1. The Califa and Hipass velocity function for all morphological galaxy types
- Author
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Bekerait��, S., Walcher, C. J., Wisotzki, L., Croton, D. J., Falc��n-Barroso, J., Lyubenova, M., Obreschkow, D., S��nchez, S. F., Spekkens, K., Torrey, P., van de Ven, G., Zwaan, M. A., Ascasibar, Y., Bland-Hawthorn, J., Gonz��lez-Delgado, R., Husemann, B., Marino, R. A., Vogelsberger, M., Ziegler, B., and collaboration, the CALIFA
- Subjects
Astrophysics of Galaxies (astro-ph.GA) ,FOS: Physical sciences ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics - Astrophysics of Galaxies ,Astrophysics::Galaxy Astrophysics - Abstract
The velocity function is a fundamental observable statistic of the galaxy population, similarly impor- tant as the luminosity function, but much more difficult to measure. In this work we present the first directly measured circular velocity function that is representative between 60 < v_circ < 320 km/s for galaxies of all morphological types at a given rotation velocity. For the low mass galaxy population (60 < v_circ < 170 km/s), we use the HIPASS velocity function. For the massive galaxy population (170 < v_circ < 320 km/s), we use stellar circular velocities from the Calar Alto Legacy Integral Field Area Survey (CALIFA). In earlier work we obtained the measurements of circular velocity at the 80% light radius for 226 galaxies and demonstrated that the CALIFA sample can produce volume- corrected galaxy distribution functions. The CALIFA velocity function includes homogeneous velocity measurements of both late and early-type rotation-supported galaxies and has the crucial advantage of not missing gas-poor massive ellipticals that HI surveys are blind to. We show that both velocity functions can be combined in a seamless manner, as their ranges of validity overlap. The resulting observed velocity function is compared to velocity functions derived from cosmological simulations of the z = 0 galaxy population. We find that dark matter-only simulations show a strong mismatch with the observed VF. Hydrodynamic simulations fare better, but still do not fully reproduce observations., Accepted to ApJL. Keywords: Galaxies: kinematics and dynamics - galaxies: statistics - galaxies: evolution 7 pages, 3 figures
- Published
- 2016