Papers - OKUMURA Akira

Detection of the 2021 Outburst of RS Ophiuchi with the LST-1

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

Proceedings of Science   Vol. 444   2024.9

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Novae are luminous explosions in close binaries which host a white dwarf and a companion donor star. They are triggered by a thermonuclear runaway when the white dwarf accretes a critical amount of matter from the secondary. Though novae are established as high-energy gamma-ray emitters through observations by the Fermi Large Area Telescope (LAT), the origin of the gamma-ray emission, whether it is hadronic or leptonic, had been under intense debate until very recently. RS Ophiuchi (RS Oph) is a well-known recurrent symbiotic nova with a recurrence time scale of 15 years. The most recent outburst of RS Oph in 2021 brought the first detection of very-high-energy (VHE) gamma rays from a nova ever. The first Large-Sized Telescope prototype (LST-1) of the Cherenkov Telescope Array observed this historic event along with H.E.S.S. and MAGIC. The LST-1 observations in the first days after the burst onset show a clear VHE gamma-ray signal from RS Oph. The low energy threshold of LST-1 allows us to reconstruct the RS Oph gamma-ray spectrum down to ∼30 GeV, providing the best connection of the VHE gamma-ray data to the Fermi LAT energy range. The results from the analysis of the LST-1 observations are consistent with those obtained with H.E.S.S. and MAGIC, and also support a hadronic origin for the observed gamma-ray fluxes. In this contribution, we will present the analysis results of the LST-1 observations of the 2021 outburst of RS Oph.

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Detecting and characterizing pulsar halos with the Cherenkov Telescope Array Observatory

Eckner C., Abe K., Abe S., Acharyya A., Adam R., Aguasca-Cabot A., Agudo I., Alfaro J., Alvarez-Crespo N., Alves Batista R., Amans J.P., Amato E., Ambrosino F., Angüner E.O., Antonelli L.A., Aramo C., Arcaro C., Arrabito L., Asano K., Aschersleben J., Ashkar H., Augusto Stuani L., Baack D., Backes M., Balazs C., Balbo M., Baquero Larriva A., Barbosa Martins V., Barres de Almeida U., Barrio J.A., Bastieri D., Batista P.I., Batkovic I., Batzofin R., Baxter J., Beck G., Becker Tjus J., Beiske L., Belardinelli D., Benbow W., Bernardini E., Bernete Medrano J., Bernlöhr K., Berti A., Beshley V., Bhattacharjee P., Bhattacharyya S., Bi B., Biederbeck N., Biland A., Bissaldi E., Blanch O., Blazek J., Boisson C., Bolmont J., Bonnoli G., Bordas P., Bosnjak Z., Bradascio F., Braiding C., Bronzini E., Brose R., Brown A.M., Brun F., Brunelli G., Bulgarelli A., Burelli I., Burmistrov L., Burton M., Bylund T., Calisse P.G., Campoy-Ordaz A., Cantlay B.K., Capalbi M., Caproni A., Capuzzo-Dolcetta R., Carlile C., Caroff S., Carosi A., Carosi R., Carrasco M.S., Cascone E., Cassol F., Castrejon N., Catalani F., Cerasole D., Cerruti M., Chaty S., Chen A.W., Chernyakova M., Chiavassa A., Chudoba J., Coimbra Araujo C.H., Conforti V., Conte F., Contreras J.L., Cossou C., Costa A., Costantini H., Cristofari P.

Proceedings of Science   Vol. 444   2024.9

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The recently identified source class of pulsar halos may be populated and bright enough at TeV energies to constitute a large fraction of the sources that will be observed with the Cherenkov Telescope Array (CTA), especially in the context of the planned Galactic Plane Survey (GPS). In this study, we examine the prospects offered by CTA for the detection and characterization of such objects. CTA will cover energies from 20 GeV to 300 TeV, bridging the ranges already probed with the Fermi Large Area Telescope and High Altitude Water Cherenkov Observatory, and will also have a better angular resolution than the latter instruments, thus providing a complementary look at the phenomenon. From simple models for individual pulsar halos and their population in the Milky Way, we examine under which conditions such sources can be detected and studied from the GPS observations. In the framework of a full spatial-spectral likelihood analysis, using the most recent estimates for the instrument response function and prototypes for the science tools, we derive the spectral and morphological sensitivity of the CTA GPS to the specific intensity distribution of pulsar halos. From these, we quantify the physical parameters for which pulsar halos can be detected, identified, and characterized, and what fraction of the Galactic population could be accessible. We also discuss the effect of interstellar emission and data analysis systematics on these prospects.

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Defining the data legacy of the MAGIC telescopes: adopting a standardised data format and open-source analysis tools

Nigro C., 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., Barrio J.A., Batković I., Baxter J., Becerra González J., Bednarek W., Bernardini E., Bernardos M., 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., Ceribella G., Chai Y., Chilingarian A., 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., Fröse S., Fukami S., Fukazawa Y., García López R.J., Garczarczyk M., Gasparyan S., Gaug M., Giesbrecht Paiva J.G., 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., Hrupec D., Hütten M., Imazawa R., Inada T., Iotov R., Ishio K., Jiménez Martínez I., Jormanainen J.

