Reconstructing the velocity dispersion profiles from the line-of-sight kinematic data in disc galaxies

We present a modification of the method for reconstructing the stellar velocity ellipsoid (SVE) in disc galaxies. Our version does not need any parametrization of the velocity dispersion profiles and uses only one assumption that the ratio sigma z/ sigma R remains constant along the profile or along...

Full description

Saved in:
Bibliographic Details
Published in:Monthly notices of the Royal Astronomical Society 2017-03, Vol.465 (4), p.4956-4956
Main Authors: Marchuk, A A, Sotnikova, N Y
Format: Article
Language:English
Subjects:
Asymmetry
Constants
Disk galaxies
Dispersion
Galaxies
Inclination
Kinematics
Line of sight
Mathematical analysis
Stars & galaxies
Velocity
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We present a modification of the method for reconstructing the stellar velocity ellipsoid (SVE) in disc galaxies. Our version does not need any parametrization of the velocity dispersion profiles and uses only one assumption that the ratio sigma z/ sigma R remains constant along the profile or along several pieces of the profile. The method was tested on two galaxies from the sample of other authors and for the first time applied to three lenticular galaxies NGC 1167, NGC 3245 and NGC 4150, as well as to one Sab galaxy NGC 338. We found that for galaxies with a high inclination (i > 55 degree -60 degree ) it is difficult or rather impossible to extract the information about SVE, while for galaxies at an intermediate inclination the procedure of extracting is successful. For NGC 1167 we managed to reconstruct SVE, provided that the value of sigma z/ sigma R is piecewise constant. We found sigma z/ sigma R = 0.7 for the inner parts of the disc and sigma z/ sigma R = 0.3 for the outskirts. We also obtained a rigid constraint on the value of the radial velocity dispersion sigma R for highly inclined galaxies, and tested the result using the asymmetric-drift equation, provided that the gas rotation curve is available.
ISSN:0035-8711
1365-2966
DOI:10.1093/mnras/stw3092