low state of M 87. The gamma-ray emission is compatible with a single emission region at the radio core of M 87. These results, with the help of two multiple-component models, constrain the maximum cosmic-ray to thermal pressure ratio to X$_{CR, max.}$ ≲ 0.32 and the total energy in cosmic-ray protons to U$_{CR}$ ≲ 5 × 10$^{58}$ erg in the inner 20 kpc of the Virgo Cluster for an assumed cosmic-ray proton power-law distribution in momentum with spectral index α$_{p}$ = 2.1.
Dostawca treści:: Repozytorium Uniwersytetu Jagiellońskiego

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