Experimental Astronomy最新文献

{"title":"Machine learning applications to energy reconstruction of gamma-ray showers for the Tibet AS(gamma ) experiment","authors":"Y. Meng,&nbsp;J. Huang,&nbsp;D. Chen,&nbsp;K Y. Hu,&nbsp;Y. Zhang,&nbsp;L M. Zhai,&nbsp;Y H. Zou,&nbsp;Y L. Yu,&nbsp;Y Y. Li","doi":"10.1007/s10686-025-09993-9","DOIUrl":"10.1007/s10686-025-09993-9","url":null,"abstract":"<div><p>In order to improve the energy reconstruction accuracy of gamma-ray events observed by ground-based array experiments, this work propose a new energy estimator based on machine learning (ML) algorithm to determine the energies of gamma ray induced air showers in the energy range between 1 TeV and 10 PeV. We carry out a full Monte Carlo (MC) simulation using the Tibet air shower array and underground muon detector array, located at an altitude of 4,300 m above sea level. The MC simulated gamma-ray data are used to extract characteristic parameters depicting the air shower information, which are then fed into the ML model for training on both high-energy data sets (<span>(E &gt;sim 10)</span> TeV) and low-energy data sets (<span>(E &lt; 10)</span> TeV). In our simulation data tests, we found that the ML method showed significant advantages over traditional energy estimators (S50, <span>(N_e)</span>, and <span>(sum rho )</span>), with improved energy resolution for both low and high energy datasets. Compared to the traditional estimator, the energy resolution improves by approximately 30% for the inner array events and 55% for the outer array events at <span>(E &lt; 10)</span> TeV. At around 100 TeV, the energy resolution for large zenith angle events in the outer array improves by approximately 20%. This work also found that while the energy resolution of events falling the inside array can only be slightly improved, however, events outside array and at large zenith shower clear improvements. Moreover, it is particularly noteworthy that the ML method has little difference in the energy resolution of the inner and outer array events. The enhanced energy resolution achieved through the machine learning method for outer array events reduces the limitations imposed by the observation area, resulting in an approximately 30% improvement in statistical events. This method is suitable for ground-based array experiments in gamma-ray astronomy, and provides some technical support for further study of the primary gamma-ray energy reconstruction.</p></div>","PeriodicalId":551,"journal":{"name":"Experimental Astronomy","volume":"59 2","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10686-025-09993-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143740871","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Introduction to the SATech-01 satellite HEBS (GECAM-C)","authors":"Xinqiao Li,&nbsp;Xiangyang Wen,&nbsp;Shaolin Xiong,&nbsp;Zhenghua An,&nbsp;Yanbing Xu,&nbsp;Xiaohua Liang,&nbsp;Xiaojing Liu,&nbsp;Sheng Yang,&nbsp;Fan Zhang,&nbsp;Xilei Sun,&nbsp;Shuangnan Zhang,&nbsp;Min Gao,&nbsp;Jinzhou Wang,&nbsp;Dali Zhang,&nbsp;Ke Gong,&nbsp;Yaqing Liu,&nbsp;Xiaoyun Zhao,&nbsp;Zhenxia Zhang,&nbsp;Hong Lu,&nbsp;Wenxi Peng,&nbsp;Rui Qiao,&nbsp;Dongya Guo,&nbsp;Hui Wang,&nbsp;Yanguo Li,&nbsp;Chao Zheng,&nbsp;Chenwei Wang,&nbsp;Yanqiu Zhang,&nbsp;Lu Wang,&nbsp;Zhiqiang Ding,&nbsp;Xiaofeng Zhang","doi":"10.1007/s10686-025-09991-x","DOIUrl":"10.1007/s10686-025-09991-x","url":null,"abstract":"<div><p>The primary scientific objective of the High Energy Burst Searcher (HEBS) is