Journal Article

Tidal streams in newly discovered M32 analogues: evidence for the stripping scenario

A. P. Huxor, S. Phillipps, J. Price and R. Harniman

in Monthly Notices of the Royal Astronomical Society

Published on behalf of The Royal Astronomical Society

Volume 414, issue 4, pages 3557-3565
Published in print July 2011 | ISSN: 0035-8711
Published online July 2011 | e-ISSN: 1365-2966 | DOI: http://dx.doi.org/10.1111/j.1365-2966.2011.18655.x
Tidal streams in newly discovered M32 analogues: evidence for the stripping scenario

Show Summary Details

Preview

We present two newly discovered compact elliptical (cE) galaxies, exhibiting clear evidence of tidal steams, and found during a search of SDSS DR7 for cE candidates. The structural parameters of the cEs are derived using galfit, giving effective radii, Re, of 388 and 263 pc, and B-band mean surface brightnesses within Re of 19.4 and 19.2 mag arcsec−2. We have re-analysed the SDSS spectra, which indicate that they possess young to intermediate-age stellar populations. These two cEs provide direct evidence, a ‘smoking gun’, for the process of tidal stripping that is believed to be the origin of M32-type galaxies. Both are in small groups with a large spiral fraction, suggesting that we may be seeing the formation of such cE galaxies in dynamically young environments. The more compact of the galaxies is found in a small group not unlike the Local Group, and thus it provides an additional model for the understanding of M32.

Keywords: galaxies: dwarf; galaxies: formation; galaxies: structure

Journal Article.  6758 words.  Illustrated.

Subjects: Astronomy and Astrophysics

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.