Proceedings of Science   Vol. 444   2024.9

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Very-high-energy (VHE, E > 100 GeV) gamma-ray telescopes have traditionally conducted science with proprietary data and software. After two decades of operations, they have accumulated thousands of hours of observations whose full scientific exploitation cannot be accomplished by the restricted group of scientists operating these instruments. The advent of a new generation of open gamma-ray observatories and, at the same time, the forthcoming end of their scientific operations, call for the realisation of public archives of their observations. With the objective to facilitate the exchange and dissemination of data from current- and next-generation gamma-ray instruments, the "Data formats for gamma-ray astronomy" (GADF) initiative was formed to provide an open and standardised format for gamma-ray astronomical data. In this contribution, we present the effort to produce data of the Major Atmospheric Gamma-ray Imaging Cherenkov (MAGIC) telescopes in this standardised format. A total of 150 hours of observations of different sources were converted to the GADF format and then validated by analysing them with the open-source software Gammapy and comparing the results obtained against those produced with the MAGIC proprietary software, MARS. The effort to standardise and validate the MAGIC data in an open and shared format constitute the first fundamental milestone towards the realisation of its public data legacy.

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Dark matter searches in dwarf spheroidal galaxies with the Cherenkov Telescope Array

Saturni F.G., Doro M., Morselli A., Rodríguez-Fernández G., Abe K., Abe S., Acharyya A., Adam R., Aguasca-Cabot A., Agudo I., Alfaro J., Alvarez-Crespo N., Alves Batista R., Amans J.P., Amato E., Ambrosino F., Angüner E.O., Antonelli L.A., Aramo C., Arcaro C., Arrabito L., Asano K., Aschersleben J., Ashkar H., Augusto Stuani L., Baack D., Backes M., Balazs C., Balbo M., Baquero Larriva A., Barbosa Martins V., Barres de Almeida U., Barrio J.A., Bastieri D., Batista P.I., Batkovic I., Batzofin R., Baxter J., Beck G., Becker Tjus J., Beiske L., Belardinelli D., Benbow W., Bernardini E., Bernete Medrano J., Bernlöhr K., Berti A., Beshley V., Bhattacharjee P., Bhattacharyya S., Bi B., Biederbeck N., Biland A., Bissaldi E., Blanch O., Blazek J., Boisson C., Bolmont J., Bonnoli G., Bordas P., Bosnjak Z., Bradascio F., Braiding C., Bronzini E., Brose R., Brown A.M., Brun F., Brunelli G., Bulgarelli A., Burelli I., Burmistrov L., Burton M., Bylund T., Calisse P.G., Campoy-Ordaz A., Cantlay B.K., Capalbi M., Caproni A., Capuzzo-Dolcetta R., Carlile C., Caroff S., Carosi A., Carosi R., Carrasco M.S., Cascone E., Cassol F., Castrejon N., Catalani F., Cerasole D., Cerruti M., Chaty S., Chen A.W., Chernyakova M., Chiavassa A., Chudoba J., Coimbra Araujo C.H., Conforti V., Conte F., Contreras J.L., Cossou C.

Proceedings of Science   Vol. 444   2024.9

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Dark matter (DM) is one of the major components in the Universe. However, at present its existence is still only inferred through indirect astronomical observations. DM particles can annihilate or decay, producing final-state Standard Model pairs that subsequently annihilate into high-energy γrays. The dwarf spheroidal galaxies (dSphs) in the Milky Way DM halo have long been considered optimal targets to search for annihilating DM signatures in GeV-to-TeV γ-ray spectra due to their high DM densities (hence high astrophysical factors), as well as the expected absence of intrinsic γ-ray emission of astrophysical origin. For such targets, it is important to compute the amount of DM in their halos in a consistent way to optimize the γ-ray data analysis. Such estimates directly affect the observability of DM signals in dSphs, as well as the DM constraints that can be derived in case of null detection. In this contribution, we present the results on the sensitivity of the Cherenkov Telescope Array (CTA) for DM annihilation and decay searches using planned observations of the Milky Way dSphs. We select the most promising targets among all presently known dwarf satellites, providing new determinations of their expected DM signal. This study shows an improvement of approximately an order of magnitude in sensitivity compared to current searches in similar targets. We also discuss the results in terms of cuspy and cored DM models, and investigate the sensitivity obtained by the combination of observations from different dSphs. Finally, we explore the optimal strategies for CTA observations of dSphs.

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Ctapipe - Prototype Open Event Reconstruction Pipeline for the Cherenkov Telescope Array

Linhoff M., Beiske L., Biederbeck N., Fröse S., Kosack K., Nickel L., Abe K., Abe S., Acharyya A., Adam R., Aguasca-Cabot A., Agudo I., Alfaro J., Alvarez-Crespo N., Alves Batista R., Amans J.P., Amato E., Ambrosino F., Angüner E.O., Antonelli L.A., Aramo C., Arcaro C., Arrabito L., Asano K., Aschersleben J., Ashkar H., Augusto Stuani L., Baack D., Backes M., Balazs C., Balbo M., Baquero Larriva A., Barbosa Martins V., de Almeida U.B., Barrio J.A., Bastieri D., Batista P.I., Batkovic I., Batzofin R., Baxter J., Beck G., Becker Tjus J., Belardinelli D., Benbow W., Bernardini E., Bernete Medrano J., Bernlöhr K., Berti A., Beshley V., Bhattacharjee P., Bhattacharyya S., Bi B., Biland A., Bissaldi E., Blanch O., Blazek J., Boisson C., Bolmont J., Bonnoli G., Bordas P., Bosnjak Z., Bradascio F., Braiding C., Bronzini E., Brose R., Brown A.M., Brun F., Brunelli G., Bulgarelli A., Burelli I., Burmistrov L., Burton M., Bylund T., Calisse P.G., Campoy-Ordaz A., Cantlay B.K., Capalbi M., Caproni A., Capuzzo-Dolcetta R., Carlile C., Caroff S., Carosi A., Carosi R., Carrasco M.S., Cascone E., Cassol F., Castrejon N., Catalani F., Cerasole D., Cerruti M., Chaty S., Chen A.W., Chernyakova M., Chiavassa A., Chudoba J., Coimbra Araujo C.H., Conforti V., Conte F.

