Bibcode
Bekeraitė, S.; Walcher, C. J.; Wisotzki, L.; Croton, D. J.; Falcón-Barroso, J.; Lyubenova, M.; Obreschkow, D.; Sánchez, S. F.; Spekkens, K.; Torrey, P.; van de Ven, G.; Zwaan, M. A.; Ascasibar, Y.; Bland-Hawthorn, J.; González Delgado, R.; Husemann, B.; Marino, R. A.; Vogelsberger, M.; Ziegler, B.
Referencia bibliográfica
The Astrophysical Journal Letters, Volume 827, Issue 2, article id. L36, 6 pp. (2016).
Fecha de publicación:
8
2016
Número de citas
11
Número de citas referidas
10
Descripción
The velocity function (VF) is a fundamental observable statistic of the
galaxy population that is similar to the luminosity function in
importance, but much more difficult to measure. In this work we present
the first directly measured circular VF that is representative between
60 \lt {v}{circ} \lt 320 km s‑1 for
galaxies of all morphological types at a given rotation velocity. For
the low-mass galaxy population (60 \lt {v}{circ} \lt 170 km
s‑1), we use the HI Parkes All Sky Survey VF. For the
massive galaxy population (170 \lt {v}{circ} \lt 320 km
s‑1), 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 VF 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 VFs can be combined in a seamless manner, as their ranges of
validity overlap. The resulting observed VF is compared to VFs 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.