{"title":"高红移类星体21cm信号的研究","authors":"XIANG Hong-bin , MA Qing-bo","doi":"10.1016/j.chinastron.2022.09.005","DOIUrl":null,"url":null,"abstract":"<div><p><span>We use the results of high resolution numerical simulations to fix the theoretical model of high redshift quasars (QSOs) ionizing and heating neutral gas, and predict the signal characteristics and signal/noise (S/N) ratios for Five-hundred-meter Aperture Spherical Telescope (FAST) to observe the 21 cm radiation around QSO. Our conclusions are summarized as: (1) the 21 cm frequency spectrum under the FAST field has full HII region for the QSO at </span><span><math><mrow><mi>z</mi><mo>=</mo><mn>8</mn></mrow></math></span> and with luminosity similar to ULAS J1120+0641, while has only a small trough for the QSO at <span><math><mrow><mi>z</mi><mo>=</mo><mn>10</mn></mrow></math></span> and with low luminosity; (2) the effect of Finite Light Travel Time (FLTT) obviously changes the 21 cm frequency spectrum of high redshift QSOs, makes the transition curve at lower frequency much steeper than that at higher frequency; (3) the FAST telescope can observe the 21 cm radiation of high redshift QSO with very high S/N ratio as high as <span><math><mrow><mo>∼</mo><mn>12</mn></mrow></math></span>, thus can identify the HII regions and the FLTT effect.</p></div>","PeriodicalId":35730,"journal":{"name":"Chinese Astronomy and Astrophysics","volume":"46 3","pages":"Pages 236-248"},"PeriodicalIF":0.0000,"publicationDate":"2022-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Study on 21 cm Signal of High Redshift Quasars\",\"authors\":\"XIANG Hong-bin , MA Qing-bo\",\"doi\":\"10.1016/j.chinastron.2022.09.005\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p><span>We use the results of high resolution numerical simulations to fix the theoretical model of high redshift quasars (QSOs) ionizing and heating neutral gas, and predict the signal characteristics and signal/noise (S/N) ratios for Five-hundred-meter Aperture Spherical Telescope (FAST) to observe the 21 cm radiation around QSO. Our conclusions are summarized as: (1) the 21 cm frequency spectrum under the FAST field has full HII region for the QSO at </span><span><math><mrow><mi>z</mi><mo>=</mo><mn>8</mn></mrow></math></span> and with luminosity similar to ULAS J1120+0641, while has only a small trough for the QSO at <span><math><mrow><mi>z</mi><mo>=</mo><mn>10</mn></mrow></math></span> and with low luminosity; (2) the effect of Finite Light Travel Time (FLTT) obviously changes the 21 cm frequency spectrum of high redshift QSOs, makes the transition curve at lower frequency much steeper than that at higher frequency; (3) the FAST telescope can observe the 21 cm radiation of high redshift QSO with very high S/N ratio as high as <span><math><mrow><mo>∼</mo><mn>12</mn></mrow></math></span>, thus can identify the HII regions and the FLTT effect.</p></div>\",\"PeriodicalId\":35730,\"journal\":{\"name\":\"Chinese Astronomy and Astrophysics\",\"volume\":\"46 3\",\"pages\":\"Pages 236-248\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2022-07-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Chinese Astronomy and Astrophysics\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0275106222000625\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q4\",\"JCRName\":\"Physics and Astronomy\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Chinese Astronomy and Astrophysics","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0275106222000625","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"Physics and Astronomy","Score":null,"Total":0}
We use the results of high resolution numerical simulations to fix the theoretical model of high redshift quasars (QSOs) ionizing and heating neutral gas, and predict the signal characteristics and signal/noise (S/N) ratios for Five-hundred-meter Aperture Spherical Telescope (FAST) to observe the 21 cm radiation around QSO. Our conclusions are summarized as: (1) the 21 cm frequency spectrum under the FAST field has full HII region for the QSO at and with luminosity similar to ULAS J1120+0641, while has only a small trough for the QSO at and with low luminosity; (2) the effect of Finite Light Travel Time (FLTT) obviously changes the 21 cm frequency spectrum of high redshift QSOs, makes the transition curve at lower frequency much steeper than that at higher frequency; (3) the FAST telescope can observe the 21 cm radiation of high redshift QSO with very high S/N ratio as high as , thus can identify the HII regions and the FLTT effect.
期刊介绍：
The vigorous growth of astronomical and astrophysical science in China led to an increase in papers on astrophysics which Acta Astronomica Sinica could no longer absorb. Translations of papers from two new journals the Chinese Journal of Space Science and Acta Astrophysica Sinica are added to the translation of Acta Astronomica Sinica to form the new journal Chinese Astronomy and Astrophysics. Chinese Astronomy and Astrophysics brings English translations of notable articles to astronomers and astrophysicists outside China.
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