Open AccessGHASP: an Hα kinematic survey of spiral and irregular galaxies – III. 15 new velocity fields and study of 46 rotation curves
Author(s) -
Garrido O.,
Marcelin M.,
Amram P.
Publication year - 2004
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2004.07483.x
Subject(s) - physics , galaxy rotation curve , astrophysics , spiral galaxy , rotation (mathematics) , galaxy , irregular galaxy , radius , kinematics , bulge , spiral (railway) , tully–fisher relation , elliptical galaxy , geometry , lenticular galaxy , galaxy formation and evolution , classical mechanics , mathematical analysis , mathematics , computer security , computer science
We present Fabry–Pérot observations obtained in the frame of the GHASP survey (Gassendi HAlpha survey of SPirals). We have derived the Hα maps, the velocity fields and the rotation curves for a set of 15 galaxies. The data presented in this paper are combined with the data published in our two previous papers in order to make a preliminary analysis of the rotation curves obtained for 46 galaxies. We check the consistency of our data with the Tully–Fisher relationship and conclude that our Hα rotation curves reach the maximum velocity in most of the cases, even with solid‐body rotating galaxies. We find that our rotation curves, on average, almost reach the isophotal radius R 25 . We confirm the trend, already mentioned by Rubin, Waterman & Kenney and Márquez et al., that the maximum extension of the Hα rotation curves increases with the type of the spiral galaxy, up to t ∼ 7–8 and we find that it decreases for magellanic and irregular galaxies. We also confirm the trend seen by Márquez et al. that later types tend to have lower values of the internal slope of the rotation curve, in agreement with Rubin et al.