Proceedings of Science   Vol. 444   2024.9

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The Cherenkov Telescope Array Observatory (CTAO) is the next-generation ground-based gamma-ray observatory currently under construction. It will improve over the current generation of imaging atmospheric Cherenkov telescopes (IACTs) by a factor of five to ten in sensitivity and it will be able to observe the whole sky from a combination of two sites: a northern site in La Palma, Spain, and a southern one in Paranal, Chile. CTAO will also be the first open ground-based gamma-ray observatory. Accordingly, the CTAO data processing pipeline is developed as open-source software and ctapipe will be a core package therein. The event reconstruction pipeline accepts raw data of the telescopes and processes it to produce suitable input for the higher-level science tools. Its primary tasks include reconstructing the physical properties of each recorded air shower and providing the corresponding instrument response functions. ctapipe is a python framework providing algorithms and command-line tools to facilitate raw data calibration, image extraction, image parametrization and event reconstruction. Its current main focus is the analysis of simulated data but it has also been successfully applied for the analysis of data obtained with the CTA prototype telescopes, and first science results have now been obtained by the LST-1 collaboration using ctapipe. A plugin system also allows the processing of nonCTA data. Recent updates, including event reconstruction using machine learning and a new plugin system as well as the roadmap towards a 1.0 release will be presented.

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

D’Amico G., Batković I., Doro M., Manganaro M., 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., Barrio J.A., Baxter J., Becerra González J., Bednarek W., Bernardini E., Bernardos M., 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., Ceribella G., Chai Y., Chilingarian A., Cifuentes A., Cikota S., Colombo E., Contreras J.L., Cortina J., Covino S., 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., Elsaesser D., Emery G., Escudero J., Fariña L., Fattorini A., Foffano L., Font L., Fröse S., Fukami S., Fukazawa Y., García López R.J., Garczarczyk M., Gasparyan S., Gaug M., Giesbrecht Paiva J.G., 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., Hrupec D., Hütten M., Imazawa R., Inada T., Iotov R., Ishio K., Jiménez Martínez I., Jormanainen J.

Proceedings of Science   Vol. 444   2024.9

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Axion-like particles (ALPs) are pseudo-Nambu-Goldston bosons that appear in theories beyond the standard model and are capable of converting to photons in the presence of magnetic fields. Such interaction can have an observable effect on the gamma-ray spectrum of astrophysical targets. We have examined about 40 hours of observations made with the ground-based MAGIC Cherenkov telescopes in the direction of the Perseus Galaxy Cluster. The sources of VHE gamma rays present in the cluster and object of the study are the radiogalaxy NGC1275 and the HBL object IC310. These sources are bright in gamma rays and embedded in the cluster’s high magnetic field, making them very good targets for this kind of study. Having not found statistical evidence for ALPs, we exclude ALPs models with masses in the sub-eV range in line with previous results. Last, we address the potential for gamma-ray-based instruments, both current and future, to identify ALP signals using this analysis technique, finding that the search for wiggles in TeV gamma-ray spectra is very unlikely to be sensitive enough for observations with IACTs.

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Chasing Gravitational Waves with the Cherenkov Telescope Array Open Access

Green J.G., Carosi A., Nava L., Patricellix B., Schüssler F., Seglar-Arroyo M., Stamerra A., Abe K., Abe S., Acharyya A., Adam R., Aguasca-Cabot A., Agudo I., Alfaro J., Alvarez-Crespo N., Alves Batista R., Amans J.P., Amato E., Ambrosino F., Angüner E.O., Antonelli L.A., Aramo C., Arcaro C., Arrabito L., Asano K., Aschersleben J., Ashkar H., Augusto Stuani L., Baack D., Backes M., Balazs C., Balbo M., Baquero Larriva A., Barbosa Martins V., Barres de Almeida U., Barrio J.A., Bastieri D., Batista P.I., Batkovic I., Batzofin R., Baxter J., Beck G., Becker Tjus J., Beiske L., Belardinelli D., Benbow W., Bernardini E., Bernete Medrano J., Bernlöhr K., Berti A., Beshley V., Bhattacharjee P., Bhattacharyya S., Bi B., Biederbeck N., Biland A., Bissaldi E., Blanch O., Blazek J., Boisson C., Bolmont J., Bonnoli G., Bordas P., Bosnjak Z., Bradascio F., Braiding C., Bronzini E., Brose R., Brown A.M., Brun F., Brunelli G., Bulgarelli A., Burelli I., Burmistrov L., Burton M., Bylund T., Calisse P.G., Campoy-Ordaz A., Cantlay B.K., Capalbi M., Caproni A., Capuzzo-Dolcetta R., Carlile C., Caroff S., Carosi R., Carrasco M.S., Cascone E., Cassol F., Castrejon N., Catalani F., Cerasole D., Cerruti M., Chaty S., Chen A.W., Chernyakova M., Chiavassa A., Chudoba J., Coimbra Araujo C.H., Conforti V.

Proceedings of Science   Vol. 444   2024.9

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The detection of gravitational waves (GWs) from a binary neutron star (BNS) merger by Advanced LIGO and Advanced Virgo (GW170817), along with the discovery of the electromagnetic counterparts of this GW event, ushered in a new era of multimessenger astronomy, providing the first direct evidence that BNS mergers are progenitors of short gamma-ray bursts (GRBs). Such events may also produce very-high-energy (VHE, > 100GeV) photons which have yet to be detected in coincidence with a GW signal. The Cherenkov Telescope Array (CTA) is a next-generation VHE observatory which aims to be indispensable in this search, with an unparalleled sensitivity and ability to slew anywhere on the sky within a few tens of seconds. Achieving such a feat will require a comprehensive real-time strategy capable of coordinating searches over potentially very large regions of the sky. This work will evaluate and provide estimations on the number of GW-CTA events determined from simulated BNS systems and short GRBs, considering both on- and off-axis emission. In addition, we will present and discuss the prospects of potential follow-up strategies with CTA.

