The Lobster Eye Imager for Astronomy(LEIA),a pathfinder of the Wide-field X-ray Telescope of the Einstein Probe mission,was successfully launched onboard the SATech-01 satellite of the Chinese Academy of Sciences on20...The Lobster Eye Imager for Astronomy(LEIA),a pathfinder of the Wide-field X-ray Telescope of the Einstein Probe mission,was successfully launched onboard the SATech-01 satellite of the Chinese Academy of Sciences on2022 July 27.In this paper,we introduce the design and on-ground test results of the LEIA instrument.Using stateof-the-art Micro-Pore Optics(MPO),a wide field of view of 346 square degrees(18.6°×18.6°)of the X-ray imager is realized.An optical assembly composed of 36 MPO chips is used to focus incident X-ray photons,and four large-format complementary metal-oxide semiconductor(CMOS)sensors,each of size 6 cm×6 cm,are used as the focal plane detectors.The instrument has an angular resolution of 4’-8’(in terms of FWHM)for the central focal spot of the point-spread function,and an effective area of 2-3 cm^(2) at 1 keV in essentially all the directions within the field of view.The detection passband is 0.5-4 keV in soft X-rays and the sensitivity is2-3×10^(-11) erg s^(-1) cm^(-2)(about 1 milliCrab)with a 1000 s observation.The total weight of LEIA is 56 kg and the power is 85 W.The satellite,with a design lifetime of 2 yr,operates in a Sun-synchronous orbit of 500 km with an orbital period of 95 minutes.LEIA is paving the way for future missions by verifying in flight the technologies of both novel focusing imaging optics and CMOS sensors for X-ray observation,and by optimizing the working setups of the instrumental parameters.In addition,LEIA is able to carry out scientific observations to find new transients and to monitor known sources in the soft X-ray band,albeit with limited useful observing time available.展开更多
The measurement of the bound-state decay of^(205)Tl at the Experimental Storage Ring(ESR)at GSI,Darmstadt,has recently been reported,with substantial impact on the use of^(205)Pb as an early Solar System chronometer a...The measurement of the bound-state decay of^(205)Tl at the Experimental Storage Ring(ESR)at GSI,Darmstadt,has recently been reported,with substantial impact on the use of^(205)Pb as an early Solar System chronometer and on the low-energy measurement of the solar neutrino spectrum via the LOREX project.Owing to the technical challenges in producing a high-purity^(205)T^(l81+)secondary beam,a robust statistical method was developed to estimate the variation in the contaminant^(205)Pb^(81+)produced in the fragmentation reaction,which was subsequently transmitted and stored in the ESR.Here,we show that Bayesian and Monte Carlo methods produce comparable estimates for the contaminant variation,each with unique advantages and challenges given the complex statistical problems for this experiment.We recommend the adoption of such methods in future experiments that exhibit unknown statistical fluctuations.展开更多
基金supported by the Einstein Probe project,a mission in the Strategic Priority Program on Space Science of CAS(grant Nos.XDA15310000,XDA15052100)in part been supported by the European Union’s Horizon 2020 Program under the AHEAD2020 project(grant No.871158).
文摘The Lobster Eye Imager for Astronomy(LEIA),a pathfinder of the Wide-field X-ray Telescope of the Einstein Probe mission,was successfully launched onboard the SATech-01 satellite of the Chinese Academy of Sciences on2022 July 27.In this paper,we introduce the design and on-ground test results of the LEIA instrument.Using stateof-the-art Micro-Pore Optics(MPO),a wide field of view of 346 square degrees(18.6°×18.6°)of the X-ray imager is realized.An optical assembly composed of 36 MPO chips is used to focus incident X-ray photons,and four large-format complementary metal-oxide semiconductor(CMOS)sensors,each of size 6 cm×6 cm,are used as the focal plane detectors.The instrument has an angular resolution of 4’-8’(in terms of FWHM)for the central focal spot of the point-spread function,and an effective area of 2-3 cm^(2) at 1 keV in essentially all the directions within the field of view.The detection passband is 0.5-4 keV in soft X-rays and the sensitivity is2-3×10^(-11) erg s^(-1) cm^(-2)(about 1 milliCrab)with a 1000 s observation.The total weight of LEIA is 56 kg and the power is 85 W.The satellite,with a design lifetime of 2 yr,operates in a Sun-synchronous orbit of 500 km with an orbital period of 95 minutes.LEIA is paving the way for future missions by verifying in flight the technologies of both novel focusing imaging optics and CMOS sensors for X-ray observation,and by optimizing the working setups of the instrumental parameters.In addition,LEIA is able to carry out scientific observations to find new transients and to monitor known sources in the soft X-ray band,albeit with limited useful observing time available.
基金funding from the European Research Council(ERC)under the European Union's Horizon 2020 research and innovation programme(Grant Agreement No.682841"ASTRUm"and No.654002"ENSAR2")The research of G.Leckenby,I.Dillmann,and C.Griffin was funded by the Canadian Natural Sciences and Engineering Research Council(NSERC)via the grant SAPIN-2019-00030+1 种基金J.Glorius,M.S.Sanjari,Yu.A.Litvinov and C.Brandau acknowledge support by the State of Hesse within the Research Cluster ELEMENTS(Project ID 500/10.006)E.Menz and Yu.A.Litvinov acknowledge support by the project"NRW-FAIR",a part of the programme"Netzwerke 2021",an initiative of the Ministry of Culture and Science of the State of North Rhine-Westphalia.R.Gernhäuser acknowledges support by the Excellence Cluster ORIGINS from the German Research Foundation DFG(Excellence Strategy EXC-2094-390783311)。
文摘The measurement of the bound-state decay of^(205)Tl at the Experimental Storage Ring(ESR)at GSI,Darmstadt,has recently been reported,with substantial impact on the use of^(205)Pb as an early Solar System chronometer and on the low-energy measurement of the solar neutrino spectrum via the LOREX project.Owing to the technical challenges in producing a high-purity^(205)T^(l81+)secondary beam,a robust statistical method was developed to estimate the variation in the contaminant^(205)Pb^(81+)produced in the fragmentation reaction,which was subsequently transmitted and stored in the ESR.Here,we show that Bayesian and Monte Carlo methods produce comparable estimates for the contaminant variation,each with unique advantages and challenges given the complex statistical problems for this experiment.We recommend the adoption of such methods in future experiments that exhibit unknown statistical fluctuations.
