Decoupled gas kinematics in isolated early-type disc galaxies
Abstract
We have studied a sample of completely isolated galaxies by means of long-slit spectroscopy at the 6-m telescope. We have found that 7 of 12 (58 +/- 14 %) galaxies have revealed a presence of large-scale ionized-gas component which angular momentum is mostly differ from stellar one: 5 of 7 (71 +/- 17 %) show a visible counterrottation. The diagnostic diagram demonstrates a wide range of gas excitation mechanism. We have estimated the gas oxygen abundance in the cases where excitation mechanism by young stars dominates and have found that ionized gas has a subsolar metallicity. We concluded that cold-gas accretion from primordial cosmological filaments is unlikely for these objects, while external accretion from dwarf gas-rich satellites is more suitable.
Keywords
Cite
@article{arxiv.1312.6572,
title = {Decoupled gas kinematics in isolated early-type disc galaxies},
author = {Ivan Katkov and Olga Sil'chenko and Victor Afanasiev},
journal= {arXiv preprint arXiv:1312.6572},
year = {2014}
}
Comments
4 pages, 2 figures; ; to appear in the proceedings of "Multi-spin galaxies" conference, Naples, Italy, September 30 - October 3, 2013