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Free keywords:
Astrophysics, Cosmology and Extragalactic Astrophysics, astro-ph.CO, Astrophysics, Galaxy Astrophysics, astro-ph.GA
MPINP:
Infrarot-Astrophysik - Abteilung Hofmann
Abstract:
We report the morphological classification of 3727 galaxies from the Galaxy
and Mass Assembly survey with M_r < -17.4 mag and in the redshift range 0.025 <
z < 0.06 (2.1 x 10^5 Mpc^3 ) into E, S0-Sa, SB0-SBa, Sab-Scd, SBab-SBcd, Sd-Irr
and little blue spheroid classes. Approximately 70% of galaxies in our sample
are disk dominated systems, with the remaining ~30% spheroid dominated. We
establish the robustness of our classifications, and use them to derive
morphological-type luminosity functions and luminosity densities in the
ugrizYJHK passbands, improving on prior studies that split by global colour or
light profile shape alone. We find that the total galaxy luminosity function is
best described by a double-Schechter function while the constituent
morphological-type luminosity functions are well described by a
single-Schechter function.
These data are also used to derive the star-formation rate densities for each
Hubble class, and the attenuated and unattenuated (corrected for dust) cosmic
spectral energy distributions, i.e., the instantaneous energy production
budget. While the observed optical/near-IR energy budget is dominated 58:42 by
galaxies with a significant spheroidal component, the actual energy production
rate is reversed, i.e., the combined disk dominated populations generate ~1.3x
as much energy as the spheroid dominated populations. On the grandest scale,
this implies that chemical evolution in the local Universe is currently
confined to mid-type spiral classes like our Milky Way.
