TY - JOUR
T1 - Mapping H I in the NGC 4636 galaxy group with FAST
AU - Zuo, Pei
AU - Yang, Dong
AU - Wang, Jing
AU - Staveley-Smith, Lister
AU - Lin, Xuchen
AU - For, Bi-Qing
AU - Westmeier, Tobias
AU - Wang, Jie
AU - Spekkens, Kristine
AU - Kilborn, Virginia
AU - Wong, O. Ivy
AU - Li, Di
AU - Lee-Waddell, Karen
AU - Catinella, Barbara
AU - Ho, Luis C.
AU - Koribalski, Bärbel
AU - Lee, Bumhyun
AU - Zhu, Ming
PY - 2022
Y1 - 2022
N2 - 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 SoFiA 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.
AB - 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 SoFiA 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.
UR - https://hdl.handle.net/1959.7/uws:69802
U2 - 10.1088/1674-4527/ac7f86
DO - 10.1088/1674-4527/ac7f86
M3 - Article
SN - 0275-1062
VL - 22
JO - Research in Astronomy and Astrophysics
JF - Research in Astronomy and Astrophysics
IS - 9
M1 - 95016
ER -