to serve as a crucial component of the global space monitoring network for high-energy celestial burst sources. HEBS aims to monitor the high-energy electromagnetic counterparts of gravitational wave events, as well as the high-energy radiation from rapid radio bursts, gamma-ray bursts, magnetar flares, and other high-energy celestial phenomena across the entire sky. This effort will provide essential data support for related physical research, including energy spectra, light curves, and positional information. The probe is deployed on the Satech-01 satellite and operates in a 500 km solar-synchronous orbit. HEBS is equipped with two types of detectors: the Gamma Ray Detector (GRD) and the Charged Particle Detector (CPD). The GRD employs lanthanum bromide crystals coupled with silicon photomultiplier (SiPM) technology, as well as sodium iodide crystals paired with SiPM technology, to detect X-rays and gamma rays in the energy range of 6 keV to 5.9 MeV. It enables the localization of gamma-ray bursts and other high-energy events through the coordinated detection of multiple probes oriented in different directions. The CPD utilizes plastic scintillator technology coupled with SiPM to detect charged particles within the energy range of 150 keV to 5 MeV. When combined with the GRD, it effectively identifies and distinguishes space particle events from actual celestial phenomena. The payload processor (Electronics Box, EBOX) features onboard triggering and positioning capabilities, transmitting trigger times and positional data via Beidou short messaging in quasi-real time. This information will guide other telescopes in conducting follow-up observations.</p></div>","PeriodicalId":551,"journal":{"name":"Experimental Astronomy","volume":"59 2","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143716949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A novel optical design for wide-field imaging in X-ray astronomy","authors":"Neeraj K. Tiwari,&nbsp;Santosh V. Vadawale,&nbsp;N. P. S. Mithun","doi":"10.1007/s10686-025-09992-w","DOIUrl":"10.1007/s10686-025-09992-w","url":null,"abstract":"<div><p>Over the decades, astronomical X-ray telescopes have utilized the Wolter type-1 optical design, which provides stigmatic imaging in axial direction but suffers from coma and higher-order aberrations for off-axis sources. The Wolter-Schwarzschild design, with stigmatic imaging in the axial direction, while suffering from higher-order aberrations, is corrected for coma, thus performing better than the Wolter type-1. The Wolter type-1 and Wolter-Schwarzschild designs are optimized for on-axis but have reduced angular resolution when averaged over a wide field of view, with the averaging weighted by the area covered in the field of view. An optical design that maximizes angular resolution at the edge of the field of view rather than at the center is more suitable for wide-field X-ray telescopes required for deep-sky astronomical surveys or solar observations. A Hyperboloid-Hyperboloid optical design can compromise axial resolution to enhance field angle resolution, hence providing improved area-weighted average angular resolution over the Wolter-Schwarzschild design, but only for fields of view exceeding a specific size. Here, we introduce a new optical design that is free from coma aberration and capable of maximizing angular resolution at any desired field angle. This design consistently outperforms Wolter-1, Wolter-Schwarzschild, and Hyperboloid-Hyperboloid designs when averaged over any field of view size. The improvement in performance remains consistent across variations in other telescope parameters such as diameter, focal length, and mirror lengths. By utilizing this new optical design, we also present a design for a full-disk imaging solar X-ray telescope.