Faculty Profiles - OKUMURA Akira

Papers - OKUMURA Akira

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Transplanted Brazilian Portuguese in Japan Mobility, contact, and koine formation among Latin American immigrants

Matsumoto, K; Okumura, A; Matsuda, K

ASIA-PACIFIC LANGUAGE VARIATION Vol. 10 ( 1 ) page： 40 - 66 2024.8

Language：English Publishing type：Research paper (scientific journal) Publisher：Asia-Pacific Language Variation

This paper explores an emerging Brazilian Portuguese koiné spoken among Brazilian-dominant Latin American immigrants in Japan's Greater Tokyo Area. It examines Strong-R (onset/r/) realizations by 79 speakers in the context of dialect and language contact within the diasporic setting. The results highlight (a) levelling and focussing towards [h] as a result of koineization and (b) early stages of the adoption of [ϕ], a xenolectal feature, resulting from contact with Japanese. The external and internal motivations for change towards [h] are identified as oca and supra oca levelling and drift. The transition to [ϕ], and its linguistic and social embedding, are discussed in terms of acquisition order, the structure of the Japanese kana syllabary, and speakers' social networks. The conclusion emphasizes the importance for koiné genesis of input dialects, ongoing language change in the homeland, the social meaning of variants in both pre- and post-contact societies, and speakers' social networks and mobilities.

DOI： 10.1075/aplv.21004.mat

GRB 221009A observations with LST-1 at VHE gamma rays

K. Abe, S. Abe, A. Abhishek, F. Acero, A. Aguasca-Cabot, I. Agudo, N. Alvarez Crespo, L. A. Antonelli, C. Aramo, A. Arbet-Engels, C. Arcaro, K. Asano, P. Aubert, A. Baktash, A. Bamba, A. Baquero Larriva, U. Barres de Almeida, J. A. Barrio, L. Barrios Jiménez, I. Batkovic, J. Baxter, J. Becerra González, E. Bernardini, J. Bernete Medrano, A. Berti, P. Bhattacharjee, C. Bigongiari, E. Bissaldi, O. Blanch, G. Bonnoli, P. Bordas, G. Brunelli, A. Bulgarelli, I. Burelli, L. Burmistrov, M. Buscemi, M. Cardillo, S. Caroff, A. Carosi, M. S. Carrasco, F. Cassol, N. Castrejón, D. Cauz, D. Cerasole, G. Ceribella, Y. Chai, K. Cheng, A. Chiavassa, M. Chikawa, G. Chon, L. Chytka, G. M. Cicciari, A. Cifuentes, J. L. Contreras, J. Cortina, H. Costantini, P. Da Vela, M. Dalchenko, F. Dazzi, A. De Angelis, M. de Bony de Lavergne, B. De Lotto, R. de Menezes, L. Del Peral, C. Delgado, J. Delgado Mengual, D. della Volpe, M. Dellaiera, A. Di Piano, F. Di Pierro, R. Di Tria, L. Di Venere, C. Díaz, R. M. Dominik, D. Dominis Prester, A. Donini, D. Dorner, M. Doro, L. Eisenberger, D. Elsässer, G. Emery, J. Escudero, V. Fallah Ramazani, F. Ferrarotto, A. Fiasson, L. Foffano, L. Freixas Coromina, S. Fröse, Y. Fukazawa, R. Garcia López, C. Gasbarra, D. Gasparrini, D. Geyer, J. Giesbrecht Paiva, N. Giglietto, F. Giordano, P. Gliwny, N. Godinovic, R. Grau, D. Green

Proceedings of Science Vol. 461 2024.7

Language：English Publishing type：Research paper (international conference proceedings)

On October 9th, 2022, the brightest gamma-ray burst (GRB) since the first GRB observation in the late sixties was detected by the Fermi-GBM and Swift-BAT telescopes (GRB 221009A). The outstanding characteristics of this GRB triggered extensive follow-up observations of the source across all wavebands, including at very-high-energy (VHE) gamma rays with the Large-Sized Telescope prototype (LST-1) of the upcoming Cherenkov Telescope Array Observatory (CTAO). In this contribution, we present the analysis and results of the LST-1 observation campaign in October 2022, focusing on the data taken under nominal observing conditions and above 200 GeV.

Constraints on Lorentz invariance violation from the extraordinary Mrk 421 flare of 2014 using a novel analysis method Open Access

S. Abe, J. Abhir, A. Abhishek, V. A. Acciari, A. Aguasca-Cabot, I. Agudo, T. Aniello, S. Ansoldi, L. A. Antonelli, A. Arbet Engels, C. Arcaro, M. Artero, K. Asano, A. Babić, A. Baquero, U. Barres de Almeida, J. A. Barrio, I. Batković, A. Bautista, J. Baxter, J. Becerra González, W. Bednarek, E. Bernardini, J. Bernete, A. Berti, J. Besenrieder, C. Bigongiari, A. Biland, O. Blanch, G. Bonnoli, Z. Bošnjak, E. Bronzini, I. Burelli, G. Busetto, A. Campoy-Ordaz, A. Carosi, R. Carosi, M. Carretero-Castrillo, A. J. Castro-Tirado, D. Cerasole, G. Ceribella, Y. Chai, A. Cifuentes, E. Colombo, J. L. Contreras, J. Cortina, S. Covino, G. D'Amico, V. D'Elia, P. Da Vela, F. Dazzi, A. De Angelis, B. De Lotto, R. de Menezes, A. Del Popolo, M. Delfino, J. Delgado, C. Delgado Mendez, F. Di Pierro, R. Di Tria, L. Di Venere, D. Dominis Prester, A. Donini, D. Dorner, M. Doro, D. Elsaesser, G. Emery, J. Escudero, L. Fariña, A. Fattorini, L. Foffano, L. Font, S. Fröse, S. Fukami, Y. Fukazawa, R. J. García López, M. Garczarczyk, S. Gasparyan, M. Gaug, J. G. Giesbrecht Paiva, N. Giglietto, F. Giordano, P. Gliwny, N. Godinović, T. Gradetzke, R. Grau, D. Green, J. G. Green, P. Günther, D. Hadasch, A. Hahn, T. Hassan, L. Heckmann, J. Herrera, D. Hrupec, M. Hütten, R. Imazawa, K. Ishio, I. Jiménez Martínez, J. Jormanainen

Journal of Cosmology and Astroparticle Physics Vol. 2024 ( 7 ) 2024.7

Language：English Publishing type：Research paper (scientific journal)

The Lorentz Invariance Violation (LIV), a proposed consequence of certain quantum gravity (QG) scenarios, could instigate an energy-dependent group velocity for ultra-relativistic particles. This energy dependence, although suppressed by the massive QG energy scale E_QG, expected to be on the level of the Planck energy 1.22 × 1019 GeV, is potentially detectable in astrophysical observations. In this scenario, the cosmological distances traversed by photons act as an amplifier for this effect. By leveraging the observation of a remarkable flare from the blazar Mrk 421, recorded at energies above 100 GeV by the MAGIC telescopes on the night of April 25 to 26, 2014, we look for time delays scaling linearly and quadratically with the photon energies. Using for the first time in LIV studies a binned-likelihood approach we set constraints on the QG energy scale. For the linear scenario, we set 95% lower limits E_QG>2.7×1017 GeV for the subluminal case and E_QG> 3.6 ×1017 GeV for the superluminal case. For the quadratic scenario, the 95% lower limits for the subluminal and superluminal cases are E_QG>2.6 ×1010 GeV and E_QG>2.5×1010 GeV, respectively.

DOI： 10.1088/1475-7516/2024/07/044

Dark matter line searches with the Cherenkov Telescope Array Open Access

S. Abe, J. Abhir, A. Abhishek, F. Acero, A. Acharyya, R. Adam, A. Aguasca-Cabot, I. Agudo, A. Aguirre-Santaella, J. Alfaro, R. Alfaro, N. Alvarez-Crespo, R. Alves Batista, J. P. Amans, E. Amato, G. Ambrosi, L. Angel, C. Aramo, C. Arcaro, T. T.H. Arnesen, L. Arrabito, K. Asano, Y. Ascasibar, J. Aschersleben, H. Ashkar, M. Backes, A. Baktash, C. Balazs, M. Balbo, A. Baquero Larriva, V. Barbosa Martins, U. Barres De Almeida, J. A. Barrio, I. Batkovic, R. Batzofin, J. Baxter, J. Becerra González, G. Beck, W. Benbow, D. Berge, E. Bernardini, J. Bernete, K. Bernlöhr, A. Berti, B. Bertucci, P. Bhattacharjee, S. Bhattacharyya, C. Bigongiari, A. Biland, E. Bissaldi, J. Biteau, O. Blanch, J. Blazek, F. Bocchino, C. Boisson, J. Bolmont, G. Bonnoli, A. Bonollo, P. Bordas, Z. Bosnjak, E. Bottacini, M. Böttcher, T. Bringmann, E. Bronzini, R. Brose, A. M. Brown, G. Brunelli, A. Bulgarelli, T. Bulik, I. Burelli, L. Burmistrov, M. Burton, M. Buscemi, T. Bylund, J. Cailleux, A. Campoy-Ordaz, B. K. Cantlay, G. Capasso, A. Caproni, R. Capuzzo-Dolcetta, P. Caraveo, S. Caroff, A. Carosi, R. Carosi, E. Carquin, M. S. Carrasco, F. Cassol, L. Castaldini, N. Castrejon, A. J. Castro-Tirado, D. Cerasole, M. Cerruti, P. M. Chadwick, S. Chaty, A. W. Chen, M. Chernyakova, A. Chiavassa, J. Chudoba, L. Chytka, G. M. Cicciari

Journal of Cosmology and Astroparticle Physics Vol. 2024 ( 7 ) 2024.7

Language：English Publishing type：Research paper (scientific journal)

Monochromatic gamma-ray signals constitute a potential smoking gun signature for annihilating or decaying dark matter particles that could relatively easily be distinguished from astrophysical or instrumental backgrounds. We provide an updated assessment of the sensitivity of the Cherenkov Telescope Array (CTA) to such signals, based on observations of the Galactic centre region as well as of selected dwarf spheroidal galaxies. We find that current limits and detection prospects for dark matter masses above 300 GeV will be significantly improved, by up to an order of magnitude in the multi-TeV range. This demonstrates that CTA will set a new standard for gamma-ray astronomy also in this respect, as the world's largest and most sensitive high-energy gamma-ray observatory, in particular due to its exquisite energy resolution at TeV energies and the adopted observational strategy focussing on regions with large dark matter densities. Throughout our analysis, we use up-to-date instrument response functions, and we thoroughly model the effect of instrumental systematic uncertainties in our statistical treatment. We further present results for other potential signatures with sharp spectral features, e.g. box-shaped spectra, that would likewise very clearly point to a particle dark matter origin.