DOI： 10.22323/1.444.1534

Open Access

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Characterization of SiPM and development of test bench modules for the next-generation cameras for Large-Sized Telescopes for Cherenkov Telescope Array

Saito T., Hashiyama K., Iwasaki H., Kubo H., Mizote M., Okumura A., Tajima H., Yamamoto T.

Proceedings of Science   Vol. 444   2024.9

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The recent improvements in the performance of the silicon photomultipliers (SiPMs) made them attractive options as photo sensors of imaging atmospheric Cherenkov telescopes (IACTs). In fact, they are already adopted in some IACTs such as FACT and the Small-Sized Telescopes of the Cherenkov Telescope Array (CTA). However, the application to the Large-Sized Telescopes (LSTs) of CTA requires additional studies. As the pixel size of LSTs is larger than the nominal size of SiPMs, the signal from multiple sensors must be summed up. Also, the high detection efficiency of the night sky background (NSB) photons may degrade the telescope performance. To overcome this, the pulse width must be as small as 3 ns and the detection efficiency for NSB photons must be suppressed as much as possible. Heat generation and gain stabilization are also issues. We studied different types of SiPMs from Hamamatsu photonics and characterized them for the LST application, addressing the previous points. Also, to prove the SiPM performance in LST, we are developing a SiPM module which can be installed in the exisiting LST camera. Here we present the results of this evaluation and the status of the test bench module development.

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Bright blazar flares with CTA

Cerruti M., Finke J., Grolleron G., Lenain J.P., Hovatta T., Joshi M., Lindfors E., Morris P., Petropoulou M., Romano P., Vercelloneh S., Zacharias M., Abe K., Abe S., Acharyya A., Adam R., Aguasca-Cabot A., Agudo I., Alfaro J., Alvarez-Crespo N., Alves Batista R., Amans J.P., Amato E., Ambrosino F., Angüner E.O., Antonelli L.A., Aramo C., Arcaro C., Arrabito L., Asano K., Aschersleben J., Ashkar H., Augusto Stuani L., Baack D., Backes M., Balazs C., Balbo M., Baquero Larriva A., Barbosa Martins V., de Almeida U.B., Barrio J.A., Bastieri D., Batista P.I., Batkovic I., Batzofin R., Baxter J., Beck G., Becker Tjus J., Beiske L., Belardinelli D., Benbow W., Bernardini E., Bernete Medrano J., Bernlöhr K., Berti A., Beshley V., Bhattacharjee P., Bhattacharyya S., Bi B., Biederbeck N., Biland A., Bissaldi E., Blanch O., Blazek J., Boisson C., Bolmont J., Bonnoli G., Bordas P., Bosnjak Z., Bradascio F., Braiding C., Bronzini E., Brose R., Brown A.M., Brun F., Brunelli G., Bulgarelli A., Burelli I., Burmistrov L., Burton M., Bylund T., Calisse P.G., Campoy-Ordaz A., Cantlay B.K., Capalbi M., Caproni A., Capuzzo-Dolcetta R., Carlile C., Caroff S., Carosi A., Carosi R., Carrasco M.S., Cascone E., Cassol F., Castrejon N., Catalani F., Cerasole D., Chaty S., Chen A.W., Chernyakova M.

Proceedings of Science   Vol. 444   2024.9

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The TeV extragalactic sky is dominated by blazars, radio-loud active galactic nuclei with a relativistic jet pointing towards the Earth. Blazars show variability that can be quite exceptional both in terms of flux (orders of magnitude of brightening) and time (down to the minute timescale). This bright flaring activity contains key information on the physics of particle acceleration and photon production in the emitting region, as well as the structure and physical properties of the jet itself. The TeV band is accessed from the ground by Cherenkov telescopes that image the pair cascade triggered by the interaction of the gamma ray with the Earth's atmosphere. The Cherenkov Telescope Array (CTA) represents the upcoming generation of imaging atmospheric Cherenkov telescopes, with a significantly higher sensitivity and larger energy coverage with respect to current instruments. It will thus provide us with unprecedented statistics on blazar light-curves and spectra. In this contribution we present the results from realistic simulations of CTA observations of bright blazar flares, taking as input state-of-the-art numerical simulations of blazar emission models and including all relevant observational constraints.

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Performance of the Large-Sized Telescope prototype of the Cherenkov Telescope Array

Morcuende D., López-Coto R., Moralejo A., Nozaki S., Vuillaume T., Abe K., Abe S., Aguasca-Cabot A., Agudo I., Alvarez Crespo N., Antonelli L.A., Aramo C., Arbet-Engels A., Arcaro C., Artero M., Asano K., Aubert P., Baktash A., Bamba A., Baquero Larriva A., Baroncelli L., Barres de Almeida U., Barrio J.A., Batkovic I., Baxter J., Becerra González J., Bernardini E., Bernardos M.I., Bernete Medrano J., Berti A., Bhattacharjee P., Biederbeck N., Bigongiari C., Bissaldi E., Blanch O., Bonnoli G., Bordas P., Bulgarelli A., Burelli I., Burmistrov L., Buscemi M., Cardillo M., Caroff S., Carosi A., Carrasco M.S., Cassol F., Cauz D., Cerasole D., Ceribella G., Chai Y., Cheng K., Chiavassa A., Chikawa M., Chytka L., Cifuentes A., Contreras J.L., Cortina J., Costantini H., Dalchenko M., Dazzi F., De Angelis A., de Bony de Lavergne M., De Lotto B., De Lucia M., de Menezes R., Del Peral L., Deleglise G., Delgado C., Delgado Mengual J., della Volpe D., Dellaiera M., Di Piano A., Di Pierro F., Di Pilato A., Di Tria R., Di Venere L., Díaz C., Dominik R.M., Dominis Prester D., Donini A., Dorner D., Doro M., Eisenberger L., Elsässer D., Emery G., Escudero J., Fallah Ramazani V., Ferrara G., Ferrarotto F., Fiasson A., Foffano L., Freixas Coromina L., Fröse S., Fukami S., Fukazawa Y., Garcia E., Garcia López R., Gasbarra C., Gasparrini D., Geyer D.