</p></div>","PeriodicalId":551,"journal":{"name":"Experimental Astronomy","volume":"59 2","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143612205","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optical optimization of a dual-band sun-as-a-star extreme ultraviolet spectrograph for measuring the line-of-sight velocity of coronal mass ejections","authors":"Sifan Guo,&nbsp;Yufei Feng,&nbsp;Xianyong Bai,&nbsp;Hui Tian,&nbsp;Wei Duan,&nbsp;Xiaoming Zhu,&nbsp;Yajie Chen,&nbsp;Yuanyong Deng,&nbsp;Haiying Zhang,&nbsp;Zhiyong Zhang,&nbsp;Zhiwei Feng,&nbsp;Xiao Yang,&nbsp;Qi Yang,&nbsp;Mohamed Sedik","doi":"10.1007/s10686-025-09990-y","DOIUrl":"10.1007/s10686-025-09990-y","url":null,"abstract":"<div><p>The detection of Line-of-sight (LOS) velocity of coronal mass ejections (CMEs) is crucial for understanding and forecasting their propagation. The LOS velocity can be derived from the Sun-as-a-star extreme ultraviolet spectrograph based on the Doppler effect. However, the poor spectral resolution of existing instruments is not sufficient for detection. In the paper, we propose a dual-band Sun-as-a-star spectrograph with high spectral resolution for measuring the LOS velocity of CMEs. Based on a multilayer concave grating operating in a normal incident mode, we optimized the parameters of the spectrograph for the wavelength ranges of 18.3<span>( sim )</span>21.3 nm and 49.6<span>( sim )</span>52.9 nm. The spectral resolving power for these two ranges exceeds 1000 and 2000, respectively, which is about three times higher than that of the Extreme ultraviolet Variability Experiment onboard the Solar Dynamics Observatory. B<span>(_4)</span>C/Al and B<span>(_4)</span>C/Mo/Al multilayer structures were optimized to improve the diffraction efficiency across both bands simultaneously. We also evaluated the instrument performance by calculating the photon numbers. Additionally, we discussed the degradation of spectral resolution caused by the stability of satellite platform, determining that the stability should be better than ±7.2<span>(^{prime prime })</span>(<span>( pm )</span>0.002<span>(^circ )</span>) within the exposure time of 60 s. Our investigation provides a new way to observe Sun-as-a-star extreme ultraviolet spectrum.</p></div>","PeriodicalId":551,"journal":{"name":"Experimental Astronomy","volume":"59 2","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143571107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simultaneous multi-spacecraft observations with VLBI radio telescopes to study the interplanetary phase scintillation","authors":"N. M. M. Said,&nbsp;G. Molera Calvés,&nbsp;P. Kummamuru,&nbsp;J. Edwards,&nbsp;M. Maoli,&nbsp;G. Cimo’","doi":"10.1007/s10686-025-09989-5","DOIUrl":"10.1007/s10686-025-09989-5","url":null,"abstract":"<div><p>Ground-based observations of spacecraft signals have been used to study space weather. However, single spacecraft measurements observed from the Earth have limitations in studying the structure and evolution of solar plasma as they are unable to differentiate spatial and temporal variations. To overcome this limitation and improve our understanding of interplanetary scintillation, we