DOI： 10.1088/1475-7516/2024/07/047

Insights into the broadband emission of the TeV blazar Mrk 501 during the first X-ray polarization measurements Open Access

S. Abe, J. Abhir, V. A. Acciari, A. Aguasca-Cabot, I. Agudo, T. Aniello, S. Ansoldi, L. A. Antonelli, A. Arbet Engels, C. Arcaro, K. Asano, A. Babić, A. Baquero, U. Barres De Almeida, J. A. Barrio, I. Batković, A. Bautista, J. Baxter, J. Becerra González, W. Bednarek, E. Bernardini, M. Bernardos, J. Bernete, A. Berti, J. Besenrieder, C. Bigongiari, A. Biland, O. Blanch, G. Bonnoli, Bošnjak, I. Burelli, G. Busetto, A. Campoy-Ordaz, A. Carosi, R. Carosi, M. Carretero-Castrillo, A. J. Castro-Tirado, G. Ceribella, Y. Chai, A. Cifuentes, E. Colombo, J. L. Contreras, J. Cortina, S. Covino, G. D'Amico, V. D'Elia, P. Da Vela, F. Dazzi, A. De Angelis, B. De Lotto, R. De Menezes, A. Del Popolo, M. Delfino, J. Delgado, C. Delgado Mendez, F. Di Pierro, L. Di Venere, D. Dominis Prester, A. Donini, D. Dorner, M. Doro, D. Elsaesser, G. Emery, J. Escudero, L. Fariña, A. Fattorini, L. Foffano, L. Font, S. Fröse, Y. Fukazawa, R. J. García López, M. Garczarczyk, S. Gasparyan, M. Gaug, J. G. Giesbrecht Paiva, N. Giglietto, F. Giordano, P. Gliwny, N. Godinović, T. Gradetzke, R. Grau, D. Green, J. G. Green, P. Günther, D. Hadasch, A. Hahn, T. Hassan, L. Heckmann, J. Herrera, D. Hrupec, M. Hütten, R. Imazawa, K. Ishio, I. Jiménez Martínez, T. Kayanoki, D. Kerszberg, G. W. Kluge, Y. Kobayashi, P. M. Kouch, H. Kubo

Astronomy and Astrophysics Vol. 685 2024.5

Language：English Publishing type：Research paper (scientific journal)

Aims. We present the first multiwavelength study of Mrk 501 that contains simultaneous very-high-energy (VHE) γ-ray observations and X-ray polarization measurements from the Imaging X-ray Polarimetry Explorer (IXPE). Methods. We used radio-to-VHE data from a multiwavelength campaign carried out between March 1, 2022, and July 19, 2022 (MJD 59639 to MJD 59779). The observations were performed by MAGIC, Fermi-LAT, NuSTAR, Swift (XRT and UVOT), and several other instruments that cover the optical and radio bands to complement the IXPE pointings. We characterized the dynamics of the broadband emission around the X-ray polarization measurements through its multiband fractional variability and correlations, and compared changes observed in the polarization degree to changes seen in the broadband emission using a multi-zone leptonic scenario. Results. During the IXPE pointings, the VHE state is close to the average behavior, with a 0.2- 1 TeV flux of 20%- 50% of the emission of the Crab Nebula. Additionally, it shows low variability and a hint of correlation between VHE γ-rays and X-rays. Despite the average VHE activity, an extreme X-ray behavior is measured for the first two IXPE pointings, taken in March 2022 (MJD 59646 to 59648 and MJD 59665 to 59667), with a synchrotron peak frequency > 1 keV. For the third IXPE pointing, in July 2022 (MJD 59769 to 59772), the synchrotron peak shifts toward lower energies and the optical/X-ray polarization degrees drop. All three IXPE epochs show an atypically low Compton dominance in the γ-rays. The X-ray polarization is systematically higher than at lower energies, suggesting an energy stratification of the jet. While during the IXPE epochs the polarization angles in the X-ray, optical, and radio bands align well, we find a clear discrepancy in the optical and radio polarization angles in the middle of the campaign. Such results further support the hypothesis of an energy-stratified jet. We modeled broadband spectra taken simultaneous to the IXPE pointings, assuming a compact zone that dominates in the X-rays and the VHE band, and an extended zone stretching farther downstream in the jet that dominates the emission at lower energies. NuSTAR data allow us to precisely constrain the synchrotron peak and therefore the underlying electron distribution. The change between the different states observed in the three IXPE pointings can be explained by a change in the magnetization and/or the emission region size, which directly connects the shift in the synchrotron peak to lower energies with the drop in the polarization degree.

DOI： 10.1051/0004-6361/202348709

Constraints on axion-like particles with the Perseus Galaxy Cluster with MAGIC

Abe, H; Abe, S; Abhir, J; Acciari, VA; Agudo, I; Aniello, T; Ansoldi, S; Antonelli, LA; Engels, AA; Arcaro, C; Artero, M; Asano, K; Baack, D; Babic, A; Baquero, A; de Almeida, UB; Barrio, JA; Batkovic, I; Baxter, J; González, JB; Bednarek, W; Bernardini, E; Bernete, J; Berti, A; Besenrieder, J; Bigongiari, C; Biland, A; Blanch, O; Bonnoli, G; Bosnjak, Z; Burelli, I; Busetto, G; Campoy-Ordaz, A; Carosi, A; Carosi, R; Carretero-Castrillo, M; Castro-Tirado, AJ; Ceribella, G; Chai, Y; Cifuentes, A; Cikota, S; Colombo, E; Contreras, JL; Cortina, J; Covino, S; D'Amico, G; D'Elia, V; Da Vela, P; Dazzi, F; De Angelis, A; De Lotto, B; Del Popolo, A; Delgado, J; Mendez, CD; Depaoli, D; Di Pierro, F; Di Venere, L; Prester, DD; Donini, A; Dorner, D; Doro, M; Elsaesser, D; Emery, G; Escudero, J; Fariña, L; Fattorini, A; Foffano, L; Font, L; Fukami, S; Fukazawa, Y; López, RJG; Garczarczyk, M; Gasparyan, S; Gaug, M; Paiva, JGG; Giglietto, N; Giordano, F; Gliwny, P; Godinovic, N; Grau, R; Green, D; Green, JG; Hadasch, D; Hahn, A; Hassan, T; Heckmann, L; Herrera, J; Hrupec, D; Hütten, M; Imazawa, R; Inada, T; Iotov, R; Ishio, K; Martínez, IJ; Jormanainen, J; Kerszberg, D; Kluge, GW; Kobayashi, Y; Kouch, PM; Kubo, H; Kushida, J; Lezáun, ML; Lamastra, A; Leone, F; Lindfors, E; Linhoff, L; Lombardi, S; Longo, F; López-Coto, R; López-Moya, M; López-Oramas, A; Loporchio, S; Lorini, A; Fraga, BMD; Majumdar, P; Makariev, M; Maneva, G; Mang, N; Manganaro, M; Mangano, S; Mannheim, K; Mariotti, M; Martínez, M; Martínez-Chicharro, M; Mas-Aguilar, A; Mazin, D; Menchiari, S; Mender, S; Miceli, D; Miener, T; Miranda, JM; Mirzoyan, R; González, MM; Molina, E; Mondal, HA; Moralejo, A; Morcuende, D; Nakamori, T; Nanci, C; Nava, L; Neustroev, V; Nickel, L; Rosillo, MN; Nigro, C; Nikolic, L; Nilsson, K; Nishijima, K; Ekoume, TN; Noda, K; Nozaki, S; Ohtani, Y; Okumura, A; Otero-Santos, J; Paiano, S; Palatiello, M; Paneque, D; Paoletti, R; Paredes, JM; Pavlovic, D; Persic, M; Pihet, M; Pirola, G; Podobnik, F; Moroni, PGP; Prandini, E; Principe, G; Priyadarshi, C; Rhode, W; Ribó, M; Rico, J; Righi, C; Sahakyan, N; Saito, T; Satalecka, K; Saturni, FG; Schleicher, B; Schmidt, K; Schmuckermaier, F; Schubert, JL; Schweizer, T; Sciaccaluga, A; Sitarek, J; Sliusar, V; Sobczynska, D; Spolon, A; Stamerra, A; Striskovic, J; Strom, D; Strzys, M; Suda, Y; Suutarinen, S; Tajima, H; Takahashi, M; Takeishi, R; Tavecchio, F; Temnikov, P; Terauchi, K; Terzic, T; Teshima, M; Tosti, L; Truzzi, S; Tutone, A; Ubach, S; van Scherpenberg, J; Acosta, MV; Ventura, S; Verguilov, V; Viale, I; Vigorito, CF; Vitale, V; Vovk, I; Walter, R; Will, M; Yamamoto, T

PHYSICS OF THE DARK UNIVERSE Vol. 44 2024.5

Language：English Publishing type：Research paper (scientific journal) Publisher：Physics of the Dark Universe

Axion-like particles (ALPs) are pseudo-Nambu–Goldstone bosons that emerge in various theories beyond the standard model. These particles can interact with high-energy photons in external magnetic fields, influencing the observed gamma-ray spectrum. This study analyzes 41.3 h of observational data from the Perseus Galaxy Cluster collected with the MAGIC telescopes. We focused on the spectra the radio galaxy in the center of the cluster: NGC 1275. By modeling the magnetic field surrounding this target, we searched for spectral indications of ALP presence. Despite finding no statistical evidence of ALP signatures, we were able to exclude ALP models in the sub-micro electronvolt range. Our analysis improved upon previous work by calculating the full likelihood and statistical coverage for all considered models across the parameter space. Consequently, we achieved the most stringent limits to date for ALP masses around 50 neV, with cross sections down to gaγ=3×10−12 GeV−1.

DOI： 10.1016/j.dark.2024.101425

First characterization of the emission behavior of Mrk 421 from radio to very high-energy gamma rays with simultaneous X-ray polarization measurements Open Access

S. Abe, J. Abhir, V. A. Acciari, I. Agudo, T. Aniello, S. Ansoldi, L. A. Antonelli, A. Arbet-Engels, C. Arcaro, M. Artero, K. Asano, A. Babić, A. Baquero, U. Barres de Almeida, J. A. Barrio, I. Batković, J. Baxter, J. Becerra González, W. Bednarek, E. Bernardini, J. Bernete, A. Berti, J. Besenrieder, C. Bigongiari, A. Biland, O. Blanch, G. Bonnoli, Bošnjak, I. Burelli, G. Busetto, A. Campoy-Ordaz, A. Carosi, R. Carosi, M. Carretero-Castrillo, A. J. Castro-Tirado, G. Ceribella, Y. Chai, A. Cifuentes, S. Cikota, E. Colombo, J. L. Contreras, J. Cortina, S. Covino, F. D'Ammando, G. D'Amico, V. D'Elia, P. Da Vela, F. Dazzi, A. De Angelis, B. De Lotto, R. de Menezes, A. Del Popolo, J. Delgado, C. Delgado Mendez, F. Di Pierro, L. Di Venere, D. Dominis Prester, A. Donini, D. Dorner, M. Doro, D. Elsaesser, G. Emery, J. Escudero, L. Fariña, A. Fattorini, L. Foffano, L. Font, S. Fröse, S. Fukami, Y. Fukazawa, R. J.García López, M. Garczarczyk, S. Gasparyan, M. Gaug, J. G.Giesbrecht Paiva, N. Giglietto, F. Giordano, P. Gliwny, N. Godinović, T. Gradetzke, R. Grau, D. Green, J. G. Green, P. Günther, D. Hadasch, A. Hahn, T. Hassan, L. Heckmann, J. Herrera, D. Hrupec, M. Hütten, R. Imazawa, T. Inada, K. Ishio, I. Jiménez Martínez, J. Jormanainen, D. Kerszberg, G. W. Kluge, Y. Kobayashi, P. M. Kouch

Astronomy and Astrophysics Vol. 684 2024.4

Language：English Publishing type：Research paper (scientific journal)

Aims. We have performed the first broadband study of Mrk 421 from radio to TeV gamma rays with simultaneous measurements of the X-ray polarization from IXPE. Methods. The data were collected as part of an extensive multiwavelength campaign carried out between May and June 2022 using MAGIC, Fermi-LAT, NuSTAR, XMM-Newton, Swift, and several optical and radio telescopes to complement IXPE data. Results. During the IXPE exposures, the measured 0.2-1 TeV flux was close to the quiescent state and ranged from 25% to 50% of the Crab Nebula without intra-night variability. Throughout the campaign, the very high-energy (VHE) and X-ray emission are positively correlated at a 4σ significance level. The IXPE measurements reveal an X-ray polarization degree that is a factor of 2-5 higher than in the optical/radio bands; that implies an energy-stratified jet in which the VHE photons are emitted co-spatially with the X-rays, in the vicinity of a shock front. The June 2022 observations exhibit a rotation of the X-ray polarization angle. Despite no simultaneous VHE coverage being available during a large fraction of the swing, the Swift-XRT monitoring reveals an X-ray flux increase with a clear spectral hardening. This suggests that flares in high synchrotron peaked blazars can be accompanied by a polarization angle rotation, as observed in some flat spectrum radio quasars. Finally, during the polarization angle rotation, NuSTAR data reveal two contiguous spectral hysteresis loops in opposite directions (clockwise and counterclockwise), implying important changes in the particle acceleration efficiency on approximately hour timescales.