Proceedings of Science   Vol. 444   2024.9

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The next-generation ground-based gamma-ray Cherenkov Telescope Array Observatory (CTAO) will consist of imaging atmospheric Cherenkov telescopes (IACTs) of three different sizes distributed in two sites. The Large-Sized Telescopes will cover the low-energy end of the CTA energy range, starting at about 20 GeV. After its first years of operation at the CTA northern site, the Large-Sized Telescope prototype (LST-1) is in the final stage of its commissioning phase, having collected a significant amount of scientific data to date. In this contribution, we present the physics performance of the telescope using low-zenith Crab Nebula observations and Monte Carlo simulations fine-tuned accordingly. We show performance figures of merit such as the energy threshold, effective area, energy and angular resolution, and sensitivity based on the standard Hillas-parameters approach and following the source-independent and dependent analysis methods. The analysis threshold is estimated at 30 GeV. The energy resolution is around 30%, and the angular resolution is 0.3 degrees at 100 GeV. The best integral sensitivity of LST-1 is about 1.1% of the Crab Nebula flux above 250 GeV for 50 hours of observations. We also show the spectral energy distribution and light curve from Crab Nebula observations, which agree with results from other IACTs and link smoothly with Fermi-LAT when considering statistical and systematic uncertainties near the energy threshold.

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Update on the performance of the MAGIC Intensity Interferometer

Martínez I.J., Acciari V.A., Cifuentes A., Colombo E., Cortina J., Delgado C., Díaz C., Fiori M., Fink D., Guberman D., Hassan T., Lyard E., Mariotti M., Martínez G., Mirzoyan R., Naletto G., Njoh Ekoume T., Polo M., Produit N., Rodríguez-Vázquez J.J., Saha P., Schweizer T., Walter R., Wunderlich C.W., Zampieri L., Abe H., Abe S., Abhir J., 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., Barrio J.A., Batković I., Baxter J., Be-Cerra González J., Bednarek W., Bernardini E., Bernardos M., 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., Ceribella G., Chai Y., Chilingarian A., Cikota S., Contreras J.L., 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., Fröse S., Fukami S., Fukazawa Y., García López R.J.

Proceedings of Science   Vol. 444   2024.9

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In recent years, the MAGIC telescopes have been equipped with a setup that allows its Imaging Atmospheric Cherenkov Telescopes (IACTs) to function as an Intensity Interferometer. The deadtime-free setup includes a 4-channel GPU-based real-time correlator together with optical filters in the 350-450 nm wavelength range and specialized Active Mirror Control (AMC) configurations. This implementation allows MAGIC to perform measurements of the spatial coherence (visibility) of the intensity fluctuations of an object’s starlight over several separations (baselines) and construct a model of said object. The accessible baseline range for MAGIC is 40-90 m which translates into an angular resolution of 0.5-1 mas. Additionally, thanks to the AMC it can access even smaller baselines, of less than 17 m (which is the diameter of each of both dishes) to measure objects of greater angular size (>1 mas) and even measure the zero-baseline correlation, which is key to calibrate the system. We present the latest measurements that allow us to understand the performance and systematics of our setup and validate our analysis.

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The Real Time Analysis framework of the Cherenkov Telescope Array’s Large-Sized Telescope

Caroff S., Aubert P., Garcia E., Maurin G., Pollet V., Vuillaume T., Abe K., Abe S., Aguasca-Cabot A., Agudo I., Alvarez Crespo N., Antonelli L.A., Aramo C., Arbet-Engels A., Arcaro C., Artero M., Asano K., Baktash A., Bamba A., Baquero Larriva A., Baroncelli L., Barres de Almeida U., Barrio J.A., Batkovic I., Baxter J., Becerra González J., Bernardini E., Bernardos M.I., Bernete Medrano J., Berti A., Bhattacharjee P., Biederbeck N., Bigongiari C., Bissaldi E., Blanch O., Bonnoli G., Bordas P., Bulgarelli A., Burelli I., Burmistrov L., Buscemi M., Cardillo M., Carosi A., Carrasco M.S., Cassol F., Cauz D., Cerasole D., Ceribella G., Chai Y., Cheng K., Chiavassa A., Chikawa M., Chytka L., Cifuentes A., Contreras J.L., Cortina J., Costantini H., Dalchenko M., Dazzi F., De Angelis A., de Bony de Lavergne M., De Lotto B., De Lucia M., de Menezes R., Del Peral L., Deleglise G., Delgado C., Delgado Mengual J., della Volpe D., Dellaiera M., Di Piano A., Di Pierro F., Di Pilato A., Di Tria R., Di Venere L., Díaz C., Dominik R.M., Dominis Prester D., Donini A., Dorner D., Doro M., Eisenberger L., Elsässer D., Emery G., Escudero J., Fallah Ramazani V., Ferrara G., Ferrarotto F., Fiasson A., Foffano L., Freixas Coromina L., Fröse S., Fukami S., Fukazawa Y., Garcia E., Garcia López R., Gasbarra C., Gasparrini D.

