Détails Publication
GHASP: an H α kinematical survey of spiral galaxies - XIII. Distribution of luminous and dark matter in spiral and irregular nearby galaxies using H α and H I rotation curves and WISE photometry,
Discipline: Sciences de la Terre
Auteur(s): M. Korsaga, B. Epinat, P. Amram, C. Carignan, P. Adamczyk and A. Sorgho
Auteur(s) tagués: KORSAGA Marie
Renseignée par : KORSAGA Marie
Résumé

We present the mass models of 31 spiral and irregular nearby galaxies obtained using hybrid rotation curves (RCs) combining high-resolution GHASP Fabry-Perot Hα RCs and extended WHISP H I ones together with 3.4 μm WISE photometry. The aim is to compare the dark matter (DM) halo properties within the optical radius using only H α RCs with the effect of including and excluding the mass contribution of the neutral gas component, and when using HI or hybrid RCs. Pseudo-isothermal (ISO) core and Navarro-Frenk-White (NFW) cuspy DM halo profiles are used with various fiducial fitting procedures. Mass models using Hα RCs including or excluding the HI gas component provide compatible disc M/L. The correlations between DM halo and baryon parameters do not strongly depend on the RC. Clearly, the differences between the fitting procedures are larger than between the different data sets. Hybrid and HI RCs lead to higher M/L values for both ISO and NFW best-fitting models but lower central densities for ISO haloes and higher concentration for NFW haloes than when using H α RCs only. The agreement with the mass model parameters deduced using hybrid RCs, considered as a reference, is better for HI than for Hα RCs. ISO density profiles better fit the RCs than the NFW ones, especially when using Hα or hybrid RCs. Halo masses at the optical radius determined using the various data sets are compatible even if they tend to be overestimated with Hα RCs. Hybrid RCs are thus ideal to study the mass distribution within the optical radius.

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