The coincidental detection of the gravitational wave event GW 170817 and the associated gamma-ray burst GRB 170817A marked the advent of multi-messenger astronomy and represented a milestone in the study of GRBs. In this context, the launch of SVOM in mid-2022, with its two wide-field high-energy instruments ECLAIRs and GRM, will foster the possibilities of coincidental transient detection with gravitational waves and gamma-rays events. The purpose of this paper is to assess the ability of SVOM/ECLAIRs to detect and quickly characterize high-energy transients in the local Universe (z<0.3), and to discuss the contribution of this instrument to multi-messenger astronomy and to gamma-ray burst(GRB) astrophysics in the 2020s. A list of local HE transients, along with their main characteristics, is constructed through an extensive literature survey. The detectability of these transients with ECLAIRs is assessed with detailed simulations using tools developed for the SVOM mission, including a GEANT4 simulation of the energy response and a simulated trigger algorithm representative of the onboard trigger algorithm. The SNR for almost all detections will be sufficiently high to allow the on-board ECLAIRs trigger algorithm to detect and derive the localisation of the transient, transmitting it to the SVOM satellite and ground-based instruments. Coupled with the anti-solar pointing strategy of SVOM, this will enable an optimal follow-up of the events, allowing the observation of their afterglows, supernovae/kilonovae counterparts, and host galaxies. We conclude the paper with a discussion of the unique contribution expected from SVOM and of the possibility of simultaneous GW detection for each type of transient in our sample.
The soft gamma-ray telescope ECLAIRs with its Scientific Trigger Unit is in charge of detecting Gamma-Ray Bursts (GRBs) on-board the future SVOM satellite. Using the "scientific software model" (SSM), we study the efficiency of both implemented trigger algorithms, the Count-Rate Trigger for time-scales below 20s and the Image Trigger for larger ones. The SMM provides a simulation of ECLAIRs with photon projection through the coded-mask onto the detection plane. We developed an input GRB database for the SSM based on GRBs light curves detected by the Fermi GBM instrument. We extrapolated the GR…
Ultra-long gamma-ray bursts (ULGRBs) have very atypical durations of more than 2000 seconds. Even if their origins are discussed, the SVOM mission with its soft gamma-ray telescope ECLAIRs could detect ULGRBs and increase the sample of the few which have been detected so far by the Burst Alert Telescope aboard the Neil Gehrels Swift Observatory and some other instruments. In this paper, after a short description of the SVOM mission, we present methods developed to clean detector images from non-flat background and known source contributions in the onboard imaging process. We present an estimat…
SVOM (Space-based multi-band astronomical Variable Object Monitor) is a future Chinese-French satellite mission which is dedicated to Gamma-Ray Burst (GRB) studies. Its anti-solar pointing strategy makes the Earth cross the field of view of its payload every orbit. In this paper, we present the variations of the gamma-ray background of the two high energy instruments aboard SVOM, the Gamma-Ray Monitor (GRM) and ECLAIRs, as a function of the Earth position. We conclude with an estimate of the Earth influence on their sensitivity and their GRB detection capability.
