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1,369 results on '"Dmytriiev, A"'

1. Searching for Internal Absorption Signatures in High-Redshift Blazars

Author: Dmytriiev, Anton, Acharyya, Atreya, and Böttcher, Markus
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: The gamma-ray emission from Flat Spectrum Radio Quasars (FSRQs), a sub-class of blazars, is believed to be generated through interactions of high-energy leptons and/or hadrons in the jet with the ambient photon fields, including those from the accretion disk, the broad line region (BLR), and the dusty torus. However, these same photon fields can also attenuate gamma-rays through internal photon-photon (gamma-gamma) absorption, imprinting characteristic spectral features. Investigating the internal absorption is crucial for unraveling the complex structure of FSRQs and constraining the poorly known location of the gamma-ray emission region. In this study, we select a sample of gamma-ray detected FSRQs with high redshift (z >= 3), to search for absorption features appearing at lower photon energies due to a substantial redshift. We extract the Fermi-LAT gamma-ray spectra of these sources and perform physical modeling using a detailed gamma-gamma opacity model, assuming that the BLR photon field dominates the absorption and focusing on the energy range ~25 GeV/(1+z), where the absorption feature due to Ly{\alpha} photons is expected. Our analysis reveals a hint of internal absorption for one source (the lowest redshift object in our sample, z~3) and provides constraints on the location of its gamma-ray emitting region along the jet. For the remaining, higher-redshift sources, the limited photon statistics prevent a reliable detection of internal opacity features., Comment: 10 pages, 3 figures. Accepted for publication in ApJ
Published: 2025

2. An orphan flare from a plasma blob crossing the broad-line region ?

Author: Bihan, Sébastien Le, Dmytriiev, Anton, and Zech, Andreas
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: The blazar 3C 279 is well known for its prolific emission of rapid flares. A particular event occurred on 12/20/2013, exhibiting a large flux increase with a doubling time scale of a few hours, a very hard gamma-ray spectrum, and a time-asymmetric light curve with slow decay, but no significant variations detected in the optical range. We propose a novel scenario to interpret this flare, based on two emission zones, a stationary blob and a moving plasma blob. The stationary blob, located within the BLR, accounts for the low-state emission. The moving blob decouples from the stationary zone, accelerates and crosses the BLR. The high-energy flare is attributed to the variable external Compton emission as the blob moves through the BLR, while variations in the synchrotron emission are negligible. Our interpretation differs from previous interpretations by attributing the flare to the bulk motion and geometry of the external photon fields, without invoking varying electron injection., Comment: 5 pages, 4 figures, Proceeding of the 8th Heidelberg International Symposium on High Energy Gamma Ray Astronomy, Milano, 2024
Published: 2025

3. Detection of very-high-energy gamma-ray emission from Eta Carinae during its 2020 periastron passage

Author: Collaboration, H. E. S. S., Aharonian, F., Benkhali, F. Ait, Aschersleben, J., Ashkar, H., Martins, V. Barbosa, Batzofin, R., Becherini, Y., Berge, D., Bernlöhr, K., Böttcher, M., Boisson, C., Bolmont, J., de Lavergne, M. de Bony, Bradascio, F., Brose, R., Brown, A., Brun, F., Bruno, B., Burger-Scheidlin, C., Casanova, S., Celic, J., Cerruti, M., Chand, T., Chandra, S., Chen, A., Chibueze, J., Chibueze, O., Collins, T., Cotter, G., Mbarubucyeye, J. Damascene, Scarpin, J. de Assis, Devin, J., Djannati-Ataï, A., Djuvsland, J., Dmytriiev, A., Egberts, K., Einecke, S., Ernenwein, J. -P., Nieves, C. Escañuela, Feijen, K., Filipovic, M., Fontaine, G., Funk, S., Gabici, S., Glicenstein, J. F., Grolleron, G., Grondin, M. -H., Haerer, L., Heß, B., Hinton, J. A., Hofmann, W., Holch, T. L., Holler, M., Horns, D., Huang, Zhiqiu, Jamrozy, M., Jankowsky, F., Jardin-Blicq, A., Jung-Richardt, I., Katarzyński, K., Khatoon, R., Khélifi, B., Kluźniak, W., Komin, Nu., Kosack, K., Kostunin, D., Lang, R. G., Stum, S. Le, Lemière, A., Lemoine-Goumard, M., Lenain, J. -P., Luashvili, A., Mackey, J., Malyshev, D., Marandon, V., Marcowith, A., Martí-Devesa, G., Marx, R., Mehta, A., Mitchell, A., Moderski, R., Moghadam, M. O., Mohrmann, L., Moulin, E., de Naurois, M., Niemiec, J., Ohm, S., Olivera-Nieto, L., Wilhelmi, E. de Ona, Ostrowski, M., Panny, S., Panter, M., Parsons, R. D., Pensec, U., Pühlhofer, G., Quirrenbach, A., Ravikularaman, S., Regeard, M., Reimer, A., Reimer, O., Remy, Q., Ren, H., Reville, B., Rieger, F., Rowell, G., Rudak, B., Ruiz-Velasco, E., Sabri, K., Sahakian, V., Salzmann, H., Santangelo, A., Sasaki, M., Schäfer, J., Schüssler, F., Schutte, H. M., Shapopi, J. N. S., Spencer, S., Stawarz, Ł., Steenkamp, R., Steinmassl, S., Steppa, C., Streil, K., Tanaka, T., Terrier, R., Tluczykont, M., Tsirou, M., Tsuji, N., van Eldik, C., Vecchi, M., Venter, C., Wach, T., Wagner, S. J., Werner, F., White, R., Wierzcholska, A., Zacharias, M., Zdziarski, A. A., Zech, A., and Żywucka, N.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: The colliding-wind binary system $\eta$ Carinae has been identified as a source of high-energy (HE, below $\sim$100\,GeV) and very-high-energy (VHE, above $\sim$100\,GeV) gamma rays in the last decade, making it unique among these systems. With its eccentric 5.5-year-long orbit, the periastron passage, during which the stars are separated by only $1-2$\,au, is an intriguing time interval to probe particle acceleration processes within the system. In this work, we report on an extensive VHE observation campaign that for the first time covers the full periastron passage carried out with the High Energy Stereoscopic System (H.E.S.S.) in its 5-telescope configuration with upgraded cameras. VHE gamma-ray emission from $\eta$ Carinae was detected during the periastron passage with a steep spectrum with spectral index $\Gamma= 3.3 \pm 0.2_{\mathrm{stat}} \, \pm 0.1_{\mathrm{syst}}$. Together with previous and follow-up observations, we derive a long-term light curve sampling one full orbit, showing hints of an increase of the VHE flux towards periastron, but no hint of variability during the passage itself. An analysis of contemporaneous Fermi-LAT data shows that the VHE spectrum represents a smooth continuation of the HE spectrum. From modelling the combined spectrum we conclude that the gamma-ray emission region is located at distances of ${\sim}10 - 20$\,au from the centre of mass of the system and that protons are accelerated up to energies of at least several TeV inside the system in this phase., Comment: Accepted at A&A; 11 pages, 9 figures
Published: 2025
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4. Bound-State Beta Decay of $\mathbf{\mathrm{^{205}{Tl}^{81+}}}$ Ions and the LOREX Project

Author: Sidhu, R. S., Leckenby, G., Chen, R. J., Mancino, R., Litvinov, Yu. A., Martínez-Pinedo, G., Amthauer, G., Bai, M., Blaum, K., Boev, B., Bosch, F., Brandau, C., Cvetković, V., Dickel, T., Dillmann, I., Dmytriiev, D., Faestermann, T., Forstner, O., Franczak, B., Geissel, H., Gernhäuser, R., Glorius, J., Griffin, C., Gumberidze, A., Haettner, E., Hillenbrand, P. -M., Kienle, P., Korten, W., Kozhuharov, Ch., Kuzminchuk, N., Langanke, K., Litvinov, S., Menz, E., Morgenroth, T., Neff, T., Nociforo, C., Nolden, F., Pavícević, M. K., Petridis, N., Popp, U., Purushothaman, S., Reifarth, R., Sanjari, M. S., Scheidenberger, C., Spillmann, U., Steck, M., Stöhlker, Th., Tanaka, Y. K., Trassinelli, M., Trotsenko, S., Varga, L., Wang, M., Weick, H., Woods, P. J., Yamaguchi, T., Zhang, Y. H., Zhao, J., and Zuber, K.
Subjects: Nuclear Experiment, Astrophysics - Solar and Stellar Astrophysics, Physics - Instrumentation and Detectors
Abstract: Stable $^{205}$Tl ions have the lowest known energy threshold for capturing electron neutrinos ($\nu_e$) of ${ E}_{\nu_e}\ge50.6$\,keV. The Lorandite Experiment (LOREX), proposed in the 1980s, aims at obtaining the longtime averaged solar neutrino flux by utilizing natural deposits of Tl-bearing lorandite ores. To determine the $\nu_e$ capture cross section, it is required to know the strength of the weak transition connecting the ground state of $^{205}$Tl and the 2.3 keV first excited state in $^{205}$Pb. The only way to experimentally address this transition is to measure the bound-state beta decay ($\beta_{b}$) of fully ionized $\mathrm{^{205}Tl^{81+}}$ ions. After three decades of meticulous preparation, the half-life of the $\beta_{b}$ decay of $\mathrm{^{205}Tl^{81+}}$ has been measured to be $291_{-27}^{+33}$ days using the Experimental Storage Ring (ESR) at GSI, Darmstadt. The longer measured half-life compared to theoretical estimates reduces the expected signal-to-noise ratio in the LOREX, thus challenging its feasibility.
Published: 2025
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5. A Comprehensive Hadronic Code Comparison for Active Galactic Nuclei

Author: Cerruti, Matteo, Rudolph, Annika, Petropoulou, Maria, Böttcher, Markus, Stathopoulos, Stamatios I., Oikonomou, Foteini, Dimitrakoudis, Stavros, Dmytriiev, Anton, Gao, Shan, Inoue, Susumu, Mastichiadis, Apostolos, Murase, Kohta, Reimer, Anita, Robinson, Joshua, Rodrigues, Xavier, Winter, Walter, and Zech, Andreas
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: We perform the first dedicated comparison of five hadronic codes (AM$^3$, ATHE$\nu$A, B13, LeHa-Paris, and LeHaMoC) that have been extensively used in modeling of the spectral energy distribution (SED) of jetted active galactic nuclei. The purpose of this comparison is to identify the sources of systematic errors (e.g., implementation method of proton-photon interactions) and to quantify the expected dispersion in numerical SED models computed with the five codes. The outputs from the codes are first tested in synchrotron self-Compton scenarios that are the simplest blazar emission models used in the literature. We then compare the injection rates and spectra of secondary particles produced in pure hadronic cases with monoenergetic and power-law protons interacting on black-body and power-law photon fields. We finally compare the photon SEDs and the neutrino spectra for realistic proton-synchrotron and leptohadronic blazar models. We find that the codes are in excellent agreement with respect to the spectral shape of the photons and neutrinos. There is a remaining spread in the overall normalization that we quantify, at its maximum, at the level of $\pm 40\%$. This value should be used as an additional, conservative, systematic uncertainty term when comparing numerical simulations and observations., Comment: 32 pages; prepared for submission to AAS journals
Published: 2024

6. High-temperature $^{205}$Tl decay clarifies $^{205}$Pb dating in early Solar System

Author: Leckenby, G., Sidhu, R. S., Chen, R. J., Mancino, R., Szányi, B., Bai, M., Battino, U., Blaum, K., Brandau, C., Cristallo, S., Dickel, T., Dillmann, I., Dmytriiev, D., Faestermann, T., Forstner, O., Franczak, B., Geissel, H., Gernhäuser, R., Glorius, J., Griffin, C., Gumberidze, A., Haettner, E., Hillenbrand, P. -M., Karakas, A., Kaur, T., Korten, W., Kozhuharov, C., Kuzminchuk, N., Langanke, K., Litvinov, S., Litvinov, Y. A., Lugaro, M., Martínez-Pinedo, G., Menz, E., Meyer, B., Morgenroth, T., Neff, T., Nociforo, C., Petridis, N., Pignatari, M., Popp, U., Purushothaman, S., Reifarth, R., Sanjari, S., Scheidenberger, C., Spillmann, U., Steck, M., Stöhlker, T., Tanaka, Y. K., Trassinelli, M., Trotsenko, S., Varga, L., Vescovi, D., Wang, M., Weick, H., López, A. Yagüe, Yamaguchi, T., Zhang, Y., and Zhao, J.
Subjects: Nuclear Experiment, Astrophysics - Earth and Planetary Astrophysics, Astrophysics - Solar and Stellar Astrophysics
Abstract: Radioactive nuclei with lifetimes on the order of millions of years can reveal the formation history of the Sun and active nucleosynthesis occurring at the time and place of its birth. Among such nuclei whose decay signatures are found in the oldest meteorites, $^{205}$Pb is a powerful example, as it is produced exclusively by slow neutron captures (the s process), with most being synthesized in asymptotic giant branch (AGB) stars. However, making accurate abundance predictions for $^{205}$Pb has so far been impossible because the weak decay rates of $^{205}$Pb and $^{205}$Tl are very uncertain at stellar temperatures. To constrain these decay rates, we measured for the first time the bound-state $\beta^-$ decay of fully ionized $^{205}$Tl$^{81+}$, an exotic decay mode that only occurs in highly charged ions. The measured half-life is 4.7 times longer than the previous theoretical estimate and our 10% experimental uncertainty has eliminated the main nuclear-physics limitation. With new, experimentally backed decay rates, we used AGB stellar models to calculate $^{205}$Pb yields. Propagating those yields with basic galactic chemical evolution (GCE) and comparing with the $^{205}$Pb/$^{204}$Pb ratio from meteorites, we determined the isolation time of solar material inside its parent molecular cloud. We find positive isolation times that are consistent with the other s-process short-lived radioactive nuclei found in the early Solar System. Our results reaffirm the site of the Sun's birth as a long-lived, giant molecular cloud and support the use of the $^{205}$Pb--$^{205}$Tl decay system as a chronometer in the early Solar System., Comment: 21 pages and 11 figures/tables. Published in Nature (2024)
Published: 2024
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7. High-Statistics Measurement of the Cosmic-Ray Electron Spectrum with H.E.S.S

Author: Aharonian, F., Benkhali, F. Ait, Aschersleben, J., Ashkar, H., Backes, M., Martins, V. Barbosa, Batzofin, R., Becherini, Y., Berge, D., Bernlöhr, K., Bi, B., Böttcher, M., Boisson, C., Bolmont, J., de Lavergne, M. de Bony, Borowska, J., Bouyahiaoui, M., Brose, R., Brown, A., Brun, F., Bruno, B., Bulik, T., Burger-Scheidlin, C., Bylund, T., Casanova, S., Celic, J., Cerruti, M., Chand, T., Chandra, S., Chen, A., Chibueze, J., Chibueze, O., Collins, T., Cotter, G., Mbarubucyeye, J. Damascene, Devin, J., Djuvsland, J., Dmytriiev, A., Egberts, K., Einecke, S., Ernenwein, J. -P., Fegan, S., Feijen, K., Fontaine, G., Funk, S., Gabici, S., Gallant, Y. A., Glicenstein, J. F., Glombitza, J., Grolleron, G., Heß, B., Hofmann, W., Holch, T. L., Holler, M., Horns, D., Huang, Zhiqiu, Jamrozy, M., Jankowsky, F., Joshi, V., Jung-Richardt, I., Kasai, E., Katarzynski, K., Kerszberg, D., Khatoon, R., Khelifi, B., Kluzniak, W., Komin, Nu., Kosack, K., Kostunin, D., Kundu, A., Lang, R. G., Stum, S. Le, Leitl, F., Lemiere, A., Lemoine-Goumard, M., Lenain, J. -P., Leuschner, F., Luashvili, A., Mackey, J., Malyshev, D., Marandon, V., Marinos, P., Marti-Devesa, G., Marx, R., Meyer, M., Mitchell, A., Moderski, R., Moghadam, M. O., Mohrmann, L., Montanari, A., Moulin, E., de Naurois, M., Niemiec, J., Ohm, S., Olivera-Nieto, L., Wilhelmi, E. de Ona, Ostrowski, M., Panny, S., Panter, M., Parsons, D., Pensec, U., Peron, G., Pühlhofer, G., Punch, M., Quirrenbach, A., Ravikularaman, S., Regeard, M., Reimer, A., Reimer, O., Reis, I., Ren, H., Reville, B., Rieger, F., Rowell, G., Rudak, B., Ruiz-Velasco, E., Sahakian, V., Salzmann, H., Santangelo, A., Sasaki, M., Schäfer, J., Schüssler, F., Schutte, H. M., Shapopi, J. N. S., Sharma, A., Sol, H., Spencer, S., Stawarz, L., Steinmassl, S., Steppa, C., Suzuki, H., Takahashi, T., Tanaka, T., Taylor, A. M., Terrier, R., Tsirou, M., van Eldik, C., Vecchi, M., Venter, C., Vink, J., Wach, T., Wagner, S. J., Wierzcholska, A., Zacharias, M., Zdziarski, A. A., Zech, A., and Zywucka, N.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: Owing to their rapid cooling rate and hence loss-limited propagation distance, cosmic-ray electrons and positrons (CRe) at very high energies probe local cosmic-ray accelerators and provide constraints on exotic production mechanisms such as annihilation of dark matter particles. We present a high-statistics measurement of the spectrum of CRe candidate events from 0.3 to 40 TeV with the High Energy Stereoscopic System (H.E.S.S.), covering two orders of magnitude in energy and reaching a proton rejection power of better than $10^{4}$. The measured spectrum is well described by a broken power law, with a break around 1 TeV, where the spectral index increases from $\Gamma_1 = 3.25$ $\pm$ 0.02 (stat) $\pm$ 0.2 (sys) to $\Gamma_2 = 4.49$ $\pm$ 0.04 (stat) $\pm$ 0.2 (sys). Apart from the break, the spectrum is featureless. The absence of distinct signatures at multi-TeV energies imposes constraints on the presence of nearby CRe accelerators and the local CRe propagation mechanisms., Comment: main paper: 8 pages, 4 figures, supplemental material: 12 pages, 14 figures, accepted for publication in Physical Review Letters https://journals.aps.org/prl/
Published: 2024
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8. Very-high-energy $\gamma$-ray emission from young massive star clusters in the Large Magellanic Cloud