Proceedings of Science   Vol. 444   2024.9

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The Large-Sized Telescopes (LSTs) of the Cherenkov Telescope Array Observatory (CTAO) will play a crucial role in the study of transient gamma-ray sources, such as gamma-ray bursts and flaring active galactic nuclei. The low energy threshold of LSTs makes them particularly well suited for the detection of these phenomena. The ability to detect and analyze gamma-ray transients in real-time is essential for quickly identifying and studying these rare and fleeting events. In this conference, we will present recent advances in the real-time analysis of data from the LST-1, the first prototype of LST located in the Canary island of La Palma. We will discuss in particular the development of new algorithms for event reconstruction and background rejection. These advances will enable rapid identification and follow-up observation of transient gamma-ray sources, making the LST-1 a powerful tool for the study of the dynamic universe. The implementation of this framework in the future Array Control and Data Acquisition System (ACADA) of CTAO will be discussed as well, based on the experience with LST.

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The rapporteur report on the diversity session at the ICRC2023 Open Access

Takahashi S., Ishihara A., Okumura A., Itow Y.

Proceedings of Science   Vol. 444   2024.9

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The Diversity Session at ICRC2023 marked a significant step towards enhancing inclusivity within the astroparticle community. This report not only documents the lively discussions of the session but also highlights a cornerstone of our efforts: the outcomes of the pre-conference diversity survey. Professor Hiromi Yokoyama’s thought-provoking presentation illuminated a pivotal aspect: the factors affecting the attrition of female students, particularly in the field of physics.

DOI： 10.22323/1.444.0038

Open Access

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The next generation cameras for the Large-Sized Telescopes of the Cherenkov Telescope Array Observatory

Heller M., Altet J., Aragones X., Barrio J.A., Bellato M., Bernasconi E., Biland A., Blanch O., Burmistrov L., Charbon E., Dalchenko M., Di Pierro F., Giangrande L., Gascon D., Gòmez S., Hoffmann D., Martinez G., Mariotti M., Matteo D., Montaruli T., Okumura A., Aguilera A.P., Manera R., Rando R., Saito T., Sanuy A., Tejedor L.A., Uzun Y.

Proceedings of Science   Vol. 444   2024.9

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The latest generation of silicon photomultipliers (SiPM) offers twice as much sensitivity to Cherenkov light observed at ground level when compared to photomultipliers. Their use for imaging atmospheric Cherenkov telescopes is increasing, from the FACT telescope, the pioneer, to the small-sized telescopes of the Cherenkov Telescope Array (CTA) or the LHAASO WFCTA camera. The robustness of the SiPMs represents a unique opportunity to ensure long-term operation with low maintenance. In this work, we present the latest developments and performance of a SiPM camera aiming at upgrading the large-sized telescopes (LST) cameras of CTA. The SiPM camera, equipped with 0.05 deg pixels, provides images of improved resolution for better feature extraction. The increase in the number of pixels has driven the development of low-power front-end electronics whose design is presented in this work. We also present the fully digital readout architecture of the proposed camera, which will enable the implementation of novel triggering algorithms based on artificial intelligence.

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The Cosmic-ray Electron and Positron Spectrum Measured with MAGIC

Chai Y., Ishio K., Kerszberg D., Mangano S., 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., Barrio J.A., Batković I., Baxter J., Becerra González J., Bednarek W., Bernardini E., Bernardos M., 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., Ceribella G., Chai Y., Chilingarian A., 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., Fröse S., Fukami S., Fukazawa Y., García López R.J., Garczarczyk M., Gasparyan S., Gaug M., Giesbrecht Paiva J.G., 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., Hrupec D., Hütten M., Imazawa R., Inada T., Iotov R.

Proceedings of Science   Vol. 444   2024.9

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Cosmic-ray electrons and positrons (CREs) of TeV energies suffer severe energy loss during propagation due to inverse Compton scattering and synchrotron radiation process, they are therefore very useful to constrain the local cosmic-ray sources in the Galaxy. The ability to measure CREs by ground-based imaging atmospheric Cherenkov telescopes (IACTs) has been demonstrated in the past. In this proceeding, we will present two methods – a template fit method and a tight cut method based on a two-steps-trained Random Forest (RF) – optimized for the detection and study of CREs and will report on the measurement of the CREs energy spectrum from 300 GeV to 6 TeV with the MAGIC telescopes.

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Study on the gain and photon detection efficiency drops of silicon photomultipliers under bright background conditions

Okumura A., Wakazono K., Furuta K., Tajima H.

Proceedings of Science   Vol. 444   2024.9

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The use of silicon photomultipliers (SiPMs) in imaging atmospheric Cherenkov telescopes is expected to extend the observation times of very-high-energy gamma-ray sources, particularly within the highest energy domain of 50–300 TeV, where the Cherenkov signal from celestial gamma rays is adequate even under bright moonlight background conditions. Unlike conventional photomultiplier tubes, SiPMs do not exhibit quantum efficiency or gain degradation, which can be observed after long exposures to bright illumination. However, under bright conditions, the photon detection efficiency of a SiPM can be undergo temporary degradation because a fraction of its avalanche photodiode cells can saturate owing to photons from the night-sky background (NSB). In addition, the large current generated by the high NSB rate can increase the temperature of the silicon substrate, resulting in shifts in the SiPM breakdown voltages and consequent gain changes. Moreover, this large current changes the effective bias voltage because it causes a voltage drop across the protection resistor of 100–1000 Ω. Hence, these three factors, namely the avalanche photodiode (APD) saturation, Si temperature, and voltage drop must be carefully compensated for and/or considered in the energy calibration of Cherenkov telescopes with SiPM cameras. In this study, we measured the signal output charge of a SiPM and its variation as a function of different NSB-like background conditions up to 1 GHz/pixel. The results verify that the product of the SiPM gain and photon detection efficiency is well characterized by these three factors.

