Journal Article

GHASP: an Hα kinematic survey of 203 spiral and irregular galaxies – VII. Revisiting the analysis of Hα data cubes for 97 galaxies

B. Epinat, P. Amram and M. Marcelin

in Monthly Notices of the Royal Astronomical Society

Published on behalf of The Royal Astronomical Society

Volume 390, issue 2, pages 466-504
Published in print October 2008 | ISSN: 0035-8711
Published online October 2008 | e-ISSN: 1365-2966 | DOI:
GHASP: an Hα kinematic survey of 203 spiral and irregular galaxies – VII. Revisiting the analysis of Hα data cubes for 97 galaxies

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The Gassendi HAlpha survey of SPirals survey (GHASP) consists of 3D Hα data cubes for 203 spiral and irregular galaxies, covering a large range in morphological types and absolute magnitudes, for kinematics analysis. It is the largest sample of Fabry–Perot data published up to now. In order to provide an homogenous sample, reduced and analysed using the same procedure, we present in this paper the new reduction and analysis for a set of 97 galaxies already published in previous papers but now using the new data reduction procedure adopted for the whole sample. The GHASP survey is now achieved and the whole sample is reduced using the adaptive binning techniques based on Voronoi tessellations. We have derived Hα data cubes from which are computed Hα maps, radial velocity fields as well as residual velocity fields, position–velocity diagrams, rotation curves and kinematical parameters for almost all galaxies. The rotation curves, the kinematical parameters and their uncertainties are computed homogeneously using the new method based on the power spectrum of the residual velocity field. This paper provides the kinematical parameters for the whole sample. For the first time, the integrated Hα profiles have been computed and are presented for the whole sample. The total Hα fluxes deduced from these profiles have been used in order to provide a flux calibration for the 203 GHASP galaxies. This paper confirms the conclusions already drawn from half the sample concerning (i) the increased accuracy of position angles measurements using kinematical data, (ii) the difficulty to have robust determinations of both morphological and kinematical inclinations in particular for low-inclination galaxies and (iii) the very good agreement between the Tully–Fisher relationship derived from our data and previous determinations found in the literature.

Keywords: galaxies: dwarf; galaxies: irregular; galaxies: kinematics and dynamics; galaxies: spiral

Journal Article.  13270 words.  Illustrated.

Subjects: Astronomy and Astrophysics

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