Author: Aharonian, F., Benkhali, F. Ait, Aschersleben, J., Ashkar, H., Backes, M., Martins, V. Barbosa, Batzofin, R., Becherini, Y., Berge, D., Bernlöhr, K., Böttcher, M., Bolmont, J., de Lavergne, M. de Bony, Borowska, J., Brose, R., Brown, A., Brun, F., Bruno, B., Burger-Scheidlin, C., Casanova, S., Celic, J., Cerruti, M., Chand, T., Chandra, S., Chen, A., Chibueze, J., Chibueze, O., Cotter, G., Cristofari, P., Devin, J., Djannati-Ataï, A., Djuvsland, J., Dmytriiev, A., Egberts, K., Einecke, S., Feijen, K., Filipovic, M., Fontaine, G., Funk, S., Gabici, S., Gallant, Y. A., Glicenstein, J. F., Glombitza, J., Grolleron, G., Haerer, L., Heß, B., Hinton, J. A., Hofmann, W., Holch, T. L., Horns, D., Huang, Zhiqiu, Jamrozy, M., Jankowsky, F., Jung-Richardt, I., Kasai, E., Katarzyński, K., Khatoon, R., Khélifi, B., Kluźniak, W., Komin, Nu., Kosack, K., Kostunin, D., Kundu, A., Lang, R. G., Stum, S. Le, Lemière, A., Lemoine-Goumard, M., Lenain, J. -P., Leuschner, F., Mackey, J., Marandon, V., Martí-Devesa, G., Marx, R., Mehta, A., Mitchell, A., Moderski, R., Moghadam, M. O., Mohrmann, L., Montanari, A., Moulin, E., de Naurois, M., Niemiec, J., Ohm, S., Olivera-Nieto, L., Wilhelmi, E. de Ona, Ostrowski, M., Panny, S., Pensec, U., Peron, G., Pühlhofer, G., Quirrenbach, A., Ravikularaman, S., Regeard, M., Reimer, A., Reimer, O., Ren, H., Renaud, M., Reville, B., Rieger, F., Rowell, G., Rudak, B., Ruiz-Velasco, E., Sabri, K., Sahakian, V., Salzmann, H., Santangelo, A., Sasaki, M., Schäfer, J., Schüssler, F., Schutte, H. M., Sol, H., Spencer, S., Stawarz, Ł., Steinmassl, S., Steppa, C., Streil, K., Sushch, I., Taylor, A. M., Terrier, R., Tsirou, M., Tsuji, N., van Eldik, C., Vecchi, M., Venter, C., Vink, J., Wagner, S. J., White, R., Wierzcholska, A., Zacharias, M., Zdziarski, A. A., Zech, A., and Żywucka, N.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: The Tarantula Nebula in the Large Magellanic Cloud is known for its high star formation activity. At its center lies the young massive star cluster R136, providing a significant amount of the energy that makes the nebula shine so brightly at many wavelengths. Recently, young massive star clusters have been suggested to also efficiently produce high-energy cosmic rays, potentially beyond PeV energies. Here, we report the detection of very-high-energy $\gamma$-ray emission from the direction of R136 with the High Energy Stereoscopic System, achieved through a multicomponent, likelihood-based modeling of the data. This supports the hypothesis that R136 is indeed a very powerful cosmic-ray accelerator. Moreover, from the same analysis, we provide an updated measurement of the $\gamma$-ray emission from 30 Dor C, the only superbubble detected at TeV energies presently. The $\gamma$-ray luminosity above $0.5\,\mathrm{TeV}$ of both sources is $(2-3)\times 10^{35}\,\mathrm{erg}\,\mathrm{s}^{-1}$. This exceeds by more than a factor of 2 the luminosity of HESS J1646$-$458, which is associated with the most massive young star cluster in the Milky Way, Westerlund 1. Furthermore, the $\gamma$-ray emission from each source is extended with a significance of $>3\sigma$ and a Gaussian width of about $30\,\mathrm{pc}$. For 30 Dor C, a connection between the $\gamma$-ray emission and the nonthermal X-ray emission appears likely. Different interpretations of the $\gamma$-ray signal from R136 are discussed., Comment: 10+11 pages, 4+6 figures. Corresponding authors: L. Mohrmann, N. Komin
Published: 2024
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9. H.E.S.S. observations of the 2021 periastron passage of PSR B1259-63/LS 2883

Author: Collaboration, H. E. S. S., Aharonian, F., Benkhali, F. Ait, Aschersleben, J., Ashkar, H., Backes, M., Martins, V. Barbosa, Batzofin, R., Becherini, Y., Berge, D., Bernlöhr, K., Böttcher, M., Boisson, C., Bolmont, J., de Lavergne, M. de Bony, Borowska, J., Bouyahiaoui, M., Brose, R., Brown, A., Brun, F., Bruno, B., Bulik, T., Burger-Scheidlin, C., Caroff, S., Casanova, S., Celic, J., Cerruti, M., Chand, T., Chandra, S., Chen, A., Chibueze, J., Chibueze, O., Cotter, G., Mbarubucyeye, J. Damascene, Devin, J., Djuvsland, J., Dmytriiev, A., Egberts, K., Einecke, S., Ernenwein, J. -P., Fontaine, G., Funk, S., Gabici, S., Gallant, Y. A., Glawion, D., Glicenstein, J. F., Goswami, P., Grolleron, G., Haerer, L., Heß, B., Hofmann, W., Holch, T. L., Holler, M., Huang, Zhiqiu, Jamrozy, M., Jankowsky, F., Joshi, V., Jung-Richardt, I., Kasai, E., Katarzyński, K., Khangulyan, D., Khatoon, R., Khélifi, B., Kluźniak, W., Komin, Nu., Kosack, K., Kostunin, D., Kundu, A., Lang, R. G., Stum, S. Le, Leitl, F., Lemière, A., Lemoine-Goumard, M., Lenain, J. -P., Leuschner, F., Mackey, J., Malyshev, D., Martí-Devesa, G., Marx, R., Mehta, A., Meintjes, P. J., Mitchell, A., Moderski, R., Mohrmann, L., Montanari, A., Moulin, E., Murach, T., de Naurois, M., Niemiec, J., Ohm, S., Wilhelmi, E. de Ona, Ostrowski, M., Panny, S., Panter, M., Parsons, R. D., Pensec, U., Peron, G., Prokhorov, D. A., Pühlhofer, G., Punch, M., Quirrenbach, A., Regeard, M., Reimer, A., Reimer, O., Reis, I., Ren, H., Rieger, F., Rudak, B., Ruiz-Velasco, E., Sahakian, V., Salzmann, H., Santangelo, A., Sasaki, M., Schäfer, J., Schüssler, F., Schutte, H. M., Shapopi, J. N. S., Spencer, S., Stawarz, Ł., Steenkamp, R., Steinmassl, S., Steppa, C., Streil, K., Sushch, I., Takahashi, T., Tanaka, T., Taylor, A. M., Terrier, R., Thorpe-Morgan, C., Tluczykont, M., Unbehaun, T., van Eldik, C., van Soelen, B., Vecchi, M., Venter, C., Vink, J., Wach, T., Wagner, S. J., Werner, F., Wierzcholska, A., Zacharias, M., Zdziarski, A. A., Zech, A., and Żywucka, N.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: PSR B1259-63 is a gamma-ray binary system that hosts a pulsar in an eccentric orbit, with a 3.4 year period, around an O9.5Ve star. At orbital phases close to periastron passages, the system radiates bright and variable non-thermal emission. We report on an extensive VHE observation campaign conducted with the High Energy Stereoscopic System, comprised of ~100 hours of data taken from $t_p-24$ days to $t_p+127$ days around the system's 2021 periastron passage. We also present the timing and spectral analyses of the source. The VHE light curve in 2021 is consistent 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 $\Gamma = 2.65 \pm 0.04_{\text{stat}}$ $\pm 0.04_{\text{sys}}$, a value consistent with the previous H.E.S.S. observations of the source. We report spectral variability with a difference of $\Delta \Gamma = 0.56 ~\pm~ 0.18_{\text{stat}}$ $~\pm~0.10_{\text{sys}}$ at 95% c.l., between sub-periods of the 2021 dataset. We also 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 $\sim t_p-23$ days to $\sim t_p+126$ days. This suggests that the GeV and TeV emission originate from different electron populations., Comment: accepted to A&A
Published: 2024

10. Two models for the orbital modulation of $\gamma$-rays in Cyg X-3

Author: Dmytriiev, Anton, Zdziarski, Andrzej A., Malyshev, Denys, Bosch-Ramon, Valenti, and Chernyakova, Maria
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: We model the currently available $\gamma$-ray data from the Fermi Large Area Telescope on Cyg X-3. Thanks to its very strong $\gamma$-ray activity during 2018--2021, the data quality has significantly improved. We study the strong orbital modulation of the $\gamma$-rays observed during at high $\gamma$-ray fluxes. The modulation, as found earlier, is well modeled by anisotropic Compton scattering of the donor blackbody emission by relativistic electrons in a jet strongly misaligned with respect to the orbital axis. We confirm that this model fits well both the average $\gamma$-ray modulation light curve and the spectrum. However, we find that if the jet is aligned with the spin axis of a rotating black hole, it would undergo geodetic precession with the period of $\sim$50 years. However, its presence is ruled out by both the $\gamma$-ray and radio data. Therefore, we consider an alternative model in which the average jet direction jet is aligned, but it is bent to outside the orbit owing to the thrust of the donor stellar wind, and thus precesses at the orbital period. The $\gamma$-ray modulation appears then owing to the variable Doppler boosting of synchrotron self-Compton jet emission. The model also fits well the data. However, the fitted bending angle is much larger than the theoretical one based on the binary and wind parameters as currently known. Thus, both models disagree with important aspects of our current theoretical understanding of the system. We discuss possible ways to find the correct model., Comment: ApJ, in press
Published: 2024

11. Unveiling extended gamma-ray emission around HESS J1813-178

Author: Aharonian, F., Benkhali, F. Ait, Aschersleben, J., Ashkar, H., Backes, M., Baktash, A., Martins, V. Barbosa, Barnard, J., Batzofin, R., Becherini, Y., Berge, D., Bernlöhr, K., Bi, B., Böttcher, M., Boisson, C., Bolmont, J., de Lavergne, M. de Bony, Borowska, J., Bouyahiaoui, M., Breuhaus, M., Brose, R., Brun, F., Bruno, B., Bulik, T., Burger-Scheidlin, C., Caroff, S., Casanova, S., Cecil, R., Celic, J., Cerruti, M., Chambery, P., Chand, T., Chen, A., Chibueze, J., Chibueze, O., Cotter, G., Mbarubucyeye, J. Damascene, Djannati-Ataï, A., Dmytriiev, A., Doroshenko, V., Einecke, S., Ernenwein, J. -P., Feijen, K., Filipovic, M., Fontaine, G., Füßling, M., Funk, S., Gabici, S., Gallant, Y. A., Ghafourizadeh, S., Giavitt, G., Glawion, D., Glicenstein, J. F., Goswami, P., Grolleron, G., Grondin, M. -H., Hinton, J. A., Hofmann, W., Holch, T. L., Holler, M., Jamrozy, M., Jankowsky, F., Joshi, V., Jung-Richardt, I., Katarzyński, K., Khatoon, R., Khélifi, B., Klepser, S., Kluźniak, W., Komin, Nu., Kosack, K., Kostunin, D., Kundu, A., Lang, R. G., Stum, S. Le, Leitl, F., Lemière, A., Lemoine-Goumard, M., Lenain, J. -P., Leuschner, F., Mackey, J., Malyshev, D., Marandon, V., Marinos, P., Martí-Devesa, G., Marx, R., Mehta, A., Mitchell, A., Moderski, R., Mohrmann, L., Montanari, A., Moulin, E., Murach, T., de Naurois, M., Niemiec, J., Noel, A. Priyana, O'Brien, P., Ohm, S., Olivera-Nieto, L., Wilhelmi, E. de Ona, Ostrowski, M., Panny, S., Panter, M., Parsons, R. D., Prokhorov, D. A., Pühlhofer, G., Punch, M., Quirrenbach, A., Regeard, M., Reichherzer, P., Reimer, A., Reimer, O., Ren, H., Renaud, M., Reville, B., Rieger, F., Roellinghoff, G., Rudak, B., Sahakian, V., Salzmann, H., Sasaki, M., Schüssler, F., Schutte, H. M., Shapopi, J. N. S., Specovius, A., Spencer, S., Steenkamp, R., Steinmassl, S., Steppa, C., Sushch, I., Suzuki, H., Takahashi, T., Tanaka, T., Terrier, R., Tluczykont, M., Tsuji, N., Unbehaun, T., van Eldik, C., Vecchi, M., Veh, J., Venter, C., Vink, J., Wach, T., Wagner, S. J., Wierzcholska, A., Zacharias, M., Zargaryan, D., Zdziarski, A. A., Zouari, S., and Żywucka, N.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: HESS J1813$-$178 is a very-high-energy $\gamma$-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 data set. Using data taken by the High Energy Stereoscopic System (H.E.S.S.) experiment and the Fermi-LAT, we aim to describe the $\gamma$-ray emission in the region with a consistent model, to provide insights into its origin. We performed a likelihood-based analysis on 32 hours of H.E.S.S. data and 12 years of Fermi-LAT data and fit a spectro-morphological model to the combined datasets. These results allowed us to develop a physical model for the origin of the observed $\gamma$-ray emission in the region. In addition to the compact very-high-energy $\gamma$-ray emission centered 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. This study suggests that HESS J1813$-$178 is associated with a $\gamma$-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., Comment: 13+5 pages, 13+11 figures. Accepted for publication in A&A. Corresponding authors: T.Wach, A.Mitchell, V.Joshi, P.Chamb\'ery
Published: 2024
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12. Effects of non-continuous inverse Compton cooling in blazars

Author: Dmytriiev, Anton and Böttcher, Markus
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: Context. Blazar flares provide a window into the extreme physical processes occurring in relativistic outflows. Most numerical codes used for modeling blazar emission during flares utilize a simplified continuous-loss description of particle cooling due to the inverse Compton (IC) process, neglecting non-continuous (discrete) effects that arise in the Klein-Nishina (KN) regime. The significance of such effects has not been explored in detail yet. Aims. In this study, we investigate the importance of non-continuous Compton cooling losses and their impact on the electron spectrum and spectral energy distribution (SED) of blazars during high flux states (flares), as well as in the low state. Methods. We solve numerically the full transport equation accounting for large relative jumps in energy, by extending our existing blazar flare modeling code EMBLEM. We perform a detailed physical modeling of the brightest gamma-ray flare of the archetypal Flat Spectrum Radio Quasar (FSRQ) 3C 279 detected in June 2015. We then compare results obtained using the full cooling term and using the continuous-loss approximation. Results. We show that during flaring states of FSRQs characterized by high Compton dominance, the non-continuous cooling can lead to a significant modification of the electron spectrum, introducing a range of distinct features, such as low-energy tails, hardening/softening, narrow and extended particle excesses, and shifts in the cooling break position. Such distortion translates to differences in the associated SED up to 50%. This highlights the importance of non-continuous effects and the need to consider them in blazar emission models, particularly applied to extreme gamma-ray flares., Comment: 9 pages, 3 figures, accepted for publication in A&A
Published: 2024
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13. Spectrum and extension of the inverse-Compton emission of the Crab Nebula from a combined Fermi-LAT and H.E.S.S. analysis

Author: Aharonian, F., Benkhali, F. Ait, Aschersleben, J., Ashkar, H., Backes, M., Baktash, A., Martins, V. Barbosa, Batzofin, R., Becherini, Y., Berge, D., Bernlöhr, K., Bi, B., Böttcher, M., Boisson, C., Bolmont, J., de Lavergne, M. de Bony, Borowska, J., Bradascio, F., Breuhaus, M., Brose, R., Brown, A., Brun, F., Bruno, B., Bulik, T., Burger-Scheidlin, C., Bylund, T., Caroff, S., Casanova, S., Cecil, R., Celic, J., Cerruti, M., Chambery, P., Chand, T., Chandra, S., Chen, A., Chibueze, J., Chibueze, O., Cotter, G., Cristofari, P., Devin, J., Djannati-Ataï, A., Djuvsland, J., Dmytriiev, A., Einecke, S., Ernenwein, J. -P., Fegan, S., Feijen, K., Filipović, M., Fontaine, G., Füßling, M., Funk, S., Gabici, S., Gallant, Y. A., Giavitto, G., Glawion, D., Glicenstein, J. F., Glombitza, J., Goswami, P., Grolleron, G., Grondin, M. -H., Haerer, L., Hinton, J. A., Hofmann, W., Holch, T. L., Holler, M., Horns, D., Jamrozy, M., Jankowsky, F., Joshi, V., Kasai, E., Katarzyński, K., Khatoon, R., Khélifi, B., Kluźniak, W., Komin, Nu., Kosack, K., Kostunin, D., Kundu, A., Lang, R. G., Stum, S. Le, Leitl, F., Lemière, A., Lemoine-Goumard, M., Lenain, J. -P., Leuschner, F., Luashvili, A., Mackey, J., Malyshev, D., Marandon, V., Marinos, P., Martí-Devesa, G., Marx, R., Mehta, A., Meyer, M., Mitchell, A., Moderski, R., Mohrmann, L., Montanari, A., Moulin, E., Murach, T., de Naurois, M., Niemiec, J., O'Brien, P., Ohm, S., Olivera-Nieto, L., Wilhelmi, E. de Ona, Ostrowski, M., Panny, S., Panter, M., Parsons, R. D., Peron, G., Prokhorov, D. A., Pühlhofer, G., Punch, M., Quirrenbach, A., Regeard, M., Reichherzer, P., Reimer, A., Reimer, O., Ren, H., Renaud, M., Reville, B., Rieger, F., Roellinghoff, G., Rudak, B., Sahakian, V., Salzmann, H., Sasaki, M., Schüssler, F., Schutte, H. M., Shapopi, J. N. S., Specovius, A., Spencer, S., Stawarz, Ł., Steenkamp, R., Steinmassl, S., Steppa, C., Streil, K., Sushch, I., Suzuki, H., Takahashi, T., Tanaka, T., Terrier, R., Tluczykont, M., Tsuji, N., Unbehaun, T., van Eldik, C., Vecchi, M., Veh, J., Venter, C., Vink, J., Wach, T., Wagner, S. J., Wierzcholska, A., Zacharias, M., Zargaryan, D., Zdziarski, A. A., Zech, A., Zouari, S., Żywucka, N., and Harding, A.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: The Crab Nebula is a unique laboratory for studying the acceleration of electrons and positrons through their non-thermal radiation. Observations of very-high-energy $\gamma$ rays from the Crab Nebula have provided important constraints for modelling its broadband emission. We present the first fully self-consistent analysis of the Crab Nebula's $\gamma$-ray emission between 1 GeV and $\sim$100 TeV, that is, over five orders of magnitude in energy. Using the open-source software package Gammapy, we combined 11.4 yr of data from the Fermi Large Area Telescope and 80 h of High Energy Stereoscopic System (H.E.S.S.) data at the event level and provide a measurement of the spatial extension of the nebula and its energy spectrum. We find evidence for a shrinking of the nebula with increasing $\gamma$-ray energy. Furthermore, we fitted several phenomenological models to the measured data, finding that none of them can fully describe the spatial extension and the spectral energy distribution at the same time. Especially the extension measured at TeV energies appears too large when compared to the X-ray emission. Our measurements probe the structure of the magnetic field between the pulsar wind termination shock and the dust torus, and we conclude that the magnetic field strength decreases with increasing distance from the pulsar. We complement our study with a careful assessment of systematic uncertainties., Comment: 18+6 pages, 15+2 figures. Accepted for publication in A&A. Corresponding authors: M. Meyer, L. Mohrmann, T. Unbehaun. v2: after A&A language editing
Published: 2024
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14. Curvature in the very-high energy gamma-ray spectrum of M87

