Disentangling the stellar population properties of bulges and disks in cluster galaxies

• Main Author: Stefania Barsanti
• Format: Thesis
• Language: unknown
• Published: 2021
• Subjects: Other education not elsewhere classified; galaxy evolution; galaxy clusters; bulge disks; sami
• Online Access: https://doi.org/10.25949/23902518.v1; https://figshare.com/articles/thesis/Disentangling_the_stellar_population_properties_of_bulges_and_disks_in_cluster_galaxies/23902518

The formation of S0 galaxies is still highly debated. Our aim is to shed light on the role of the environment in the evolution of S0 galaxies. Since environmental mechanisms can influence the bulge and disk components of galaxies in different ways, it is crucial to study their respective stellar populations separately. As a first step towards understanding the bulge and disk stellar populations, we use the multiband optical imaging of eight low-redshift clusters of galaxies. The deep spectroscopy from the Sydney-AAO Multi-object Integral field (SAMI) Cluster Redshift Survey allows us to analyse cluster members with M ⁎ / M ☉ > 10 9.5 and into the cluster outskirts up to the cluster-centric distance ~ 2.5 R 200 . We perform 2D photometric bulge-disk decomposition in the g , r and i -bands, from which we identify 469 double-component galaxies. Most bulges are found to be redder than their surrounding disks. Bulge colours do not correlate with environment metrics. Disk colours become significantly bluer at larger cluster-centric radii. The disk colour-radius relation is driven by galaxies at 0 ≤ R / R 200 < 0.5. No significant difference is found for the disk colours of backsplash and infalling galaxies. Beyond R 200 , the disk colours do not change with the local galaxy density, indicating that the colours of double-component galaxies are not affected by pre-processing. A significant colour-density relation is observed for single-component disk-dominated galaxies beyond R 200 . We conclude that the formation of S0 galaxies is primarily driven by cluster core processes acting on the disks. To obtain a more detailed understanding of bulge and disk stellar populations, we disentangle the ages and metallicities. We take advantage of the spectroscopic data from the SAMI Galaxy Survey for 192 double-component cluster galaxies with M ⁎ > 10 10 M ☉ and R < R 200 . We measure mass-weighted ages and metallicities of bulges and disks investigating three methods for separating the stellar population properties for ...