Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.618516
Title: Kinematics and shapes of galaxies in rich clusters
Author: D'Eugenio, Francesco
ISNI:       0000 0004 5349 7217
Awarding Body: University of Oxford
Current Institution: University of Oxford
Date of Award: 2014
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Abstract:
In this work we have studied the relationship between the kinematics and shapes of Early Type Galaxies (ETGs) in rich clusters. In particular we were interested to extend the kinematic morphology density relation to the richest clusters. We obtained data from FLAMES/GIRAFFE to probe the stellar kinematics of a sample of 30 ETGs in the massive cluster Abell 1689 at z = 0.183, to classify them as Slow Rotators (SRs) or Fast Rotators (Frs). To date, this is the highest redshift cluster studied in this way. We simulated FLAMES/GIRAFFE observations of the local SAURON galaxies to account for the bias introduced compared to the ATLAS3D sample, which we used as a local comparison. We find that the luminosity function of SRs in Abell 1689 is the same as that in ATLAS3D, down to the faintest objects probed (MK ≈ -23). The number fraction of SRs over the ETG population in Abell 1689 is fSR = 0.15 +/- 0.03, consistent with the value found in the Virgo Cluster. However, within the cluster, fSR rises sharply with the projected number density of galaxies, rising from fSR = 0.01 in the least dense bin to fSR = 0.58 in the densest bin. We conclude that the fraction of SRs is not determined by the local number density of galaxies, but rather by the physical location within the cluster. This might be due to dynamical processes which cause SRs (on average more massive) to sink in the gravitational potential of the cluster. Next we explore the distribution of projected ellipticity ε in galaxies belonging to a sample of clusters from SDSS (z 0.4. We find that even the intrinsically flat FRs are on average rounder at lower projected cluster-centric distance. We conclude that the observed trend is due either to the dynamic heating of the stellar discs being strongest near the centre of clusters, or due to an anti-correlation of the bulge fractions with the cluster-centric distance.
Supervisor: Davies, Roger L. Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.618516  DOI: Not available
Keywords: galaxies ; cluster of galaxies ; kinematics ; ellipticity ; spectroscopy ; astrophysics ; astronomy
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