Author: Collaboration, H. E. S. S., Aharonian, F., Benkhali, F. Ait, Aschersleben, J., Ashkar, H., Backes, M., Martins, V. Barbosa, Batzofin, R., Becherini, Y., Berge, D., Bernlöhr, K., Böttcher, M., Boisson, C., Bolmont, J., de Lavergne, M. de Bony, Bradascio, F., Brose, R., Brun, F., Bruno, B., Burger-Scheidlin, T. Bulik C., Bylund, T., Casanova, S., Cecil, R., Celic, J., Cerruti, M., Chand, T., Chandra, S., Chen, A., Chibueze, J., Chibueze, O., Collins, T., Cotter, G., Mbarubucyeye, J. Damascene, Djannati-Ataï, A., Djuvsland, J., Dmytriiev, A., Egberts, K., Einecke, S., Fegan, S., Fontaine, G., Funk, S., Gabici, S., Glicenstein, J. F., Glombitza, J., Grolleron, G., Haerer, L., Hofmann, W., Holch, T. L., Holler, M., Horns, D., Jamrozy, M., Jankowsky, F., Joshi, V., Jung-Richardt, I., Kasai, E., Katarzyński, K., Khatoon, R., Khélifi, B., Kluźniak, W., Komin, Nu., Kosack, K., Kostunin, D., Kundu, A., Lang, R. G., Stum, S. Le, Leitl, F., Lemière, A., Lemoine-Goumard, M., Lenain, J. -P., Lypova, I., Luashvili, A., Mackey, J., Malyshev, D., Martí-Devesa, G., Marx, R., Mehta, A., Meyer, M., Mitchell, A., Moderski, R., Moghadam, M. O., Mohrmann, L., Montanari, A., Moulin, E., Murach, T., de Naurois, M., Niemiec, J., Ohm, S., Olivera-Nieto, L., Wilhelmi, E. de Ona, Panny, S., Panter, M., Parsons, R. D., Pensec, U., Pita, S., Pühlhofer, G., Punch, M., Quirrenbach, A., Regeard, M., Reimer, A., Reimer, O., Ren, H., Reville, B., Rieger, F., Rudak, B., Ruiz-Velasco, E., Sahakian, V., Salzmann, H., Santangelo, A., Sasaki, M., Schüssler, F., Schutte, H. M., Shapopi, J. N. S., Sol, H., Spencer, S., Stawarz, Ł., Steenkamp, R., Steinmassl, S., Steppa, C., Streil, K., Takahashi, T., Tanaka, T., Taylor, A. M., Terrier, R., Tsirou, M., van Eldik, C., Venter, C., Vink, J., Wach, T., Wagner, S. J., Wierzcholska, A., Zacharias, M., Zdziarski, A. A., Zech, A., Zilberman, P., and Zywucka, N.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract: The radio galaxy M87 is a variable very-high energy (VHE) gamma-ray source, exhibiting three major flares reported in 2005, 2008, and 2010. Despite extensive studies, the origin of the VHE gamma-ray emission is yet to be understood. In this study, we investigate the VHE gamma-ray spectrum of M87 during states of high gamma-ray activity, utilizing 20.2$\,$ hours the H.E.S.S. observations. Our findings indicate a preference for a curved spectrum, characterized by a log-parabola model with extra-galactic background light (EBL) model above 0.3$\,$TeV at the 4$\sigma$ level, compared to a power-law spectrum with EBL. We investigate the degeneracy between the absorption feature and the EBL normalization and derive upper limits on EBL models mainly sensitive in the wavelength range 12.4$\,$$\mu$m - 40$\,$$\mu$m., Comment: 10 pages, 7 figures. Accepted for publication in A&A. Corresponding authors: Victor Barbosa Martins, Rahul Cecil, Iryna Lypova, Manuel Meyer, Perri Zilberman. Supplementary material: https://zenodo.org/records/10781524
Published: 2024
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15. Acceleration and transport of relativistic electrons in the jets of the microquasar SS 433

Author: Aharonian, F., Benkhali, F. Ait, Aschersleben, J., Ashkar, H., Backes, M., Martins, V. Barbosa, Batzofin, R., Becherini, Y., Berge, D., Bernlöhr, K., Bi, B., Böttcher, M., Boisson, C., Bolmont, J., de Lavergne, M. de Bony, Borowska, J., Bouyahiaou, M., Breuhau, M., Brose, R., Brown, A. M., Brun, F., Bruno, B., Bulik, T., Burger-Scheidlin, C., Caroff, S., Casanova, S., Cecil, R., Celic, J., Cerruti, M., Chand, T., Chandra, S., Chen, A., Chibueze, J., Chibueze, O., Cotter, G., Dai, S., Mbarubucyeye, J. Damascene, Djannati-Ataï, A., Dmytriiev, A., Doroshenko, V., Egberts, K., Einecke, S., Ernenwein, J. -P., Filipovic, M., Fontaine, G., Funk, S., Gabici, S., Ghafourizadeh, S., Giavitto, G., Glawion, D., Glicenstein, J. F., Grolleron, G., Haerer, L., Hinton, J. A., Hofmann, W., Holch, T. L., Holler, M., Horns, D., Jamrozy, M., Jankowsky, F., Jardin-Blicq, A., Joshi, V., Jung-Richardt, I., Kasai, E., Katarzyński, K., Khatoon, R., Khélifi, B., Klepser, S., Kluźniak, W., Komin, Nu., Kosack, K., Kostunin, D., Kundu, A., Lang, R. G., Stum, S. Le, Leitl, F., Lemière, A., Lenain, J. -P., Leuschner, F., Lohse, T., Luashvili, A., Mackey, J., Malyshev, D., Marandon, V., Marchegiani, P., Marcowith, A., Martí-Devesa, G., Marx, R., Mehta, A., Mitchell, A., Moderski, R., Mohrmann, L., Montanari, A., Moulin, E., Murach, T., Nakashima, K., de Naurois, M., Niemiec, J., Noel, A. Priyana, Ohm, S., Olivera-Nieto, L., Wilhelmi, E. de Ona, Ostrowski, M., Panny, S., Panter, M., Parsons, R. D., Peron, G., Prokhorov, D. A., Pühlhofer, G., Punch, M., Quirrenbach, A., Reichherzer, P., Reimer, A., Reimer, O., Ren, H., Renaud, M., Reville, B., Rieger, F., Rowell, G., Rudak, B., Ricarte, H. Rueda, Ruiz-Velasco, E., Sahakian, V., Salzman, H., Santangelo, A., Sasaki, M., Schäfer, J., Schüssler, F., Schwanke, U., Shapopi, J. N. S., Sol, H., Specovius, A., Spencer, S., Stawarz, Ł., Steenkamp, R., Steinmassl, S., Steppa, C., Streil, K., Sushch, I., Suzuki, H., Takahashi, T., Tanaka, T., Taylor, A. M., Terrier, R., Tsirou, M., Tsuji, N., Unbehaun, T., van Eldik, C., Vecchi, M., Veh, J., Venter, C., Vink, J., Wach, T., Wagner, S. J., Werner, F., White, R., Wierzcholska, A., Wong, Yu Wun, Zacharias, M., Zargaryan, D., Zdziarski, A. A., Zech, A., Zouari, S., and Żywucka, N.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: SS 433 is a microquasar, a stellar binary system with collimated relativistic jets. We observed SS 433 in gamma rays using the High Energy Stereoscopic System (H.E.S.S.), finding an energy-dependent shift in the apparent position of the gamma-ray emission of the parsec-scale jets. These observations trace the energetic electron population and indicate the gamma rays are produced by inverse-Compton scattering. Modelling of the energy-dependent gamma-ray morphology constrains the location of particle acceleration and requires an abrupt deceleration of the jet flow. We infer the presence of shocks on either side of the binary system at distances of 25 to 30 parsecs and conclude that self-collimation of the precessing jets forms the shocks, which then efficiently accelerate electrons., Comment: Submitted 20th Apr. 2023, published 25th January 2024 (accepted version)
Published: 2024
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16. Measurement of the Isolated Nuclear Two-Photon Decay in $^{72}\mathrm{Ge}$

Author: Freire-Fernández, D., Korten, W., Chen, R. J., Litvinov, S., Litvinov, Yu. A., Sanjari, M. S., Weick, H., Akinci, F. C., Albers, H. M., Armstrong, M., Banerjee, A., Blaum, K., Brandau, C., Brown, B. A., Bruno, C. G., Carroll, J. J., Chen, X., Chiara, Ch. J., Cortes, M. L., Dellmann, S. F., Dillmann, I., Dmytriiev, D., Forstner, O., Geissel, H., Glorius, J., Görgen, A., Górska, M., Griffin, C. J., Gumberidze, A., Harayama, S., Hess, R., Hubbard, N., Ide, K. E., John, Ph. R., Joseph, R., Jurado, B., Kalaydjieva, D., Kanika, K., Kondev, F. G., Koseoglou, P., Kosir, G., Kozhuharov, Ch., Kulikov, I., Leckenby, G., Lorenz, B., Marsh, J., Mistry, A., Ozawa, A., Pietralla, N., Podolyák, Zs., Polettini, M., Sguazzin, M., Sidhu, R. S., Steck, M., Stöhlker, Th., Swartz, J. A., Vesic, J., Walker, P. M., Yamaguchi, T., and Zidarova, R.
Subjects: Nuclear Experiment, Nuclear Theory
Abstract: The nuclear two-photon or double-gamma ($2\gamma$) decay is a second-order electromagnetic process whereby a nucleus in an excited state emits two gamma rays simultaneously. To be able to directly measure the $2\gamma$ decay rate in the low-energy regime below the electron-positron pair-creation threshold, we combined the isochronous mode of a storage ring with Schottky resonant cavities. The newly developed technique can be applied to isomers with excitation energies down to $\sim100$\,keV and half-lives as short as $\sim10$\,ms. The half-life for the $2\gamma$ decay of the first-excited $0^+$ state in bare $^{72}\mathrm{Ge}$ ions was determined to be $23.9\left(6\right)$\,ms, which strongly deviates from expectations., Comment: Submitted to Physical Review Letters, 8 pages, 3 figures, 2 tables, 7 equations
Published: 2023

17. One-loop correction contributions in the decoupling limit of generalized Yukawa model

Author: Dmytriiev, Mykyta and Skalozub, Volodymyr
Subjects: High Energy Physics - Phenomenology
Abstract: We consider the generalized Yukawa model consisting of two Dirac fermions and two scalar fields. One of the scalars is assumed to be much heavier than the other particles, so it decouples at low energies. Low-energy effective Lagrangian (EL) of the model is derived. It describes the contributions of the heavy scalar into observables in the limit when this particle is decoupled. We consider the cross-sections of $s$- and $t$-channel processes, obtained within the complete model and its low-energy approximation. The contributions of the one-loop corrections in the cross-sections coming from light particles are analyzed. These are corrections to the parameters of the heavy boson and the contributions of the one-loop mixing of light and heavy scalars. We identify the ranges of Yukawa's couplings where the corrections are significant. We find that if the interaction between fermions and either light or heavy scalar is strong enough, the derived EL could not be applied for the description of the analyzed cross-sections even if the heavy scalar decouples. Implications of our results in searching for new particles beyond the Standard model are discussed.
Published: 2023
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18. Discovery of a Radiation Component from the Vela Pulsar Reaching 20 Teraelectronvolts

Author: Collaboration, The H. E. S. S., Aharonian, F., Benkhali, F. Ait, Aschersleben, J., Ashkar, H., Backes, M., Martins, V. Barbosa, Batzofin, R., Becherini, Y., Berge, D., Bernlöhr, K., Bi, B., Böttcher, M., Boisson, C., Bolmont, J., de Lavergne, M. de Bony, Borowska, J., Bradascio, F., Breuhaus, M., Brose, R., Brun, F., Bruno, B., Bulik, T., Burger-Scheidlin, C., Bylund, T., Cangemi, F., Caroff, S., Casanova, S., Celic, J., Cerruti, M., Chand, T., Chandra, S., Chen, A., Chibueze, O., Cotter, G., Mbarubucyeye, J. Damascene, Djannati-Ataï, A., Dmytriiev, A., Egberts, K., Ernenwein, J. -P., Feijen, K., Fiasson, A., de Clairfontaine, G. Fichet, Fontaine, G., Füßling, M., Funk, S., Gabici, S., Gallant, Y. A., Ghafourizadeh, S., Giavitto, G., Giunti, L., Glawion, D., Glicenstein, J. F., Goswami, P., Grolleron, G., Grondin, M. -H., Haerer, L., Haupt, M., Hinton, J. A., Hofmann, W., Holch, T. L., Holler, M., Horns, D., Huang, Zhiqiu, Jamrozy, M., Jankowsky, F., Joshi, V., Jung-Richardt, I., Kasai, E., Katarzyński, K., Khélifi, B., Klepser, S., Kluźniak, W., Komin, Nu., Kosack, K., Kostunin, D., Lang, R. G., Stum, S. Le, 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., Maurin, G., Meyer, M., Mitchell, A., Moderski, R., Mohrmann, L., Montanari, A., Moulin, E., Muller, J., Murach, T., Nakashima, K., de Naurois, M., Niemiec, J., Noel, A. Priyana, OBrien, P., Ohm, S., Olivera-Nieto, L., Wilhelmi, E. de Ona, Ostrowski, M., Panny, S., Panter, M., Parsons, R. D., Peron, G., Pita, S., Prokhorov, D. A., Prokoph, H., Pühlhofer, G., Punch, M., Quirrenbach, A., Reichherzer, P., Reimer, A., Reimer, O., Renaud, M., Rieger, F., Rowell, G., Rudak, B., Ruiz-Velasco, E., Sahakian, V., Sailer, S., Salzmann, H., Sanchez, D. A., Santangelo, A., Sasaki, M., Schüssler, F., Schwanke, U., Shapopi, J. N. S., Sinha, A., Sol, H., Specovius, A., Spencer, S., Spir-Jacob, M., Stawarz, L., Steenkamp, R., Steinmassl, S., Steppa, C., Sushch, I., Suzuki, H., Takahashi, T., Tanaka, T., Tavernier, T., Terrier, R., Thorpe-Morgan, C., Tluczykont, M., Tsirou, M., Tsuji, N., van Eldik, C., Vecchi, M., Veh, J., Venter, C., Vink, J., Wagner, S. J., Werner, F., White, R., Wierzcholska, A., Wong, Yu Wun, Yassin, H., Zacharias, M., Zargaryan, D., Zdziarski, A. A., Zech, A., Zhu, S. J., Zouari, S., Żywucka, N., Zanin, R., Kerr, M., Johnston, S., Shannon, R. M., and Smith, D. A.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: Gamma-ray observations have established energetic isolated pulsars as outstanding particle accelerators and antimatter factories in the Galaxy. There is, however, no consensus regarding the acceleration mechanisms and the radiative processes at play, nor the locations where these take place. The spectra of all observed gamma-ray pulsars to date show strong cutoffs or a break above energies of a few gigaelectronvolt (GeV). Using the H.E.S.S. array of Cherenkov telescopes, we discovered a novel radiation component emerging beyond this generic GeV cutoff in the Vela pulsar's broadband spectrum. The extension of gamma-ray pulsation energies up to at least 20 teraelectronvolts (TeV) shows that Vela pulsar can accelerate particles to Lorentz factors higher than $4\times10^7$. This is an order of magnitude larger than in the case of the Crab pulsar, the only other pulsar detected in the TeV energy range. Our results challenge the state-of-the-art models for high-energy emission of pulsars while providing a new probe, i.e. the energetic multi-TeV component, for constraining the acceleration and emission processes in their extreme energy limit., Comment: 38 pages, 6 figures. This preprint has not undergone peer review or any post-submission improvements or corrections. The Version of Record of this article is published in Nature Astronomy, Nat Astron (2023), and is available online at https://doi.org/10.1038/s41550-023-02052-3
Published: 2023
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19. Target of Opportunity observations of flaring blazars with H.E.S.S.$\ $

Author: Cerruti, M., Boisson, C., Böttcher, M., Chibueze, O., Davids, I., Dmytriiev, A., Grolleron, G., Jankowsky, F., Lenain, J. P., Luashvili, A., and Zacharias, M.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: Blazars are the most common class of TeV extragalactic emitters. In the framework of the AGN unified model, they are understood as AGNs with a relativistic jet pointing close the line of sight. They are characterized by extreme variability, observed to be as fast as minutes. These flares are usually observed at multiple wavelengths and their study require fast reaction and coordination among multiwavelength observatories. An important part of blazars observations with the H.E.S.S. array of Cherenkov telescopes is thus in the form of Target of Opportunity (ToO) observations. In this contribution the H.E.S.S. blazar ToO program is presented, with a focus on recent results., Comment: to appear in the proceedings of the ICRC 2023 Conference
Published: 2023

20. The vanishing of the primary emission region in PKS 1510-089

Author: Aharonian, F., Benkhali, F. Ait, Aschersleben, J., Ashkar, H., Backes, M., Martins, V. Barbosa, Barnard, J., Batzofin, R., Becherini, Y., Berge, D., Bernloehr, K., Bi, B., de Lavergne, M. de Bony, Boettcher, M., Boisson, C., Bolmont, J., Borowska, J., Bouyahiaoui, M., Bradascio, F., Breuhaus, M., Brose, R., Brown, A. M., Brun, F., Bruno, B., Bulik, T., Burger-Scheidlin, C., Caroff, S., Casanova, S., Cecil, R., Celic, J., Cerruti, M., Chand, T., Chandra, S., Chen, A., Chibueze, J., Chibueze, O., Cotter, G., Mbarubucyeye, J. Damascene, Davids, I. D., Djannati-Atai, A., Dmytriiev, A., Doroshenko, V., Egberts, K., Einecke, S., Ernenwein, J. -P., Fegan, S., Fontaine, G., Fuessling, M., Funk, S., Gabici, S., Ghafourizadeh, S., Giavitto, G., Glawion, D., Glicenstein, J. F., Goswami, P., Grolleron, G., Haerer, L., Hofmann, W., Holch, T. L., Holler, M., Horns, D., Jamrozy, M., Jankowsky, F., Joshi, V., Jung-Richardt, I., Kasai, E., Katarzyski, K., Khatoon, R., Khelifi, B., Klu/'zniak, W., Komin, Nu., Kosack, K., Kostunin, D., Lang, R. G., Stum, S. Le, Leitl, F., Lemiere, A., Lenain, J. -P., Leuschner, F., Luashvili, A., Mackey, J., Marandon, V., Marchegiani, P., Marti-Devesa, G., Marx, R., Mehta, A., Meyer, M., Mitchell, A., Moderski, R., Mohrmann, L., Montanari, A., Moulin, E., de Naurois, M., Niemiec, J., Noel, A. Priyana, O'Brien, P., Ohm, S., Olivera-Nieto, L., Wilhelmi, E. de Ona, Ostrowski, M., Panny, S., Panter, M., Peron, G., Prokhorov, D. A., Puehlhofer, G., Punch, M., Quirrenbach, A., Reichherzer, P., Reimer, A., Reimer, O., Ren, H., Rieger, F., Rowell, G., Rudak, B., Ricarte, H. Rueda, Ruiz-Velasco, E., Sahakian, V., Salzmann, H., Sanchez, D. A., Santangelo, A., Sasaki, M., Schuessler, F., Schutte, H. M., Schwanke, U., Shapopi, J. N. S., Sol, H., Specovius, A., Spencer, S., Stawarz, L., Steenkamp, R., Steinmassl, S., Steppa, C., Sushch, I., Suzuki, H., Takahashi, T., Tanaka, T., Terrier, R., Tsuji, N., van Eldik, C., van Soelen, B., Vecchi, M., Veh, J., Vink, J., Wach, T., Wagner, S. J., Wierzcholska, A., Zacharias, M., Zargaryan, D., Zdziarski, A. A., Zech, A., Zouari, S., Zywucka, N., Buckley, D. A. H., Cooper, J., and Groenewald, D.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies
Abstract: In July 2021, PKS 1510-089 exhibited a significant flux drop in the high-energy gamma-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 gamma-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 gamma-ray and X-ray fluxes originate from a different emission region than the vanished parts of the high-energy gamma-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., Comment: 18 pages, 4 figures, 6 tables; accepted for publication in ApJ Letters; corresponding authors: Joleen Barnard, Markus Boettcher, Hester Schutte, Michael Zacharias
Published: 2023
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21. New methods of treatment for severe and moderate postoperative pain syndrome in patients with cancer