simultaneously observed radio signals transmitted by two co-orbiting spacecraft: the ESA Mars Express (MEX) and the Chinese National Space Administration Tianwen-1 (TIW-1). We conducted the observations from April to November 2021 using the University of Tasmania’s VLBI radio telescopes at 8.4 GHz. We employed the Planetary Radio Interferometer and Doppler Experiment (PRIDE) technique to determine the topocentric Doppler measurements and residual phase of the carrier signal. These observables were used to quantify the phase fluctuations of the spacecraft signals caused by solar wind and hydrodynamic turbulence in the interplanetary medium. The measured phase fluctuations RMS from both spacecraft show small differences which are caused by factors such as the spacecraft’s motion, onboard electronics, and variations in the uplink signal path through Earth’s ionosphere. These fluctuations decrease with solar elongation and correlate with solar radio flux at 10.7 cm (2800 MHz), indicating solar activity. The estimated total electron contents along MEX and TIW-1’s radio lines of sight are similar, with higher values at lower solar elongations. Simultaneous multi-spacecraft observations also enable RFI characterization, frequent spacecraft performance comparisons, and investigation of solar activity effects on spacecraft performance and scientific outcomes.</p></div>","PeriodicalId":551,"journal":{"name":"Experimental Astronomy","volume":"59 2","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10686-025-09989-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143564509","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The X-ray Integral Field Unit at the end of the Athena reformulation phase","authors":"Philippe Peille,&nbsp;Didier Barret,&nbsp;Edoardo Cucchetti,&nbsp;Vincent Albouys,&nbsp;Luigi Piro,&nbsp;Aurora Simionescu,&nbsp;Massimo Cappi,&nbsp;Elise Bellouard,&nbsp;Céline Cénac-Morthé,&nbsp;Christophe Daniel,&nbsp;Alice Pradines,&nbsp;Alexis Finoguenov,&nbsp;Richard Kelley,&nbsp;J. Miguel Mas-Hesse,&nbsp;Stéphane Paltani,&nbsp;Gregor Rauw,&nbsp;Agata Rozanska,&nbsp;Jiri Svoboda,&nbsp;Joern Wilms,&nbsp;Marc Audard,&nbsp;Enrico Bozzo,&nbsp;Elisa Costantini,&nbsp;Mauro Dadina,&nbsp;Thomas Dauser,&nbsp;Anne Decourchelle,&nbsp;Jan-Willem den Herder,&nbsp;Andrea Goldwurm,&nbsp;Peter Jonker,&nbsp;Alex Markowitz,&nbsp;Mariano Mendez,&nbsp;Giovanni Miniutti,&nbsp;Silvano Molendi,&nbsp;Fabrizio Nicastro,&nbsp;François Pajot,&nbsp;Etienne Pointecouteau,&nbsp;Gabriel W. Pratt,&nbsp;Joop Schaye,&nbsp;Jacco Vink,&nbsp;Natalie Webb,&nbsp;Simon Bandler,&nbsp;Marco Barbera,&nbsp;Maria Teresa Ceballos,&nbsp;Ivan Charles,&nbsp;Roland den Hartog,&nbsp;W. Bertrand Doriese,&nbsp;Jean-Marc Duval,&nbsp;Flavio Gatti,&nbsp;Brian Jackson,&nbsp;Caroline Kilbourne,&nbsp;Claudio Macculi,&nbsp;Sylvain Martin,&nbsp;Yann Parot,&nbsp;Frederick Porter,&nbsp;Damien Prêle,&nbsp;Laurent Ravera,&nbsp;Stephen Smith,&nbsp;Jan Soucek,&nbsp;Tanguy Thibert,&nbsp;Eija Tuominen,&nbsp;Fabio Acero,&nbsp;Stefano Ettori,&nbsp;Nicolas Grosso,&nbsp;Jelle Kaastra,&nbsp;Pasquale Mazzotta,&nbsp;Jon Miller,&nbsp;Salvatore Sciortino,&nbsp;Sophie Beaumont,&nbsp;Matteo D’Andrea,&nbsp;Jelle de Plaa,&nbsp;Megan Eckart,&nbsp;Luciano Gottardi,&nbsp;Maurice Leutenegger,&nbsp;Simone Lotti,&nbsp;Alexei Molin,&nbsp;Lorenzo Natalucci,&nbsp;Muhammad Qazi Adil,&nbsp;Andrea Argan,&nbsp;Elisabetta Cavazzuti,&nbsp;Mauro Fiorini,&nbsp;Pourya Khosropanah,&nbsp;Eduardo Medinaceli Villegas,&nbsp;Gabriele