A Minimalist Merger Interpretation of XRISM's Gas Velocity Measurements in the Coma Cluster
Fuente:
arXiv
Saved in:
| Main Authors: | , , , , , |
|---|---|
| Format: | Preprint |
| Published: |
2026
|
| Subjects: | |
| Online Access: | |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866917191931133952 |
|---|---|
| author | Zhang, Congyao Churazov, Eugene Khabibullin, Ildar Lyskova, Natalya Werner, Norbert Zhuravleva, Irina |
| author_facet | Zhang, Congyao Churazov, Eugene Khabibullin, Ildar Lyskova, Natalya Werner, Norbert Zhuravleva, Irina |
| contents | The recent microcalorimetric X-ray observations of the Coma cluster by XRISM have sparked active discussion regarding the physical origin of its gas velocity features. Here, we demonstrate that an off-axis minor merger in its early phase $-$ when the infalling subhalo is near its primary apocenter and the stripped tail is not yet mixed with the main cluster atmosphere $-$ can drive intracluster gas motions generally consistent with the XRISM results. These include a pronounced velocity gradient and an approximately uniform velocity dispersion of $\simeq100-200\,\rm{km\,s^{-1}}$ in the cluster core. Our merger scenario was originally suggested in Lyskova et al. (2019) to reproduce the major X-ray morphological features of Coma. In addition, we introduce a simple and robust diagnostic of intracluster gas motions based on the ratio of the line-of-sight velocity to the velocity dispersion. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2601_05803 |
| institution | arXiv |
| publishDate | 2026 |
| record_format | arxiv |
| spellingShingle | A Minimalist Merger Interpretation of XRISM's Gas Velocity Measurements in the Coma Cluster Zhang, Congyao Churazov, Eugene Khabibullin, Ildar Lyskova, Natalya Werner, Norbert Zhuravleva, Irina High Energy Astrophysical Phenomena Astrophysics of Galaxies The recent microcalorimetric X-ray observations of the Coma cluster by XRISM have sparked active discussion regarding the physical origin of its gas velocity features. Here, we demonstrate that an off-axis minor merger in its early phase $-$ when the infalling subhalo is near its primary apocenter and the stripped tail is not yet mixed with the main cluster atmosphere $-$ can drive intracluster gas motions generally consistent with the XRISM results. These include a pronounced velocity gradient and an approximately uniform velocity dispersion of $\simeq100-200\,\rm{km\,s^{-1}}$ in the cluster core. Our merger scenario was originally suggested in Lyskova et al. (2019) to reproduce the major X-ray morphological features of Coma. In addition, we introduce a simple and robust diagnostic of intracluster gas motions based on the ratio of the line-of-sight velocity to the velocity dispersion. |
| title | A Minimalist Merger Interpretation of XRISM's Gas Velocity Measurements in the Coma Cluster |
| topic | High Energy Astrophysical Phenomena Astrophysics of Galaxies |
| url | https://arxiv.org/abs/2601.05803 |