http://arxiv.org/abs/1405.5731
Using 3D spectroscopy with a scanning Fabry-Perot interferometer, we study the ionized gas kinematics in 58 nearby dwarf galaxies. Combining our results with data from literature, we provide a global relation between the gas velocity dispersion sigma and the star formation rate SFR and Halpha luminosity for galaxies in a very broad range of star formation rates SFR=0.001-300 Mo/yr. We find that the slope of the L_Halpha – sigma relation for dwarf galaxies is significantly different from that of large galaxies: L_H\alpha = sigma**6.1 for L_H\alpha<1.e41erg/s as compared to L_Halpha = sigma**2.7 for brighter galaxies. We also find no correlation between sigma and the circular velocity of galaxies V_max. This implies that velocity dispersion of the ionized gas does not reflect the virial motions in the gravitational potential of dwarf galaxies, the view which was often suggested. We find that the ionized gas turbulent motions are mainly determined by the energy injected into the interstellar medium by the ongoing star formation.
A. Moiseev, A. Tikhonov and A. Klypin
Fri, 23 May 14
44/44
Comments: 14 pages, submitted to MNRAS
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