DOI： 10.1051/0004-6361/202347988

The variability patterns of the TeV blazar PG 1553 + 113 from a decade of MAGIC and multiband observations

Abe H., Abe S., Abhir J., Acciari V.A., Agudo I., Aniello T., Ansoldi S., Antonelli L.A., Arbet Engels A., Arcaro C., Artero M., Asano K., Baack D., Babić A., Baquero A., Barres de Almeida U., Batković I., Baxter J., Becerra González J., Bernardini E., Bernete J., Berti A., Besenrieder J., Bigongiari C., Biland A., Blanch O., Bonnoli G., Bošnjak , Burelli I., Busetto G., Campoy-Ordaz A., Carosi A., Carosi R., Carretero-Castrillo M., Castro-Tirado A.J., Chai Y., Cifuentes 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., Delgado Mendez C., Depaoli D., Di Pierro F., Di Venere L., Dominis Prester D., Donini A., Dorner D., Doro M., Elsaesser D., Emery G., Escudero J., Fariña L., Fattorini A., Foffano L., Font L., Fukami S., Fukazawa Y., García López R.J., Gasparyan S., Gaug M., Giesbrecht Paiva J.G., Giglietto N., Giordano F., Gliwny P., Grau R., Green J.G., Hadasch D., Hahn A., Heckmann L., Herrera J., Hovatta T., Hrupec D., Hütten M., Imazawa R., Inada T., Iotov R., Ishio K., Jimenez Martínez I., Jormanainen J., Kerszberg D., Kluge G.W., Kobayashi Y., Kouch P.M., Kubo H., Kushida J., Láinez Lezáun M., Lamastra A., Leone F., Lindfors E.

Monthly Notices of the Royal Astronomical Society Vol. 529 ( 4 ) page： 3894 - 3911 2024.4

Language：English Publishing type：Research paper (scientific journal) Publisher：Monthly Notices of the Royal Astronomical Society

PG 1553 + 113 is one of the few blazars with a convincing quasi-periodic emission in the gamma-ray band. The source is also a very high energy (VHE; >100 GeV) gamma-ray emitter. To better understand its properties and identify the underlying physical processes driving its variability, the MAGIC Collaboration initiated a multiyear, multiwavelength monitoring campaign in 2015 involving the OVRO 40-m and Medicina radio telescopes, REM, KVA, and the MAGIC telescopes, Swift and Fermi satellites, and the WEBT network. The analysis presented in this paper uses data until 2017 and focuses on the characterization of the variability. The gamma-ray data show a (hint of a) periodic signal compatible with literature, but the X-ray and VHE gamma-ray data do not show statistical evidence for a periodic signal. In other bands, the data are compatible with the gamma-ray period, but with a relatively high p-value. The complex connection between the low- and high-energy emission and the non-monochromatic modulation and changes in flux suggests that a simple one-zone model is unable to explain all the variability. Instead, a model including a periodic component along with multiple emission zones is required.

DOI： 10.1093/mnras/stae649

Performance and first measurements of the MAGIC stellar intensity interferometer Open Access

S. Abe, J. Abhir, V. A. Acciari, A. Aguasca-Cabot, I. Agudo, T. Aniello, S. Ansoldi, L. A. Antonelli, A. Arbet Engels, C. Arcaro, M. Artero, K. Asano, A. Babić, A. Baquero, U. Barres De Almeida, J. A. Barrio, I. Batković, A. Bautista, J. Baxter, J. Becerra González, E. Bernardini, M. Bernardos, J. Bernete, A. Berti, J. Besenrieder, C. Bigongiari, A. Biland, O. Blanch, G. Bonnoli, Bošnjak, I. Burelli, G. Busetto, A. Campoy-Ordaz, A. Carosi, R. Carosi, M. Carretero-Castrillo, G. Ceribella, Y. Chai, A. Cifuentes, E. Colombo, J. L. Contreras, J. Cortina, S. Covino, G. D'Amico, V. D'Elia, P. Da Vela, F. Dazzi, A. De Angelis, B. De Lotto, R. De Menezes, A. Del Popolo, M. Delfino, J. Delgado, C. Delgado Mendez, F. Di Pierro, L. Di Venere, D. Dominis Prester, A. Donini, D. Dorner, M. Doro, D. Elsaesser, G. Emery, J. Escudero, L. Fariña, A. Fattorini, L. Foffano, L. Font, S. Fröse, S. Fukami, Y. Fukazawa, R. J. García López, M. Garczarczyk, S. Gasparyan, M. Gaug, J. G. Giesbrecht Pai V A, N. Giglietto, F. Giordano, P. Gliwny, T. Gradetzke, R. Grau, D. Green, J. G. Green, P. Günther, D. Hadasch, A. Hahn, T. Hassan, L. Heckmann, J. Herrera, D. Hrupec, M. Hütten, R. Imazawa, K. Ishio, I. Jiménez Martínez, J. Jormanainen, T. Kayanoki, D. Kerszberg, G. W. Kluge, Y. Kobayashi, P. M. Kouch, H. Kubo

Monthly Notices of the Royal Astronomical Society Vol. 529 ( 4 ) page： 4387 - 4404 2024.3

Language：English Publishing type：Research paper (scientific journal)

In recent years, a new generation of optical intensity interferometers has emerged, leveraging the existing infrastructure of Imaging Atmospheric Cherenkov Telescopes (IACTs). The MAGIC telescopes host the MAGIC-SII system (Stellar Intensity Interferometer), implemented to investigate the feasibility and potential of this technique on IACTs. After the first successful measurements in 2019, the system was upgraded and now features a real-time, dead-time-free, 4-channel, GPU-based correlator. These hardware modifications allow seamless transitions between MAGIC's standard very-high-energy gamma-ray observations and optical interferometry measurements within seconds. We establish the feasibility and potential of employing IACTs as competitive optical Intensity Interferometers with minimal hardware adjustments. The measurement of a total of 22 stellar diameters are reported, 9 corresponding to reference stars with previous comparable measurements, and 13 with no prior measurements. A prospective implementation involving telescopes from the forthcoming Cherenkov Telescope Array Observatory's Northern hemisphere array, such as the first prototype of its Large-Sized Telescopes, LST-1, is technically viable. This integration would significantly enhance the sensitivity of the current system and broaden the UV-plane coverage. This advancement would enable the system to achieve competitive sensitivity with the current generation of long-baseline optical interferometers over blue wavelengths.

DOI： 10.1093/mnras/stae697

Silicon photomultipliers for the SST camera of the Cherenkov Telescope Array

Depaoli, D; Lapington, J; Leach, S; Okumura, A; Sofia, I; Tajima, H

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT Vol. 1060 2024.3

Language：English Publishing type：Research paper (scientific journal) Publisher：Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment

The Cherenkov Telescope Array Observatory (CTAO) will be the major global observatory for gamma-ray astronomy over the next decade and beyond. It will consist of two arrays of telescopes of different sizes, one for each hemisphere, and will be sensitive to gamma rays in the energy range from a few tens of GeV to hundreds of TeV. The Small-Sized Telescopes (SSTs) are a crucial component of the southern array, as they will extend the sensitivity of the observatory to the highest energies. Their focal plane will be equipped with 2048 Silicon Photomultiplier (SiPM) pixels, each one read independently by a state-of-the-art full waveform sampling readout. These solid-state sensors offer advantages over the traditional photomultiplier tubes, such as lower operating voltage, higher photon detection efficiency, and tolerance to bright illumination. In particular, they are the best choice for a small and compact camera such as the SST one. After a detailed comparative study, LVR3-type SiPMs from Hamamatsu Photonics were selected, with an active area of 6 mm × 6 mm, a microcell of 50 μm and without a protective coating, for optimum performance. The sensors demonstrated to have a higher photon detection efficiency and a lower crosstalk compared to the competitors, alongside a low dark count rate. In this contribution, we present the selection process and the latest measurements performed on the SiPMs mounted on the SST Camera module.

DOI： 10.1016/j.nima.2023.169047

Multi-year characterisation of the broad-band emission from the intermittent extreme BL Lac 1ES 2344+514

Abe, H; Abe, S; Acciari, VA; Agudo, I; Aniello, T; Ansoldi, S; Antonelli, LA; Engels, AA; Arcaro, C; Artero, M; Asano, K; Baack, D; Babic, A; Baquero, A; de Almeida, UB; Batkovic, I; Baxter, J; González, JB; Bernardini, E; Bernete, J; Berti, A; Besenrieder, J; Bigongiari, C; Biland, A; Blanch, O; Bonnoli, G; Bosnjak, Z; Burelli, I; Busetto, G; Campoy-Ordaz, A; Carosi, A; Carosi, R; Carretero-Castrillo, M; Castro-Tirado, AJ; Chai, Y; Cifuentes, A; Cikota, S; Colombo, E; Contreras, JL; Cortina, J; Covino, S; D'Amico, G; D'Ammando, F; D'Elia, V; Da Vela, P; Dazzi, F; De Angelis, A; De Lotto, B; Del Popolo, A; Delfino, M; Delgado, J; Mendez, CD; Depaoli, D; Di Pierro, F; Di Venere, L; Prester, DD; Dorner, D; Doro, M; Elsaesser, D; Emery, G; Escudero, J; Fariña, L; Fattorini, A; Foffano, L; Font, L; Fukami, S; Fukazawa, Y; López, RJG; Gasparyan, S; Gaug, M; Paiva, JGG; Giglietto, N; Giordano, F; Gliwny, P; Grau, R; Green, JG; Hadasch, D; Hahn, A; Heckmann, L; Herrera, J; Hrupec, D; Hütten, M; Imazawa, R; Inada, T; Iotov, R; Ishio, K; Martínez, IJ; Jormanainen, J; Kerszberg, D; Kluge, GW; Kobayashi, Y; Kouch, PM; Kubo, H; Kushida, J; Lezáun, ML; Lamastra, A; Leone, F; Lindfors, E; Linho, L; Lombardi, S; Longo, F; López-Moya, M; López-Oramas, A; Loporchio, S; Lorini, A; Fraga, BMD; Majumdar, P; Makariev, M; Maneva, G; Mang, N; Manganaro, M; Mariotti, M; Martínez, M; Martínez-Chicharro, M; Mas-Aguilar, A; Mazin, D; Menchiari, S; Mender, S; Miceli, D; Miener, T; Miranda, JM; Mirzoyan, R; González, MM; Molina, E; Mondal, HA; Moralejo, A; Morcuende, D; Nakamori, T; Nanci, C; Neustroev, V; Nigro, C; Nikolic, L; Nishijima, K; Ekoume, TN; Noda, K; Nozaki, S; Ohtani, Y; Okumura, A; Otero-Santos, J; Paiano, S; Palatiello, M; Paneque, D; Paoletti, R; Paredes, JM; Pavlovic, D; Persic, M; Pihet, M; Pirola, G; Podobnik, F; Moroni, PGP; Prandini, E; Principe, G; Priyadarshi, C; Rhode, W; Ribó, M; Rico, J; Righi, C; Sahakyan, N; Saito, T; Satalecka, K; Saturni, FG; Schleicher, B; Schmidt, K; Schmuckermaier, F; Schubert, JL; Schweizer, T; Sciaccaluga, A; Sitarek, J; Spolon, A; Stamerra, A; Striskovic, J; Strom, D; Suda, Y; Tajima, H; Takeishi, R; Tavecchio, F; Temnikov, P; Terauchi, K; Terzic, T; Teshima, M; Tosti, L; Truzzi, S; Tutone, A; Ubach, S; van Scherpenberg, J; Ventura, S; Verguilov, V; Viale, I; Vigorito, CF; Vitale, V; Walter, R; Wunderlich, C; Yamamoto, T; Perri, M; Verrecchia, F; Leto, C; Das, S; Chatterjee, R; Raiteri, CM; Villata, M; Semkov, E; Ibryamov, S; Bachev, R; Strigachev, A; Damljanovic, G; Vince, O; Jovanovic, MD; Stojanovic, M; Larionov, VM; Grishina, TS; Kopatskaya, EN; Larionova, EG; Morozova, DA; Savchenko, SS; Troitskiy, IS; Troitskaya, YV; Vasilyev, AA; Chen, WP; Hou, WJ; Lin, CS; Tsai, A; Jorstad, SG; Weaver, ZR; Acosta-Pulido, JA; Carnerero, MI; Carosati, D; Kurtanidze, SO; Kurtanidze, OM; Jordan, B; Ivanidze, RZ; Gazeas, K; Vrontaki, K; Hovatta, T; Liodakis, I; Readhead, ACS; Kiehlmann, S; Zheng, W; Filippenko, AV; Ramazani, VF

