A COUNTER-ROTATING TILTED GAS DISC IN THE PEANUT GALAXY NGC-128

Citation
E. Emsellem et R. Arsenault, A COUNTER-ROTATING TILTED GAS DISC IN THE PEANUT GALAXY NGC-128, Astronomy and astrophysics, 318(2), 1997, pp. 39-42
Citations number
25
Categorie Soggetti
Astronomy & Astrophysics
Journal title
ISSN journal
00046361
Volume
318
Issue
2
Year of publication
1997
Pages
39 - 42
Database
ISI
SICI code
0004-6361(1997)318:2<39:ACTGDI>2.0.ZU;2-#
Abstract
We have obtained V, R(c), I-c HRCAM images and TIGER spectrography of the central region of the peanut galaxy NGC 128. The colour images rev eal 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 moment um vectors of the stellar and gaseous components are reversed. We ther efore suggest that the gas orbits belong to the so-called anomalous fa mily, which is evidence for a tumbling triaxial potential (a bar) asso ciated 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 retr ograde orbits.