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Disentangling the Effects of Ram Pressure Stripping in Cluster Galaxies using Resolved Spectroscopy

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posted on 2023-08-23, 01:27 authored by Gabriella QuattropaniGabriella Quattropani

Ram pressure stripping (RPS) is a hydrodynamical mechanism that can strip ISM material from galaxies as they move through the hot intracluster medium permeating galaxy clusters. Signatures of RPS can be seen in ionised gas emission through the kinematics as well as emission line ratios. A key observational indicator of a ram pressure stripped galaxy is an ionised gas tail of the stripped material. Additionally, galaxies affected by RPS usually have a truncated gas disk compared to the stellar disk. This is because the removal of the ISM as a result of RPS can act to quench star formation. In order to gain a deeper understanding of the RPS process, we perform a detailed analysis of two galaxies from galaxy cluster Abell 119 that were selected from the SAMI Galaxy survey as they showed evidence of quenching due to RPS, 9011900166 and 9011900084. Previous investigations using data from the wide-field IFU KOALA instrument on the Anglo Australian Telescope revealed an ionised gas tail for both galaxies but only used one Gaussian component for the emission line fits. The signatures of RPS and other hydrodynamical mechanisms can be spatially coincident along the line of sight so 1-component fits are only able to identify the dominant ionising mechanism. We implement multi-component Gaussian fits of the KOALA IFU emission line data to enable the disentanglement of different physical sources of ionisation that are spatially coincident. This takes advantage of the different kinematic signatures (in terms of their velocity and velocity dispersion) as well as different emission line flux ratios that are associated with different ionising mechanisms. We examine how these physical components vary spatially and whether they are results of RPS. We find truncated star-forming gas disks in both galaxies but 9011900084 is offset in velocity to the stars in the disk, ionised gas tails in both galaxies that are not consistent with shocks when compared to shock models as well as a previously undetected interface region in galaxy 9011900166 has properties consistent with shock ionisations when compared to models.


Table of Contents

1. Introduction -- 2. Data and Methods -- 3. Results and Discussion -- 4. Conclusion -- References

Awarding Institution

Macquarie University

Degree Type

Thesis MRes

Department, Centre or School

School of Mathematical and Physical Sciences

Year of Award


Principal Supervisor

Matt Owers


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