ASTRONOMY & ASTROPHYSICS Vol. 682 2024.2

Language：English Publishing type：Research paper (scientific journal) Publisher：Astronomy and Astrophysics

Aims. The BL Lac 1ES 2344+514 is known for temporary extreme properties characterised by a shift of the synchrotron spectral energy distribution (SED) peak energy νsynch;p above 1 keV. While those extreme states have only been observed during high flux levels thus far, additional multi-year observing campaigns are required to achieve a coherent picture. Here, we report the longest investigation of the source from radio to very high energy (VHE) performed so far, focussing on a systematic characterisation of the intermittent extreme states. Methods.We organised a monitoring campaign covering a 3-year period from 2019 to 2021.Morethan ten instruments participated in the observations in order to cover the emission from radio to VHE. In particular, sensitive X-ray measurements by XMM-Newton, NuSTAR, and AstroSat took place simultaneously with multi-hour MAGIC observations, providing an unprecedented constraint of the two SED components for this blazar. Results. While our results confirm that 1ES 2344+514 typically exhibits νsynch;p > 1 keV during elevated flux periods, we also find periods where the extreme state coincides with low flux activity. A strong spectral variability thus happens in the quiescent state, and is likely caused by an increase in the electron acceleration efficiency without a change in the electron injection luminosity. On the other hand, we also report a strong X-ray flare (among the brightest for 1ES 2344+514) without a significant shift of νsynch;p. During this particular flare, the X-ray spectrum is among the softest of the campaign. It unveils complexity in the spectral evolution, where the common harder-when-brighter trend observed in BL Lacs is violated. By combining Swift-XRT and Swift-UVOT measurements during a low and hard X-ray state, we find an excess of the UV flux with respect to an extrapolation of the X-ray spectrum to lower energies. This UV excess implies that at least two regions significantly contribute to the infrared/optical/ultraviolet/X-ray emission. Using the simultaneous MAGIC, XMM-Newton, NuSTAR, and AstroSat observations, we argue that a region possibly associated with the 10 GHz radio core may explain such an excess. Finally, we investigate a VHE flare, showing an absence of simultaneous variability in the 0.3-2 keV band. Using time-dependent leptonic modelling, we show that this behaviour, in contradiction to single-zone scenarios, can instead be explained by a two-component model.

DOI： 10.1051/0004-6361/202347845

MAGIC detection of GRB 201216C at z=1.1

Abe, H; Abe, S; Acciari, VA; Aguda, ; Aniello, T; Ansoldi, S; Antonelli, LA; Engels, AA; Arcaro, C; Artero, M; Asano, K; Baack, D; Babic, A; Baquero, A; de Almeida, UB; Barrio, JA; Batkovic, I; Baxter, J; González, JB; Bednarek, W; Bernardini, E; Bernete, J; Berti, A; Besenrieder, J; Bigongiari, C; Biland, A; Blanch, O; Bonnoli, G; Bosnjak, Z; Burelli, I; Busetto, G; Campoy-Ordaz, A; Carosi, A; Carosi, R; Carretero-Castrillo, M; Castro-Tirado, AJ; Ceribella, G; Chai, Y; Cifuentes, A; Cikota, S; Colombo, E; Contreras, JL; 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, CD; Depaoli, D; Di Pierro, F; Di Venere, L; Prester, DD; Donini, A; Dorner, D; Doro, M; Elsaesser, D; Emery, G; Escudero, J; Fariña, L; Fattorini, A; Foffano, L; Font, L; Fukami, S; Fukazawa, Y; López, RJG; Garczarczyk, M; Gasparyan, S; Gaug, M; Paiva, JGG; Giglietto, N; Giordano, F; Gliwny, P; Godinovic, N; Grau, R; Green, D; Green, JG; Hadasch, D; Hahn, A; Hassan, T; Heckmann, L; Herrera, J; Hrupec, D; Hütten, M; Imazawa, R; Inada, T; Iotov, R; Ishio, K; Martínez, IJ; Jormanainen, J; Kerszberg, D; Kluge, GW; Kobayashi, Y; Kouch, PM; Kubo, H; Kushida, J; Lezáun, ML; Lamastra, A; 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, BMD; Majumdar, P; Makariev, M; Maneva, G; Mang, N; Manganaro, M; Mangano, S; Mannheim, K; Mariotti, M; Martínez, M; Mas-Aguilar, A; Mazin, D; Menchiari, S; Mender, S; Micanovic, S; Miceli, D; Miener, T; Miranda, JM; Mirzoyan, R; González, MM; Molina, E; Mondal, HA; Moralejo, A; Morcuende, D; Nanci, C; Nava, L; Neustroev, V; Rosillo, MN; Nigro, C; Nikolic, L; Nilsson, K; Nishijima, K; Ekoume, TN; Noda, K; Nozaki, S; Ohtani, Y; Okumura, A; Otero-Santos, J; Paiano, S; Palatiello, M; Paneque, D; Paoletti, R; Paredes, JM; Pavletic, L; Pavlovic, D; Persic, M; Pihet, M; Pirola, G; Podobnik, F; Moroni, PGP; Prandini, E; Principe, G; Priyadarshi, C; Rhode, W; Ribó, M; Rico, J; Righi, C; Sahakyan, N; Saito, T; Satalecka, K; Saturni, FG; Schleicher, B; Schmidt, K; Schmuckermaier, F; Schubert, JL; Schweizer, T; Sciaccaluga, A; Sitarek, J; Sliusar, V; Sobczynska, D; Spolon, A; Stamerra, A; Striskovic, J; Strom, D; Strzys, M; Suda, Y; Suutarinen, S; Tajima, H; Takahashi, M; Takeishi, R; Tavecchio, F; Temnikov, P; Terauchi, K; Terzic, T; Teshima, M; Tosti, L; Truzzi, S; Tutone, A; Ubach, S; van Scherpenberg, J; Acosta, MV; Ventura, S; Verguilov, V; Viale, I; Vigorito, CF; Vitale, V; Vovk, I; Walter, R; Will, M; Yamamoto, T; Gomboc, A; Jordana-Mitjans, N; Melandri, A; Mundell, CG; Shrestha, M; Steele, IA

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY Vol. 527 ( 3 ) page： 5856 - 5867 2024.1

Language：English Publishing type：Research paper (scientific journal) Publisher：Monthly Notices of the Royal Astronomical Society

Gamma-ray bursts (GRBs) are explosive transient events occurring at cosmological distances, releasing a large amount of energy as electromagnetic radiation over several energy bands. We report the detection of the long GRB 201216C by the MAGIC telescopes. The source is located at z = 1.1 and thus it is the farthest one detected at very high energies. The emission above 70 GeV of GRB 201216C is modelled together with multiwavelength data within a synchrotron and synchrotron self-Compton (SSC) scenario. We find that SSC can explain the broad-band data well from the optical to the very-high-energy band. For the late-time radio data, a different component is needed to account for the observed emission. Differently from previous GRBs detected in the very-high-energy range, the model for GRB 201216C strongly favours a wind-like medium. The model parameters have values similar to those found in past studies of the afterglows of GRBs detected up to GeV energies.

DOI： 10.1093/mnras/stad2958

Performance of the MAGIC stellar intensity interferometer and expansion to MAGIC + CTAO-LST1 stellar intensity interferometer

Cifuentes A., Acciari V.A., Barnes F., Chon G., Colombo E., Cortina J., Delgado C., Díaz C., Fiori M., Fink D., Hassan T., Martínez I.J., Jorge I., Kerszberg D., Lyard E., Martínez G., Mirzoyan R., Polo M., Produit N., Rodríguez-Vázquez J.J., Saha P., Schweizer T., Strom D., Walter R., Wunderlich C.W., Abe K., Abe S., Abhir J., Abhishek A., Aguasca-Cabot A., Agudo I., Aniello T., Ansoldi S., Antonelli L.A., Engels A.A., Arcaro C., Artero M., Asano K., Babić A., de Almeida U.B., Barrio J.A., Batković I., Bautista A., Baxter J., González J.B., Bednarek W., Bernardini E., Bernete J., Berti A., Besenrieder J., Bigongiari C., Biland A., Blanch O., Bonnoli G., Bošnjak , Bronzini E., Burelli I., Busetto G., Campoy-Ordaz A., Carosi A., Carosi R., Carretero-Castrillo M., Castro-Tirado A.J., Cerasole D., Ceribella G., Chai Y., Chilingarian A., Contreras J.L., Covino S., D'Amico G., D'Elia V., Da Vela P., Dazzi F., De Angelis A., De Lotto B., de Menezes R., Delfino M., Delgado J., Mendez C.D., Di Pierro F., Di Tria R., Di Venere L., Prester D.D., Donini A., Dorner D., Doro M., Elsaesser D., Escudero J., Fariña L., Fattorini A., Foffano L., Font L., Fröse S., Fukami S., Fukazawa Y., López R.J.G., Garczarczyk M., Gasparyan S., Gaug M., Paiva J.G.G.

Proceedings of SPIE - The International Society for Optical Engineering Vol. 13095 2024

Language：English Publishing type：Research paper (scientific journal) Publisher：Proceedings of SPIE - The International Society for Optical Engineering

A new generation of optical intensity interferometers are emerging in recent years taking advantage of the existing infrastructure of Imaging Atmospheric Cherenkov Telescopes (IACTs). The MAGIC SII (Stellar Intensity Interferometer) in La Palma, Spain, has been operating since its first successful measurements in 2019 and its current design allows it to operate regularly. The current setup is ready to follow up on bright optical transients, as changing from regular gamma-ray observations to SII mode can be done in a matter of minutes. A paper studying the system performance, first measurements and future upgrades has been recently published. MAGIC SII's first scientific results are the measurement of the angular size of 22 stars, 13 of which with no previous measurements in the B band. More recently the Large Sized Telescope prototype from the Cherenkov Telescope Array Observatory (CTAOLST1) has been upgraded to operate together with MAGIC as a SII, leading to its first correlation measurements at the beginning of 2024. MAGIC+CTAO-LST1 SII will be further upgraded by adding the remaining CTAO-LSTs at the north site to the system (which are foreseen to be built by the end of 2025). MAGIC+CTAO-LST1 SII shows a feasible technical solution to extend SII to the whole CTAO.

DOI： 10.1117/12.3016905

Status of the Small-Sized Telescopes programme for the Cherenkov Telescope Array Observatory

Trois A., Dournaux J., Scuderi S., White R., Tagliaferri G., Proserpio L., Tosti G., Bruno P., Cailleux J., Conforti V., El Mouden A., De Frondat F., Gargano C., Germani S., Gianotti F., Giavitto G., Giordano V., Grassi L., Iovenitti S., Laporte P., La Palombara N., Lessio L., Leto G., Marchetti A., Millul R., Molfese C., Russo F., Saturni F., Sironi G., Antonelli A., Funk S., Hinton J., Pareschi G., Sol H., Able M., Attinà P., Barcelo M., Baryshev A., Chadwick P., Depaoli D., Einecke S., Lapington J., Lee S., Okumura A., Rol E., Rowell G., Schaefer J., Sofia I., Tajima H., Watson J., Wohlleben F., Zanmar Sanchez R., Zink A., Balbo M., Bang S., Bekema M., Bellassai G., Berge D., Bigongiari C., Bonnoli G., Brown A., Bulgarelli A., Cappi M., Caraveo P., Cotter G., Cristofari P., Falceta-Gonçalves D., De Gouveia Dal Pino E., De Simone N., del Valle M.V., Fermino C., Giuliani A., Greenshaw T., Kowal G., Lloyd S., Lombardi S., Lucarelli F., Martinetti E., Mineo T., Nayak A., Oughton W., Penno M., Righi C., Ross D., Rulten C., Santos-Lima R., Schwab B., Sliusar V., Stamerra A., Takahashi M., Tavecchio F., Vecchi M., Vercellone S., Vink J., Walter R., Zampieri L., Zech A.

