English

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

Astrophysics of Galaxies 2015-05-27 v1

Abstract

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 parsecs, and B-band mean surface brightnesses within Re of 19.4 and 19.2 magnitudes per arcsec squared. 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 provides an additional model for understanding M32.

Keywords

Cite

@article{arxiv.1103.1257,
  title  = {Tidal streams in newly discovered M32 analogues: evidence for the stripping scenario},
  author = {Avon Huxor and Steve Phillipps and James Price and Rob Harniman},
  journal= {arXiv preprint arXiv:1103.1257},
  year   = {2015}
}

Comments

9 pages, 10 figures. Accepted to MNRAS