H i absorption associated with Norma’s brightest cluster galaxy
| Autor: | Baerbel Koribalski, Manasvee Saraf, O. Ivy Wong, Luca Cortese |
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| Rok vydání: | 2022 |
| Předmět: | |
| Zdroj: | Monthly Notices of the Royal Astronomical Society. 519:4128-4141 |
| ISSN: | 1365-2966 0035-8711 |
| Popis: | ESO 137-G006 is the brightest cluster galaxy (BCG) of the cool-core and dynamically young Norma cluster. We discover an atomic hydrogen (HI) absorption line associated with this BCG using the Australia Telescope Compact Array. We estimate a gas column density of $ \approx (1.3 \pm 0.2) \times 10^{20}\,T_{\rm{spin}}$ atoms cm$^{-2}$ with spin temperature, $T_{\rm{spin}} \leq 194$ K, consistent with the HI properties of other early-type galaxies and cool-core cluster BCGs. The relationship between the presence of cold gas and a cluster cooling flow is unclear. Our results support the scenario that ESO 137-G006 may be a recent arrival to the cluster centre and not the original BCG. This scenario is consistent with the observed spatial alignment of the BCG's wide-angle tail radio lobes with Norma's X-ray sub-cluster and the significant line-of-sight velocity offset between the mean velocity of Norma and that of the BCG. Accepted for publication in MNRAS. 10 pages, 3 figures (additional 4 pages, 3 figures in appendix) |
| Databáze: | OpenAIRE |
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