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Article
Ultra compact dwarfs in the core of the Perseus Cluster: UCD formation via tidal stripping
Monthly Notices of the Royal Astronomical Society (2014)
  • S. J. Penny, Monash University
  • D. A. Forbes
  • J. Strader, Michigan State University
  • C. Usher
  • J. P. Brodie, University of California - Santa Cruz
  • Aaron J. Romanowsky, San Jose State University
Abstract

We present the results of a Keck/DEIMOS survey of Ultra Compact Dwarfs (UCDs) in the Perseus Cluster core. We confirm cluster membership for 14 UCDs, with radial velocities ~5300 km s−1. Two of these confirmed Perseus UCDs have extremely blue colours (B−R<0.6 mag), reside in star forming filaments surrounding NGC 1275, and have likely formed as massive star clusters in the last ~100 Myr. We also measure a central velocity dispersion of a third, UCD13 (σ0=38±8 km s−1), the most extended UCD in our sample. We determine it to have radius Re=85±1.1 pc, a dynamical mass of (2.3±0.8)×108 M⊙, and a metallicity [Z/H]=−0.52+0.33−0.29 dex. UCD13 and the cluster's central galaxy, NGC 1275, have a projected separation of 30 kpc and a radial velocity difference of ~20 km s−1. Based on its size, red colour, internal velocity dispersion, dynamical mass, metallicity and proximity to NGC 1275, we argue that UCD13 is likely the remnant nucleus of a tidally stripped dE, with this progenitor dE having MB≈−16 mag and mass ∼109 M⊙.

Publication Date
2014
Publisher Statement
This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society © 2014 Aaron Romanowsky. Published by Oxford University Press on behalf of Monthly Notices of the Royal Astronomical Society . All rights reserved.
Citation Information
S. J. Penny, D. A. Forbes, J. Strader, C. Usher, et al.. "Ultra compact dwarfs in the core of the Perseus Cluster: UCD formation via tidal stripping" Monthly Notices of the Royal Astronomical Society (2014)
Available at: http://works.bepress.com/aaron_romanowsky/74/