Proceedings of SPIE - The International Society for Optical Engineering Vol. 13094 2024

Language：English Publishing type：Research paper (scientific journal) Publisher：Proceedings of SPIE - The International Society for Optical Engineering

The Cherenkov Telescope Array Observatory (CTAO) will include telescopes of three different sizes, the smallest of which are the Small-Sized Telescopes (SSTs). In particular, the SSTs will be installed at the southern site of CTAO, on the Chilean Andes, and will cover the highest energy range of CTAO (up to ~300 TeV). The SSTs are developed by an international consortium of institutes that will provide them as an in-kind contribution to CTAO. The optical design of the SSTs is based on a Schwarzschild-Couder-like dual-mirror polynomial configuration, with a primary aperture of 4.3m diameter. They are equipped with a focal plane camera based on SiPM detectors covering a field of view of ~9°. The preliminary design of the SST telescopes was evaluated and approved during the Product Review (PR) organised with CTAO in February 2023. The SST project is now going through a consolidation phase leading to the finalisation and submission of the final design to the Critical Design Review (CDR), expected to occur late 2024, after which the production and construction of the telescopes will begin leading to a delivery of the telescopes to CTAO southern site starting at the end of 2025-early 2026 onward. In this contribution we will present the progress of the SST programme, including the results of the PDR, the consolidation phase of the project and the plan up to the on-site integration of the telescopes.

DOI： 10.1117/12.3019790

Performance of the joint LST-1 and MAGIC observations evaluated with Crab Nebula data

Abe, H; Abe, K; Abe, S; Acciari, VA; Aguasca-Cabot, A; Agudo, I; Crespo, NA; Aniello, T; Ansoldi, S; Antonelli, LA; Aramo, C; Arbet-Engels, A; Arcaro, C; Artero, M; Asano, K; Aubert, P; Baack, D; Babic, A; Baktash, A; Bamba, A; Larriva, AB; Baroncelli, L; de Almeida, UB; Barrio, JA; Batkovic, I; Baxter, J; González, JB; Bednarek, W; Bernardini, E; Bernardos, MI; Medrano, JB; Berti, A; Besenrieder, J; Bhattacharjee, P; Biederbeck, N; Bigongiari, C; Biland, A; Bissaldi, E; Blanch, O; Bonnoli, G; Bordas, P; Bosnjak, Z; Bulgarelli, A; Burelli, I; Burmistrov, L; Buscemi, M; Busetto, G; Ordaz, AC; Cardillo, M; Caroff, S; Carosi, A; Carosi, R; Carrasco, MS; Carretero-Castrillo, M; Cassol, F; Castro-Tirado, AJ; Cauz, D; Cerasole, D; Ceribella, G; Chai, Y; Cheng, K; Chiavassa, A; Chikawa, M; Chytka, L; Cifuentes, A; Cikota, S; Colombo, E; Contreras, JL; Cornelia, A; Cortina, J; Costantini, H; Covino, S; D'Amico, G; D'Elia, V; Da Vela, P; Dalchenko, M; Dazzi, F; De Angelis, A; de Lavergne, MD; De Lotto, B; De Lucia, M; de Menezes, R; Del Peral, L; Del Popolo, A; Deleglise, G; Delfino, M; Mendez, CD; Mengual, JD; della Volpe, D; Dellaiera, M; Depaoli, D; De Angelis, A; Di Piano, A; Di Pierro, F; Di Pilato, A; Di Tria, R; Di Venere, L; Dominik, RM; Prester, DD; Donini, A; Dorner, D; Doro, M; Díaz, C; Eisenberger, L; Elsässer, D; Emery, G; Escudero, J; Ramazani, VF; Fariña, L; Fattorini, A; Ferrara, G; Ferrarotto, F; Fiasson, A; Foffano, L; Font, L; Coromina, LF; Fröse, S; Fukami, S; Fukazawa, Y; López, RJG; Garcia, E; Garczarczyk, M; Gasbarra, C; Gasparrini, D; Gasparyan, S; Gaug, M; Geyer, D; Paiva, JGG; Giglietto, N; Giordano, F; Gliwny, P; Godinovic, N; Grau, R; Green, D; Green, JG; Gunji, S; Günther, P; Hackfeld, J; Hadasch, D; Hahn, A; Hashiyama, K; Hassan, T; Hayashi, K; Heckmann, L; Heller, M; Llorente, JH; Hirotani, K; Hoffmann, D; Horns, D; Houles, J; Hrabovsky, M; Hrupec, D; Hui, D; Hütten, M; Iarlori, M; Imazawa, R; Inada, T; Inome, Y; Ioka, K; Iori, M; Iotov, R; Ishio, K; Jacquemont, M; Martínez, IJ; Jobst, E; Jormanainen, J; Jurysek, J; Kagaya, M; Karas, V; Katagiri, H; Kataoka, J; Kerszberg, D; Kluge, GW; Kobayashi, Y; Kohri, K; Kong, A; Kouch, PM; Kubo, H; Kushida, J; Lainez, M; Lamanna, G; Lamastra, A; Le Flour, T; Leone, F; Lindfors, E; Linhoff, L; Linhoff, M; Lombardi, S; Longo, F; Loporchio, S; Lorini, A; Bahilo, JL; Luque-Escamilla, PL; Lyard, E; Lezáun, ML; López-Coto, R; López-Moya, M; López-Oramas, A; Fraga, BMD; Majumdar, P; Makariev, M; Mandat, D; Maneva, G; Manganaro, M; Mangano, S; Mang, N; Manicò, G; Mannheim, K; Mariotti, M; Marquez, P; Marsella, G; Martinez, O; Martínez, G; Martínez, M; Martí, J; Mas-Aguilar, A; Maurin, G; Mazin, D; Menchiari, S; Mender, S; Guillen, EM; Micanovic, S; Miceli, D; Miener, T; Miranda, JM; Mirzoyan, R; Mizuno, T; Micanovic, S; González, MM; Molina, E; Mondal, HA; Montaruli, T; Monteiro, I; Moralejo, A; Morcuende, D; Morselli, A; Moya, V; Muraishi, H; Murase, K; Nagataki, S; Nakamori, T; Nanci, C; Neronov, A; Neustroev, V; Nickel, L; Rosillo, MN; Nigro, C; Nikolic, L; Nilsson, K; Nishijima, K; Ekoume, TN; Noda, K; Nosek, D; Nozaki, S; Ohishi, M; Ohtani, Y; Oka, T; Okumura, A; Orito, R; Otero-Santos, J; Paiano, S; Palatiello, M; Paneque, D; Pantaleo, FR; Paoletti, R; Paredes, JM; Pavletic, L; Pech, M; Pecimotika, M; Peresano, M; Persic, M; Pfeiffle, F; Pietropaolo, E; Pihet, M; Pirola, G; Plard, C; Podobnik, F; Poireau, V; Polo, M; Pons, E; Moroni, PGP; Prandini, E; Prast, J; Principe, G; Priyadarshi, C; Prouza, M; Rando, R; Rhode, W; Ribó, M; Rico, J; Righi, C; Rizi, V; Fernandez, GR; Frías, MDR; Sahakyan, N; Saito, T; Sakurai, S; Sanchez, DA; Satalecka, K; Sato, M; Sato, Y; Saturni, FG; Savchenko, V; Schleicher, B; Schmidt, K; Schmuckermaier, F; Schubert, JL; Schussler, F; Schweizer, T; Sciaccaluga, A; Siegert, T; Silvia, R; Sitarek, J; Sliusar, V; Sobczynska, D; Spolon, A; Stamerra, A; Striskovic, J; Strom, D; Strzys, M; Suda, Y; Suutarinen, S; Saric, T; Tajima, H; Takahashi, H; Takahashi, M; Takata, J; Takeishi, R; Tam, PHT; Tanaka, SJ; Tateishi, D; Tavecchio, F; Temnikov, P; Terada, Y; Terauchi, K; Terzic, T; Teshima, M; Tluczykont, M; Tokanai, F; Torres, DF; Tosti, L; Travnicek, P; Truzzi, S; Tutone, A; Ubach, S; Vacula, M; Vallania, P; van Scherpenberg, J; Acosta, MV; Ventura, S; Verguilov, V; Viale, I; Vigliano, A; Vigorito, CF; Visentin, E; Vitale, V; Voutsinas, G; Vovk, I; Vuillaume, T; Acosta, M; Walter, R; Wei, Z; Will, M; Yamamoto, T; Yamazaki, R; Yoshida, T; Yoshikoshi, T; Zywucka, N

ASTRONOMY & ASTROPHYSICS Vol. 680 2023.12

Language：English Publishing type：Research paper (scientific journal) Publisher：Astronomy and Astrophysics

Aims. Large-Sized Telescope 1 (LST-1), the prototype for the Large-Sized Telescope at the upcoming Cherenkov Telescope Array Observatory, is concluding its commissioning phase at the Observatorio del Roque de los Muchachos on the island of La Palma. The proximity of LST-1 to the two MAGIC (Major Atmospheric Gamma Imaging Cherenkov) telescopes makes it possible to carry out observations of the same gamma-ray events with both systems. Methods. We describe the joint LST-1+MAGIC analysis pipeline and used simultaneous Crab Nebula observations and Monte Carlo simulations to assess the performance of the three-telescope system. The addition of the LST-1 telescope allows for the recovery of events in which one of the MAGIC images is too dim to survive analysis quality cuts. Results. Thanks to the resulting increase in the collection area and stronger background rejection, we found a significant improvement in sensitivity, allowing for the detection of 30% weaker fluxes in the energy range between 200 GeV and 3 TeV. The spectrum of the Crab Nebula, reconstructed in the energy range between ∼60 GeV and ∼10 TeV, is in agreement with previous measurements.

DOI： 10.1051/0004-6361/202346927

Star tracking for pointing determination of Imaging Atmospheric Cherenkov Telescopes

