Mayuri Sathyanarayana Rao, N. Udaya Shankar, Ravi Subrahmanyan, Saurabh Singh
{"title":"用SKA探测宇宙黎明和再电离时代的全球信号","authors":"Mayuri Sathyanarayana Rao, N. Udaya Shankar, Ravi Subrahmanyan, Saurabh Singh","doi":"10.1007/s12036-023-09911-5","DOIUrl":null,"url":null,"abstract":"<div><p>A key science project for SKA-Low is the interferometer imaging of spatio-temporal fluctuations in the hydrogen ionization fraction and spin temperature as a diagnostic of cosmic dawn (CD) and epoch of reionization (EoR) in the redshift range <span>\\(6 \\lesssim z \\lesssim 28\\)</span>. However, detection of the global CD/EoR signal, which provides the differential HI 21-cm brightness temperature with respect to the background radiation temperature, is outside the current purview of SKA-Low observing in interferometer mode. This global CD/EoR signal can provide the critical zero-spacing measurement vital for establishing the base level of fluctuations measured by SKA-Low interferometers. We present here, a concept to detect the global CD/EoR signal as a supplement to the CD/EoR key science of SKA-Low. This would be enabled by adding a compact array of outrigger antennas interspersed between the core stations of SKA-Low. The autocorrelations of the outrigger antennas would form the measurement set for the global CD/EoR. The visibilities measured between outriggers and SKA stations would be ‘blind’ to the global CD/EoR signal and would provide a Global Sky Model and calibration of the bandpass and mode-coupling in the primary beam of the outriggers. The global signal measurement capability will strengthen the SKA-Low CD/EoR program.</p></div>","PeriodicalId":610,"journal":{"name":"Journal of Astrophysics and Astronomy","volume":null,"pages":null},"PeriodicalIF":1.1000,"publicationDate":"2023-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Detecting global signal from cosmic dawn and epoch of reionization with SKA\",\"authors\":\"Mayuri Sathyanarayana Rao, N. Udaya Shankar, Ravi Subrahmanyan, Saurabh Singh\",\"doi\":\"10.1007/s12036-023-09911-5\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>A key science project for SKA-Low is the interferometer imaging of spatio-temporal fluctuations in the hydrogen ionization fraction and spin temperature as a diagnostic of cosmic dawn (CD) and epoch of reionization (EoR) in the redshift range <span>\\\\(6 \\\\lesssim z \\\\lesssim 28\\\\)</span>. However, detection of the global CD/EoR signal, which provides the differential HI 21-cm brightness temperature with respect to the background radiation temperature, is outside the current purview of SKA-Low observing in interferometer mode. This global CD/EoR signal can provide the critical zero-spacing measurement vital for establishing the base level of fluctuations measured by SKA-Low interferometers. We present here, a concept to detect the global CD/EoR signal as a supplement to the CD/EoR key science of SKA-Low. This would be enabled by adding a compact array of outrigger antennas interspersed between the core stations of SKA-Low. The autocorrelations of the outrigger antennas would form the measurement set for the global CD/EoR. The visibilities measured between outriggers and SKA stations would be ‘blind’ to the global CD/EoR signal and would provide a Global Sky Model and calibration of the bandpass and mode-coupling in the primary beam of the outriggers. The global signal measurement capability will strengthen the SKA-Low CD/EoR program.</p></div>\",\"PeriodicalId\":610,\"journal\":{\"name\":\"Journal of Astrophysics and Astronomy\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":1.1000,\"publicationDate\":\"2023-03-28\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Astrophysics and Astronomy\",\"FirstCategoryId\":\"101\",\"ListUrlMain\":\"https://link.springer.com/article/10.1007/s12036-023-09911-5\",\"RegionNum\":4,\"RegionCategory\":\"物理与天体物理\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"ASTRONOMY & ASTROPHYSICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Astrophysics and Astronomy","FirstCategoryId":"101","ListUrlMain":"https://link.springer.com/article/10.1007/s12036-023-09911-5","RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ASTRONOMY & ASTROPHYSICS","Score":null,"Total":0}
Detecting global signal from cosmic dawn and epoch of reionization with SKA
A key science project for SKA-Low is the interferometer imaging of spatio-temporal fluctuations in the hydrogen ionization fraction and spin temperature as a diagnostic of cosmic dawn (CD) and epoch of reionization (EoR) in the redshift range \(6 \lesssim z \lesssim 28\). However, detection of the global CD/EoR signal, which provides the differential HI 21-cm brightness temperature with respect to the background radiation temperature, is outside the current purview of SKA-Low observing in interferometer mode. This global CD/EoR signal can provide the critical zero-spacing measurement vital for establishing the base level of fluctuations measured by SKA-Low interferometers. We present here, a concept to detect the global CD/EoR signal as a supplement to the CD/EoR key science of SKA-Low. This would be enabled by adding a compact array of outrigger antennas interspersed between the core stations of SKA-Low. The autocorrelations of the outrigger antennas would form the measurement set for the global CD/EoR. The visibilities measured between outriggers and SKA stations would be ‘blind’ to the global CD/EoR signal and would provide a Global Sky Model and calibration of the bandpass and mode-coupling in the primary beam of the outriggers. The global signal measurement capability will strengthen the SKA-Low CD/EoR program.
期刊介绍:
The journal publishes original research papers on all aspects of astrophysics and astronomy, including instrumentation, laboratory astrophysics, and cosmology. Critical reviews of topical fields are also published.
Articles submitted as letters will be considered.