Understanding the Evolution of Galaxies in Dense Environments, and the Search for Jellyfish Galaxies

22/06/2022 - 14:00 - 15:00
Remoto, com transmissão pela internet
Understanding the Evolution of Galaxies in Dense Environments, and the Search for Jellyfish Galaxies
Dr. Jacob Crossett
(U. Valparaiso, CL)
It is well-established that galaxy environment is an important driver of galaxy evolution. Large structures such as galaxy groups and clusters enable processes such as mergers, harassment, and ram pressure stripping to change galaxies from blue, star-forming, spirals to red ellipticals. While we understand how groups and clusters can change galaxy properties, observational evidence of these transformations is still limited.
We will show how the intra-cluster medium of groups can be used as a marker for group formation time. When comparing similar mass groups, we find that groups of higher X-ray luminosity have properties that suggest an earlier formation time, compared with groups with low X-ray luminosity. This includes changes to star formation fraction, group magnitude gap, and tentatively, the fraction of merging and ram pressure stripped galaxies within the group. Furthermore, we find that despite the lower average halo mass, many groups in our sample are still able to facilitate ram pressure stripping. We compare our group ram pressure stripped galaxies with those found in clusters.
Finally, we describe efforts to discover new ram pressure stripped candidates. By compiling large samples of known jellyfish galaxies, we are able to understand the broad properties of ram pressure stripped galaxies using this large sample. We detail how we will use the photometric and morphological properties of these galaxies to help uncover new ram pressure stripping candidates.
Jacob Crossett is a postdoctoral researcher at the Instituto de Fisica y Astronomia in Valparaiso, Chile. Born and raised in Australia, as a child he gained a love of astronomy while staring out at the dark Australian sky with his toy telescope. He completed his bachelors degree and PhD at Monash University in Melbourne Australia, while also spending a sabbatical year at the University of Hull, UK. Following this, he moved to the University of Birmingham as a postdoctoral research associate where he was working on galaxy evolution in groups and clusters. He currently has a Fondecyt fellowship at the Universidad de Valparaíso, to help identify new jellyfish galaxies in large surveys, and is once again enjoying living on the coast under the Southern Hemisphere skies.