Abe, K; Abe, S; Aguasca-Cabot, A; Agudo, I; Crespo, NA; Antonelli, LA; Aramo, C; Arbet-Engels, A; Cornelia, A; Artero, M; Asano, K; Aubert, P; Baktash, A; Bamba, A; Larriva, AB; Baroncelli, L; de Almeida, UB; Barrio, JA; Batkovic, I; Baxter, J; Gonzalez, JB; Bernardini, E; Bernardos, M; Medrano, JB; Berti, A; Bhattacharjee, P; Biederbeck, N; Bigongiari, C; Bissaldi, E; Blanch, O; Bonnoli, G; Bordas, P; Bulgarelli, A; Burelli, ; Burmistrov, L; Buscemi, M; Cardillo, M; Caroff, S; Carosi, A; Cassol, F; Cauz, D; Ceribella, G; Chai, Y; Cheng, K; Chiavassa, A; Chikawa, M; Chytka, L; Cifuentes, A; Contreras, JL; Cortina, J; Costantini, H; Dalchenko, M; De Angelis, A; de Lavergne, MD; De Lotto, B; de Menezes, R; Deleglise, G; Delgado, C; Mengual, JD; della Volpe, D; Dellaiera, M; Di Piano, A; Di Pierro, F; Di Tria, R; Di Venere, L; Diaz, C; Dominik, RM; Prester, DD; Donini, A; Dorner, D; Doro, M; Elsässer, D; Emery, G; Escudero, J; Ramazani, VF; Ferrara, G; Ferrarotto, F; Fiasson, A; Coromina, LF; Fröse, S; Fukami, S; Fukazawa, Y; Garcia, E; Lopez, RG; Gasbarra, C; Gasparrini, D; Geyer, D; Paiva, JG; Giglietto, N; Giordano, F; Giro, E; Gliwny, P; Godinovic, N; Grau, R; Green, D; Green, J; Gunji, S; Guenther, P; Hackfeld, J; Hadasch, D; Hahn, A; Hashiyama, K; Hassan, T; Hayashi, K; Heckmann, L; Heller, M; Llorente, JH; Hirotani, K; Hoffmann, D; Horns, D; Houles, J; Hrabovsky, M; Hrupec, D; Hui, D; Hütten, M; Iarlori, M; Imazawa, R; Inada, T; Inome, Y; Ioka, K; Iori, M; Ishio, K; Jacquemont, M; Martinez, IJ; Jurysek, J; Kagaya, M; Karas, V; Katagiri, H; Kataoka, J; Kerszberg, D; Kobayashi, Y; Kohri, K; Kong, A; Kubo, H; Kushida, J; Lainez, M; Lamanna, G; Lamastra, A; Le Flour, T; Linhoff, M; Longo, F; Lopez-Coto, R; Lopez-Oramas, A; Loporchio, S; Lorini, A; Luque-Escamilla, PL; Majumdar, P; Makariev, M; Mandat, D; Manganaro, M; Manico, G; Mannheim, K; Mariotti, M; Marquez, P; Marsella, G; Marti, J; Martinez, O; Martinez, G; Martinez, M; Mas-Aguilar, A; Maurin, G; Mazin, D; Guillen, EM; Micanovic, S; Miceli, D; Miener, T; Miranda, JM; Mirzoyan, R; Mizuno, T; Gonzalez, MM; Molina, E; Montaruli, T; Monteiro, I; Moralejo, A; Morcuende, D; Morselli, A; Muraishi, H; Murase, K; Nagataki, S; Nakamori, T; Nickel, L; Nievas, M; Nishijima, K; Noda, K; Nosek, D; Nozaki, S; Ohishi, M; Ohtani, Y; Oka, T; Okumura, A; Orito, R; Otero-Santos, J; Palatiello, M; Paneque, D; Pantaleo, FR; Paoletti, R; Paredes, JM; Pech, M; Pecimotika, M; Peresano, M; Pfeiffle, F; Pietropaolo, E; Pirola, G; Plard, C; Podobnik, F; Poireau, ; Polo, M; Pons, E; Prandini, E; Prast, J; Principe, G; Priyadarshi, C; Prouza, M; Rando, R; Rhode, W; Ribo, M; Rizi, V; Fernandez, GR; Saito, T; Sakurai, S; Sanchez, DA; Saric, T; Sato, Y; Saturni, FG; Schleicher, B; Schmuckermaier, F; Schubert, JL; Schussler, F; Schweizer, T; Sato, M; Siegert, T; Silvia, R; Sitarek, J; Sliusar, V; Spolon, A; Striskovic, J; Strzys, M; Suda, Y; Tajima, H; Takahashi, H; Takahashi, M; Takata, J; Takeishi, R; Tam, PHT; Tanaka, SJ; Tateishi, D; Temnikov, P; Terada, Y; Terauchi, K; Terzic, T; Teshima, M; Tluczykont, M; Tokanai, F; Torres, DF; Travnicek, P; Truzzi, S; Tutone, A; Vacula, M; Vallania, P; van Scherpenberg, J; Acosta, MV; Viale, ; Vigliano, A; Vigorito, CF; Vitale, V; Voutsinas, G; Vovk, I; Vuillaume, T; Walter, R; Wei, Z; Will, M; Yamamoto, T; Yamazaki, R; Yoshida, T; Yoshikoshi, T; Zywucka, N

ASTRONOMY & ASTROPHYSICS Vol. 679 2023.11

Language：English Publishing type：Research paper (scientific journal) Publisher：Astronomy and Astrophysics

We present a novel approach to the determination of the pointing of Imaging Atmospheric Cherenkov Telescopes (IACTs) using the trajectories of the stars in their camera s field of view. The method starts with the reconstruction of the star positions from the Cherenkov camera data, taking into account the point spread function of the telescope, to achieve a satisfying reconstruction accuracy of the pointing position. A simultaneous fit of all reconstructed star trajectories is then performed with the orthogonal distance regression (ODR) method. ODR allows us to correctly include the star position uncertainties and use the time as an independent variable. Having the time as an independent variable in the fit makes it better suitable for various star trajectories. This method can be applied to any IACT and requires neither specific hardware nor interface or special data-taking mode. In this paper, we use the Large-Sized Telescope (LST) data to validate it as a useful tool to improve the determination of the pointing direction during regular data taking. The simulation studies show that the accuracy and precision of the method are comparable with the design requirements on the pointing accuracy of the LST (=14''). With the typical LST event acquisition rate of 10 kHz, the method can achieve up to 50 Hz pointing monitoring rate, compared to O(1) Hz achievable with standard techniques. The application of the method to the LST prototype (LST-1) commissioning data shows the stable pointing performance of the telescope.

DOI： 10.1051/0004-6361/202347128

Observations of the Crab Nebula and Pulsar with the Large-sized Telescope Prototype of the Cherenkov Telescope Array

Abe, H; Abe, K; Abe, S; Aguasca-Cabot, A; Agudo, ; Crespo, NA; Antonelli, LA; Aramo, C; Arbet-Engels, A; Arcaro, C; Artero, M; Asano, K; Aubert, P; Baktash, A; Bamba, A; Larriva, AB; Baroncelli, L; de Almeida, UB; Barrio, JA; Batkovic, I; Baxter, J; González, JB; Bernardini, E; Bernardos, MI; Medrano, JB; Berti, A; Bhattacharjee, P; Biederbeck, N; Bigongiari, C; Bissaldi, E; Blanch, O; Bonnoli, G; Bordas, P; Borghese, A; Bulgarelli, A; Burelli, I; Buscemi, M; Cardillo, M; Caroff, S; Carosi, A; Cassol, F; Cauz, D; Ceribella, G; Chai, Y; Cheng, K; Chiavassa, A; Chikawa, M; Chytka, L; Cifuentes, A; Contreras, JL; Cortina, J; Costantini, H; D'Amico, G; Dalchenko, M; De Angelis, A; de Lavergne, MD; de Lotto, B; de Menezes, R; Deleglise, G; Delgado, C; Mengual, JD; della Volpe, D; Dellaiera, M; Depaoli, D; Di Piano, A; Di Pierro, F; Di Tria, R; Di Venere, L; Díaz, C; Dominik, RM; Prester, DD; Donini, A; Dorner, D; Doro, M; Elsässer, D; Emery, G; Escudero, J; Ramazani, VF; Ferrara, G; Ferrarotto, F; Fiasson, A; Coromina, LF; Fröse, S; Fukami, S; Fukazawa, Y; Garcia, E; López, RG; Gasbarra, C; Gasparrini, D; Geyer, F; Paiva, JG; Giglietto, N; Giordano, F; Giro, E; Gliwny, P; Godinovic, N; Grau, R; Green, D; Green, J; Gunji, S; Hackfeld, J; Hadasch, D; Hahn, A; Hashiyama, K; Hassan, T; Hayashi, K; Heckmann, L; Heller, M; Llorente, JH; Hirotani, K; Hoffmann, D; Horns, D; Houles, J; Hrabovsky, M; Hrupec, D; Hui, D; Hütten, M; Iarlori, M; Imazawa, R; Inada, T; Inome, Y; Ioka, K; Iori, M; Ishio, K; Iwamura, Y; Jacquemont, M; Martinez, IJ; Jurysek, J; Kagaya, M; Karas, V; Katagiri, H; Kataoka, J; Kerszberg, D; Kobayashi, Y; Kong, A; Kubo, H; Kushida, J; Lainez, M; Lamanna, G; Lamastra, A; Le Flour, T; Linhoff, M; Longo, F; López-Coto, R; López-Moya, M; López-Oramas, A; Loporchio, S; Lorini, A; Luque-Escamilla, PL; Majumdar, P; Makariev, M; Mandat, D; Manganaro, M; Manicò, G; Mannheim, K; Mariotti, M; Marquez, P; Marsella, G; Martí, J; Martinez, O; Martínez, G; Martínez, M; Marusevec, P; Mas-Aguilar, A; Maurin, G; Mazin, D; Guillen, EM; Micanovic, S; Miceli, D; Miener, T; Miranda, JM; Mirzoyan, R; Mizuno, T; Gonzalez, MM; Molina, E; Montaruli, T; Monteiro, I; Moralejo, A; Morcuende, D; Morselli, A; Mrakovcic, K; Murase, K; Nagai, A; Nagataki, S; Nakamori, T; Nickel, L; Nievas, M; Nishijima, K; Noda, K; Nosek, D; Nozaki, S; Ohishi, M; Ohtani, Y; Oka, T; Okazaki, N; Okumura, A; Orito, R; Otero-Santos, J; Palatiello, M; Paneque, D; Pantaleo, FR; Paoletti, R; Paredes, JM; Pech, M; Pecimotika, M; Peresano, M; Pérez, A; Pietropaolo, E; Pirola, G; Plard, C; Podobnik, F; Poireau, V; Polo, M; Pons, E; Prandini, E; Prast, J; Principe, G; Priyadarshi, C; Prouza, M; Rando, R; Rhode, W; Ribó, M; Rizi, V; Fernandez, GR; Ruíz, JE; Saito, T; Sakurai, S; Sanchez, DA; Saric, T; Sato, Y; Saturni, FG; Schleicher, B; Schmuckermaier, F; Schubert, JL; Schussler, F; Schweizer, T; Arroyo, MS; Silvia, R; Sitarek, J; Sliusar, V; Spolon, A; Striskovic, J; Strzys, M; Suda, Y; Sunada, Y; Tajima, H; Takahashi, H; Takahashi, M; Takata, J; Takeishi, R; Tam, PHT; Tanaka, SJ; Tateishi, D; Tejedor, LA; Temnikov, P; Terada, Y; Terauchi, K; Terzic, T; Teshima, M; Tluczykont, M; Tokanai, F; Torres, DF; Travnicek, P; Truzzi, S; Tutone, A; Uhlrich, G; Vacula, M; Vallania, P; van Scherpenberg, J; Acosta, MV; Verguilov, V; Viale, I; Vigliano, A; Vigorito, CF; Vitale, V; Voutsinas, G; Vovk, I; Vuillaume, T; Walter, R; Will, M; Yamamoto, T; Yamazaki, R; Yoshida, T; Yoshikoshi, T; Zywucka, N; Bernlöhr, K; Gueta, O; Kosack, K; Maier, G; Watson, J

ASTROPHYSICAL JOURNAL Vol. 956 ( 2 ) 2023.10

Language：English Publishing type：Research paper (scientific journal) Publisher：Astrophysical Journal

The Cherenkov Telescope Array (CTA) is a next-generation ground-based observatory for gamma-ray astronomy at very high energies. The Large-Sized Telescope prototype (LST-1) is located at the CTA-North site, on the Canary Island of La Palma. LSTs are designed to provide optimal performance in the lowest part of the energy range covered by CTA, down to ≃20 GeV. LST-1 started performing astronomical observations in 2019 November, during its commissioning phase, and it has been taking data ever since. We present the first LST-1 observations of the Crab Nebula, the standard candle of very-high-energy gamma-ray astronomy, and use them, together with simulations, to assess the performance of the telescope. LST-1 has reached the expected performance during its commissioning period—only a minor adjustment of the preexisting simulations was needed to match the telescope’s behavior. The energy threshold at trigger level is around 20 GeV, rising to ≃30 GeV after data analysis. Performance parameters depend strongly on energy, and on the strength of the gamma-ray selection cuts in the analysis: angular resolution ranges from 0.°12-0.°40, and energy resolution from 15%-50%. Flux sensitivity is around 1.1% of the Crab Nebula flux above 250 GeV for a 50 hr observation (12% for 30 minutes). The spectral energy distribution (in the 0.03-30 TeV range) and the light curve obtained for the Crab Nebula agree with previous measurements, considering statistical and systematic uncertainties. A clear periodic signal is also detected from the pulsar at the center of the Nebula.