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Sensitivity of the Cherenkov Telescope Array to the gamma-ray emission from neutrino sources detected by IceCube

Sergijenko O., Brown A.M., Fiorillo D., de León A.R., Satalecka K., Tung C.F., Taboada I., Abe K., Abe S., Acharyya A., Adam R., Aguasca-Cabot A., Agudo I., Alfaro J., Alvarez-Crespo N., Alves Batista R., Amans J.P., Amato E., Ambrosino F., Angüner E.O., Antonelli L.A., Aramo C., Arcaro C., Arrabito L., Asano K., Aschersleben J., Ashkar H., Augusto Stuani L., Baack D., Backes M., Balazs C., Balbo M., Baquero Larriva A., Barbosa Martins V., Barres de Almeida U., Barrio J.A., Bastieri D., Batista P.I., Batkovic I., Batzofin R., Baxter J., Beck G., Becker Tjus J., Beiske L., Belardinelli D., Benbow W., Bernardini E., Bernete Medrano J., Bernlöhr K., Berti A., Beshley V., Bhattacharjee P., Bhattacharyya S., Bi B., Biederbeck N., Biland A., Bissaldi E., Blanch O., Blazek J., Boisson C., Bolmont J., Bonnoli G., Bordas P., Bosnjak Z., Bradascio F., Braiding C., Bronzini E., Brose R., Brun F., Brunelli G., Bulgarelli A., Burelli I., Burmistrov L., Burton M., Bylund T., Calisse P.G., Campoy-Ordaz A., Cantlay B.K., Capalbi M., Caproni A., Capuzzo-Dolcetta R., Carlile C., Caroff S., Carosi A., Carosi R., Carrasco M.S., Cascone E., Cassol F., Castrejon N., Catalani F., Cerasole D., Cerruti M., Chaty S., Chen A.W., Chernyakova M., Chiavassa A., Chudoba J., Coimbra Araujo C.H., Conforti V.

Proceedings of Science   Vol. 444   2024.9

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Gamma-ray observations of the astrophysical neutrino sources are fundamentally important for understanding the underlying neutrino production mechanism. We investigate the Cherenkov Telescope Array (CTA) ability to detect the very-high-energy (VHE) gamma-ray counterparts to the neutrino-emitting Active Galaxies. The CTA performance under different configurations and array layouts is computed based on the neutrino and gamma-ray simulations of steady and transient types of sources, assuming that the neutrino events are detected with the IceCube neutrino telescope. The CTA detection probability is calculated for both CTA sites taking into account the visibility constraints. We find that, under optimal observing conditions, CTA could observe the VHE gamma-ray emission from at least 3 neutrino events per year.

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Pybkgmodel - a background modelling toolbox for the CTA

Strzys M.C., Abe S., de Bony de Lavergne M., Hütten M., Mender S., Vovk I., Abe K., Abe S., Acharyya A., Adam R., Aguasca-Cabot A., Agudo I., Alfaro J., Alvarez-Crespo N., Alves Batista R., Amans J.P., Amato E., Ambrosino F., Angüner E.O., Antonelli L.A., Aramo C., Arcaro C., Arrabito L., Asano K., Aschersleben J., Ashkar H., Augusto Stuani L., Baack D., Backes M., Balazs C., Balbo M., Baquero Larriva A., Barbosa Martins V., de Almeida U.B., Barrio J.A., Bastieri D., Batista P.I., Batkovic I., Batzofin R., Baxter J., Beck G., Becker Tjus J., Beiske L., Belardinelli D., Benbow W., Bernardini E., Bernete Medrano J., Bernlöhr K., Berti A., Beshley V., Bhattacharjee P., Bhattacharyya S., Bi B., Biederbeck N., Biland A., Bissaldi E., Blanch O., Blazek J., Boisson C., Bolmont J., Bonnoli G., Bordas P., Bosnjak Z., Bradascio F., Braiding C., Bronzini E., Brose R., Brown A.M., Brun F., Brunelli G., Bulgarelli A., Burelli I., Burmistrov L., Burton M., Bylund T., Calisse P.G., Campoy-Ordaz A., Cantlay B.K., Capalbi M., Caproni A., Capuzzo-Dolcetta R., Carlile C., Caroff S., Carosi A., Carosi R., Carrasco M.S., Cascone E., Cassol F., Castrejon N., Catalani F., Cerasole D., Cerruti M., Chaty S., Chen A.W., Chernyakova M., Chiavassa A., Chudoba J., Coimbra Araujo C.H., Conforti V., Conte F.

Proceedings of Science   Vol. 444   2024.9

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Despite the advancement in background rejection techniques, observation of the very-high-energy gamma-ray sky by imaging atmospheric Cherenkov telescopes (IACTs) are subject to an irreducible background from gamma-like hadron- or electron-induced air showers. The determination of this residual background is crucial for accurate spectral and spatial measurements. The Cherenkov Telescope Array (CTA) will become the next generation of IACTs. To unveil its full potential, the improved reconstruction performance of CTA needs to be coupled with a reliable background estimate across the entire field of view. This may become especially important in the case of the planned surveys of large areas of the sky. In this contribution we will present pybkgmodel, an open-source python software package developed for CTA. It aims at providing in a consistent way the various background modelling methods, based on the experience from current IACTs such as H.E.S.S, MAGIC, and VERITAS. It is designed as a toolbox allowing a user to easily choose the optimal reconstruction approach for various target regions or a combination of several algorithms. We will introduce the design of the package as well as demonstrate its functionality using data for the CTA Large-Sized Telescope prototype (LST-1).

