Oral Presentation Astronomical Society of Australia Annual Scientific Meeting including HWWS 2013

What Shapes the Local Universe K-Band Galaxy Luminosity Function? (#77)

Nicolas J Bonne 1 , Michael Brown 1
  1. MoCA, Monash University, Clayton, VIC, Australia

We have calculated morphology and colour selected K-band luminosity functions for 13,489 galaxies in the local Universe. Each galaxy has an established morphological type and redshift measurement. We select galaxies by a magnitude limit of 2MASS Ks < 10.75 and a redshift limit of 704 < cz < 20,000 km/s. We find that the bright end of our luminosity function is dominated by a population of high stellar mass, red spiral galaxies, with a total of 1,221 red spirals spread over the entire function. These red spirals are able to account for the difference in shape between luminosity functions of colour and morphology. If red spirals are formed through the truncation of star formation, these objects must be relics of a much earlier age. Alternatively, these red spirals may not be passive, continuing to form stars and grow. Regardless, where do these spirals fit into our current idea of galaxy evolution?