DOI： 10.3847/1538-4357/ace89d

Sensitivity of the Cherenkov Telescope Array to spectral signatures of hadronic PeVatrons with application to Galactic Supernova Remnants

Acero, F; Acharyya, A; Adam, R; Aguasca-Cabot, A; Agudo, I; Aguirre-Santaella, A; Alfaro, J; Aloisio, R; Crespo, NA; Batista, RA; Amati, L; Amato, E; Ambrosi, G; Angüner, EO; Aramo, C; Arcaro, C; Armstrong, T; Asano, K; Ascasibar, Y; Aschersleben, J; Backes, M; Baktash, A; Balazs, C; Balbo, M; Ballet, J; Larriva, AB; Martins, VB; de Almeida, UB; Barrio, JA; Bastieri, D; Baxter, JR; Tjus, JB; Benbow, W; Bernardos-Martín, MI; Bernete, J; Berti, A; Bertucci, B; Beshley, V; Bhattacharjee, P; Bhattacharyya, S; Biland, A; Bissaldi, E; Biteau, J; Blanch, O; Bordas, P; Bottacini, E; Bregeon, J; Brose, R; Bucciantini, N; Bulgarelli, A; Capasso, M; Dolcetta, RAC; Caraveo, P; Cardillo, M; Carosi, R; Casanova, S; Cascone, E; Cassol, F; Catalani, F; Cerruti, M; Chadwick, P; Chaty, S; Chen, A; Chernyakova, M; Chiavassa, A; Chudoba, J; Coimbra-Araujo, C; Conforti, V; Contreras, JL; Costa, A; Costantini, H; Cristofari, P; Crocker, R; D'Amico, G; D'Ammando, F; De Angelis, A; De Caprio, V; Dal Pino, EMD; Wilhelmi, ED; de Souza, V; Delgado, C; della Volp, D; Depaoli, D; Di Girolamo, T; Di Pierro, F; Di Tria, R; Di Venere, L; Diebold, S; Djuvsland, JI; Donini, A; Doro, M; Dos Anjos, RDC; Dwarkadas, VV; Einecke, S; Elsässer, D; Emery, G; Evoli, C; Falceta-Goncalves, D; Fedorova, E; Fegan, S; Ferrand, G; Fiandrini, E; Filipovic, M; Fioretti, V; Fiori, M; Foffano, L; Fontaine, G; Fukami, S; Galanti, G; Galaz, G; Gammaldi, V; Gasbarra, C; Ghalumyan, A; Ghirlanda, G; Giarrusso, M; Giavitto, G; Giglietto, N; Giordano, F; Giroletti, M; Giuliani, A; Giunti, L; Godinovic, N; Coelho, JG; Gréaux, L; Green, D; Grondin, MH; Gueta, O; Gunji, S; Hassan, T; Heller, M; Hernández-Cadena, S; Hinton, J; Hnatyk, B; Hnatyk, R; Hoffmann, D; Hofmann, W; Holder, J; Horan, D; Horvath, P; Hrabovsky, M; Hrupec, D; Inada, T; Incardona, F; Inoue, S; Ishio, K; Jamrozy, M; Janecek, P; Martínez, IJ; Jin, W; Jung-Richardt, I; Jurysek, J; Kaaret, P; Karas, V; Katz, U; Kerszberg, D; Khélifi, B; Kieda, DB; Kissmann, R; Kleiner, T; Kluge, G; Kluzniak, W; Knödlseder, J; Kobayashi, Y; Kohri, K; Komin, N; Kornecki, P; Kubo, H; La Palombara, N; Láinez, M; Lamastra, A; Lapington, J; Lemoine-Goumard, M; Lenain, JP; Leone, F; Leto, G; Leuschner, F; Lindfors, E; Liodakis, I; Lohse, T; Lombardi, S; Longo, F; López-Coto, R; López-Moya, M; López-Oramas, A; Loporchio, S; Luque-Escamilla, PL; Macias, O; Mackey, J; Majumdar, P; Mandat, D; Manganaro, M; Manicò, G; Marconi, M; Martí, J; Martínez, G; Martinez, M; Martinez, O; Mello, AJTS; Menchiari, S; Meyer, DMA; Micanovic, S; Miceli, D; Miceli, M; Michalowski, J; Miener, T; Miranda, JM; Mitchell, A; Mode, B; Moderski, R; Mohrmann, L; Molina, E; Montaruli, T; Morcuende, D; Morlino, G; Morselli, A; Mosè, M; Moulin, E; Mukherjee, R; Munari, K; Murach, T; Nagai, A; Nagataki, S; Nemmen, R; Niemiec, J; Nieto, D; Rosillo, MN; Nikolajuk, M; Nishijima, K; Noda, K; Novosyadlyj, B; Nozaki, S; Ohishi, M; Ohm, S; Ohtani, Y; Okumura, A; Olmi, B; Ong, RA; Orienti, M; Orito, R; Orlandini, M; Orlando, E; Orlando, S; Ostrowski, M; Oya, I; Pantaleo, FR; Paredes, JM; Patricelli, B; Pecimotika, M; Peresano, M; Pérez-Romero, J; Persic, M; Petruk, O; Piano, G; Pietropaolo, E; Pirola, G; Pittori, C; Pohl, M; Ponti, G; Prandini, E; Principe, G; Priyadarshi, C; Pueschel, E; Pühlhofer, G; Pumo, ML; Quirrenbach, A; Rando, R; Razzaque, S; Reichherzer, P; Reimer, A; Reimer, O; Renaud, M; Reposeur, T; Ribó, M; Richtler, T; Rico, J; Rieger, F; Rigoselli, M; Riitano, L; Rizi, V; Roache, E; Romano, P; Romeo, G; Rosado, J; Rowell, G; Rudak, B; Sadeh, I; Safi-Harb, S; Saha, L; Sailer, S; Sánchez-Conde, M; Sarkar, S; Satalecka, K; Saturni, FG; Scherer, A; Schovánek, P; Schussler, F; Schwanke, U; Scuderi, S; Seglar-Arroyo, M; Sergijenko, O; Servillat, M; Shang, RY; Sharma, P; Siejkowski, H; Sliusar, V; Slowikowska, A; Sol, H; Specovius, A; Spencer, ST; Spengler, G; Stamerra, A; Stanic, S; Starecki, T; Starling, R; Stolarczyk, T; Pereira, LAS; Suda, Y; Suomijarvi, T; Sushch, I; Tajima, H; Tam, PHT; Tanaka, SJ; Tavecchio, F; Testa, V; Tian, W; Tibaldo, L; Torres, DF; Tothill, N; Vallage, B; Vallania, P; van Eldik, C; van Scherpenberg, J; Vandenbroucke, J; Acosta, MV; Vecchi, M; Vercellone, S; Verna, G; Viana, A; Vignatti, J; Vitale, V; Vodeb, V; Vorobiov, S; Vuillaume, T; Wagner, SJ; Walter, R; White, M; Wierzcholska, A; Will, M; Williams, D; Yang, L; Yoshida, T; Yoshikoshi, T; Zaharijas, G; Zampieri, L; Zavrtanik, D; Zavrtanik, M; Zhdanov, VI; Zivec, M

ASTROPARTICLE PHYSICS Vol. 150 2023.8

Language：English Publishing type：Research paper (scientific journal) Publisher：Astroparticle Physics

The local Cosmic Ray (CR) energy spectrum exhibits a spectral softening at energies around 3 PeV. Sources which are capable of accelerating hadrons to such energies are called hadronic PeVatrons. However, hadronic PeVatrons have not yet been firmly identified within the Galaxy. Several source classes, including Galactic Supernova Remnants (SNRs), have been proposed as PeVatron candidates. The potential to search for hadronic PeVatrons with the Cherenkov Telescope Array (CTA) is assessed. The focus is on the usage of very high energy γ-ray spectral signatures for the identification of PeVatrons. Assuming that SNRs can accelerate CRs up to knee energies, the number of Galactic SNRs which can be identified as PeVatrons with CTA is estimated within a model for the evolution of SNRs. Additionally, the potential of a follow-up observation strategy under moonlight conditions for PeVatron searches is investigated. Statistical methods for the identification of PeVatrons are introduced, and realistic Monte-Carlo simulations of the response of the CTA observatory to the emission spectra from hadronic PeVatrons are performed. Based on simulations of a simplified model for the evolution for SNRs, the detection of a γ-ray signal from in average 9 Galactic PeVatron SNRs is expected to result from the scan of the Galactic plane with CTA after 10 h of exposure. CTA is also shown to have excellent potential to confirm these sources as PeVatrons in deep observations with O(100) hours of exposure per source.

DOI： 10.1016/j.astropartphys.2023.102850

Sensitivity of the Cherenkov Telescope Array to TeV photon emission from the Large Magellanic Cloud

Acharyya, A; Adam, R; Aguasca-Cabot, A; Agudo, I; Aguirre-Santaella, A; Alfaro, J; Aloisio, R; Batista, RA; Amato, E; Angüner, EO; Aramo, C; Arcaro, C; Asano, K; Aschersleben, J; Ashkar, H; Backes, M; Baktash, A; Balazs, C; Balbo, M; Ballet, J; Bamba, A; Larriva, AB; Martins, VB; de Almeida, UB; Barrio, JA; Bastieri, D; Batista, P; Batkovic, I; Baxter, JR; Gonzalez, JB; Tjus, JB; Benbow, W; Bernardini, E; Martín, MIB; Medrano, JB; Berti, A; Bertucci, B; Beshley, V; Bhattacharjee, P; Bhattacharyya, S; Bigongiari, C; Biland, A; Bissaldi, E; Bocchino, F; Bordas, P; Borkowski, J; Bottacini, E; Böttcher, M; Bradascio, F; Brown, AM; Bulgarelli, A; Burmistrov, L; Caroff, S; Carosi, A; Carquín, E; Casanova, S; Cascone, E; Cassol, F; Cerruti, M; Chadwick, P; Chaty, S; Chen, A; Chiavassa, A; Chytka, L; Conforti, V; Cortina, J; Costa, A; Costantini, H; Cotter, G; Crestan, S; Cristofari, P; D'Ammando, F; Dalchenko, M; Dazzi, F; De Angelis, A; De Caprio, V; Dal Pino, EMD; De Martino, D; de Naurois, M; de Souza, V; del Valle, MV; Giler, AGD; Delgado, C; della Volpe, D; Depaoli, D; Di Girolamo, T; Di Piano, A; Di Pierro, F; Di Tria, R; Di Venere, L; Diebold, S; Doro, M; Dumora, D; Dwarkadas, VV; Eckner, C; Egberts, K; Emery, G; Escudero, J; Falceta-Goncalves, D; Fedorova, E; Fegan, S; Feng, Q; Ferenc, D; Ferrand, G; Fiandrini, E; Filipovic, M; Fioretti, V; Foffano, L; Fontaine, G; Fukui, Y; Gaggero, D; Galanti, G; Galaz, G; Gallozzi, S; Gammaldi, V; Garczarczyk, M; Gasbarra, C; Gasparrini, D; Ghalumyan, A; Giarrusso, M; Giavitto, G; Giglietto, N; Giordano, F; Giuliani, A; Glicenstein, JF; Goldoni, P; Coelho, JG; Granot, J; Green, D; Green, JG; Grondin, MH; Gueta, O; Hadasch, D; Hamal, P; Hassan, T; Hayashi, K; Heller, M; Cadena, SH; Hiroshima, N; Hnatyk, B; Hnatyk, R; Hofmann, W; Holder, J; Holler, M; Horan, D; Horvath, P; Hrabovsky, M; Hütten, M; Iarlori, M; Inada, T; Incardona, F; Inoue, S; Iocco, F; Jamrozy, M; Jin, W; Jung-Richardt, I; Jurysek, J; Kantzas, D; Karas, V; Katagiri, H; Kerszberg, D; Knödlseder, J; Komin, N; Kornecki, P; Kosack, K; Kowal, G; Kubo, H; Lamastra, A; Lapington, J; Lemoine-Goumard, M; Lenain, JP; Leone, F; Leto, G; Leuschner, F; Lindfors, E; Lohse, T; Lombardi, S; Longo, F; López-Coto, R; López-Oramas, A; Loporchio, S; Luque-Escamilla, PL; Macias, O; Majumdar, P; Mandat, D; Mangano, S; Manicò, G; Mariotti, M; Marquez, P; Marsella, G; Martí, J; Martin, P; Martínez, M; Mazin, D; Menchiari, S; Meyer, DMA; Miceli, D; Miceli, M; Michalowski, J; Mitchell, A; Moderski, R; Mohrmann, L; Molero, M; Molina, E; Montaruli, T; Moralejo, A; Morcuende, D; Morselli, A; Moulin, E; Moya, V; Mukherjee, R; Munari, K; Muraczewski, A; Nagataki, S; Nakamori, T; Nayak, A; Niemiec, J; Nievas, M; Nikolajuk, M; Nishijima, K; Noda, K; Nosek, D; Novosyadlyj, B; Nozaki, S; Ohishi, M; Ohm, S; Okumura, A; Olmi, B; Ong, RA; Orienti, M; Orito, R; Orlandini, M; Orlando, E; Orlando, S; Ostrowski, M; Oya, I; Pagliaro, A; Palatka, M; Pantaleo, FR; Paoletti, R; Paredes, JM; Parmiggiani, N; Patricelli, B; Pech, M; Pecimotika, M; Persic, M; Petruk, O; Pierre, E; Pietropaolo, E; Pirola, G; Pohl, M; Prandini, E; Priyadarshi, C; Pühlhofer, G; Pumo, ML; Punch, M; Queiroz, FS; Quirrenbach, A; Rainò, S; Rando, R; Razzaque, S; Reimer, A; Reimer, O; Reposeur, T; Ribó, M; Richtler, T; Rico, J; Rieger, F; Rigoselli, M; Rizi, V; Roache, E; Fernandez, GR; Romano, P; Romeo, G; Rosado, J; de Leon, AR; Rudak, B; Rulten, C; Sadeh, I; Saito, T; Sanchez-Conde, M; Sano, H; Santangelo, A; Santos-Lima, R; Sarkar, S; Saturni, FG; Scherer, A; Schovanek, P; Schussler, F; Schwanke, U; Sergijenko, O; Servillat, M; Siejkowski, H; Siqueira, C; Spencer, S; Stamerra, A; Stanic, S; Steppa, C; Stolarczyk, T; Suda, Y; Tavernier, T; Teshima, M; Tibaldo, L; Torres, DF; Tothill, N; Vacula, M; Vallage, B; Vallania, P; van Eldik, C; Acosta, MV; Vecchi, M; Ventura, S; Vercellone, S; Viana, A; Vigorito, CF; Vink, J; Vitale, V; Vodeb, V; Vorobiov, S; Vuillaume, T; Wagner, SJ; Walter, R; White, M; Wierzcholska, A; Will, M; Yamazaki, R; Yang, L; Yoshikoshi, T; Zacharias, M; Zaharijas, G; Zavrtanik, D; Zavrtanik, M; Zdziarski, AA; Zhdanov, VI; Zietara, K; Zivec, M

