Deep H i Mapping of Stephan’s Quintet and Its Neighborhood
Metadatos
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Institute of Physics
Materia
Hickson compact group Galaxy groups H I line emission
Fecha
2023-08-23Referencia bibliográfica
Cheng Cheng et al. 2023. Deep H i Mapping of Stephan’s Quintet and Its Neighborhood. ApJ 954 74. [https://doi.org/10.3847/1538-4357/ace03e]
Patrocinador
Anhui Province 2022AH010013, 2022YFA1605300; CAMS-CAS; Proyecto A-FQM-510-UGR20; Zhejiang Lab Open Research Project K2022PE0AB01; Chinese Academy of Sciences South America Center for Astronomy 11733006, 11803044, 12173045, CMS-CSST-2021-A05 CASSACA; Consejería de Transformación Económica, Industria, Conocimiento y Universidades; National Natural Science Foundation of China 11873055, 11933003, 12273051, MCIN/AEI/10.13039/501100011033, P20_00334, PID2020-114414GB-100 NSFC; Chinese Academy of Sciences CAS; Knut och Alice Wallenbergs Stiftelse; European Regional Development Fund ERDF; People's Government of Yunnan Province; Junta de Andalucía; National Key Research and Development Program of China 2017YFA0402704, 2018YFE0202900 NKRDPCResumen
We carried out deep mapping observations of the atomic hydrogen (H i) 21 cm line emission in a field centered on the famous galaxy group Stephan's Quintet (SQ), using the Five-hundred-meter Aperture Spherical Telescope (FAST) equipped with a 19-beam receiver. The final data cube reaches an H i column density sensitivity of 5σ = 2.1 × 1017 cm-2 per 20 km s-1 channel with an angular resolution of 4.′0. The discovery of a large diffuse feature of the H i emission in the outskirts of the intragroup medium of SQ was reported in a previous paper (Xu et al.). Here we present a new study of the total H i emission of SQ and the detection of several neighboring galaxies, exploiting the high sensitivity and the large sky coverage of the FAST observations. A total H i mass of M H I = 3.48 ± 0.35 × 1010 M ☉ is found for SQ, which is significantly higher than previous measurements in the literature. This indicates that, contrary to earlier claims, SQ is not H i deficient. The excessive H i gas is mainly found in the velocity ranges of 6200-6400 km s-1 and 6800-7000 km s-1, which were undetected in previous observations that are less sensitive than ours. Our results suggest that the "missing H i"in compact groups may be hidden in the low-density diffuse neutral gas instead of in the ionized gas.