Ultra-long Gamma-Ray Bursts (ulGRBs) are Gamma-Ray Bursts (GRBs) with an unusually long emission in X and gamma rays, reaching durations of thousands of seconds. They could form a specific class of high-energy transient events, whose origin is still under discussion. The current sample of known ulGRBs consists of a few tens of events which have been detected so far by the Burst Alert Telescope (BAT) aboard the Neil Gehrels Swift Observatory and some other instruments. The SVOM mission which is scheduled to begin operations after 2021 could help to detect and observe more ulGRBs thanks to its s…
The coded mask of the ECLAIRs telescope onboard the SVOM space mission
Université Paris Cité, CNRS, Astroparticule et Cosmologie（巴黎西岱大学，法国国家科学研究中心，粒子与宇宙学）；CEA Paris-Saclay, Institut de Recherche sur les lois Fondamentales de l’Univers（巴黎萨克雷原子能委员会，基础定律研究所）；CNES（法国国家空间研究中心）
Université Paris Cité（巴黎西岱大学）；CNRS（法国国家科学研究中心）；CEA（法国原子能和替代能源委员会）；Astroparticule et Cosmologie（粒子天体物理与宇宙学）；CEA Paris-Saclay（巴黎萨克雷CEA）；Irfu（法国原子能和替代能源研究院）；Département d’Astrophysique（天体物理学系）；AIM（物质、宇宙与辐射相互作用实验室）
The SVOM mission under development will carry four instruments, and in particular the coded-mask telescope named ECLAIRs, with a large field of view of about 2 sr, operating in the 4-150 keV energy band. The trigger software on board ECLAIRs will search for high-energy transients such as gamma-ray bursts and peculiar behaviour (e.g. strong outbursts) from known X-ray sources, in order to repoint the satellite to perform follow-up observations with the onboard narrow field of view instruments. The image trigger, one of the two algorithms implemented in the software on board ECLAIRs, produces im…
ECLAIRs: the SVOM high-energy transient trigger camera
IRAP, Université de Toulouse/CNRS/CNES（图卢兹大学/法国国家科学研究中心/法国国家空间研究中心 IRAP）；CEA Paris-Saclay, Institut de Recherche sur les lois Fondamentales de l’Univers（巴黎-萨克雷原子能委员会基础定律研究所）；Université Paris Cité, CNRS, CEA, Astroparticule et Cosmologie（巴黎西岱大学/法国国家科学研究中心/法国原子能和替代能源署 粒子物理与宇宙学）；Laboratoire Universe et Particules de Montpellier, CNRS/IN2P3（蒙彼利埃宇宙与粒子实验室/法国国家科学研究中心/法国国家核子和粒子物理研究所）；CNES（法国国家空间研究中心）
The GRB joint scientific analysis pipeline of the ECLAIRs and GRM instruments on board SVOM
Laboratoire Univers et Particules de Montpellier, Université Montpellier, CNRS/IN2P3（蒙彼利埃宇宙与粒子实验室，蒙彼利埃大学，法国国家科学研究中心/法国国家核子和粒子物理研究所）；Sorbonne Université, CNRS, UMR 7095, Institut d’Astrophysique de Paris（索邦大学，法国国家科学研究中心，联合研究单位7095，巴黎天体物理学研究所）；Institut Universitaire de France（法兰西学院）；INAF –Osservatorio Astronomico di Brera（意大利国家天体物理研究所-布雷拉天文台）
We report on an on-going test campaign of more than 5000 Schottky CdTe detectors (4x4x1 mm^3), over a sample of twelve thousands, provided by Acrorad Co., Ltd (Japan). 6400 of these detectors will be used to build the detection plane of the ECLAIRs camera on the Chinese-French gamma-ray burst mission SVOM. These tests are mandatory to fulfill the prime requirement of ECLAIRs to detect gamma-ray burst photons down to 4 keV. The detectors will be operated at -20C under a reverse bias of 600 V. We found that 78% of the detectors already tested could be considered for the flight model. We measured…
The SVOM mission under development will carry various instruments, and in particular the coded-mask telescope ECLAIRs, with a large field of view of about 2 sr, operating in the 4--150 keV energy band, whose goal is to detect high energy transients such as gamma-ray bursts. The trigger software onboard ECLAIRs will search for new hard X-ray sources appearing in the sky, as well as peculiar behaviour (e.g. strong outbursts) from known sources, in order to repoint the satellite to perform follow-up observations with its onboard narrow field of view instruments. The presence of known X-ray source…
GRM (Gamma-Ray Monitor) is the high energy detector on-board the future Chinese-French satellite SVOM (Space-based multi-band astronomical Variable Object Monitor) which is dedicated to Gamma-Ray Burst (GRB) studies. This paper presents the investigation of the on-board counting rate trigger algorithms of GRM. The trigger threshold and trigger efficiency based on the given GRB sample are calculated with the algorithms. The trigger characteristics of GRM and ECLAIRs are also analyzed. In addition, the impact of solar flares on GRM is estimated, and the method to distinguish solar flares from GR…