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY Vol. 523 ( 4 ) page： 5353 - 5387 2023.6

Language：English Publishing type：Research paper (scientific journal) Publisher：Monthly Notices of the Royal Astronomical Society

A deep survey of the Large Magellanic Cloud at ∼0.1-100 TeV photon energies with the Cherenkov Telescope Array is planned. We assess the detection prospects based on a model for the emission of the galaxy, comprising the four known TeV emitters, mock populations of sources, and interstellar emission on galactic scales. We also assess the detectability of 30 Doradus and SN 1987A, and the constraints that can be derived on the nature of dark matter. The survey will allow for fine spectral studies of N 157B, N 132D, LMC P3, and 30 Doradus C, and half a dozen other sources should be revealed, mainly pulsar-powered objects. The remnant from SN 1987A could be detected if it produces cosmic-ray nuclei with a flat power-law spectrum at high energies, or with a steeper index 2.3-2.4 pending a flux increase by a factor of >3-4 over ∼2015-2035. Large-scale interstellar emission remains mostly out of reach of the survey if its >10 GeV spectrum has a soft photon index ∼2.7, but degree-scale 0.1-10 TeV pion-decay emission could be detected if the cosmic-ray spectrum hardens above >100 GeV. The 30 Doradus star-forming region is detectable if acceleration efficiency is on the order of 1−10 per cent of the mechanical luminosity and diffusion is suppressed by two orders of magnitude within <100 pc. Finally, the survey could probe the canonical velocity-averaged cross-section for self-annihilation of weakly interacting massive particles for cuspy Navarro-Frenk-White profiles.

DOI： 10.1093/mnras/stad1576

Multimessenger Characterization of Markarian 501 during Historically Low X-Ray and <i>γ</i>-Ray Activity

Abé, H; Abé, S; Acciari, VA; Agudo, I; Aniello, T; Ansoldi, S; Antonelli, LA; Arbet-Engels, A; Arcaro, C; Artero, M; Asano, K; Baack, D; Babic, A; Baquero, A; de Almeida, UB; Barrio, JA; Batkovic, I; Baxter, J; González, JB; Bednarek, W; Bernardini, E; Bernardos, M; Berti, A; Besenrieder, J; Bhattacharyya, W; Bigongiari, C; Biland, A; Blanch, O; Bonnoli, G; Bosnjak, Z; Burelli, I; Busetto, G; Carosi, R; Carretero-Castrillo, M; Castro-Tirado, AJ; Ceribella, G; Chai, Y; Chilingarian, A; Cikota, S; Colombo, E; Contreras, JL; 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, CD; Depaoli, D; Di Pierro, F; Di Venere, L; Espiñeira, EDS; Prester, DD; Donini, A; Dorner, D; Doro, M; Elsaesser, D; Emery, G; Escudero, J; Ramazani, VF; Fariña, L; Fattorini, A; Foffano, L; Font, L; Fruck, C; Fukami, S; Fukazawa, Y; López, RJG; Garczarczyk, M; Gasparyan, S; Gaug, M; Paiva, JGG; Giglietto, N; Giordano, F; Gliwny, P; Godinovic, N; Grau, R; Green, D; Green, JG; Hadasch, D; Hahn, A; Hassan, T; Heckmann, L; Herrera, J; Hrupec, D; Hütten, M; Imazawa, R; Inada, T; Iotov, R; Ishio, K; Martínez, IJ; 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, BMD; Majumdar, P; Makariev, M; Maneva, G; Mang, N; Manganaro, M; Mangano, S; Mannheim, K; Mariotti, M; Martínez, M; Mas-Aguilar, A; Mazin, D; Menchiari, S; Mender, S; Micanovic, S; Miceli, D; Miener, T; Miranda, JM; Mirzoyan, R; Molina, E; Mondal, HA; Moralejo, A; Morcuende, D; Moreno, V; Nakamori, T; Nanci, C; Nava, L; Neustroev, V; Rosillo, MN; Nigro, C; Nilsson, K; Nishijima, K; Ekoume, TN; Noda, K; Nozaki, S; Ohtani, Y; Oka, T; Okumura, A; Otero-Santos, J; Paiano, S; Palatiello, M; Paneque, D; Paoletti, R; Paredes, JM; Pavletic, L; Persic, M; Pihet, M; Pirola, G; Podobnik, F; Moroni, PGP; Prandini, E; Principe, G; Priyadarshi, C; Rhode, W; Ribó, M; Rico, J; Righi, C; Rugliancich, A; Sahakyan, N; Saito, T; Sakurai, S; Satalecka, K; Saturni, FG; Schleicher, B; Schmidt, K; Schmuckermaier, F; Schubert, JL; Schweizer, T; Sitarek, J; Sliusar, V; Sobczynska, D; Spolon, A; Stamerra, A; Striskovic, J; Strom, D; Strzys, M; Suda, Y; Suric, T; Tajima, H; Takahashi, M; Takeishi, R; Tavecchio, F; Temnikov, P; Terauchi, K; Terzic, T; Teshima, M; Tosti, L; Truzzi, S; Tutone, A; Ubach, S; van Scherpenberg, J; Acosta, MV; Ventura, S; Verguilov, V; Viale, I; Vigorito, CF; Vitale, V; Vovk, I; Walter, R; Will, M; Wunderlich, C; Yamamoto, T; Zaric, D; Cerruti, M; Acosta-Pulido, JA; Apolonio, G; Bachev, R; Balokovic, M; Benítez, E; Björklund, I; Bozhilov, V; Brown, LF; Bugg, A; Carbonell, W; Carnerero, MI; Carosati, D; Casadio, C; Chamani, W; Chen, WP; Chigladze, RA; Damljanovic, G; Epps, K; Erkenov, A; Feige, M; Finke, J; Fuentes, A; Gazeas, K; Giroletti, M; Grishina, TS; Gupta, AC; Gurwell, MA; Heidemann, E; Hiriart, D; Hou, WJ; Hovatta, T; Ibryamov, S; Joner, MD; Jorstad, SG; Kania, J; Kiehlmann, S; Kimeridze, GN; Kopatskaya, EN; Kopp, M; Korte, M; Kotas, B; Koyama, S; Kramer, JA; Kunkel, L; Kurtanidze, SO; Kurtanidze, OM; Lähteenmäki, A; López, JM; Larionov, VM; Larionova, EG; Larionova, LV; Leto, C; Lorey, C; Mújica, R; Madejski, GM; Marchili, N; Marscher, AP; Minev, M; Modaressi, A; Morozova, DA; Mufakharov, T; Myserlis, I; Nikiforova, AA; Nikolashvili, MG; Ovcharov, E; Perri, M; Raiteri, CM; Readhead, ACS; Reimer, A; Reinhart, D; Righini, S; Rosenlehner, K; Sadun, AC; Savchenko, SS; Scherbantin, A; Schneider, L; Schoch, K; Seifert, D; Semkov, E; Sigua, LA; Singh, C; Sola, P; Sotnikova, Y; Spencer, M; Steineke, R; Stojanovic, M; Strigachev, A; Tornikoski, M; Traianou, E; Tramacere, A; Troitskaya, YV; Troitskiy, IS; Trump, JB; Tsai, A; Valcheva, A; Vasilyev, AA; Verrecchia, F; Villata, M; Vince, O; Vrontaki, K; Weaver, ZR; Zaharieva, E; Zottmann, N

ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES Vol. 266 ( 2 ) 2023.6

Language：English Publishing type：Research paper (scientific journal) Publisher：Astrophysical Journal, Supplement Series

We study the broadband emission of Mrk 501 using multiwavelength observations from 2017 to 2020 performed with a multitude of instruments, involving, among others, MAGIC, Fermi's Large Area Telescope (LAT), NuSTAR, Swift, GASP-WEBT, and the Owens Valley Radio Observatory. Mrk 501 showed an extremely low broadband activity, which may help to unravel its baseline emission. Nonetheless, significant flux variations are detected at all wave bands, with the highest occurring at X-rays and very-high-energy (VHE) 3-rays. A significant correlation (>3σ) between X-rays and VHE 3-rays is measured, supporting leptonic scenarios to explain the variable parts of the emission, also during low activity. This is further supported when we extend our data from 2008 to 2020, and identify, for the first time, significant correlations between the Swift X-Ray Telescope and Fermi-LAT. We additionally find correlations between high-energy 3-rays and radio, with the radio lagging by more than 100 days, placing the 3-ray emission zone upstream of the radio-bright regions in the jet. Furthermore, Mrk 501 showed a historically low activity in X-rays and VHE 3-rays from mid-2017 to mid-2019 with a stable VHE flux (>0.2 TeV) of 5% the emission of the Crab Nebula. The broadband spectral energy distribution (SED) of this 2 yr long low state, the potential baseline emission of Mrk 501, can be characterized with one-zone leptonic models, and with (lepto)-hadronic models fulfilling neutrino flux constraints from IceCube. We explore the time evolution of the SED toward the low state, revealing that the stable baseline emission may be ascribed to a standing shock, and the variable emission to an additional expanding or traveling shock.

DOI： 10.3847/1538-4365/acc181

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