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arXiv · 2409.15215

Unveiling Multiple Physical Processes on a Cluster Galaxy at z=0.3 Using JWST

Peter J. Watson·Benedetta Vulcani·Ariel Werle·Bianca Poggianti·Marco Gullieuszik·Michele Trenti·Xin Wang·Namrata Roy
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Abstract

We present a study of a previously identified candidate jellyfish galaxy in the Abell 2744 cluster, F0083, which showed faint signs of a tidal interaction in archival imaging. We used publicly available PSF-matched deep photometric data from the Hubble and James Webb Space Telescopes to infer the spatially resolved star formation history of this galaxy. F0083 shows clear signs of ram-pressure stripping (RPS), with a recently enhanced star formation rate (SFR) orientated towards the south-west quadrant of the stellar disc. The stellar mass surface density is heavily asymmetric, with a variation of nearly 1 dex between the western spiral arm and the postulated tidal feature. This feature appears to contain a high proportion of older stars, ruling out RPS as the cause of this `unwinding'. We identified two potential interaction candidates, 28171 and 26055, with masses $\log_{10}(M_*/\rm{M}_{\odot})=8.56\pm0.06$ and $\log_{10}(M_*/\rm{M}_{\odot})=9.24\pm0.09$, respectively, and projected separations of 31 kpc and 46 kpc. The star formation history (SFH) of the tidal feature in F0083 indicates a steep change in SFR at lookback times $t_L\lesssim1\,$Gyr, consistent with a burst in the SFH of 26055. The most probable formation scenario of F0083 thus indicates a significant tidal interaction, followed by RPS as the combined system approaches pericentre passage. Our results demonstrate that by using photometric data we are able to distinguish between these consecutive processes, and represent the first observational analysis of the contributions of each process at this redshift.

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Peter J. Watson, Benedetta Vulcani, Ariel Werle, Bianca Poggianti, Marco Gullieuszik, Michele Trenti, Xin Wang, Namrata Roy. 2025-06-17. Unveiling Multiple Physical Processes on a Cluster Galaxy at z=0.3 Using JWST. https://doi.org/10.1051/0004-6361%2F202452348

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