Author: D.V. Dmytriiev and M.M. Barsa
Subjects: dinalbuphine sebacate, postoperative pain, oncology, mammoplasty, Medical emergencies. Critical care. Intensive care. First aid, RC86-88.9
Abstract: Background. Anesthesia management in oncology surgeries poses significant challenges for anesthesiologists due to the extent of surgical trauma and the presence of pre-existing conditions such as chronic pain and prolonged use of narcotic analgesics. This necessitates the development of novel strategies to optimize postoperative pain management, particularly in this cohort. Objective: to evaluate the clinical efficacy and safety of a medicinal product with active ingredient dinalbuphine sebacate (150 mg/2 ml) in patients with moderate to severe pain syndrome following reconstructive mammoplasty due to breast cancer surgery. Materials and methods. This was a multicenter, randomized, prospective, open-label study involving 60 inpatients who underwent mammoplasty as a result of breast cancer surgery. Both groups received medications in accordance with multimodal analgesia protocols (paracetamol 1 g four times daily, dexketoprofen 50 mg three times daily, additional doses of non-steroidal anti-inflammatory drugs (NSAIDs) as needed) and morphine as needed at a maximum dose of 40 mg/day. Patients in the experimental group (30 participants) received 150 mg of dinalbuphine sebacate intramuscularly 12–24 hours before surgery. The primary endpoints included pain intensity measured on a numerical rating scale at 6, 24, 48, 96, and 120 hours postoperatively, the number of doses of NSAIDs and morphine as needed, and the incidence and nature of complications associated with drug administration. Results. A statistically significant difference in pain levels on the numerical rating scale was observed at 6 and 24 hours (p < 0.05). After 48, 96, and 120 hours, pain levels did not differ between the groups. Morphine consumption differed significantly between the experimental and control groups on the first postoperative day (0 [0; 10] mg vs. 10.0 [0; 10] mg, respectively, p < 0.05). On the second day, the values were 0 [0; 10] mg vs. 0 [0; 10] mg, respectively, p = 0.232. Additional NSAIDs administration was required by 83.3 % of patients in the experimental group and 93.4 % of controls. Conclusions. The study demonstrated that dinalbuphine sebacate is an effective and safe component of multimodal analgesia. In the experimental group, target levels of postoperative pain control were achieved during the first 24 hours following surgery, unlike the control group.
Published: 2024
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22. Multiwavelength Observations of the Blazar PKS 0735+178 in Spatial and Temporal Coincidence with an Astrophysical Neutrino Candidate IceCube-211208A

Author: Acharyya, A., Adams, C. B., Archer, A., Bangale, P., Bartkoske, J. T., Batista, P., Benbow, W., Brill, A., Buckley, J. H., Christiansen, J. L., Chromey, A. J., Errando, M., Falcone, A., Feng, Q., Foote, G. M., Fortson, L., Furniss, A., Gallagher, G., Hanlon, W., Hanna, D., Hervet, O., Hinrichs, C. E., Hoang, J., Holder, J., Humensky, T. B., Jin, W., Kaaret, P., Kertzman, M., Kherlakian, M., Kieda, D., Kleiner, T. K., Korzoun, N., Kumar, S., Lang, M. J., Lundy, M., Maier, G., McGrath, C. E, Millard, M. J., Millis, J., Mooney, C. L., Moriarty, P., Mukherjee, R., O'Brien, S., Ong, R. A., Pohl, M., Pueschel, E., Quinn, J., Ragan, K., Reynolds, P. T., Ribeiro, D., Roache, E., Sadeh, I., Sadun, A. C., Saha, L., Santander, M., Sembroski, G. H., Shang, R., Splettstoesser, M., Talluri, A. Kaushik, Tucci, J. V., Vassiliev, V. V., Weinstein, A., Williams, D. A., Wong, S. L., Woo, J., Aharonian, F., Aschersleben, J., Backes, M., Martins, V. Barbosa, Batzofin, R., Becherini, Y., Berge, D., Bernlohr, K., Bi, B., Bottcher, M., Boisson, C., Bolmont, J., de Lavergne, M. de Bony, Borowska, J., Bouyahiaoui, M., Bradascio, F., Breuhaus, M., Brose, R., Brun, F., Bruno, B., Bulik, T., Burger-Scheidlin, C., Caroff, S., Casanova, S., Cecil, R., Celic, J., Cerruti, M., Chand, T., Chandra, S., Chen, A., Chibueze, J., Chibueze, O., Cotter, G., Dai, S., Mbarubucyeye, J. Damascene, Djannati-Atai, A., Dmytriiev, A., Doroshenko, V., Einecke, S., Ernenwein, J. -P., de Clairfontaine, G. Fichet, Filipovic, M., Fontaine, G., Fussling, M., Funk, S., Gabici, S., Ghafourizadeh, S., Giavitto, G., Glawion, D., Glicenstein, J. F., Goswami, P., Grolleron, G., Haerer, L., Hinton, J. A., Holch, T. L., Holler, M., Horns, D., Jamrozy, M., Jankowsky, F., Joshi, V., Jung-Richardt, I., Kasai, E., Katarzynski, K., Khatoon, R., Khelifi, B., Klepser, S., Kluzniak, W., Kosack, K., Kostunin, D., Lang, R. G., Stum, S. Le, Lemiere, A., Lenain, J. P., Leuschner, F., Lohse, T., Luashvili, A., Lypova, I., Mackey, J., Malyshev, D., Marandon, V., Marchegiani, P., Marcowith, A., Marti-Devesa, G., Marx, R., Mitchell, A., Moderski, R., Mohrmann, L., Montanari, A., Moulin, E., Murach, T., Nakashima, K., Niemiec, J., Noel, A. Priyana, O'Brien, P., Olivera-Nieto, L., Wilhelmi, E. de Ona, Ostrowski, M., Panny, S., Panter, M., Peron, G., Prokhorov, D. A., Puhlhofer, G., Punch, M., Quirrenbach, A., Reichherzer, P., Reimer, A., Reimer, O., Ren, H., Renaud, M., Rieger, F., Rudak, B., Ruiz-Velasco, E., Sahakian, V., Santangelo, A., Sasaki, M., Schafer, J., Schussler, F., Schutte, H. M., Schwanke, U., Shapopi, J. N. S., Specovius, A., Spencer, S., Stawarz, L., Steenkamp, R., Steinmassl, S., Sushch, I., Suzuki, H., Takahashi, T., Tanaka, T., Terrier, R., van Eldik, C., Vecchi, M., Veh, J., Venter, C., Vink, J., White, R., Wierzcholska, A., Wong, Yu Wun, Zacharias, M., Zargaryan, D., Zdziarski, A. A., Zech, A., Zouari, S., Zywucka, N., and Mori, K.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: We report on multiwavelength target-of-opportunity observations of the blazar PKS 0735+178, located 2.2$^\circ$ away from the best-fit position of the IceCube neutrino event IceCube-211208A detected on December 8, 2021. The source was in a high-flux state in the optical, ultraviolet, X-ray, and GeV gamma-ray bands around the time of the neutrino event, exhibiting daily variability in the soft X-ray flux. The X-ray data from Swift-XRT and NuSTAR characterize the transition between the low-energy and high-energy components of the broadband spectral energy distribution (SED), and the gamma-ray data from Fermi -LAT, VERITAS, and H.E.S.S. require a spectral cut-off near 100 GeV. Both X-ray and gamma-ray measurements provide strong constraints on the leptonic and hadronic models. We analytically explore a synchrotron self-Compton model, an external Compton model, and a lepto-hadronic model. Models that are entirely based on internal photon fields face serious difficulties in matching the observed SED. The existence of an external photon field in the source would instead explain the observed gamma-ray spectral cut-off in both leptonic and lepto-hadronic models and allow a proton jet power that marginally agrees with the Eddington limit in the lepto-hadronic model. We show a numerical lepto-hadronic model with external target photons that reproduces the observed SED and is reasonably consistent with the neutrino event despite requiring a high jet power., Comment: 21 pages, 3 figures, accepted by ApJ
Published: 2023

23. Detection of extended gamma-ray emission around the Geminga pulsar with H.E.S.S

Author: Collaboration, H. E. S. S., Aharonian, F., Benkhali, F. Ait, Aschersleben, J., Ashkar, H., Backes, M., Martins, V. Barbosa, Batzofin, R., Becherini, Y., Berge, D., Bernlöhr, K., Bi, B., Böttcher, M., Boisson, C., Bolmont, J., Borowska, J., Bouyahiaoui, M., Bradascio, F., Brose, R., Brun, F., Bruno, B., Bulik, T., Scheidlin, C. Burger, Cangemi, F., Caroff, S., Casanova, S., Celic, J., Cerruti, M., Chambery, P., Chand, T., Chandra, S., Chen, A., Chibueze, J., Chibueze, O., Cotter, G., Mbarubucyeye, J. Damascene, Devin, J., Djannati-Ataï, A., Dmytriiev, A., Egberts, K., Einecke, S., Ernenwein, J. P., Feijen, K., de Clairfontaine, G. Fichet, Filipovic, M., Fontaine, G., Füssling, M., Funk, S., Gabici, S., Gallant, Y. A., Ghafourizadeh, S., Giavitto, G., Giunti, L., Glawion, D., Glicenstein, J. F., Goswami, P., Grolleron, G., Grondin, M. -H., Haerer, L., Haupt, M., Hermann, G., Hinton, J. A., Hofmann, W., Holch, T. L., Holler, M., Horns, D., Huang, Zhiqiu, Jamrozy, M., Jankowsky, F., Joshi, V., Jung-Richardt, I., Kasai, E., Katarzyński, K., Khélifi, B., Kluźniak, W., Komin, Nu., Kosack, K., Kostunin, D., Lang, R. G., Stum, S. Le, 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., Maurin, G., Meintjes, P. J., Meyer, M., Mitchell, A., Moderski, R., Mohrmann, L., Montanari, A., Moulin, E., Muller, J., Nakashima, K., de Naurois, M., Niemiec, J., Noel, A. Priyana, O'Brien, P., Ohm, S., Olivera-Nieto, L., Wilhelmi, E. de Ona, Ostrowski, M., Panny, S., Panter, M., Parsons, R. D., Peron, G., Prokhorov, D. A., Pühlhofer, G., Quirrenbach, A., Reimer, A., Reimer, O., Renaud, M., Reville, B., Rieger, F., Rowell, G., Rudak, B., Ricarte, H. Rueda, Ruiz-Velasco, E., Sahakian, V., Salzmann, H., Santangelo, A., Sasaki, M., Schüssler, F., Schutte, H. M., Schwanke, U., Shapopi, J. N. S., Sinha, A., Sol, H., Specovius, A., Spencer, S., Stawarz, Ł., Steinmassl, S., Sushch, I., Suzuki, H., Takahashi, T., Tanaka, T., Tavernier, T., Taylor, A. M., Terrier, R., Thorpe-Morgan, C., Tsirou, M., Tsuji, N., Vecchi, M., Venter, C., Vink, J., Wagner, S. J., White, R., Wierzcholska, A., Wong, Yu Wun, Zacharias, M., Zargaryan, D., Zdziarski, A. A., Zech, A., Zouari, S., and Żywucka, N.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: Geminga is an enigmatic radio-quiet gamma-ray pulsar located at a mere 250 pc distance from Earth. Extended very-high-energy gamma-ray emission around the pulsar was discovered by Milagro and later confirmed by HAWC, which are both water Cherenkov detector-based experiments. However, evidence for the Geminga pulsar wind nebula in gamma rays has long evaded detection by imaging atmospheric Cherenkov telescopes (IACTs) despite targeted observations. The detection of gamma-ray emission on angular scales > 2 deg poses a considerable challenge for the background estimation in IACT data analysis. With recent developments in understanding the complementary background estimation techniques of water Cherenkov and atmospheric Cherenkov instruments, the H.E.S.S. IACT array can now confirm the detection of highly extended gamma-ray emission around the Geminga pulsar with a radius of at least 3 deg in the energy range 0.5-40 TeV. We find no indications for statistically significant asymmetries or energy-dependent morphology. A flux normalisation of $(2.8\pm0.7)\times10^{-12}$ cm$^{-2}$s$^{-1}$TeV$^{-1}$ at 1 TeV is obtained within a 1 deg radius region around the pulsar. To investigate the particle transport within the halo of energetic leptons around the pulsar, we fitted an electron diffusion model to the data. The normalisation of the diffusion coefficient obtained of $D_0 = 7.6^{+1.5}_{-1.2} \times 10^{27}$ cm$^2$s$^{-1}$, at an electron energy of 100 TeV, is compatible with values previously reported for the pulsar halo around Geminga, which is considerably below the Galactic average., Comment: 16 pages, 15 figures, 7 tables. Accepted for publication in Astronomy & Astrophysics
Published: 2023
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24. Correlation between emission-line luminosity and gamma-ray dominance in the blazar 3C 279

Author: Dmytriiev, Anton, Boettcher, Markus, and Machipi, Thabiso O.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: Despite numerous studies, the origin of the gamma-ray emission from blazars is still debated, in particular whether it is produced by leptonic or hadronic processes. In this study, we are testing the leptonic scenario for the Flat Spectrum Radio Quasar (FSRQ) 3C 279, assuming that the gamma-ray emission is generated by inverse Compton scattering of external target photons from Broad Line Region (IC-BLR scenario). For this purpose we use a 10-year data set of the source consisting of the optical spectroscopy data from the Steward Observatory blazar monitoring program and Fermi-LAT gamma-ray data. We search for a possible correlation between the Compton dominance and the emission line luminosity using the discrete correlation function (DCF) analysis. As a result, we find no significant correlation between these two quantities at any time lag value, while the emission line luminosity displays a moderate correlation with the gamma-ray flux at a zero time lag. We also reveal that the optical synchrotron continuum flux shows a pronounced correlation with the gamma-ray flux, and therefore we interpret these results within the leptonic IC-BLR scenario where the Compton dominance variations are primarily induced by changes in the magnetic field, rather than in the emission line luminosity., Comment: 16 pages, 5 figures. Accepted for publication in ApJ
Published: 2023
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25. H.E.S.S. follow-up observations of GRB221009A

Author: Collaboration, H. E. S. S., Aharonian, F., Benkhali, F. Ait, Aschersleben, J., Ashkar, H., Backes, M., Baktash, A., Martins, V. Barbosa, Batzofin, R., Becherini, Y., Berge, D., Bernlöhr, K., Bi, B., Böttcher, M., Boisson, C., Bolmont, J., de Lavergne, M. de Bony, Borowska, J., Bouyahiaoui, M., Bradascio, F., Breuhaus, M., Brose, R., Brun, F., Bruno, B., Bulik, T., Burger-Scheidlin, C., Caroff, S., Casanova, S., Celic, J., Cerruti, M., Chand, T., Chandra, S., Chen, A., Chibueze, J., Chibueze, O., Cotter, G., Dai, S., Mbarubucyeye, J. Damascene, Devin, J., Djannati-Ataï, A., Dmytriiev, A., Doroshenko, V., Egberts, K., Einecke, S., Ernenwein, J. -P., Fegan, S., de Clairfontaine, G. Fichet, Filipovic, M., Fontaine, G., Füßling, M., Funk, S., Gabici, S., Ghafourizadeh, S., Giavitto, G., Glawion, D., Glicenstein, J. F., Goswami, P., Grolleron, G., Hinton, M. -H. Grondin J. A., Holch, T. L., Holler, M., Horns, D., Huang, Zhiqiu, Jamrozy, M., Jankowsky, F., Joshi, V., Jung-Richardt, I., Kasai, E., Katarzyński, K., Khatoon, R., Khélifi, B., Kluźniak, W., Komin, Nu., Konno, R., Kosack, K., Kostunin, D., Lang, R. G., Stum, S. Le, Leitl, F., Lemière, A., Lemoine-Goumard, M., Lenain, J. P., Leuschner, F., Lohse, T., Lypova, I., Mackey, J., Malyshev, D., Marandon, V., Marchegiani, P., Marcowith, A., Martí-Devesa, G., Marx, R., Meyer, M., Mitchell, A., Mohrmann, L., Montanari, A., Moulin, E., Murach, T., Nakashima, K., de Naurois, M., Niemiec, J., Noel, A. Priyana, O'Brien, P., Ohm, S., Olivera-Nieto, L., Wilhelmi, E. de Ona, Ostrowski, M., Panny, S., Panter, M., Parsons, R. D., Peron, G., Prokhorov, D. A., Prokoph, H., Pühlhofer, G., Punch, M., Quirrenbach, A., Reichherzer, P., Reimer, A., Reimer, O., Ren, H., Renaud, M., Reville, B., Rieger, F., Rowell, G., Rudak, B., Ruiz-Velasco, E., Sahakian, V., Salzmann, H., Santangelo, A., Sasaki, M., Schäfer, J., Schüssler, F., Schutte, H. M., Schwanke, U., Shapopi, J. N. S., Specovius, A., Spencer, S., Stawarz, Ł., Steenkamp, R., Steinmassl, S., Steppa, C., Sushch, I., Suzuki, H., Takahashi, T., Tanaka, T., Terrier, R., Tsuji, N., Uchiyama, Y., Vecchi, M., Venter, C., Vink, J., Wagner, S. J., White, R., Wierzcholska, A., Wong, Yu Wun, Zacharias, M., Zargaryan, D., Zdziarski, A. A., Zech, A., Zhu, S. J., and Żywucka, N.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: GRB221009A is the brightest gamma-ray burst ever detected. To probe the very-high-energy (VHE, $>$\!100 GeV) emission, the High Energy Stereoscopic System (H.E.S.S.) began observations 53 hours after the triggering event, when the brightness of the moonlight no longer precluded observations. We derive differential and integral upper limits using H.E.S.S. data from the third, fourth, and ninth nights after the initial GRB detection, after applying atmospheric corrections. The combined observations yield an integral energy flux upper limit of $\Phi_\mathrm{UL}^{95\%} = 9.7 \times 10^{-12}~\mathrm{erg\,cm^{-2}\,s^{-1}}$ above $E_\mathrm{thr} = 650$ GeV. The constraints derived from the H.E.S.S. observations complement the available multiwavelength data. The radio to X-ray data are consistent with synchrotron emission from a single electron population, with the peak in the SED occurring above the X-ray band. Compared to the VHE-bright GRB190829A, the upper limits for GRB221009A imply a smaller gamma-ray to X-ray flux ratio in the afterglow. Even in the absence of a detection, the H.E.S.S. upper limits thus contribute to the multiwavelength picture of GRB221009A, effectively ruling out an IC dominated scenario., Comment: 10 pages, 4 figures. Accepted for publication in APJL. Corresponding authors: J. Damascene Mbarubucyeye, H. Ashkar, S. J. Zhu, B. Reville, F. Sch\"ussler
Published: 2023
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26. HESS J1809$-$193: a halo of escaped electrons around a pulsar wind nebula?

