Corrugated velocity patterns in the spiral galaxies: NGC 278, NGC 1058, NGC 2500 & UGC 3574

DOI: 
10.1093/mnras/stv2206
Publication date: 
21/12/2015
Main author: 
Carmen Sánchez-Gil M.
IAA authors: 
Alfaro, E.J.;Pérez, E.
Authors: 
Carmen Sánchez-Gil M., Alfaro E.J., Pérez E.
Journal: 
Monthly Notices of the Royal Astronomical Society
Publication type: 
Article
Volume: 
454
Pages: 
3376-3390
Number: 
Abstract: 
We address the study of the H α vertical velocity field in a sample of four nearly face-on galaxies using long-slit spectroscopy taken with the Intermediate dispersion Spectrograph and Imaging System (ISIS), attached to the William Herschel Telescope (WHT) at the Roque de los Muchachos Observatory (Spain). The spatial structure of the velocity vertical component shows a radial corrugated pattern with spatial scales higher or within the order of 1 kpc. The gas is mainly ionized by high-energy photons: only in some locations of NGC 278 and NGC 1058 is there some evidence of ionization by low-velocity shocks, which, in the case of NGC 278, could be due to minor mergers. The behaviour of the gas in the neighbourhood of the spiral arms fits, in the majority of the observed cases, with that predicted by the so-called hydraulic bore mechanism, where a thick magnetized disc encounters a spiral density perturbation. The results obtained show that it is difficult to explain the H α large-scale velocity field without the presence of a magnetized, thick galactic disc. Larger samples and spatial covering of the galaxy discs are needed to provide further insight into this problem. © 2015 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society.
Database: 
WOK
SCOPUS
ADS
URL: 
https://ui.adsabs.harvard.edu/#abs/2015MNRAS.454.3376S/abstract
ADS Bibcode: 
2015MNRAS.454.3376S
Keywords: 
Galaxies: spiral; Galaxies: star formation; Instrumentation: spectrographs; Stars: kinematics and dynamics