Minervini,&nbsp;James Perry,&nbsp;Frederic Pinsard,&nbsp;Desi Raulin,&nbsp;Manuela Rigano,&nbsp;Peter Roelfsema,&nbsp;Denis Schwander,&nbsp;Santiago Terron,&nbsp;Guido Torrioli,&nbsp;Joel Ullom,&nbsp;Monika Zuchniak,&nbsp;Laurence Chaoul,&nbsp;Jose Miguel Torrejon,&nbsp;Frank Brachet,&nbsp;Beatriz Cobo,&nbsp;Malcolm Durkin,&nbsp;Valentina Fioretti,&nbsp;Hervé Geoffray,&nbsp;Lionel Jacques,&nbsp;Christian Kirsch,&nbsp;Ugo Lo Cicero,&nbsp;Joseph Adams,&nbsp;Emilie Gloaguen,&nbsp;Manuel Gonzalez,&nbsp;Samuel Hull,&nbsp;Erik Jellyman,&nbsp;Mikko Kiviranta,&nbsp;Kazuhiro Sakai,&nbsp;Emanuele Taralli,&nbsp;Davide Vaccaro,&nbsp;Paul van der Hulst,&nbsp;Jan van der Kuur,&nbsp;Bert-Joost van Leeuwen,&nbsp;Dennis van Loon,&nbsp;Nicholas Wakeham,&nbsp;Natalia Auricchio,&nbsp;Daniele Brienza,&nbsp;Oscar Cheatom,&nbsp;Philippe Franssen,&nbsp;Sabine Julien,&nbsp;Isabelle Le Mer,&nbsp;David Moirin,&nbsp;Vitor Silva,&nbsp;Michela Todaro,&nbsp;Nicolas Clerc,&nbsp;Alexis Coleiro,&nbsp;Andy Ptak,&nbsp;Simonetta Puccetti,&nbsp;Christian Surace,&nbsp;Shariefa Abdoelkariem,&nbsp;Christophe Adami,&nbsp;Corinne Aicardi,&nbsp;Jérôme André,&nbsp;Matteo Angelinelli,&nbsp;Shebli Anvar,&nbsp;Luis Horacio Arnaldi,&nbsp;Anthony Attard,&nbsp;Damian Audley,&nbsp;Florian Bancel,&nbsp;Kimberly Banks,&nbsp;Vivian Bernard,&nbsp;Jan Geralt Bij de Vaate,&nbsp;Donata Bonino,&nbsp;Anthony Bonnamy,&nbsp;Patrick Bonny,&nbsp;Charles Boreux,&nbsp;Ayoub Bounab,&nbsp;Maïmouna Brigitte,&nbsp;Marcel Bruijn,&nbsp;Clément Brysbaert,&nbsp;Andrea Bulgarelli,&nbsp;Simona Calarco,&nbsp;Thierry Camus,&nbsp;Florent Canourgues,&nbsp;Vito Capobianco,&nbsp;Nicolas Cardiel,&nbsp;Edvige Celasco,&nbsp;Si Chen,&nbsp;James Chervenak,&nbsp;Fabio Chiarello,&nbsp;Sébastien Clamagirand,&nbsp;Odile Coeur-Joly,&nbsp;Leonardo Corcione,&nbsp;Mickael Coriat,&nbsp;Anais Coulet,&nbsp;Bernard Courty,&nbsp;Alexandre Coynel,&nbsp;Antonino D’Ai,&nbsp;Eugenio Dambrauskas,&nbsp;Fabio D’anca,&nbsp;Lea Dauner,&nbsp;Matteo De Gerone,&nbsp;Natalie DeNigris,&nbsp;Johannes Dercksen,&nbsp;Martin de Wit,&nbsp;Pieter Dieleman,&nbsp;Michael DiPirro,&nbsp;Eric Doumayrou,&nbsp;Lionel Duband,&nbsp;Luc Dubbeldam,&nbsp;Michel Dupieux,&nbsp;Simon Dupourqué,&nbsp;Jean Louis Durand,&nbsp;Dominique Eckert,&nbsp;Philippe Ferrando,&nbsp;Lorenzo Ferrari Barusso,&nbsp;Fred Finkbeiner,&nbsp;Mariateresa Fiocchi,&nbsp;Hervé Fossecave,&nbsp;Stefano Gabici,&nbsp;Giovanni Gallucci,&nbsp;Florent Gant,&nbsp;Jian-Rong Gao,&nbsp;Fabio Gastaldello,&nbsp;Ludovic Genolet,&nbsp;Simona Ghizzardi,&nbsp;Elisa Giovannini,&nbsp;Margherita Giustini,&nbsp;Alain Givaudan,&nbsp;Olivier Godet,&nbsp;Alicia Gomez,&nbsp;Raoul Gonzalez,&nbsp;Ghassem Gozaliasl,&nbsp;Laurent Grandsire,&nbsp;David Granena,&nbsp;Michel Gros,&nbsp;Corentin Guerin,&nbsp;Emmanuel Guilhem,&nbsp;Gian Paolo Guizzo,&nbsp;Liyi Gu,&nbsp;Kent Irwin,&nbsp;Christian Jacquey,&nbsp;Agnieszka Janiuk,&nbsp;Jean Jaubert,&nbsp;Antoine Jolly,&nbsp;Thierry Jourdan,&nbsp;Jürgen Knödlseder,&nbsp;Ole König,&nbsp;Andrew Korb,&nbsp;Ingo Kreykenbohm,&nbsp;David Lafforgue,&nbsp;Radek Lan,&nbsp;Maélyss Larrieu,&nbsp;Philippe Laudet,&nbsp;Philippe Laurent,&nbsp;Sylvain Laurent,&nbsp;Monica Laurenza,&nbsp;Maël Le Cam,&nbsp;Jean Lesrel,&nbsp;Sebastiano Ligori,&nbsp;Maximilian Lorenz,&nbsp;Alfredo Luminari,&nbsp;Kristin Madsen,&nbsp;Océane Maisonnave,&nbsp;Lorenzo Marelli,&nbsp;Wilfried Marty,&nbsp;Zoé Massida,&nbsp;Didier Massonet,&nbsp;Irwin Maussang,&nbsp;Pablo Eleazar Merino Alonso,&nbsp;Jean Mesquida,&nbsp;Teresa Mineo,&nbsp;Nicola