Author: Collaboration, H. E. S. S., Aharonian, F., Benkhali, F. Ait, Aschersleben, J., Ashkar, H., Backes, M., Martins, V. Barbosa, 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., Mbarubucyeye, J. Damascene, 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, M., Jankowsky, F., Joshi, V., Jung-Richardt, I., Kasai, E., Katarzyński, K., Khélifi, B., Kluźniak, W., Komin, Nu., Kosack, K., Kostunin, D., Lang, R. G., Stum, S. Le, 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, A. Priyana, Ohm, S., Olivera-Nieto, L., Wilhelmi, E. de Ona, Ostrowski, M., 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, Ł., 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, A., Wong, Yu Wun, Zacharias, M., Zargaryan, D., Zdziarski, A. A., Zech, A., Zouari, S., and Żywucka, N.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: Context. HESS J1809$-$193 is an unassociated very-high-energy $\gamma$-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 $\gamma$-ray emission up to energies of $\sim$100 TeV with the HAWC observatory has led to renewed interest in HESS J1809$-$193. Aims. We aim to understand the origin of the $\gamma$-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 that exhibits a spectral cut-off at $\sim$13 TeV, and a compact component that is located close to PSR J1809$-$1917 and shows no clear spectral cut-off. The Fermi-LAT analysis also revealed extended $\gamma$-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. (abridged), Comment: 14 pages, 10 figures. Accepted for publication in A&A. Corresponding authors: Vikas Joshi, Lars Mohrmann
Published: 2023
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27. Magnetic reconnection plasmoid model for Sagittarius A* flares

Author: Aimar, N., Dmytriiev, A., Vincent, F. H., Mellah, I. El, Paumard, T., Perrin, G., and Zech, A.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: Sagittarius A*, the supermassive black hole at the center of our galaxy, exhibits episodic near-infrared flares. The recent monitoring of three such events by the GRAVITY instrument has shown that some flares are associated with orbital motions in the close environment of the black hole with super Keplerian velocity. We develop a semi-analytic model of Sagittarius~A* flares based on an ejected large plasmoid, inspired by recent particle-in-cell global simulations of black hole magnetospheres. We model the infrared astrometric and photometric signatures associated to this model. We consider a spherical large plasmoid ejected along a conical orbit around the black hole. This plasmoid is assumed to be formed by successive mergers of smaller plasmoids produced through magnetic reconnection. Non-thermal electrons are injected in the plasmoid. We compute the evolution of the electron-distribution under the influence of synchrotron cooling. We solve the radiative transfer problem and transport the radiation along null geodesics of the Schwarzschild spacetime. We also take into account the quiescent radiation of the accretion flow, on top of which the flare evolves. For the first time, we successfully account for the astrometric and flux variations of the GRAVITY data with a flare model that incorporates an explicit modeling of the emission mechanism. We find good agreement between the prediction of our model and the recent data. In particular, the azimuthal velocity is set by the magnetic field line it belongs to, which is anchored in the inner parts of the accretion flow, hence the super-Keplerian motion. The astrometric track is also shifted with respect to the center of mass due to the quiescent radiation, in agreement with the difference measured with the GRAVITY data. These results support the picture of magnetic reconnection as a viable model for Sagittarius~A* infrared flares., Comment: 20 pages, 14 figures, accepted in A&A
Published: 2023
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28. Chronic pain during 60 days of war: the impact of the Russian war on Ukrainian patients

Author: Dmytriiev, Dmytro and Garland, Eric L.
Published: 2024
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29. Study of the intensity of postoperative pain after mine-explosive injury: a pilot study of different analgesics

Author: D. Dmytriiev
Subjects: multimodal analgesia, chronic pain, postoperative pain, dinalbuphine sebacate, mine-explosive injury, Medical emergencies. Critical care. Intensive care. First aid, RC86-88.9
Abstract: Background. Mine-explosive injuries, often associated with traumatic and complex circumstances, pose unique challenges in the field of surgical interventions (SI) and subsequent pain management. That is why the main goal of this study was to determine the safety and effectiveness of a single dose of dinalbuphine sebacate 150 mg/2 ml as a component of multimodal analgesia applied intramuscularly before reconstructive surgeries due to mine-explosive lesions. Materials and methods. A prospective, open, non-randomized clinical study was carried out with the participation of 15 patients with mine-explosive injuries, who were treated using dinalbuphine sebacate 150 mg/2 ml as a component of multimodal anesthesia for postoperative pain. All patients received a single dose of dinalbuphine sebacate 150 mg/2 ml intramuscularly using the Z-technique in the gluteal area 12–24 hours before surgery. The Visual Analogue Scale (VAS) with a range from 0 to 10 points (0 = no pain, 10 = the worst imaginable pain) was used as a tool for assessing the severity of the pain syndrome. The StataCorp 2023 program was used for statistical analysis. Stata Statistical Software: Release 18. College Station, TX: StataCorp LLC. Simple linear regression analysis was used to study the relationship between Injury Severity Score (ISS) and VAS. Results. No statistically significant relationship between ISS and VAS was found. The study showed that 6 h after SI, the level of pain significantly decreased in comparison with that 6–8 hours after the use of the drug and was not statistically significantly different from the indicators of the following four days: VAS 6 hours after SI vs. 12 hours after SI — p = 0.2500, VAS 6 hours after SI vs. 24 hours after SI — p = 1.0000, VAS 6 hours after SI vs. 48 hours after SI — p= 0.4531, VAS 6 hours after SI vs. 96 hours after SI — p= 0.2188. At the same time, a statistically significant difference was found between VAS 6 hours after SI vs. 120 hours after SI — p= 0.0010. Conclusions. The efficacy and favorable to-lerability of dinalbuphine sebacate as a component of multimodal analgesia in the setting of postoperative analgesia in patients after reconstructive surgical interventions caused by mine-explosive injuries was demonstrated.
Published: 2024
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30. The role of microbial wound contamination in chronic pain development in patients with injuries

Author: K.V. Ksenchyna, O.O. Ksenchyn, O.A. Nazarchuk, and D.V. Dmytriiev
Subjects: chronic pain, infected wound, biofilms, healing, postsurgical pain, skin microbiota, Medical emergencies. Critical care. Intensive care. First aid, RC86-88.9
Abstract: Nowadays, with the start of hostilities in Ukraine, the number of people with injuries has increased and continues to grow. Of course, one of the main issues facing by medical professionals is preventing complications and restoring sufficient functional capacity. Pain is one of the protective mechanisms of the human body; its prolonged course is one of the most important causes for reducing the quality of life and limiting a person’s work capacity. Acute pain is positioned as the body’s main signal for help, usually as a disease symptom, while chronic pain can be an independent nosological unit and mostly appears after primary cause. Secondary chronic pain is one of the injury consequences that can occur and significantly worsen the patient’s prognosis and reduce quality of life. Prevention of the secondary chronic pain is possible if all prerequisites are known. Furthermore, the human body interacts with a complex community of bacteria, fungi, and viruses. Several microorganisms create the microbiome of the skin, which ensures its barrier function and plays an important role in the immune response in wounds. These processes are not always predictable, and both positive and negative effects on wound healing can be observed. After all, the duration of wound healing directly depends on the type of microorganisms and their sensitivity to the antibiotic treatment. The long process of wound surface healing can lead more likely to a violation of all physiological processes in this body part. This can be quite an important factor in chronic pain occurrence.
Published: 2024
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31. Possibilities of the ultrasound method in assessing the degree of swelling of perineural tissues at the level of the lower leg. Focus on regional anesthesia

Author: Y.V. Lysak and D.V. Dmytriiev
Subjects: swelling, ultrasound diagnosis, local anesthetic, diabetes, diabetic foot syndrome, conduction anesthesia, regional anesthesia, Medical emergencies. Critical care. Intensive care. First aid, RC86-88.9
Abstract: Widespread introduction of ultrasound-guided regional anesthesia has increased the frequency of nerve blocks and the list of available nerves for blocking, particularly on the foot. In the area of the tibiocalcaneal joint, swellings of various etiologies are often found, including in patients with diabetes, who are characterized by high comorbidity. To date, the influence of edema on the effectiveness of local anesthetics is insufficiently studied. To evaluate the ultrasound criteria, we have analyzed and characterized the ultrasound pattern of 110 patients. When performing a nerve block in the area of the tibiocalcaneal joint, the time of the block onset and duration of sensory block in patients who underwent surgery for the diabetic foot depended reliably on the degree of ultrasound-diagnosed edema in the area of the block. The ultrasound method makes it possible to assess the degree of swelling in the area of blockade directly during conduction anesthesia. Further studies are needed to determine the root cause of this phenomenon, which may depend on the pH of the edema fluid or on dilution in the edema volume.
Published: 2024
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32. On the use of immediately sequential bilateral cataract surgery (ISBCS) in Ukraine

Author: S.K. Dmytriiev, Yu.M. Lazar, and Ia.A. Grytsenko
Subjects: bilateral cataract, acute optic neuropathy, intraocular lens, Internal medicine, RC31-1245
Abstract: Cataract surgery is most commonly performed today by utilizing the standardized phacoemulsification technique which results in successful outcomes and low complication rates. At present, most patients undergo cataract surgery in both eyes on separate days, referred to as delayed sequential cataract surgery (DSCS). Immediately sequential bilateral cataract surgery (ISBCS) has emerged as an alternative to traditional DSBCS and is, however, increasingly used in clinical practice throughout the world. The question arises: How safe is ISBCS with respect to postoperative complications?
Published: 2024
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33. Hemodynamic Protective Assessment of BurnNavi-Guided Fluid Management in Burned Patients: Pilot Study

Author: Melnychenko, Mykola, Dmytriiev, Dmytro, Nazarchuk, Oleksandr, Sidorenko, Ludmila, Chornopyshchuk, Roman, Nagaichuk, Vasyl, Sidorenko, Svetlana, Magjarević, Ratko, Series Editor, Ładyżyński, Piotr, Associate Editor, Ibrahim, Fatimah, Associate Editor, Lackovic, Igor, Associate Editor, Rock, Emilio Sacristan, Associate Editor, Sontea, Victor, editor, Tiginyanu, Ion, editor, and Railean, Serghei, editor
Published: 2024
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34. Ventilation strategies and risk factors for intraoperative respiratory critical events and postoperative pulmonary complications in neonates and small infants: a secondary analysis of the NECTARINE cohort☆

Author: Veyckemans, Francis, Virag, Katalin, Hansen, Tom G., Becke-Jakob, Karin, Harlet, Pierre, Vutskits, Laszlo, Walker, Suellen M., de Graaff, Jurgen C., Zielinska, Marzena, Simic, Dusica, Breschan, Christian, Likar, Rudolf, Platzer, Manuela, Edelman, Isole, Eger, Johanes, Heschl, Stefan, Messerer, Brigitte, Vittinghof, Maria, Kroess, Ruth, Stichlberger, Martina, Kahn, David, Pirotte, Thierry, Pregardien, Caroline, Stevens, France, Berghmans, Johan, Bauters, Annemie, De Baerdemaeker, Luc, De Hert, Stefan, Lapage, Koen, Parashchanka, Aliaksandra, Van Limmen, Jurgen, Wyffels, Piet, Lauweryns, Julie, Najafi, Nadia, Vundelinckx, Joris, Butković, Diana, Sorić, Ivana Kerovec, Kralik, Sandra, Markić, Ana, Azman, Josip, Markic, Josko, Pupacic, Daniela, Frelich, Michal, Reimer, Petr, Urbanec, René, Cajková, Petra, Mixa, Vladimír, Sedláčková, Yvona, Knoppová, Lenka, Zlámalová (neé Květoňová), Alena, Vavřina, Martin, Žurek, Jiří, Hansen, Tom, Afshari, Arash, Bille, Anders Bastholm, Ellekvist, Marguerite, Ilmoja, Mari-Liis, Moor, Reet, Kikas, Reet, Väli, Merle, Kallio, Kariantti, Reponen, Elisa, Suominen, Pertti, Suvanto, Sami, Vähätalo, Raisa, Kokki, Hannu, Kokki, Merja, Harju, Jarkko, Kokkonen, Miia, Vieri, Jenni, Manner, Tuula, Amory, Catherine, Ludot, Hugues, Bert, Dina, Godart, Juliette, Laffargue, Anne, Dupont, Hervé, Urbina, Benjamin, Baujard, Catherine, Roulleau, Philippe, Staiti, Giuseppe, Bordes, Maryline, Gaulain, Karine Nouette, Hamonic, Yann, Semjen, François, Jacqmarcq, Olivier, Lejus-Bourdeau, Caroline, Magne, Cécile, Petry, Léa, Ros, Lilica, Zang, Aurélien, Bennis, Mehdi, Coustets, Bernard, Fesseau, Rose, Constant, Isabelle, Khalil, Eliane, Sabourdin, Nada, Audren, Noemie, Descarpentries, Thomas, Fabre, Fanny, Legrand, Aurélien, Druot, Emilie, Orliaguet, Gilles, Sabau, Lucie, Uhrig, Lynn, Brière, François de la, Jonckheer, Karin, Mission, Jean-Paul, Scordo, Lucia, Couchepin, Caroline, Dadure, Christophe, De la Arena, Pablo, Hertz, Laurent, Pirat, Philippe, Sola, Chrystelle, Bellon, Myriam, Dahmani, Souhayl, Julien-Marsollier, Florence, Michelet, Daphne, Depret-Donatien, Veronique, Lesage, Anne, Kaufmann, Jost, Laschat, Michael, Wappler, Frank, Becke, Karin, Brunner, Lena, Oppenrieder, Karin, Badelt, Gregor, Hochmuth, Karin, Koller, Bernhard, Reil, Anita, Richter, Sebastian, Fischer, Thomas, Diers, Anja, Schorer, Clemens, Weyland, Andreas, Cohausz, Ruth, Kretz, Franz-Josef, Löffler, Michaela, Wilbs, Markus, Hoehne, Claudia, Ulrici, Johanna, Goeters, Christiane, Flinspach, Armin, Klages, Matthias, Lindau, Simone, Messroghli, Leila, Zacharowski, Kai, Eisner, Christoph, Mueller, Thomas, Richter, Daniel, Schäfer, Melanie, Weigand, Markus, Weiterer, Sebastian, Ochsenreiter, Miriam, Schöler, Michael, Terboven, Tom, Eggemann, Isabel, Haussmann, Sascha, Leister, Nicolas, Menzel, Christoph, Trieschmann, Uwe, Yücetepe, Sirin, Keilig, Susanna, Kranke, Peter, Jelting, Yvonne, Baehner, Torsten, Ellerkmann, Richard, Ghamari, Shahab, Neumann, Claudia, Söhle, Martin, Chloropoulou, Pelagia, Ntritsou, Vagia, Papagiannopoulou, Pinelopi, Garini, Eleana, Karafotia, Afroditi, Mammi, Panagoula, Bali, Evangelia, Iordanidou, Despoina, Malisiova, Anna, Polyzoi, Artemis, Tsiotou, Adelais, Sapi, Erzsebet, Székely, Edgar, Kosik, Nandor, Maráczi, Veronika, Schnur, Janos, Csillag, Judit, Gál, János, Göbl, Gergely, Hauser, Balázs, Petróczy, András, Tövisházi, Gyula, Blain, Stuart, Gallagher, Sarah, Harte, Sinead, Jackson, Mandy, Meehan, Emma, Nawoor, Zeenat, O'Hare, Brendan, Ross, Mark, Lerro, Daniela, Astuto, Marinella, Grasso, Chiara, Scalisi, Rita, Frasacco, Giulia, Lenares, Elena, Leone, Roberto, Grazzini, Maurizia, Minardi, Carmelo, Zadra, Nicola, Cinnella, Gilda, Cotoia, Antonella, Galante, Dario, De Lorenzo, Brita, Kuppers, Beate, Bottazzi, Giulia, Caramelli, Fabio, Mondardini, Maria Cristina, Rossetti, Emanuele, Picardo, Sergio, Vittori, Alessandro, Camporesi, Anna, Calderini, Edoardo, Colantonio, Laura Brigitta, Finamore, Simona Anna, Porro, Giuliana Anna, Bonfiglio, Rachele, Disma, Nicola, Kotzeva, Svetlana, Mameli, Leila, Mattioli, Girolamo, Micalizzi, Camilla, Montaguti, Alessia, Pistorio, Angela, Zanaboni, Clelia, Guddo, Anna, Neba, Gerald Rogan, Favarato, Moreno, Locatelli, Bruno Guido, Maffioletti, Micol, Sonzogni, Valter, Garra, Rossella, Sammartino, Maria, Sbaraglia, Fabio, Cortegiani, Andrea, Moscarelli, Alessandra, Attanasi, Elena, Tesoro, Simonetta, Agapiti, Cristina, Pinzoni, Francesca, Vezzoli, Cesare, Bilotta, Federico, Barzdina, Arta, Straume, Zane, Zundane, Anda, Lukosiene, Laura, Maraulaite, Irena, Razlevice, Ilona, Schmitz, Bernd, Mifsud, Stephanie, Aehling, Carolin, Allison, Celia, De Boer, Rients, Emal, Dina, Stevens, Markus, Buitenhuis, Marielle, de Graaff, Jurgen, De Liefde, Inge, Machotta, Andreas, Scoones, Gail, Staals, Lonneke, Tomas, Jeremy, Van der Knijff-van Dortmont, Anouk, Veldhuizen, Marianne, Alders, David, Buhre, Wolfgang, Schafrat, Eva, Schreiber, Jan, Vermeulen, Petronella Mari, Hendriks, Mark, Lako, Sandra, Voet-Lindner, Marieke, Pieters, Barbe, Scheffer, Gert-Jan, Tielens, Luc, Absalom, Anthony R., Bergsma, Margot, De Ruiter, Joke, Meier, Sascha, Volkers, Martin, Zweers, Tjerk, Beukers, Anne M., Boer, Christa, Dertinger, Jurgen, Numan, Sandra, Van Zaane, Bas, Boerke, Wenche B., Ekiz, Nil, Stensrud, Kristoffer, Drage, Inger Marie, Isern, Erik Ramon, Bartkowska-Sniatkowska, Alicja, Grzeskowiak, Malgorzata, Juzwa-Sobieraj, Magdalena, Rosada-Kurasińska, Jowita, Baranowski, Artur, Jakubowska, Karina, Lewandowska, Dorota, Mierzewska-Schmidt, Magdalena, Sawicki, Piotr, Urban-Lechowicz, Magdalena, Przemyslaw, Pomianek, Leal, Teresa, Soares, Maria, Pina, Pedro, Pinho, Sílvia, Patuleia, Maria Domingas, Esteves, Catarina Cruz, Salgado, Helena, Santos, Maria João, Badeti, Rodica, Cindea, Iulia, Oana, Loredana, Gurita, Adriana, Ilie, Luminita, Mocioiu, Gabriel, Tabacaru, Radu, Trante, Irina, Munteanu, Valentin, Morariu, Mihai, Nyíri, Emese, Budic, Ivana, Marjanovic, Vesna, Drašković, Biljana, Pandurov, Marina, Ilic, Jordanka, Mandras, Ana, Rados, Zdenka, Stankovic, Nikola, Suica, Maja, Vasiljevic, Sladjana, Knezevic, Mirjana, Milojevic, Irina, Petrov, Ivana, Racic, Selena Puric, Simic, Irena, Stevic, Marija, Vulicevic, Irena, Bystrica, Banská, Cabanová, Barbora, Hanula, Miloslav, Berger, Jelena, Janjatovic, Darja, Štupnik, Špela Pirtovšek, Méndez, Dolores, Pino, Gema, Rubio, Paloma, Izquierdo, Alberto, López, Silvia, Serrano, Cristina González, Cebrián, Jesús, Peleteiro, Ana, Del Rey de Diego, Pilar, García, Ernesto Martínez, Tormo de las Heras, Carolina, Montero, Pablo Troncoso, Arbona, Celia, Artés, David, Chamizo, Alicia, Serrano, Silvia, Comas, Montserrat Suarez, Escribá, Francisco, Auli, Cristina, Pardo, Osvaldo Pérez, Biddle, Natalia Sierra, Castaño, Ceferina Suárez, Villalobos Rico, María Isabel, Muñoz, Susana Manrique, Martínez, Irene García, Estruch, Nuria Montferrer, Ortíz, Elena Vilardell, Poves-Álvarez, Rodrigo, Kohn, Ivan, Lindestam, Ulf, Reinhard, Jarl, Castellheim, Albert, Sandström, Kerstin, Bengt, Sporre, Dörenberg, Rainer, Frykholm, Peter, Garcia, Maria, Kvarnström, Ann, Pontén, Emma, Bruelisauer, Thomas, Erdoes, Gabor, Kaiser, Heiko, Marchon, Mathias, Riva, Thomas, Seiler, Stefan, Bögli, Yann, Dolci, Mirko, Marcucci, Carine, Habre, Walid, Pichon, Isabelle, Casutt, Mattias, Hölzle, Martin, Hurni, Thomas, Jöhr, Martin, Malär, Anna-Ursina, Mauch, Jacqueline, Erb, Thomas, Oeinck, Karin, Akin, Mine, Keskin, Gulsen, Senayli, Yesim, Kaya, Guner, Kendigelen, Pinar, Tutuncu, Ayse Çiğdem, Hatipoğlu, Zehra, Özcengiz, Dilek, Erdost, Hale Aksu, Öçmen, Elvan, Olguner, Çimen, Ayanoglu, Hilmi, Dincer, Pelin Corman, Umuroglu, Tumay, Azizoglu, Mustafa, Birbiçer, Handan, Doruk, Nurcan, Sagun, Aslı, Baris, Sibel, Dmytriiev, Dmytro, Kuchi, Sridevi, Masip, Nuria, Brooks, Peter, Hare, Alison, Ahmad, Nargis, Casey, Michelle, De Silva, Sam, Dobby, Nadine, Krishnan, Prakash, Sogbodjor, L. Amaki, Walker, Ellie, Walker, Suellen, King, Stephanie, Nicholson, Katy, Quinney, Michelle, Stevens, Paul, Blevin, Andrew, Giombini, Mariangela, Goonasekera, Chulananda, Adil, Sadia, Bew, Stephanie, Bodlani, Carol, Gilpin, Dan, Jinks, Stephanie, Malarkkan, Nalini, Miskovic, Alice, Pad, Rebecca, Barry, Juliet Wolfe, Abbott, Joy, Armstrong, James, Cooper, Natalie, Crate, Lindsay, Emery, John, James, Kathryn, King, Hannah, Martin, Paul, Catenacci, Stefano Scalia, Bomont, Rob, Smith, Paul, Mele, Sara, Verzelloni, Alessandra, Dix, Philippa, Bell, Graham, Gordeva, Elena, McKee, Lesley, Ngan, Esther, Scheffczik, Jutta, Tan, Li-En, Worrall, Mark, Cassar, Carmel, Goddard, Kevin, Barlow, Victoria, Oshan, Vimmi, Shah, Khairi, Bell, Sarah, Daniels, Lisa, Gandhi, Monica, Pachter, David, Perry, Chris, Robertson, Andrew, Scott, Carmen, Waring, Lynne, Barnes, David, Childs, Sophie, Norman, Joanne, Sunderland, Robin, Julia, Dowell, Prisca, Feijten, Pierre, Harlet, Sarah, Herbineaux, Brigitte, Leva, Benoît, Plichon, Katalin, Virág, Fuchs, Alexander, Engelhardt, Thomas, Marchesini, Vanessa, Riedel, Thomas, and Boda, Krisztina
Published: 2025
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35. Cardiopulmonary Exercise Testing in Pulmonary Hypertension

