This paper presents data from a 21 cm H I emission drift scan observation of a field partially covering the NGC 4636 galaxy group with the Five-hundred meter Aperture Radio Telescope(FAST). We construct a pipeline to ...This paper presents data from a 21 cm H I emission drift scan observation of a field partially covering the NGC 4636 galaxy group with the Five-hundred meter Aperture Radio Telescope(FAST). We construct a pipeline to reduce the data, and use So Fi A for source finding. When not contaminated by Radio Frequency Interference(RFI), the FAST observations are capable of detecting all of the galaxies previously detected by the Arecibo Legacy Fast ALFA(ALFALFA) survey in the same region. Comparing to ALFALFA for the detections in common, the FAST data show consistent integrated spectra when the H I disks are spatially unresolved, and capture more flux when the H I disks are resolved. The FAST data further reveal 10 new detections in the region mutually covered with ALFALFA, and 18 new detections beyond the footprint of ALFALFA. All of the new detections have the matching optical counterparts. For the member galaxies of the NGC 4636 group, the detection limit of FAST is deeper by 0.4 dex in H I mass than that of the ALFALFA data. After correcting for the incompleteness caused by RFI contamination, we show that the H I detection rate of galaxies rises steeply with radius out to the virial radius of the group, and flattens beyond that. We also examine four spatially resolved galaxy systems with potential tidal interaction features in detail. Considering that the data have been taken during the“shared-risk” period before a major source of local RFI was eliminated, the results highlight the power of FAST in detecting extragalactic H I.展开更多
The Hot Universe Baryon Surveyor(HUBS) is a proposed space-based X-ray telescope for detecting X-ray emissions from the hot gas content in our universe. With its unprecedented spatially-resolved high-resolution spectr...The Hot Universe Baryon Surveyor(HUBS) is a proposed space-based X-ray telescope for detecting X-ray emissions from the hot gas content in our universe. With its unprecedented spatially-resolved high-resolution spectroscopy and large field of view,the HUBS mission will be uniquely qualified to measure the physical and chemical properties of the hot gas in the interstellar medium, the circumgalactic medium, the intergalactic medium, and the intracluster medium. These measurements will be valuable for two key scientific goals of HUBS, namely to unravel the AGN and stellar feedback physics that governs the formation and evolution of galaxies, and to probe the baryon budget and multi-phase states from galactic to cosmological scales. In addition to these two goals, the HUBS mission will also help us solve some problems in the fields of galaxy clusters, AGNs, difuse X-ray backgrounds, supernova remnants, and compact objects. This paper discusses the perspective of advancing these fields using the HUBS telescope.展开更多
基金supported by the National Natural Science Foundation of China (11988101,11721303,11991052,12011540375,12073002,11903003)the China Manned Space Project (CMS-CSST-2021-A04+3 种基金CMS-CSST-2021-A06)support from the science research grants from the China Manned Space Project with No.CMS-CS ST-2021-B02the Australian Research Council Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D),through project No.CE170100013support from the Natural Sciences and Engineering Research Council of Canada (NSERC)。
文摘This paper presents data from a 21 cm H I emission drift scan observation of a field partially covering the NGC 4636 galaxy group with the Five-hundred meter Aperture Radio Telescope(FAST). We construct a pipeline to reduce the data, and use So Fi A for source finding. When not contaminated by Radio Frequency Interference(RFI), the FAST observations are capable of detecting all of the galaxies previously detected by the Arecibo Legacy Fast ALFA(ALFALFA) survey in the same region. Comparing to ALFALFA for the detections in common, the FAST data show consistent integrated spectra when the H I disks are spatially unresolved, and capture more flux when the H I disks are resolved. The FAST data further reveal 10 new detections in the region mutually covered with ALFALFA, and 18 new detections beyond the footprint of ALFALFA. All of the new detections have the matching optical counterparts. For the member galaxies of the NGC 4636 group, the detection limit of FAST is deeper by 0.4 dex in H I mass than that of the ALFALFA data. After correcting for the incompleteness caused by RFI contamination, we show that the H I detection rate of galaxies rises steeply with radius out to the virial radius of the group, and flattens beyond that. We also examine four spatially resolved galaxy systems with potential tidal interaction features in detail. Considering that the data have been taken during the“shared-risk” period before a major source of local RFI was eliminated, the results highlight the power of FAST in detecting extragalactic H I.
基金supported by the National Natural Science Foundation of China (Grant Nos. 11721303, 11821303, 11825303, 11873029, 11890693, 11973033, 11991052, 12025303, 12033004, 12041301, 12121003, 12133008, 12173018, 12192220, 12192223, 12221003, 12233001, 12233005, 12273010, 12273030, 12273057, 12011540375, and U1931140)the China Manned Space Project (Grant Nos. CMS-CSST-2021-A04, CMS-CSST-2021-A06, CMS-CSST-2021-A10, and CMS-CSST-2021-B02)+5 种基金the Ministry of Science and Technology of China through its National Key R&D Program (Grant No. 2018YFA0404502)the National SKA Program of China (Grant No. 2020SKA0120300)the National Key Research and Development Program of China (Grant No. 2022YFA1602903)the Outstanding Young and Middle-aged Science and Technology Innovation Teams from Hubei colleges and universities (Grant No. T2021026)the Young Top-notch Talent Cultivation Program of Hubei Province, the National Science Foundation (Grant Nos. AST-2107735, and AST-2219686)NASA (Grant No. 80NSSC22K0668)。
文摘The Hot Universe Baryon Surveyor(HUBS) is a proposed space-based X-ray telescope for detecting X-ray emissions from the hot gas content in our universe. With its unprecedented spatially-resolved high-resolution spectroscopy and large field of view,the HUBS mission will be uniquely qualified to measure the physical and chemical properties of the hot gas in the interstellar medium, the circumgalactic medium, the intergalactic medium, and the intracluster medium. These measurements will be valuable for two key scientific goals of HUBS, namely to unravel the AGN and stellar feedback physics that governs the formation and evolution of galaxies, and to probe the baryon budget and multi-phase states from galactic to cosmological scales. In addition to these two goals, the HUBS mission will also help us solve some problems in the fields of galaxy clusters, AGNs, difuse X-ray backgrounds, supernova remnants, and compact objects. This paper discusses the perspective of advancing these fields using the HUBS telescope.