XRF 241001A/SN 2024aiiq: A faint soft X-ray transient detected by SVOM with a broad-line type Ic supernova revealed by JWST
Aix Marseille University（艾克斯马赛大学）；CNRS（法国国家科学研究中心）；CNES（法国国家空间研究中心）；IRAP（天体物理研究研究所）；Université de Toulouse（图卢兹大学）；School of Physics and Astronomy, University of Birmingham（伯明翰大学物理与天文学院）；Institute for Gravitational Wave Astronomy, University of Birmingham（伯明翰大学引力波天文研究所）；CEA Paris-Saclay（巴黎萨克雷欧洲原子能委员会）；Cosmic Dawn Center (DAWN)（宇宙黎明中心）；Niels Bohr Institute, University of Copenhagen（哥本哈根大学尼尔斯玻尔研究所）；Radboud University（拉德堡德大学）；Department of Astrophysics/IMAPP, Radboud University（拉德堡德大学天体物理学系/IMAPP）；Department of Physics, University of Warwick（华威大学物理系）；Sorbonne Université（索邦大学）；Institut d’Astrophysique de Paris（巴黎天体物理研究所）；Institut Universitaire de France（法兰西学术院）；Kavli Institute for Cosmology, University of Cambridge（剑桥大学卡弗里宇宙学研究所）；Institute of Astronomy, University of Cambridge（剑桥大学天文学研究所）
SVOM/VT: Overview of data processing and GRB identifications with X-band data
National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）；School of Astronomy and Space Science, University of Chinese Academy of Sciences（中国科学院大学天文与空间科学学院）；Institute for Frontier in Astronomy and Astrophysics, Beijing Normal University（北京师范大学前沿交叉科学研究院）；School of Physics and Astronomy, Beijing Normal University（北京师范大学物理学院）
CEA Paris-Saclay, Institut de Recherche sur les lois Fondamentales de l’Univers（法国原子能和替代能源委员会巴黎萨克雷中心基础定律研究所）；National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）；Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences（中国科学院高能物理研究所粒子天体物理重点实验室）；Aix Marseille Université, CNRS, CNES, LAM（艾克斯-马赛大学）；IRAP, Université de Toulouse, CNRS, CNES（图卢兹大学）；Université Paris Cité, CNRS, CEA, Astroparticule et Cosmologie（巴黎西岱大学）；Sorbonne Université, CNRS, UMR 7095, Institut d’Astrophysique de Paris（索邦大学）
National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）；School of Astronomy and Space Science, University of Chinese Academy of Sciences（中国科学院大学天文学与空间科学学院）；CEA Paris-Saclay, Institut de Recherche sur les lois Fondamentales de l’Univers（巴黎萨克雷大学原子能与替代能源委员会基础定律研究所）；Université Paris-Saclay, Université Paris Cité, CEA, CNRS, AIM（巴黎萨克雷大学、巴黎西岱大学、CEA、CNRS、AIM）；LUX, Observatoire de Paris – PSL, CNRS, Sorbonne Université（卢克斯实验室，巴黎天文台-PSL，CNRS，索邦大学）
Early results from the SVOM Observatory Science program
Université Paris Cité, CNRS, Astroparticule et Cosmologie（巴黎西岱大学）；State Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences（中国科学院高能物理研究所）；National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）；IRAP, Université de Toulouse, CNRS, CNES（图卢兹大学）；CEA Paris-Saclay, IRFU/DAp-AIM（法国原子能和替代能源委员会）；Department of Astronomy, University of Science and Technology of China（中国科学技术大学）；Observatoire Astronomique de Strasbourg, Université de Strasbourg, CNRS（斯特拉斯堡大学）
SVOM/VT: Instrument Overview, Science Objectives, and First-Year Performance
National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）；School of Astronomy and Space Science, University of Chinese Academy of Sciences（中国科学院大学天文与空间科学学院）；Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences（中国科学院西安光学精密机械研究所）
The LIGO and Virgo scientific collaboration (LVC) alerted two binary neutron star (BNS) merger candidates, S190425z and S190426c. Fermi-GBM observed 55.6\% (for S190425z) and 100\% (for S190426c) of the probability regions of both events at the respective merger times, but no gamma-ray burst (GRB) was detected in either case. The derived luminosity upper limits suggest that a short GRB similar to GRB 170817A would not be detectable for both cases due to their larger distances than GW170817. Assuming that the jet profile obtained from the GW170817/GRB 170817A is quasi-universal for all BNS-GRB …
EP260119a: A High-Redshift Gamma-Ray Quiet Fast X-ray Transient Probing a Potentially Hidden Population of Relativistic Explosions
Universidad Nacional Autónoma de México（墨西哥国立自治大学）；Universitat de València（瓦伦西亚大学）；Aix Marseille Univ.（艾克斯-马赛大学）；Institute of High Energy Physics, Chinese Academy of Sciences（中国科学院高能物理研究所）