Author: Dmytriiev, Kostiantyn, Stickland, Michael K., and Weatherald, Jason
Published: 2025
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36. Resilience of Primary Health Care in Ukraine: Challenges of the Pandemic and War

Author: Elina Dale, Julia Novak, Denys Dmytriiev, Olga Demeshko, and Jarno Habicht
Subjects: Fragile and conflict-affected situations, primary health care, resilience, Ukraine, war, Medicine (General), R5-920, Public aspects of medicine, RA1-1270
Abstract: This commentary examines the resilience of primary health care in Ukraine amidst the ongoing war, drawing a few reflections relevant for other fragile and conflict-affected situations. Using personal observations and various published and unpublished reports, this article outlines five reflections on the strengths, challenges, and necessary adaptations of Primary Health Care (PHC) in Ukraine. It underscores the concerted efforts of the government to maintain public financing of PHC, thereby averting system collapse. The research also highlights the role of strategic adaptations during the COVID-19 pandemic in fostering resilience during the war, including the widespread use of digital communication and skills training. The commentary emphasizes the role of managerial and financial autonomy in facilitating quick and efficient organizational response to crisis. It also recognizes emerging challenges, including better access to PHC services among the internally displaced persons, shifting patient profiles and service needs, and challenges related to reliance on local government financing. Finally, the authors advocate for a coordinated approach in humanitarian response, recovery efforts, and development programs to ensure the sustainability and effectiveness of PHC in Ukraine.
Published: 2024
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37. Gamma-ray observations of MAXI J1820+070 during the 2018 outburst

Author: Abe, H., Abe, S., Acciari, V. A., Aniello, T., Ansoldi, S., Antonelli, L. A., Engels, A. Arbet, Arcaro, C., Artero, M., Asano, K., Baack, D., Babić, A., Baquero, A., de Almeida, U. Barres, Barrio, J. A., Batković, I., Baxter, J., González, J. Becerra, Bednarek, W., Bernardini, E., Bernardos, M., Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Biland, A., Blanch, O., Bonnoli, G., Bošnjak, Ž., Burelli, I., Busetto, G., Carosi, R., Carretero-Castrillo, M., Ceribella, G., Chai, Y., Chilingarian, A., Cikota, S., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., D'Amico, G., D'Elia, V., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., Del Popolo, A., Delfino, M., Delgado, J., Mendez, C. Delgado, Depaoli, D., Di Pierro, F., Di Venere, L., Prester, D. Dominis, Donini, A., Dorner, D., Doro, M., Elsaesser, D., Emery, G., Ramazani, V. Fallah, Fariña, L., Fattorini, A., Font, L., Fruck, C., Fukami, S., Fukazawa, Y., López, R. J. García, Garczarczyk, M., Gasparyan, S., Gaug, M., Paiva, J. G. Giesbrecht, Giglietto, N., Giordano, F., Gliwny, P., Godinović, N., Grau, R., Green, D., Green, J. G., Hadasch, D., Hahn, A., Hassan, T., Heckmann, L., Herrera, J., Hoang, J., Hrupec, D., Hütten, M., Imazawa, R., Inada, T., Iotov, R., Ishio, K., Martínez, I. Jiménez, Jormanainen, J., Kerszberg, D., Kobayashi, Y., Kubo, H., Kushida, J., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Linhoff, L., Lombardi, S., Longo, F., López-Coto, R., López-Moya, M., López-Oramas, A., Loporchio, S., Lorini, A., Lyard, E., Fraga, B. Machado de Oliveira, Majumdar, P., Makariev, M., Maneva, G., Mang, N., Manganaro, M., Mangano, S., Mannheim, K., Mariotti, M., Martínez, M., Aguilar, A. Mas, Mazin, D., Menchiari, S., Mender, S., Mićanović, S., Miceli, D., Miener, T., Miranda, J. M., Mirzoyan, R., Molina, E., Mondal, H. A., Moralejo, A., Morcuende, D., Moreno, V., Nakamori, T., Nanci, C., Nava, L., Neustroev, V., Rosillo, M. Nievas, Nigro, C., Nilsson, K., Nishijima, K., Ekoume, T. Njoh, Noda, K., Nozaki, S., Ohtani, Y., Oka, T., Okumura, A., Otero-Santos, J., Paiano, S., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Pavletić, L., Persic, M., Pihet, M., Pirola, G., Podobnik, F., Moroni, P. G. Prada, Prandini, E., Principe, G., Priyadarshi, C., Puljak, I., Rhode, W., Ribó, M., Rico, J., Righi, C., Rugliancich, A., Sahakyan, N., Saito, T., Sakurai, S., Satalecka, K., Saturni, F. G., Schleicher, B., Schmidt, K., Schmuckermaier, F., Schubert, J. L., Schweizer, T., Sitarek, J., Sliusar, V., Sobczynska, D., Spolon, A., Stamerra, A., Strišković, J., Strom, D., Strzys, M., Suda, Y., Surić, T., Tajima, H., Takahashi, M., Takeishi, R., Tavecchio, F., Temnikov, P., Terauchi, K., Terzić, T., Teshima, M., Tosti, L., Truzzi, S., Tutone, A., Ubach, S., van Scherpenberg, J., Acosta, M. Vazquez, Ventura, S., Verguilov, V., Viale, I., Vigorito, C. F., Vitale, V., Vovk, I., Walter, R., Will, M., Wunderlich, C., Yamamoto, T., Zarić, D., Abdalla, H., Aharonian, F., Benkhali, F. Ait, Angüner, E. O., Ashkar, H., Backes, M., Baghmanyan, V., Martins, V. Barbosa, Batzofin, R., Becherini, Y., Berge, D., Bernlöhr, K., Böttcher, M., Boisson, C., Bolmont, J., de Lavergne, M. de Bony, Bradascio, F., Breuhaus, M., Brose, R., Brun, F., Bulik, T., Bylund, T., Cangemi, F., Caroff, S., Casanova, S., Cerruti, M., Chand, T., Chandra, S., Chen, A., Chibueze, O. U., Cotter, G., Cristofari, P., Mbarubucyeye, J. Damascene, Devin, J., Djannati-Ataï, A., Dmytriiev, A., Egberts, K., Ernenwein, J. -P., Fiasson, A., de Clairfontaine, G. Fichet, Fontaine, G., Füßling, M., Funk, S., Gabici, S., Ghafourizadeh, S., Giavitto, G., Glawion, D., Glicenstein, J. F., Goswami, P., Grolleron, G., Hinton, J. A., Hörbe, M., Hoischen, C., Holch, T. L., Holler, M., Horns, D., Huang, Zhiqiu, Jamrozy, M., Jankowsky, F., Joshi, V., Jung-Richardt, I., Kasai, E., Katarzyński, K., Katz, U., Khélifi, B., Kluźniak, W., Komin, Nu., Kosack, K., Kostunin, D., Lang, R. G., Stum, S. Le, Lemière, A., Lemoine-Goumard, M., Lenain, J. -P., Leuschner, F., Lohse, T., Luashvili, A., Lypova, I., Mackey, J., Majumdar, J., Malyshev, D., Marandon, V., Marchegiani, P., Martí-Devesa, G., Marx, R., Maurin, G., Meyer, M., Mitchell, A., Moderski, R., Mohrmann, L., Montanari, A., Moulin, E., Muller, J., Murach, T., Nakashima, K., de Naurois, M., Nayerhoda, A., Niemiec, J., Noel, A. Priyana, O'Brien, P., Ohm, S., Olivera-Nieto, L., Wilhelmi, E. de Ona, Ostrowski, M., Panny, S., Panter, M., Parsons, R. D., Poireau, V., Prokhorov, D. A., Prokoph, H., Pühlhofer, G., Punch, M., Quirrenbach, A., Reichherzer, P., Reimer, A., Reimer, O., Renaud, M., Rieger, F., Rowell, G., Rudak, B., Ricarte, H. Rueda, Ruiz-Velasco, E., Sahakian, V., Salzmann, H., Santangelo, A., Sasaki, M., Schäfer, J., Schüssler, F., Schutte, H. M., Schwanke, U., Shapopi, J. N. S., Sol, H., Specovius, A., Spencer, S., Stawarz, Ł., Steenkamp, R., Steinmassl, S., Steppa, C., Sushch, I., Suzuki, H., Takahashi, T., Tanaka, T., Thorpe-Morgan, C., Tluczykont, M., Tomankova, L., Tsuji, N., Uchiyama, Y., van Eldik, C., van Soelen, B., Vecchi, M., Veh, J., Venter, C., Vink, J., Wagner, S. J., White, R., Wierzcholska, A., Wong, Yu Wun, Yusafzai, A., Zacharias, M., Zanin, R., Zargaryan, D., Zdziarski, A. A., Zech, A., Zhu, S. J., Zouari, S., Żywucka, N., Acharyya, A., Adams, C. B., Batista, P., Benbow, W., Capasso, M., Christiansen, J. L., Chromey, A. J., Errando, M., Falcone, A., Feng, Q., Finley, J. P., Foote, G. M, Fortson, L., Furniss, A., Gent, A., Hanlon, W. F, Hervet, O., Holder, J., Hona, B., Humensky, T. B., Jin, W., Kaaret, P., Kertzman, M., Kherlakian, M., Kleiner, T. K., Kumar, S., Lang, M. J., Lundy, M., Maier, G., McGrath, C. E., Millis, J., Moriarty, P., Mukherjee, R., O'Brien, S., Ong, R. A., Park, N., Patel, S. R., Pfrang, K., Pohl, M., Pueschel, E., Quinn, J., Ragan, K., Reynolds, P. T., Ribeiro, D., Roache, E., Ryan, J. L., Sadeh, I., Saha, L., Santander, M., Sembroski, G. H., Shang, R., Splettstoesser, M., Tak, D., Tucci, J. V., Weinstein, A., Williams, D. A., Williamson, T. J., Bosch-Ramon, V., Celma, C., Linares, M., Russell, D. M., and Sala, G.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: MAXI J1820+070 is a low-mass X-ray binary with a black hole as a compact object. This binary underwent an exceptionally bright X-ray outburst from March to October 2018, showing evidence of a non-thermal particle population through its radio emission during this whole period. The combined results of 59.5 hours of observations of the MAXI J1820+070 outburst with the H.E.S.S., MAGIC and VERITAS experiments at energies above 200 GeV are presented, together with Fermi-LAT data between 0.1 and 500 GeV, and multiwavelength observations from radio to X-rays. Gamma-ray emission is not detected from MAXI J1820+070, but the obtained upper limits and the multiwavelength data allow us to put meaningful constraints on the source properties under reasonable assumptions regarding the non-thermal particle population and the jet synchrotron spectrum. In particular, it is possible to show that, if a high-energy gamma-ray emitting region is present during the hard state of the source, its predicted flux should be at most a factor of 20 below the obtained Fermi-LAT upper limits, and closer to them for magnetic fields significantly below equipartition. During the state transitions, under the plausible assumption that electrons are accelerated up to ~ 500 GeV, the multiwavelength data and the gamma-ray upper limits lead consistently to the conclusion that a potential high-energy and very-high-energy gamma-ray emitting region should be located at a distance from the black hole ranging between 10^11 and 10^13 cm. Similar outbursts from low-mass X-ray binaries might be detectable in the near future with upcoming instruments such as CTA., Comment: 15 pages, 5 figures. Accepted for publication in MNRAS
Published: 2022
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38. Search for dark matter annihilation signals in the H.E.S.S. Inner Galaxy Survey

Author: Collaboration, H. E. S. S., Abdalla, H., Aharonian, F., Benkhali, F. Ait, Anguner, E. O., Armand, C., Ashkar, H., Backes, M., Baghmanyan, V., Martins, V. Barbosa, Batzofin, R., Becherini, Y., Berge, D., Bernlohr, K., Bi, B., Bottcher, M., Bolmont, J., de Lavergne, M. de Bony, Brose, R., Brun, F., Cangemi, F., Caroff, S., Cerruti, M., Chand, T., Chen, A., Cotter, G., Mbarubucyeye, J. Damascene, Devin, J., Djannati-Ataı, A., Dmytriiev, A., Doroshenko, V., Egberts, K., Fiasson, A., de Clairfontaine, G. Fichet, Fontaine, G., Funk, S., Gabici, S., Giavitto, G., Glawion, D., Glicenstein, J. F., Grondin, M. -H., Hinton, J. A., Hofmann, W., Holch, T. L., Holler, M., Horns, D., Huang, Zhiqiu, Jamrozy, M., Jankowsky, F., Kasai, E., Katarzynski, K., Katz, U., Khelifi, B., Kluzniak, W., Komin, Nu., Kosack, K., Kostunin, D., Lamanna, G., Lemoine-Goumard, M., Lenain, J. -P., Leuschner, F., Lohse, T., Luashvili, A., Lypova, I., Mackey, J., Malyshev, D., Marandon, V., Marchegiani, P., Martı-Devesa, G., Marx, R., Maurin, G., Meyer, M., Mitchell, A., Moderski, R., Montanari, A., Moulin, E., Muller, J., de Naurois, M., Niemiec, J., Noel, A. Priyana, Ohm, S., Olivera-Nieto, L., Wilhelmi, E. de Ona, Ostrowski, M., Panny, S., Panter, M., Parsons, R. D., Peron, G., Poireau, V., Prokoph, H., Puhlhofer, G., Punch, M., Quirrenbach, A., Reichherzer, P., Reimer, A., Reimer, O., Renaud, M., Rieger, F., Rowell, G., Rudak, B., Ricarte, H. Rueda, Ruiz-Velasco, E., Sahakian, V., Salzmann, H., Santangelo, A., Sasaki, M., Schussler, F., Schutte, H. M., Schwanke, U., Senniappan, M., Shapopi, J. N. S., Sol, H., Specovius, A., Spencer, S., Stawarz, L., Stegmann, C., Steinmassl, S., Steppa, C., Takahashi, T., Tanaka, T., Terrier, R., Thorpe-Morgan, C., Tluczykont, M., Tsirou, M., Tsuji, N., Uchiyama, Y., van Eldik, C., Veh, J., Vink, J., Wagner, S. J., White, R., Wierzcholska, A., Wong, Yu Wun, Zacharias, M., Zargaryan, D., Zdziarski, A. A., Zech, A., Zhu, S. J., Zouari, S., and Zywucka, N.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: The central region of the Milky Way is one of the foremost locations to look for dark matter (DM) signatures. We report the first results on a search for DM particle annihilation signals using new observations from an unprecedented gamma-ray survey of the Galactic Center (GC) region, ${\it i.e.}$, the Inner Galaxy Survey, at very high energies ($\gtrsim$ 100 GeV) performed with the H.E.S.S. array of five ground-based Cherenkov telescopes. No significant gamma-ray excess is found in the search region of the 2014-2020 dataset and a profile likelihood ratio analysis is carried out to set exclusion limits on the annihilation cross section $\langle \sigma v\rangle$. Assuming Einasto and Navarro-Frenk-White (NFW) DM density profiles at the GC, these constraints are the strongest obtained so far in the TeV DM mass range. For the Einasto profile, the constraints reach $\langle \sigma v\rangle$ values of $\rm 3.7\times10^{-26} cm^3s^{-1}$ for 1.5 TeV DM mass in the $W^+W^-$ annihilation channel, and $\rm 1.2 \times 10^{-26} cm^3s^{-1}$ for 0.7 TeV DM mass in the $\tau^+\tau^-$ annihilation channel. With the H.E.S.S. Inner Galaxy Survey, ground-based $\gamma$-ray observations thus probe $\langle \sigma v\rangle$ values expected from thermal-relic annihilating TeV DM particles., Comment: Accepted in Phys. Rev. Lett., includes Supplemental materials. 5+10 pages, 2+8 figures, 4 tables
Published: 2022
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39. Safety of performing distal block in diabetic foot syndrome

Author: Y.V. Lysak and D.V. Dmytriiev
Subjects: diabetic foot syndrome, conduction anesthesia, regional anesthesia, local anesthetic, diabetes, edema, Medical emergencies. Critical care. Intensive care. First aid, RC86-88.9
Abstract: Regional methods of anesthesia are widely used in surgical interventions on the lower limb, in particular on the foot. But to date, the risks associated with performing distal blocks in patients with diabetes are insufficiently studied. We analyzed the 30-day consequences of tibiocalcaneal nerve block in 88 patients who underwent surgery for diabetic foot syndrome. The obtained results indicate the absence of an increased risk of infectious and trophic complications in the block area in the group of patients who underwent tibiocalcaneal nerve block compared to those with popliteal nerve block and the group of spinal anesthesia. The frequency of repeated operations was not significantly different in all 3 groups.
Published: 2024
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40. Low-energy effective Lagrangian of the two-Higgs-doublet model

Author: Dmytriiev, Mykyta and Skalozub, Volodymyr
Subjects: High Energy Physics - Phenomenology
Abstract: We consider a decoupling scenario within the two-Higgs-doublet model (2HDM) with small CP-violation. Mass eigenstates of this model include one neutral scalar field with the mass of the Standard model (SM) Higgs boson and four other scalars, which decouple at low energies. We derive the effective operators of interactions between the SM fermions and the lightest scalar particle of the model. The coefficients at these operators are expressed in terms of the 2HDM parameters. The scattering processes affected by this effective Lagrangian are identified., Comment: 10 pages
Published: 2022

