China’s ambition to build a 12 m aperture optical/infrared telescope in Tibet has been recently challenged by intense disputes over its design options.The Large Optical/Infrared Telescope,or LOT,which will become the...China’s ambition to build a 12 m aperture optical/infrared telescope in Tibet has been recently challenged by intense disputes over its design options.The Large Optical/Infrared Telescope,or LOT,which will become the world’s biggest upon completion before the 30 m-level ones are in place,is expected to give Chinese astronomers a head start in exploring the early universe and exoplanets among other scientific goals.However,optical engineers and scientists are holding on to very different opinions as for what is the best technical route to get there.展开更多
The China Space Station Telescope(CSST,also known as Xuntian)is a serviceable two-meter-aperture wide-field telescope operating in the same orbit as the China Space Station.The CSST plans to survey a sky area of 17,50...The China Space Station Telescope(CSST,also known as Xuntian)is a serviceable two-meter-aperture wide-field telescope operating in the same orbit as the China Space Station.The CSST plans to survey a sky area of 17,500 deg^(2)of the medium-to-high Galactic latitude to a depth of 25-26 AB mag in at least 6 photometric bands over 255-1,000 nm.Within such a large sky area,slitless spectra will also be taken over the same wavelength range as the imaging survey.Even though the CSST survey is not dedicated to time-domain studies,it would still detect a large number of transients,such as supernovae(SNe).In this paper,we simulate photometric SN observations based on a strawman survey plan using the Sncosmo package.During its 10-year survey,the CSST is expected to observe about 5 million SNe of various types.With quality cuts,we obtain a“gold”sample that comprises roughly 7,400 SNe Ia,2,200 SNe Ibc,and 6,500 SNeⅡcandidates with correctly classified percentages reaching 91%,63%,and 93%(formally defined as classification precision),respectively.The same survey can also trigger alerts for the detection of about 15,500 SNe Ia(precision 61%)and 2,100 SNeⅡ(precision 49%)candidates at least two days before the light maxima.Moreover,the near-ultraviolet observations of the CSST will be able to catch hundreds of shock-cooling events serendipitously every year.These results demonstrate that the CSST can make a potentially significant contribution to SN studies.展开更多
文摘China’s ambition to build a 12 m aperture optical/infrared telescope in Tibet has been recently challenged by intense disputes over its design options.The Large Optical/Infrared Telescope,or LOT,which will become the world’s biggest upon completion before the 30 m-level ones are in place,is expected to give Chinese astronomers a head start in exploring the early universe and exoplanets among other scientific goals.However,optical engineers and scientists are holding on to very different opinions as for what is the best technical route to get there.
基金supported by the National Key R&D Program of China(Grant Nos.2022YFF0503400 and 2022YFF0503401)China Manned Space Program(Grant Nos.CMS-CSST-2021-B01,CMS-CSST-2021-B04,and CMS-CSST2021-A12)+2 种基金Science Program of Beijing Academy of Science and Technology(Grant No.24CD014)National Natural Science Foundation of China(Grant Nos.12288102 and 12033003)Tencent Xplorer Prize。
文摘The China Space Station Telescope(CSST,also known as Xuntian)is a serviceable two-meter-aperture wide-field telescope operating in the same orbit as the China Space Station.The CSST plans to survey a sky area of 17,500 deg^(2)of the medium-to-high Galactic latitude to a depth of 25-26 AB mag in at least 6 photometric bands over 255-1,000 nm.Within such a large sky area,slitless spectra will also be taken over the same wavelength range as the imaging survey.Even though the CSST survey is not dedicated to time-domain studies,it would still detect a large number of transients,such as supernovae(SNe).In this paper,we simulate photometric SN observations based on a strawman survey plan using the Sncosmo package.During its 10-year survey,the CSST is expected to observe about 5 million SNe of various types.With quality cuts,we obtain a“gold”sample that comprises roughly 7,400 SNe Ia,2,200 SNe Ibc,and 6,500 SNeⅡcandidates with correctly classified percentages reaching 91%,63%,and 93%(formally defined as classification precision),respectively.The same survey can also trigger alerts for the detection of about 15,500 SNe Ia(precision 61%)and 2,100 SNeⅡ(precision 49%)candidates at least two days before the light maxima.Moreover,the near-ultraviolet observations of the CSST will be able to catch hundreds of shock-cooling events serendipitously every year.These results demonstrate that the CSST can make a potentially significant contribution to SN studies.
