Dwarf galaxies in the Perseus Cluster: further evidence for a disc origin for dwarf ellipticals

Penny, Samantha J.; Forbes, Duncan A.; Pimbblet, Kevin A.; Floyd, David J. E.

Abstract

We present the results of a Keck-ESI (Echellette Spectrograph and Imager) spectroscopic study of six dwarf elliptical (dE) galaxies in the Perseus Cluster core, and confirm two dwarfs as cluster members for the first time. All six dEs follow the size–magnitude relation for dE/dSph galaxies. Central velocity dispersions are measured for three Perseus dwarfs in our sample, and all lie on the σ–luminosity relation for early-type, pressure-supported systems. We furthermore examine SA 0426-002, a unique dE in our sample with a bar-like morphology surrounded by low surface brightness wings/lobes (μB = 27 mag arcsec¯²). Given its morphology, velocity dispersion (σ₀ = 33.9 ± 6.1 km s⁻¹), velocity relative to the brightest cluster galaxy NGC 1275 (2711 km s⁻¹), size (Rₑ = 2.1 ± 0.10 kpc), and Sersic index ( ´ n = 1.2 ± 0.02), we hypothesize the dwarf has morphologically transformed from a low-mass disc to dE via harassment. The low surface brightness lobes can be explained as a ring feature, with the bar formation triggered by tidal interactions via speed encounters with Perseus Cluster members. Alongside spiral structure found in dEs in Fornax and Virgo, SA 0426-002 provides crucial evidence that a fraction of bright dEs have a disc infall origin, and are not part of the primordial cluster population.

Citation

Penny, S. J., Forbes, D. A., Pimbblet, K. A., & Floyd, D. J. E. (2014). Dwarf galaxies in the Perseus Cluster: further evidence for a disc origin for dwarf ellipticals. Monthly notices of the Royal Astronomical Society, 443(4), 3381-3387. https://doi.org/10.1093/mnras/stu1397

• Journal Article Type: Article
• Acceptance Date: Jul 8, 2014
• Online Publication Date: Aug 8, 2014
• Publication Date: Oct 1, 2014
• Deposit Date: Jun 16, 2015
• Publicly Available Date: Jun 16, 2015
• Journal: Monthly notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Electronic ISSN: 1365-2966
• Publisher: Oxford University Press
• Peer Reviewed: Peer Reviewed
• Volume: 443
• Issue: 4
• Pages: 3381-3387
• DOI: https://doi.org/10.1093/mnras/stu1397
• Keywords: Galaxies -- clusters -- general; Galaxies -- clusters -- individual -- Perseus Cluster; Galaxies -- dwarf; Galaxies -- evolution; Galaxies -- kinematics and dynamics; Galaxies -- structure
• Public URL: https://hull-repository.worktribe.com/output/375322
• Publisher URL: http://mnras.oxfordjournals.org/content/443/4/3381.abstract
• Additional Information: This article has been accepted for publication in Monthly notices of the Royal Astronomical Society ©: 2014 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.
• Contract Date: Jun 16, 2015