41. Time-resolved hadronic particle acceleration in the recurrent Nova RS Ophiuchi

Author: Collaboration, H. E. S. S., Aharonian, F., Benkhali, F. Ait, Angüner, E. O., Ashkar, H., Backes, M., Baghmanyan, V., Martins, V. Barbosa, Batzofin, R., Becherini, Y., Berge, D., Bernlöhr, K., Bi, B., Böttcher, M., Boisson, C., Bolmont, J., de Lavergne, M. de Bony, Breuhaus, M., Brose, R., Brun, F., Caroff, S., Casanova, S., Cerruti, M., Chand, T., Chen, A., Cotter, G., Mbarubucyeye, J. Damascene, Djannati-Ataï, A., Dmytriiev, A., Doroshenko, V., Duffy, C., Egberts, K., Ernenwein, J. -P., Fegan, S., Feijen, K., Fiasson, A., de Clairfontaine, G. Fichet, Fontaine, G., Füßling, M., Funk, S., Gabici, S., Gallant, Y. A., Ghafourizadeh, S., Giavitto, G., Giunti, L., Glawion, D., Glicenstein, J. F., Grondin, M. -H., Hermann, G., Hinton, J. A., Hörbe, M., Hofmann, W., Hoischen, C., Holch, T. L., Holler, M., Horns, D., Huang, Zhiqiu, Jamrozy, M., Jankowsky, F., Jung-Richardt, I., Kasai, E., Katarzyński, K., Katz, U., Khangulyan, D., Khélifi, B., Klepser, S., Kluźniak, W., Komin, Nu., Konno, R., Kosack, K., Kostunin, D., Stum, S. Le, Lemière, A., Lemoine-Goumard, M., Lenain, J. -P., Leuschner, F., Lohse, T., Luashvili, A., Lypova, I., Mackey, J., Malyshev, D., Marandon, V., Marchegiani, P., Marcowith, A., Martí-Devesa, G., Marx, R., Maurin, G., Meyer, M., Mitchell, A., Moderski, R., Mohrmann, L., Montanari, A., Moulin, E., Muller, J., Murach, T., Nakashima, K., de Naurois, M., Nayerhoda, A., Niemiec, J., Noel, A. Priyana, O'Brien, P., Ohm, S., Olivera-Nieto, L., Wilhelmi, E. de Ona, Ostrowski, M., Panny, S., Panter, M., Parsons, R. D., Peron, G., Pita, S., Poireau, V., Prokhorov, D. A., Prokoph, H., Pühlhofer, G., Punch, M., Quirrenbach, A., Reichherzer, P., Reimer, A., Reimer, O., Renaud, M., Reville, B., Rieger, F., Rowell, G., Rudak, B., Ricarte, H. Rueda, Ruiz-Velasco, E., Sahakian, V., Sailer, S., Salzmann, H., Sanchez, D. A., Santangelo, A., Sasaki, M., Schäfer, J., Schüssler, F., Schutte, H. M., Schwanke, U., Senniappan, M., Shapopi, J. N. S., Simoni, R., Sinha, A., Sol, H., Specovius, A., Spencer, S., Stawarz, Ł., Steinmassl, S., Steppa, C., Takahashi, T., Tanaka, T., Taylor, A. M., Terrier, R., Thorpe-Morgan, C., Tsirou, M., Tsuji, N., Tuffs, R., Uchiyama, Y., Unbehaun, T., van Eldik, C., van Soelen, B., Veh, J., Venter, C., Vink, J., Wagner, S. J., Werner, F., White, R., Wierzcholska, A., Wong, Yu Wun, Yusafzai, A., Zacharias, M., Zargaryan, D., Zdziarski, A. A., Zech, A., Zhu, S. J., Zouari, S., and Żywucka, N.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: Recurrent Novae are repeating thermonuclear explosions in the outer layers of white dwarfs, due to the accretion of fresh material from a binary companion. The shock generated by ejected material slamming into the companion star's wind, accelerates particles to very-high-energies. We report very-high-energy (VHE, $\gtrsim100$\,GeV) gamma rays from the recurrent nova RS\,Ophiuchi up to a month after its 2021 outburst, using the High Energy Stereoscopic System. The VHE emission has a similar temporal profile to lower-energy GeV emission, indicating a common origin, with a two-day delay in peak flux. These observations constrain models of time-dependent particle energization, favouring a hadronic emission scenario over the leptonic alternative. This confirms that shocks in dense winds provide favourable environments for efficient cosmic-ray acceleration to very-high-energies., Comment: Submitted 1st Nov. 2021, first release 10th March 2022 (accepted version)
Published: 2022
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42. Single and double $K$-shell vacancy production in slow Xe$^\textrm{54+,53+}$-Xe collisions

Author: Hillenbrand, P. -M., Hagmann, S., Kozhedub, Y. S., Benis, E. P., Brandau, C., Chen, R. J., Dmytriiev, D., Forstner, O., Glorius, J., Grisenti, R. E., Gumberidze, A., Lestinsky, M., Litvinov, Yu. A., Menz, E. B., Morgenroth, T., Nanos, S., Petridis, N., Pfäfflein, Ph., Rothard, H., Sanjari, M. S., Sidhu, R. S., Spillmann, U., Trotsenko, S., Tupitsyn, I. I., Varga, L., and Stöhlker, Th.
Subjects: Physics - Atomic Physics
Abstract: We present an experimental and theoretical study of symmetric $\textrm{Xe}^{54+}+\textrm{Xe}$ collisions at 50, 30, and 15 MeV/u, corresponding to strong perturbations with $v_K/v_\text{p}$ = 1.20, 1.55, and 2.20, respectively ($v_K$: classical $K$-shell orbital velocity, $v_\text{p}$: projectile velocity), as well as $\textrm{Xe}^{53+}+\textrm{Xe}$ collisions at 15 MeV/u. For each of these systems, x-ray spectra were measured under a forward angle of $35^\circ$ with respect to the projectile beam. Target satellite and hypersatellite radiation, $K\alpha_{2,1}^\mathrm{s}$ and $K\alpha_{2,1}^\mathrm{hs}$, respectively, were analyzed and used to derive cross section ratios for double-to-single target $K$-shell vacancy production. We compare our experimental results to relativistic time-dependent two-center calculations., Comment: 8 pages, 4 figures
Published: 2022
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43. X-ray emission associated with radiative recombination for Pb$^{82+}$ ions at threshold energies

Author: Zhu, B., Gumberidze, A., Over, T., Weber, G., Andelkovic, Z., Bräuning-Demian, A., Chen, R., Dmytriiev, D., Forstner, O., Hahn, C., Herfurth, F., Herdrich, M. O., Hillenbrand, P. -M., Kalinin, A., Kröger, F. M., Lestinsky, M., Litvinov, Y. A., Menz, E. B., Middents, W., Morgenroth, T., Petridis, N., Pfäfflein, Ph., Sanjari, M. S., Sidhu, R. S., Spillmann, U., Schuch, R., Schippers, S., Trotsenko, S., Varga, L., Vorobyev, G., and Stöhlker, Th.
Subjects: Physics - Atomic Physics
Abstract: For bare lead ions, decelerated to the low beam energy of 10 MeV/u, the x-ray emission associated with radiative recombination (RR) at "cold collision" conditions has been studied at the electron cooler of CRYRING@ESR at GSI-Darmstadt. Utilizing dedicated x-ray detection chambers installed at 0{\deg} and 180{\deg} observation geometry, we observed for the very first time for stored ions the full x-ray emission spectrum associated with RR under electron cooling conditions. Most remarkably, no line distortion effects due to delayed emission are present in the well resolved spectra, spanning over a wide range of x-ray energies (from about 5 to 100 keV) which enable to identify fine-structure resolved Lyman, Balmer as well as Paschen x-ray lines along with the RR transitions into the K-, L and M-shell of the ions. To compare with theory, an elaborate theoretical model has been applied. By considering the relativistic atomic structure of Pb$^{81+}$, this model is based on a sophisticated computation of the initial population distribution via RR for all atomic levels up to Rydberg states with principal quantum number $n=$ 165 in combination with cascade calculations based on time-dependent rate equations. Within the statistical accuracy, the experimental x-ray line emission is in very good agreement with the results of the theoretical model applied. Most notably, this comparison sheds light on the contribution of prompt and delayed X-ray emission (up to 70 ns) to the observed X-ray spectra, originating in particular from Yrast transitions into inner shells.
Published: 2022
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44. Evidence for gamma-ray emission from the remnant of Kepler's supernova based on deep H.E.S.S. observations

Author: Collaboration, H. E. S. S., Aharonian, F., Benkhali, F. Ait, Anguner, E. O., Ashkar, H., Backes, M., Martins, V. Barbosa, Batzofin, R., Becherini, Y., Berge, D., Bernloehr, K., Boettcher, M., Boisson, C., Bolmont, J., de Lavergne, M. de Bony, Breuhaus, M., Brose, R., Brun, F., Bulik, T., Bylund, T., Cangemi, F., Caroff, S., Casanova, S., Cerruti, M., Chand, T., Chen, A., Chibueze, O., Cotter, G., Cristofari, P., Mbarubucyeye, J. Damascene, Devin, J., Djannati-Atai, A., Dmytriiev, A., Egberts, K., Einecke, S., Ernenwein, J. -P., Feijen, K., Fiasson, A., de Clairfontaine, G. Fichet, Fontaine, G., Funk, S., Gabici, S., Gallant, Y. A., Ghafourizadeh, S., Giavitto, G., Giunti, L., Glawion, D., Glicenstein, J. F., Grondin, M. -H., Hoerbe, M., Hofmann, W., Holch, T. L., Holler, M., Horns, D., Huang, Zhiqiu, Jamrozy, M., Joshi, V., Jung-Richardt, I., Kasai, E., Katarzynski, K., Katz, U., Khelifi, B., Kluzniak, W., Komin, Nu., Kosack, K., Kostunin, D., Lemiere, 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., Marti-Devesa, G., Marx, R., Maurin, G., Meintjes, P. J., Meyer, M., Mitchell, A., Moderski, R., Mohrmann, L., Montanari, A., Moulin, E., Muller, J., Nakashima, K., de Naurois, M., Nayerhoda, A., Niemiec, J., Noel, A. Priyana, O'Brien, P., Ohm, S., Olivera-Nieto, L., Wilhelmi, E. de Ona, Ostrowski, M., Panny, S., Panter, M., Parsons, R. D., Peron, G., Poireau, V., Prokhorov, D. A., Puehlhofer, G., Punch, M., Quirrenbach, A., Reichherzer, P., Reimer, A., Reimer, O., Renaud, M., Reville, B., Rieger, F., Rowell, G., Rudak, B., Ricarte, H. Rueda, Sahakian, V., Sailer, S., Salzmann, H., Sanchez, D. A., Santangelo, A., Sasaki, M., Schafer, J., Schussler, F., Schutte, H. M., Schwanke, U., Shapopi, J. N. S., Simoni, R., Sol, H., Specovius, A., Spencer, S., Stawarz, L., Steinmassl, S., Steppa, C., Sushch, I., Takahashi, T., Tanaka, T., Taylor, A. M., Terrier, R., Tsirou, M., Uchiyama, Y., Unbehaun, T., van Eldik, C., Veh, J., Vink, J., Voelk, H. J., Wagner, S. J., Werner, F., White, R., Wierzcholska, A., Wong, Yu Wun, Yusafzai, A., Zacharias, M., Zargaryan, D., Zdziarski, A. A., Zech, A., Zhu, S. J., Zouari, S., and Zywucka, N.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: Observations with imaging atmospheric Cherenkov telescopes (IACTs) have enhanced our knowledge of nearby supernova (SN) remnants with ages younger than 500 years by establishing Cassiopeia A and the remnant of Tycho's SN as very-high-energy (VHE) gamma-ray sources. The remnant of Kepler's SN, which is the product of the most recent naked-eye supernova in our Galaxy, is comparable in age to the other two, but is significantly more distant. If the gamma-ray luminosities of the remnants of Tycho's and Kepler's SNe are similar, then the latter is expected to be one of the faintest gamma-ray sources within reach of the current generation IACT arrays. Here we report evidence at a statistical level of 4.6 sigma for a VHE signal from the remnant of Kepler's SN based on deep observations by the High Energy Stereoscopic System (H.E.S.S.) with an exposure of 152 hours. The measured integral flux above an energy of 226 GeV is ~0.3% of the flux of the Crab Nebula. The spectral energy distribution (SED) reveals a gamma-ray emitting component connecting the VHE emission observed with H.E.S.S. to the emission observed at GeV energies with Fermi-LAT. The overall SED is similar to that of the remnant of Tycho's SN, possibly indicating the same non-thermal emission processes acting in both these young remnants of thermonuclear SNe., Comment: Published in Astronomy and Astrophysics. A typo in the normalization constant in Sect. 4 was corrected
Published: 2022
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45. Pandrug-resistant Klebsiella pneumoniae isolated from Ukrainian war victims are hypervirulent

Author: Ljungquist, Oskar, Magda, Michal, Giske, Christian G., Tellapragada, Chaitanya, Nazarchuk, Oleksandr, Dmytriiev, Dmytro, Thofte, Oskar, Öhnström, Valdemar, Matuschek, Erika, Blom, Anna M., and Riesbeck, Kristian
Published: 2024
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46. A MeerKAT, e-MERLIN, H.E.S.S. and Swift search for persistent and transient emission associated with three localised FRBs

Author: Chibueze, James O., Caleb, M., Spitler, L., Ashkar, H., Schussler, F., Stappers, B. W., Venter, C., Heywood, I., Richards, A. M. S., Williams, D. R. A., Kramer, M., Beswick, R., Bezuidenhout, M. C., Breton, R. P., Driessen, L. N., Jankowski, F., Keane, E. F., Malenta, M., Mickaliger, M., Morello, V., Qiu, H., Rajwade, K., Sanidas, S., Surnis, M., Scragg, T. W., Walker, C. R. H., Wrigley, N., Collaboration, H. E. S. S., Aharonian, F., Benkhali, F. Ait, Anguner, E. O., Backes, M., Baghmanyan, V., Martins, V. Barbosa, Batzofin, R., Becherini, Y., Berge, D., Bottcher, M., Boisson, C., Bolmont, J., de Lavergne, M. de Bony, Breuhaus, M., Brose, R., Brun, F., Bulik, T., Cangemi, F., Caroff, S., Casanova, S., Catalano, J., Cerruti, M., Chand, T., Chen, A., Chibueze, O. U., Cotter, G., Cristofari, P., Mbarubucyeye, J. Damascene, Devin, J., Atai, A. Djannati, Dmytriiev, A., Egberts, K., Ernenwein, J. P., Fiasson, A., de Clairfontaine, G. Fichet, Fontaine, G., Funk, S., Gabici, S., Ghafourizadeh, S., Giavitto, G., Glawion, D., Grondin, M. H., Horbe, M., Hoischen, C., Holch, T. L., Huang, Zhiqiu, Jamrozy, M., Jankowsky, F., Richardt, I. Jung, Kasai, E., Katarzynski, K., Katz, U., Khelifi, B., Kluzniak, W., Komin, Nu., Kosack, K., Kostunin, D., Lemiere, A., Lenain, J. P., Leuschner, F., Lohse, T., Luashvili, A., Lypova, I., Mackey, J., Malyshev, D., Marandon, V., Marchegiani, P., Marcowith, A., Devesa, G. Marti, Marx, R., Mitchell, A., Moderski, R., Mohrmann, L., Moulin, E., Muller, J., Nakashima, K., de Naurois, M., Nayerhoda, A., Niemiec, J., Noel, A. Priyana, O'Brien, P., Ohm, S., Nieto, L. Olivera, Wilhelmi, E. de Ona, Ostrowski, M., Panny, S., Parsons, R. D., Pita, S., Poireau, V., Prokhorov, D. A., Prokoph, H., Puhlhofer, G., Quirrenbach, A., Reichherzer, P., Reimer, A., Reimer, O., Rowell, G., Rudak, B., Velasco, E. Ruiz, Sahakian, V., Sailer, S., Salzmann, H., Sanchez, D. A., Santangelo, A., Sasaki, M., Schutte, H. M., Schwanke, U., Shapopi, J. N. S., Specovius, A., Spencer, S., Steenkamp, R., Steinmassl, S., Takahashi, T., Tanaka, T., Morgan, C. Thorpe, Tsuji, N., van Eldik, C., Veh, J., Vink, J., Wagner, S. J., Wierzcholska, A., Wong, Yu Wun, Yusafzai, A., Zacharias, M., Zargaryan, D., Zdziarski, A. A., Zech, A., Zhu, S. J., Zouari, S., and Zywucka, N.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies
Abstract: We report on a search for persistent radio emission from the one-off Fast Radio Burst (FRB) 20190714A, as well as from two repeating FRBs, 20190711A and 20171019A, using the MeerKAT radio telescope. For FRB 20171019A we also conducted simultaneous observations with the High Energy Stereoscopic System (H.E.S.S.) in very high energy gamma rays and searched for signals in the ultraviolet, optical, and X-ray bands. For this FRB, we obtain a UV flux upper limit of 1.39x10^-16 erg/cm^-2/s/Amstrong, X-ray limit of ~ 6.6x10^-14 erg/cm^-2/s and a limit on the very-high-energy gamma-ray flux (Phi) (E > 120 GeV) < 1.7 x 10^-12 erg/cm^-2/s. We obtain a radio upper limit of ~15 microJy/beam for persistent emission at the locations of both FRBs 20190711A and 20171019A, but detect diffuse radio emission with a peak brightness of ~53 microJy/beam associated with FRB 20190714A at z = 0.2365. This represents the first detection of the radio continuum emission potentially associated with the host (galaxy) of FRB 20190714A, and is only the third known FRB to have such an association. Given the possible association of a faint persistent source, FRB 20190714A may potentially be a repeating FRB whose age lies between that of FRB 20121102A and FRB 20180916A. A parallel search for repeat bursts from these FRBs revealed no new detections down to a fluence of 0.08 Jy ms for a 1 ms duration burst., Comment: 15 pages, 9 figures
Published: 2021
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47. Searching for TeV gamma-ray emission from SGR\,1935+2154 during its 2020 X-ray and radio bursting phase