Montinaro,&nbsp;David Murat,&nbsp;Kenichiro Nagayoshi,&nbsp;Yaël Nazé,&nbsp;Loïc Noguès,&nbsp;François Nouals,&nbsp;Cristina Ortega,&nbsp;Francesca Panessa,&nbsp;Luigi Parodi,&nbsp;Enrico Piconcelli,&nbsp;Ciro Pinto,&nbsp;Delphine Porquet,&nbsp;Thomas Prouvé,&nbsp;Michael Punch,&nbsp;Guillaume Rioland,&nbsp;Marc-Olivier Riollet,&nbsp;Louis Rodriguez,&nbsp;Anton Roig,&nbsp;Mauro Roncarelli,&nbsp;Lionel Roucayrol,&nbsp;Gilles Roudil,&nbsp;Lander Ruiz de Ocenda,&nbsp;Luisa Sciortino,&nbsp;Olivier Simonella,&nbsp;Michael Sordet,&nbsp;Ulrich Taubenschuss,&nbsp;Guilhem Terrasa,&nbsp;Régis Terrier,&nbsp;Pietro Ubertini,&nbsp;Ludek Uhlir,&nbsp;Michela Uslenghi,&nbsp;Henk van Weers,&nbsp;Salvatore Varisco,&nbsp;Peggy Varniere,&nbsp;Angela Volpe,&nbsp;Gavin Walmsley,&nbsp;Michael Wise,&nbsp;Andreas Wolnievik,&nbsp;Grzegorz Woźniak","doi":"10.1007/s10686-025-09984-w","DOIUrl":"10.1007/s10686-025-09984-w","url":null,"abstract":"<div><p>The Athena mission entered a redefinition phase in July 2022, driven by the imperative to reduce the mission cost at completion for the European Space Agency below an acceptable target, while maintaining the flagship nature of its science return. This notably called for a complete redesign of the X-ray Integral Field Unit (X-IFU) cryogenic architecture towards a simpler active cooling chain. Passive cooling via successive radiative panels at spacecraft level is now used to provide a 50 K thermal environment to an X-IFU owned cryostat. 4.5 K cooling is achieved via a single remote active cryocooler unit, while a multi-stage Adiabatic Demagnetization Refrigerator ensures heat lift down to the 50 mK required by the detectors. Amidst these changes, the core concept of the readout chain remains robust, employing Transition Edge Sensor microcalorimeters and a SQUID-based Time-Division Multiplexing scheme. Noteworthy is the introduction of a slower pixel. This enables an increase in the multiplexing factor (from 34 to 48) without compromising the instrument energy resolution, hence keeping significant system margins to the new 4 eV resolution requirement. This allows reducing the number of channels by more than a factor two, and thus the resource demands on the system, while keeping a 4’ field of view (compared to 5’ before). In this article, we will give an overview of this new architecture, before detailing its anticipated performances. Finally, we will present the new X-IFU schedule, with its short term focus on demonstration activities towards a mission adoption in early 2027</p></div>","PeriodicalId":551,"journal":{"name":"Experimental Astronomy","volume":"59 2","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143533148","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mission analysis, design and operations plan of India’s first polarimetry satellite: X-ray Polarimetry Satellite (XPoSat)","authors":"Himani Saini,&nbsp;K. V. Madhu,&nbsp;Ritu Karidhal","doi":"10.1007/s10686-025-09988-6","DOIUrl":"10.1007/s10686-025-09988-6","url":null,"abstract":"<div><p><b>X</b>-ray <b>Po</b>larimeter <b>Sat</b>ellite (XPoSat) is India’s first landmark mission dedicated to X-ray polarimetry, with the aim of measuring and studying X-rays emitted by bright astronomical objects such as black hole X-ray binaries, pulsar wind nebulae, and accretion-powered pulsars. Polar Satellite Launch Vehicle-C58 (PSLV-C58) launched the XPoSat mission on 1st January 2024, equipped with two significant, scientific instruments: XSPECT (X-ray