The high-altitude detection of astronomical radiation(HADAR)experiment is a new Cherenkov observation technique with a wide field of view(FoV),aimed at observing the prompt emissions ofγ-ray bursts(GRBs).The bottlene...The high-altitude detection of astronomical radiation(HADAR)experiment is a new Cherenkov observation technique with a wide field of view(FoV),aimed at observing the prompt emissions ofγ-ray bursts(GRBs).The bottleneck for this type of experiment can be found in determining how to reject the high rate of nightsky background(NSB)noise from random stars.In this work,we propose a novel method for rejecting noise,which considers the spatial properties of GRBs and the temporal characteristics of Cherenkov radiation.In space coordinates,the map between the celestial sphere and the fired photomultiplier tubes(PMTs)on the telescope's camera can be expressed as f(δ(i,j))=δ'(i',j'),which means that a limited number of PMTs is selected from one direction.On the temporal scale,a 20-ns time window was selected based on the knowledge of Cherenkov radiation.This allowed integration of the NSB for a short time interval.Consequently,the angular resolution and effective area at 100 GeV in the HADAR experiment were obtained as 0.2°and 10^(4)m^(2),respectively.This method can be applied to all wide-FoV experiments.展开更多
逾20年的策划,数十人十多年的埋头苦干,迎来了羊八井宇宙线实验大发展历史机遇的到来。作为中科院规划中的国家西部基础研究平台,羊八井的学科定位、平台功能、近远期目标和科研项目,须在对学科发展、国家需要、羊八井优势和现有基础的...逾20年的策划,数十人十多年的埋头苦干,迎来了羊八井宇宙线实验大发展历史机遇的到来。作为中科院规划中的国家西部基础研究平台,羊八井的学科定位、平台功能、近远期目标和科研项目,须在对学科发展、国家需要、羊八井优势和现有基础的清楚认识的基础上加以规划。作为一个基础研究平台,羊八井需要一个功能强大、能覆盖广阔能区、能支持多个课题甚至能为多种学科长期服务的当家设备。为此,许多建议被提了出来,展现了人们从不同角度对羊八井发展的设计。文章对此作了简要评论并具体提出了“基于AR G O地毯的羊八井超级复合陈列计划”及发展多学科研究、明确平台功能和理顺管理体制等诸项建议。展开更多
The large array of imaging atmospheric Cherenkov telescopes(LACT)is a planned array of 32 Cherenkov telescopes,each featuring 6-m diameter mirrors,to be constructed at the LHAASO site.This study focused on optimizing ...The large array of imaging atmospheric Cherenkov telescopes(LACT)is a planned array of 32 Cherenkov telescopes,each featuring 6-m diameter mirrors,to be constructed at the LHAASO site.This study focused on optimizing the array layout and analyzing the performance of LACT.Two observation modes were examined:large zenith angle observations for ultra-high energy events and small zenith angle observations for lower energy thresholds.For large zenith angles(60°),simulations indicate that an 8-telescope subarray can achieve an effective area of 3km^(2)with excellent angular resolution.For small zenith angles,we optimized the layout of 4-telescope cells and the full 32-telescope array.The energy threshold of the full array is approximately 200 GeV,which is particularly crucial for studying transient phenomena such as gamma-ray bursts(GRBs)and active galactic nuclei(AGNs).This study provides essential guidance for finalizing the LACT layout design and estimating performance under various observational conditions.It also highlights the potential of LACT for conducting deep observations of ultra-high energyγ-ray sources,performing morphological studies of PeVatrons,and advancing time-domainγ-ray astronomy.展开更多
基金supported by the Key R&D Program of Sichuan Province (Nos. 2019ZYZF0001 and 2020YFSY0016)the National Natural Science Foundation of China (Nos. 11873005,12047575, 11705103, 11635011, U1831208, U1632104, 11875264U2031110)
文摘The high-altitude detection of astronomical radiation(HADAR)experiment is a new Cherenkov observation technique with a wide field of view(FoV),aimed at observing the prompt emissions ofγ-ray bursts(GRBs).The bottleneck for this type of experiment can be found in determining how to reject the high rate of nightsky background(NSB)noise from random stars.In this work,we propose a novel method for rejecting noise,which considers the spatial properties of GRBs and the temporal characteristics of Cherenkov radiation.In space coordinates,the map between the celestial sphere and the fired photomultiplier tubes(PMTs)on the telescope's camera can be expressed as f(δ(i,j))=δ'(i',j'),which means that a limited number of PMTs is selected from one direction.On the temporal scale,a 20-ns time window was selected based on the knowledge of Cherenkov radiation.This allowed integration of the NSB for a short time interval.Consequently,the angular resolution and effective area at 100 GeV in the HADAR experiment were obtained as 0.2°and 10^(4)m^(2),respectively.This method can be applied to all wide-FoV experiments.
文摘逾20年的策划,数十人十多年的埋头苦干,迎来了羊八井宇宙线实验大发展历史机遇的到来。作为中科院规划中的国家西部基础研究平台,羊八井的学科定位、平台功能、近远期目标和科研项目,须在对学科发展、国家需要、羊八井优势和现有基础的清楚认识的基础上加以规划。作为一个基础研究平台,羊八井需要一个功能强大、能覆盖广阔能区、能支持多个课题甚至能为多种学科长期服务的当家设备。为此,许多建议被提了出来,展现了人们从不同角度对羊八井发展的设计。文章对此作了简要评论并具体提出了“基于AR G O地毯的羊八井超级复合陈列计划”及发展多学科研究、明确平台功能和理顺管理体制等诸项建议。
基金supported by the National Nature Science Foundation of China(12041305)the National Youth Thousand Talents Program in China,and the Sichuan Science and Technology Department,Institute of High Energy Physics(2023YFSY0014,E25156U1)+4 种基金supported by the Sichuan Province Science Foundation for Distin-guished Young Scholars(2022JDJQ0043)the Sichuan Science and Technology Department(2023YFSY0014)the Xiejialin Foundation of IHEP(E2546IU2)the National Natural Science Foundation of China(12261141691)the Innovation Project of IHEP(E25451U2)。
文摘The large array of imaging atmospheric Cherenkov telescopes(LACT)is a planned array of 32 Cherenkov telescopes,each featuring 6-m diameter mirrors,to be constructed at the LHAASO site.This study focused on optimizing the array layout and analyzing the performance of LACT.Two observation modes were examined:large zenith angle observations for ultra-high energy events and small zenith angle observations for lower energy thresholds.For large zenith angles(60°),simulations indicate that an 8-telescope subarray can achieve an effective area of 3km^(2)with excellent angular resolution.For small zenith angles,we optimized the layout of 4-telescope cells and the full 32-telescope array.The energy threshold of the full array is approximately 200 GeV,which is particularly crucial for studying transient phenomena such as gamma-ray bursts(GRBs)and active galactic nuclei(AGNs).This study provides essential guidance for finalizing the LACT layout design and estimating performance under various observational conditions.It also highlights the potential of LACT for conducting deep observations of ultra-high energyγ-ray sources,performing morphological studies of PeVatrons,and advancing time-domainγ-ray astronomy.