Author: Collaboration, H. E. S. S., Abdalla, H., Aharonian, F., Benkhali, F. Ait, Anguner, E. O., Arcaro, C., Armand, C., Armstrong, T., Ashkar, H., Backes, M., Baghmanyan, V., Martins, V. Barbosa, Barnacka, A., Barnard, M., Becherini, Y., Berge, D., Bernlohr, K., Bi, B., Bottcher, M., Boisson, C., Bolmont, J., de Lavergne, M. de Bony, Breuhaus, M., Brose, R., Brun, F., Brun, P., Bryan, M., Buchele, M., Bulik, T., Bylund, T., Cangemi, F., Caroff, S., Carosi, A., Casanova, S., Chambery, P., Chand, T., Chandra, S., Chen, A., Cotter, G., lo, M. Cury, Mbarubucyeye, J. Damascene, Davids, I. D., Davies, J., Deil, C., Devin, J., Dirson, L., Djannati-Ataï, A., Dmytriiev, A., Donath, A., Doroshenko, V., Dreyer, L., Duffy, C., Plessis, L. Du, Dyks, J., Egberts, K., Eichhorn, F., Einecke, S., Emery, G., Ernenwein, J. -P., Feijen, K., Fegan, S., Fiasson, A., de Clairfontaine, G. Fichet, Fontaine, G., Funk, S., Füßling, M., Gabici, S., Gallant, Y. A., Ghafourizade, S., Giavitto, G., Giunti, L., Glawion, D., Glicenstein, J. F., Grondin, M. -H., Hahn, J., Haupt, M., Hattingh, S., Hermann, G., Hinton, J. A., Hofmann, W., Hoischen, C., Holch, T. L., Holler, M., Horbe, M., Horns, D., Huang, Z., Huber, D., Jamrozy, M., Jankowsky, D., Jankowsky, F., Jardin-Blicq, A., Joshi, V., Jung-Richardt, I., Kasai, E., Kastendieck, M. A., Katarzyński, K., Katz, U., Khangulyan, D., Khélifi, B., Klepser, S., Kluźniak, W., Komin, Nu., Konno, R., Kosack, K., Kostunin, D., Kreter, M., Mezek, G. Kukec, Kundu, A., Lamanna, G., Lemière, A., Lemoine-Goumard, M., Lenain, J. -P., Stum, S. Le, Leuschner, F., Levy, C., Lohse, T., Luashvili, A., Lypova, I., Mackey, J., Majumdar, J., Malyshev, D., Marandon, V., Marchegiani, P., Marcowith, A., Mares, A., Martí-Devesa, G., Marx, R., Maurin, G., Meintjes, P. J., Meyer, M., Mitchell, A., Moderski, R., Mohrmann, L., Montanari, A., Moore, C., Morris, P., Moulin, E., Muller, J., Murach, T., Nakashima, K., Nayerhoda, A., de Naurois, M., Ndiyavala, H., Niemiec, J., Oakes, L., O'Brien, P., Odaka, H., Ohm, S., Olivera-Nieto, L., Wilhelmi, E. de Ona, Ostrowski, M., Panny, S., Panter, M., Parsons, R. D., Peron, G., Peyaud, B., Piel, Q., Pita, S., Poireau, V., Noel, A. Priyana, Prokhorov, D. A., Prokoph, H., Pühlhofer, G., Punch, M., Quirrenbach, A., Raab, S., Rauth, R., Reichherzer, P., Reimer, A., Reimer, O., Remy, Q., Renaud, M., Reville, B., Rieger, F., Rinchiuso, L., Romoli, C., Rowell, G., Rudak, B., Ricarte, H. Rueda, Ruiz-Velasco, E., Sahakian, V., Sailer, S., Salzmann, H., Sanchez, D. A., Santangelo, A., Sasaki, M., Schäfer, J., Schüssler, F., Schutte, H. M., Schwanke, U., Seglar-Arroyo, M., Senniappan, M., Seyffert, A. S., Shafi, N., Shapopi, J. N. S., Shiningayamwe, K., Simoni, R., Sinha, A., Sol, H., Spackman, H., Specovius, A., Spencer, S., Spir-Jacob, M., Stawarz, L., Sun, L., Steenkamp, R., Stegmann, C., Steinmassl, S., Steppa, C., Takahashi, T., Tanaka, T., Tavernier, T., Taylor, A. M., Terrier, R., Thiersen, J. H. E., Thorpe-Morgan, C., Tiziani, D., Tluczykont, M., Tomankova, L., Trichard, C., Tsirou, M., Tsuji, N., Tuffs, R., Uchiyama, Y., van der Walt, D. J., van Eldik, C., van Rensburg, C., van Soelen, B., Vasileiadis, G., Veh, J., Venter, C., Vincent, P., Vink, J., Völk, H. J., Wadiasingh, Z., Wagner, S. J., Watson, J., Werner, F., White, R., Wierzcholska, A., deWilt, P., Wong, Yu Wun, Yassin, H., Yusafzai, A., Zacharias, M., Zanin, R., Zargaryan, D., Zdziarski, A. A., Zech, A., Zhu, S. J., Zorn, J., Zouari, S., and Żywucka, N.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: Magnetar hyperflares are the most plausible explanation for fast radio bursts (FRB) -- enigmatic powerful radio pulses with durations of several milliseconds and high brightness temperatures. The first observational evidence for this scenario was obtained in 2020 April when a FRB was detected from the direction of the Galactic magnetar and soft gamma-ray repeater SGR\,1935+2154. The FRB was preceded by two gamma-ray outburst alerts by the BAT instrument aboard the Swift satellite, which triggered follow-up observations by the High Energy Stereoscopic System (H.E.S.S.). H.E.S.S. has observed SGR\,1935+2154 for 2 hr on 2020 April 28. The observations are coincident with X-ray bursts from the magnetar detected by INTEGRAL and Fermi-GBM, thus providing the first very high energy (VHE) gamma-ray observations of a magnetar in a flaring state. High-quality data acquired during these follow-up observations allow us to perform a search for short-time transients. No significant signal at energies $E>0.6$~TeV is found and upper limits on the persistent and transient emission are derived. We here present the analysis of these observations and discuss the obtained results and prospects of the H.E.S.S. follow-up program for soft gamma-ray repeaters., Comment: Received 2021 June 13; accepted 2021 June 28; published 2021 September 29
Published: 2021
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48. LMC N132D: A mature supernova remnant with a power-law gamma-ray spectrum extending beyond 8 TeV

Author: Collaboration, H. E. S. S., Abdalla, H., Aharonian, F., Benkhali, F. Ait, Angüner, E. O., Arcaro, C., Armand, C., Armstrong, T., Ashkar, H., Backes, M., Baghmanyan, V., Martins, V. Barbosa, Barnacka, A., Barnard, M., Becherini, Y., Berge, D., Bernlöhr, K., Bi, B., Böttcher, M., Boisson, C., Bolmont, J., de Lavergne, M. de Bony, Breuhaus, M., Brun, F., Brun, P., Bryan, M., Büchele, M., Bulik, T., Bylund, T., Caroff, S., Carosi, A., Casanova, S., Chand, T., Chandra, S., Chen, A., Cotter, G., Curyło, M., Mbarubucyeye, J. Damascene, Davids, I. D., Davies, J., Deil, C., Devin, J., Dirson, L., Djannati-Atai, A., Dmytriiev, A., Donath, A., Doroshenko, V., Dreyer, L., Duffy, C., Dyks, J., Egberts, K., Eichhorn, F., Einecke, S., Emery, G., Ernenwein, J. -P., Feijen, K., Fegan, S., Fiasson, A., de Clairfontaine, G. Fichet, Fontaine, G., Funk, S., Füßling, M., Gabici, S., Gallant, Y. A., Giavitto, G., Giunti, L., Glawion, D., Glicenstein, J. F., Grondin, M. -H., Hahn, J., Haupt, M., Hermann, G., Hinton, J. A., Hofmann, W., Hoischen, C., Holch, T. L., Holler, M., Hörbe, M., Horns, D., Huber, D., Jamrozy, M., Jankowsky, D., Jankowsky, F., Jardin-Blicq, A., Joshi, V., Jung-Richardt, I., Kasai, E., Kastendieck, M. A., Katarzynski, K., Katz, U., Khangulyan, D., Khélifi, B., Klepser, S., Kluźniak, W., Komin, Nu., Konno, R., Kosack, K., Kostunin, D., Kreter, M., Lamanna, G., Lemière, A., Lemoine-Goumard, M., Lenain, J. -P., Leuschner, F., Levy, C., Lohse, T., Lypova, I., Mackey, J., Majumdar, J., Malyshev, D., Marandon, V., Marchegiani, P., Marcowith, A., Mares, A., Martí-Devesa, G., Marx, R., Maurin, G., Meintjes, P. J., Meyer, M., Mitchell, A., Moderski, R., Mohrmann, L., Montanari, A., Moore, C., Morris, P., Moulin, E., Muller, J., Murach, T., Nakashima, K., Nayerhoda, A., de Naurois, M., Ndiyavala, H., Niemiec, J., Oakes, L., O'Brien, P., Odaka, H., Ohm, S., Olivera-Nieto, L., Wilhelmi, E. de Ona, Ostrowski, M., Panny, S., Panter, M., Parsons, R. D., Peron, G., Peyaud, B., Piel, Q., Pita, S., Poireau, V., Noel, A. Priyana, Prokhorov, D. A., Prokoph, H., Pühlhofer, G., Punch, M., Quirrenbach, A., Raab, S., Rauth, R., Reichherzer, P., Reimer, A., Reimer, O., Remy, Q., Renaud, M., Rieger, F., Rinchiuso, L., Romoli, C., Rowell, G., Rudak, B., Ruiz-Velasco, E., Sahakian, V., Sailer, S., Salzmann, H., Sanchez, D. A., Santangelo, A., Sasaki, M., Scalici, M., Schäfer, J., Schüssler, F., Schutte, H. M., Schwanke, U., Seglar-Arroyo, M., Senniappan, M., Seyffert, A. S., Shafi, N., Shapopi, J. N. S., Shiningayamwe, K., Simoni, R., Sinha, A., Sol, H., Specovius, A., Spencer, S., Spir-Jacob, M., Stawarz, L., Sun, L., Steenkamp, R., Stegmann, C., Steinmassl, S., Steppa, C., Takahashi, T., Tavernier, T., Taylor, A. M., Terrier, R., Thiersen, J. H. E., Tiziani, D., Tluczykont, M., Tomankova, L., Trichard, C., Tsirou, M., Tuffs, R., Uchiyama, Y., van der Walt, D. J., van Eldik, C., van Rensburg, C., van Soelen, B., Vasileiadis, G., Veh, J., Venter, C., Vincent, P., Vink, J., Völk, H. J., Wadiasingh, Z., Wagner, S. J., Watson, J., Werner, F., White, R., Wierzcholska, A., Wong, Yu Wun, Yusafzai, A., Zacharias, M., Zanin, R., Zargaryan, D., Zdziarski, A. A., Zech, A., Zhu, S. J., Zorn, J., Zouari, S., and Żywucka, N.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: We analyzed 252 hours of High Energy Stereoscopic System (H.E.S.S.) observations towards the supernova remnant (SNR) LMC N132D that were accumulated between December 2004 and March 2016 during a deep survey of the Large Magellanic Cloud, adding 104 hours of observations to the previously published data set to ensure a > 5 sigma detection. To broaden the gamma-ray spectral coverage required for modeling the spectral energy distribution, an analysis of Fermi-LAT Pass 8 data was also included. We unambiguously detect N132D at very high energies (VHE) with a significance of 5.7 sigma. We report the results of a detailed analysis of its spectrum and localization based on the extended H.E.S.S. data set. The joint analysis of the extended H.E.S.S and Fermi-LAT data results in a spectral energy distribution in the energy range from 1.7 GeV to 14.8 TeV, which suggests a high luminosity of N132D at GeV and TeV energies. We set a lower limit on a gamma-ray cutoff energy of 8 TeV with a confidence level of 95%. The new gamma-ray spectrum as well as multiwavelength observations of N132D when compared to physical models suggests a hadronic origin of the VHE gamma-ray emission. SNR N132D is a VHE gamma-ray source that shows a spectrum extending to the VHE domain without a spectral cutoff at a few TeV, unlike the younger oxygen-rich SNR Cassiopeia A. The gamma-ray properties of N132D may be affected by an interaction with a nearby molecular cloud that partially lies inside the 95% confidence region of the source position. [Abridged], Comment: Accepted for publication in Astronomy & Astrophysics
Published: 2021
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49. The Blazar Hadronic Code Comparison Project

Author: Cerruti, Matteo, Kreter, Michael, Petropoulou, Maria, Rudolph, Annika, Oikonomou, Foteini, Böttcher, Markus, Dimitrakoudis, Stavros, Dmytriiev, Anton, Gao, Shan, Mastichiadis, Apostolos, Inoue, Susumu, Murase, Kohta, Reimer, Anita, Robinson, Joshua, Rodrigues, Xavier, Winter, Walter, Zech, Andreas, and Żywucka, Natalia
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract: Blazar hadronic models have been developed in the past decades as an alternative to leptonic ones. In hadronic models the gamma-ray emission is associated with synchrotron emission by protons, and/or secondary leptons produced in proton-photon interactions. Together with photons, hadronic emission models predict the emission of neutrinos that are therefore the smoking gun for acceleration of relativistic hadrons in blazar jets. The simulation of proton-photon interactions and all associated radiative processes is a complex numerical task, and different approaches to the problem have been adopted in the literature. So far, no systematic comparison between the different codes has been performed, preventing a clear understanding of the underlying uncertainties in the numerical simulations. To fill this gap, we have undertaken the first comprehensive comparison of blazar hadronic codes, and the results from this effort will be presented in this contribution., Comment: To appear in the proceedings of 37th International Cosmic Ray Conference, in Proceedings of Science (ICRC2021), 979
Published: 2021

50. TeV emission of Galactic plane sources with HAWC and H.E.S.S

Author: Abdalla, H., Aharonian, F., Benkhali, F. Ait, Angüner, E. O., Arcaro, C., Armand, C., Armstrong, T., Ashkar, H., Backes, M., Baghmanyan, V., Martins, V. Barbosa, Barnacka, A., Barnard, M., Becherini, Y., Berge, D., Bernlöhr, K., Bi, B., Böttcher, M., Boisson, C., Bolmont, J., de Lavergne, M. de Bony, Breuhaus, M., Brose, R., Brun, F., Brun, P., Bryan, M., Büchele, M., Bulik, T., Bylund, T., Caroff, S., Carosi, A., Chand, T., Chandra, S., Chen, A., Cotter, G., Curyło, M., Mbarubucyeye, J. Damascene, Davids, I. D., Davies, J., Deil, C., Devin, J., Dirson, L., Djannati-Ataï, A., Dmytriiev, A., Donath, A., Doroshenko, V., Dreyer, L., Duffy, C., Dyks, J., Egberts, K., Eichhorn, F., Einecke, S., Emery, G., Ernenwein, J. -P., Feijen, K., Fegan, S., Fiasson, A., de Clairfontaine, G. Fichet, Fontaine, G., Funk, S., Füßling, M., Gabici, S., Gallant, Y. A., Giavitto, G., Giunti, L., Glawion, D., Glicenstein, J. F., Gottschall, D., Grondin, M. -H., Hahn, J., Haupt, M., Hermann, G., Hinton, J. A., Hofmann, W., Hoischen, C., Holch, T. L., Holler, M., Hörbe, M., Horns, D., Huber, D., Jamrozy, M., Jankowsky, D., Jankowsky, F., Jung-Richardt, I., Kasai, E., Kastendieck, M. A., Katarzyński, K., Katz, U., Khangulyan, D., Khélifi, B., Klepser, S., Kluźniak, W., Komin, Nu., Konno, R., Kosack, K., Kostunin, D., Kreter, M., Lamanna, G., Lemière, A., Lemoine-Goumard, M., Lenain, J. -P., Leuschner, F., Levy, C., Lohse, T., Lypova, I., Mackey, J., Majumdar, J., Malyshev, D., Marandon, V., Marchegiani, P., Marcowith, A., Mares, A., Martí-Devesa, G., Marx, R., Maurin, G., Meintjes, P. J., Meyer, M., Mitchell, A. M. W., Moderski, R., Mohrmann, L., Montanari, A., Moore, C., Morris, P., Moulin, E., Muller, J., Murach, T., Nakashima, K., Nayerhoda, A., de Naurois, M., Ndiyavala, H., Niemiec, J., Oakes, L., Brien, P. O, Odaka, H., Ohm, S., Olivera-Nieto, L., Wilhelmi, E. de Ona, Ostrowski, M., Panny, S., Panter, M., Parsons, R. D., Peron, G., Peyaud, B., Piel, Q., Pita, S., Poireau, V., Noel, A. Priyana, Prokhorov, D. A., Prokoph, H., Pühlhofer, G., Punch, M., Quirrenbach, A., Raab, S., Rauth, R., Reichherzer, P., Reimer, A., Reimer, O., Remy, Q., Renaud, M., Rieger, F., Rinchiuso, L., Romoli, C., Rowell, G., Rudak, B., Sahakian, V., Sailer, S., Salzmann, H., Sanchez, D. A., Santangelo, A., Sasaki, M., Schäfer, J., Schüssler, F., Schutte, H. M., Schwanke, U., Seglar-Arroyo, M., Senniappan, M., Seyffert, A. S., Shafi, N., Shapopi, J. N. S., Shiningayamwe, K., Simoni, R., Sinha, A., Sol, H., Specovius, A., Spencer, S., Spir-Jacob, M., Stawarz, Ł., Sun, L., Steenkamp, R., Stegmann, C., Steinmassl, S., Steppa, C., Takahashi, T., Tavernier, T., Taylor, A. M., Terrier, R., Thiersen, J. H. E., Tiziani, D., Tluczykont, M., Tomankova, L., Trichard, C., Tsirou, M., Tuffs, R., Uchiyama, Y., van der Walt, D. J., van Eldik, C., van Rensburg, C., van Soelen, B., Vasileiadis, G., Veh, J., Venter, C., Vincent, P., Vink, J., Völk, H. J., Wadiasingh, Z., Wagner, S. J., Watson, J., Werner, F., White, R., Wierzcholska, A., Wong, Yu Wun, Yusafzai, A., Zacharias, M., Zanin, R., Zargaryan, D., Zdziarski, A. A., Zech, A., Zhu, S. J., Zmija, A., Zorn, J., Zouari, S., Żywucka, N., Albert, A., Alfaro, R., Alvarez, C., Arteaga-Velázquez, J. C., Arunbabu, K. P., Rojas, D. Avila, Belmont-Moreno, E., BenZvi, S. Y., Brisbois, C., Caballero-Mora, K. S., Capistrán, T., Carramiñana, A., Casanova, S., Cotti, U., Cotzomi, J., de León, S. Coutiño, De la Fuente, E., de León, C., Hernandez, R. Diaz, Díaz-Vélez, J. C., Dingus, B. L., DuVernois, M. A., Durocher, M., Ellsworth, R. W., Engel, K., Espinoza, C., Fan, K. L., Alonso, M. Fernández, Fraija, N., Galván-Gámez, A., Garcia, D., García-González, J. A., Garfias, F., Giacinti, G., González, M. M., Goodman, J. A., Harding, J. P., Hernandez, S., Hona, B., Huang, D., Hueyotl-Zahuantitla, F., Hüntemeyer, P., Iriarte, A., Jardin-Blicq, A., Joshi, V., Kieda, D., Lee, W. H., Vargas, H. León, Linnemann, J. T., Longinotti, A. L., Luis-Raya, G., López-Coto, R., Malone, K., Martinez, O., Martinez-Castellanos, I., Martínez-Castro, J., Matthews, J. A., Miranda-Romagnoli, P., Morales-Soto, J. A., Moreno, E., Mostafá, M., Nellen, L., Newbold, M., Nisa, M. U., Noriega-Papaqui, R., Omodei, N., Peisker, A., Araujo, Y. Pérez, Pérez-Pérez, E. G., Rho, C. D., Rosa-González, D., Ruiz-Velasco, E., Greus, F. Salesa, Sandoval, A., Schneider, M., Schoorlemmer, H., Serna-Franco, J., Smith, A. J., Springer, R. W., Surajbali, P., Tollefson, K., Torres, I., Torres-Escobedo, R., Turner, R., Ureña-Mena, F., Villaseñor, L., Weisgarber, T., Willox, E., and Zhou, H.
Subjects: Astrophysics - Instrumentation and Methods for Astrophysics
Abstract: The High Altitude Water Cherenkov (HAWC) observatory and the High Energy Stereoscopic System (H.E.S.S.) are two leading instruments in the ground-based very-high-energy gamma-ray domain. HAWC employs the water Cherenkov detection (WCD) technique, while H.E.S.S. is an array of Imaging Atmospheric Cherenkov Telescopes (IACTs). The two facilities therefore differ in multiple aspects, including their observation strategy, the size of their field of view and their angular resolution, leading to different analysis approaches. Until now, it has been unclear if the results of observations by both types of instruments are consistent: several of the recently discovered HAWC sources have been followed up by IACTs, resulting in a confirmed detection only in a minority of cases. With this paper, we go further and try to resolve the tensions between previous results by performing a new analysis of the H.E.S.S. Galactic plane survey data, applying an analysis technique comparable between H.E.S.S. and HAWC. Events above 1 TeV are selected for both datasets, the point spread function of H.E.S.S. is broadened to approach that of HAWC, and a similar background estimation method is used. This is the first detailed comparison of the Galactic plane observed by both instruments. H.E.S.S. can confirm the gamma-ray emission of four HAWC sources among seven previously undetected by IACTs, while the three others have measured fluxes below the sensitivity of the H.E.S.S. dataset. Remaining differences in the overall gamma-ray flux can be explained by the systematic uncertainties. Therefore, we confirm a consistent view of the gamma-ray sky between WCD and IACT techniques.
Published: 2021
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