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Potential of the Cherenkov Telescope Array for studying the young nearby supernova remnants

Prokhorov D.A., Lee S.H., Nagataki S., Vink J., Ellison D.C., Ferrand G., Patnaude D.J., Roepke F.K., Seitenzahl I.R., Slane P.O., Abe K., Abe S., Acharyya A., Adam R., Aguasca-Cabot A., Agudo I., Alfaro J., Alvarez-Crespo N., Alves Batista R., Amans J.P., Amato E., Ambrosino F., Angüner E.O., Antonelli L.A., Aramo C., Arcaro C., Arrabito L., Asano K., Aschersleben J., Ashkar H., Augusto Stuani L., Baack D., Backes M., Balazs C., Balbo M., Baquero Larriva A., Barbosa Martins V., Barres de Almeida U., Barrio J.A., Bastieri D., Batista P.I., Batkovic I., Batzofin R., Baxter J., Beck G., Becker Tjus J., Beiske L., Belardinelli D., Benbow W., Bernardini E., Bernete Medrano J., Bernlöhr K., Berti A., Beshley V., Bhattacharjee P., Bhattacharyya S., Bi B., Biederbeck N., Biland A., Bissaldi E., Blanch O., Blazek J., Boisson C., Bolmont J., Bonnoli G., Bordas P., Bosnjak Z., Bradascio F., Braiding C., Bronzini E., Brose R., Brown A.M., Brun F., Brunelli G., Bulgarelli A., Burelli I., Burmistrov L., Burton M., Bylund T., Calisse P.G., Campoy-Ordaz A., Cantlay B.K., Capalbi M., Caproni A., Capuzzo-Dolcetta R., Carlile C., Caroff S., Carosi A., Carosi R., Carrasco M.S., Cascone E., Cassol F., Castrejon N., Catalani F., Cerasole D., Cerruti M., Chaty S., Chen A.W., Chernyakova M., Chiavassa A.

Proceedings of Science   Vol. 444   2024.9

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Modern imaging atmospheric Cherenkov telescopes have extensively observed young nearby supernova remnants (SNRs), with ages of about 1000 years or less, in the very-high-energy (VHE) gamma-ray band. These efforts resulted in the detection of VHE emission from three young SNRs – Cassiopeia A, Tycho, and SN 1006 – and provided significant evidence for emission from the more distant Kepler’s SNR. However, many questions on the production of VHE gamma rays in these remnants remain unanswered. Using detailed physical models for Tycho’s SNR based on the CR-hydro-NEI code and physically motivated models for the other young nearby remnants, we simulated observations with the Cherenkov Telescope Array (CTA) of these gamma-ray sources. We highlight properties of these remnants accessible for investigation with future CTA observations and discuss which questions are expected to be answered.

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Performance update of an event-type based analysis for the Cherenkov Telescope Array

Bernete J., Gueta O., Hassan T., Linhoff M., Maier G., Sinha A., Abe K., Abe S., Acharyya A., Adam R., Aguasca-Cabot A., Agudo I., Alfaro J., Alvarez-Crespo N., Alves Batista R., Amans J.P., Amato E., Ambrosino F., Angüner E.O., Antonelli L.A., Aramo C., Arcaro C., Arrabito L., Asano K., Aschersleben J., Ashkar H., Augusto Stuani L., Baack D., Backes M., Balazs C., Balbo M., Baquero Larriva A., Barbosa Martins V., de Almeida U.B., Barrio J.A., Bastieri D., Batista P.I., Batkovic I., Batzofin R., Baxter J., Beck G., Becker Tjus J., Beiske L., Belardinelli D., Benbow W., Bernardini E., Bernete Medrano J., Bernlöhr K., Berti A., Beshley V., Bhattacharjee P., Bhattacharyya S., Bi B., Biederbeck N., Biland A., Bissaldi E., Blanch O., Blazek J., Boisson C., Bolmont J., Bonnoli G., Bordas P., Bosnjak Z., Bradascio F., Braiding C., Bronzini E., Brose R., Brown A.M., Brun F., Brunelli G., Bulgarelli A., Burelli I., Burmistrov L., Burton M., Bylund T., Calisse P.G., Campoy-Ordaz A., Cantlay B.K., Capalbi M., Caproni A., Capuzzo-Dolcetta R., Carlile C., Caroff S., Carosi A., Carosi R., Carrasco M.S., Cascone E., Cassol F., Castrejon N., Catalani F., Cerasole D., Cerruti M., Chaty S., Chen A.W., Chernyakova M., Chiavassa A., Chudoba J., Coimbra Araujo C.H., Conforti V., Conte F.

Proceedings of Science   Vol. 444   2024.9

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The Cherenkov Telescope Array (CTA) will be the next-generation observatory in the field of very-high-energy (20 GeV to 300 TeV) gamma-ray astroparticle physics. The traditional approach to data analysis in this field is to apply quality cuts, optimized using Monte Carlo simulations, on the data acquired to maximize sensitivity. Subsequent steps of the analysis typically use the surviving events to calculate one set of instrument response functions (IRFs) to physically interpret the results. However, an alternative approach is the use of event types, as implemented in experiments such as the Fermi-LAT. This approach divides events into sub-samples based on their reconstruction quality, and a set of IRFs is calculated for each sub-sample. The sub-samples are then combined in a joint analysis, treating them as independent observations. In previous works we demonstrated that event types, classified using Machine Learning methods according to their expected angular reconstruction quality, have the potential to significantly improve the CTA angular and energy resolution of a point-like source analysis. Now, we validated the production of event-type wise full-enclosure IRFs, ready to be used with science tools (such as Gammapy and ctools). We will report on the impact of using such an event-type classification on CTA high-level performance, compared to the traditional procedure.

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