English

A counter-rotating tilted gas disc in the peanut galaxy NGC~128

Astrophysics 2007-05-23 v1

Abstract

We have obtained VV, RcR_c, IcI_c HRCAM images and TIGER spectrography of the central region of the peanut galaxy NGC~128. The colour images reveal the presence of a red disc tilted by about 26 degres with respect to the major-axis of the galaxy. This tilted disc is made of dust and gas, as revealed by the 2D TIGER map of the ionized gas distribution. The TIGER stellar and gas velocity fields show that the angular momentum vectors of the stellar and gaseous components are reversed. We therefore suggest that the gas orbits belong to the so-called anomalous family, which is evidence for a tumbling triaxial potential (a bar) associated with the peanut morphology. The bar formation has very probably been triggered through the interaction with its nearby companion NGC~127, from which the dissipative component is being accreted along retrograde orbits.

Keywords

Cite

@article{arxiv.astro-ph/9701089,
  title  = {A counter-rotating tilted gas disc in the peanut galaxy NGC~128},
  author = {Eric Emsellem and Robin Arsenault},
  journal= {arXiv preprint arXiv:astro-ph/9701089},
  year   = {2007}
}

Comments

4 pages, 4 figures, LaTeX, A&A style file + macro.tex, accepted for publication in A&A Letters