Spectroscopy and Timing) and POLIX (POLarimeter Instrument in X-rays). With the launch of XPoSat, a new and important fourth dimension of polarization has been added. POLIX became the first in the world to provide measurements of polarization in <b>8–30</b> kilo electron Volt (keV) energy band. XSPECT is a spectroscopy payload responsible for providing timing and spectral information in 0.8–15 keV energy band of X-ray emissions from about 54 potential identified cosmic X-ray sources. Astronomical sources emitting X-rays are sites of strong gravity, and strong magnetic fields and have a variety of geometries for scattering, which are expected to give rise to polarization signatures in these sources. This article provides a comprehensive overview from mission specifications to mission design, mission planning, mission analysis, and mission operations aspects of spacecraft configuration, operations, and on-orbit operations of XPoSat mission with the science brought by the first-time flown payload in high energy bands, which will allow astronomers to explore materials under intense magnetic and gravitational fields. The challenges involved in planning and executing the mission operations with critical scenarios have also been highlighted.</p></div>","PeriodicalId":551,"journal":{"name":"Experimental Astronomy","volume":"59 2","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143489496","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Sliding Flux Ramp Demodulation algorithm with high sampling rate in Microwave SQUID Multiplexer","authors":"Guofu Liao,&nbsp;Congzhan Liu,&nbsp;Zhengwei Li,&nbsp;Daikang Yan,&nbsp;Xiangxiang Ren,&nbsp;Yongjie Zhang,&nbsp;Laiyu Zhang,&nbsp;Yu Xu,&nbsp;Shibo Shu,&nbsp;He Gao,&nbsp;Yifei Zhang,&nbsp;Xuefeng Lu,&nbsp;Xufang Li,&nbsp;He Xu,&nbsp;Di Wu","doi":"10.1007/s10686-025-09986-8","DOIUrl":"10.1007/s10686-025-09986-8","url":null,"abstract":"<div><p>Microwave SQUID Multiplexing (<span>(mu )</span>MUX) is a widely used technique in the low-temperature detectors community as it offers a high capacity for reading large-scale Transition-Edge Sensor (TES) arrays. This paper proposes a Sliding Flux Ramp Demodulation (SFRD) algorithm for <span>(mu )</span>MUX readout system. It can achieve a sampling rate in the order of MHz while maintaining a multiplexing ratio of about one thousand. Advancing of this large array readout technique makes it possible to observe scientific objects with improved time resolution and event count rate. This will be highly helpful for TES calorimeters in X-ray applications, such as X-ray astrophysics missions.</p></div>","PeriodicalId":551,"journal":{"name":"Experimental Astronomy","volume":"59 2","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143423113","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"SVOM-GRM trigger performance study and verification","authors":"Jiang He,&nbsp;Jian-Chao Sun,&nbsp;Yong-Wei Dong,&nbsp;Bo-Bing Wu,&nbsp;Shi-Jie Zheng,&nbsp;Lu Li,&nbsp;Jiang-Tao Liu,&nbsp;Xin Liu,&nbsp;Hao-Li Shi,&nbsp;Li-Ming Song,&nbsp;Rui-Jie Wang,&nbsp;Juan Zhang,&nbsp;Li Zhang,&nbsp;Shuang-Nan Zhang,&nbsp;Xiao-Yun Zhao,&nbsp;Xing-Guang Liu","doi":"10.1007/s10686-025-09983-x","DOIUrl":"10.1007/s10686-025-09983-x","url":null,"abstract":"<div><p>The Space-based multi-band astronomical Variable Objects Monitor (SVOM) is a collaborative satellite developed by China and France, specifically designed for observing and studying Gamma-Ray Bursts (GRBs) as well as other variable sources. Among its four on-board payloads, the Gamma-Ray Monitor (GRM) is responsible for detecting high-energy photons ranging from 15 keV to 5 MeV, equipped with real-time triggering and localization capabilities. In this paper, we primarily focus on investigating the triggering performance of GRM. Firstly, the energy response matrix of each detector is obtained by using the Geant4 simulation toolkit. Based on the results of background simulations and given samples of GRB, the instrument’s sensitivity and the detection efficiency to GRBs from different directions are estimated. The results demonstrate that GRM exhibits superior sensitivity to GRBs with harder energy spectrum, enabling more than <span>(80%)</span> of the GRBs to be triggered within its field of view. By considering satellite orbit and attitude, we conduct a 3-year simulation of GRB observations which reveals that approximately 106 GRBs can be detected annually in the energy range of 50-300 keV by GRM. Moreover, it is observed that optimal triggering energy range correlates with the hardness index values of the GRBs. Finally, we discuss the on-orbit triggering algorithm that has been implemented by GRM along with developing a ground-based multi-timescale search algorithm for identifying potential GRB events. Our work contributes to understanding the on-orbit triggering performance characteristics demonstrated by GRM, while also providing a benchmark for refining ground-based strategies focused on detecting new instances of GRBs, thus amplifying the scientific output obtained from utilizing GRM’s capabilities.</p></div>","PeriodicalId":551,"journal":{"name":"Experimental Astronomy","volume":"59 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143361647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A multi-fidelity transfer learning strategy for surface deformation measurement of large reflector antennas","authors":"Zihan Zhang,&nbsp;Qian Ye,&nbsp;Na Wang,&nbsp;Guoxiang Meng","doi":"10.1007/s10686-025-09980-0","DOIUrl":"10.1007/s10686-025-09980-0","url":null,"abstract":"<div><p>As the observation frequency of large-aperture antennas increases, the requirements for measuring main reflector deformation have become more stringent. Recently, the rapid development of deep learning has led to its application in antenna deformation prediction. However, achieving high accuracy requires a large number of high-fidelity deformation samples, which is often challenging to obtain. To address these problems, this paper establishes a high-accuracy antenna surface deformation measurement model based on a multi-fidelity transfer learning neural network (MF-TLNN). Firstly, a low-fidelity surrogate model is constructed using a large number of simulation deformation samples to ensure its robustness. Secondly, the MF-TLNN structure is designed and trained using a small number of high-fidelity samples obtained from actual measurements of the main reflector deformation via out-of-focus (OOF) holography method. Thirdly, a Zernike correction module is utilized to provide additional constraints and ensure the stability of the results. Experimental results show that the proposed method can closely approximate radio holography measurements in terms of accuracy and is almost real-time in terms of speed.</p></div>","PeriodicalId":551,"journal":{"name":"Experimental Astronomy","volume":"59 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143361942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}