AAS 201st Meeting, January, 2003
Session 42. Galaxies and Clusters
Poster, Tuesday, January 7, 2003, 9:20am-6:30pm, Exhibit Hall AB

## [42.08U] The K-band Luminosity Function of the Virgo Cluster

A.S. Hill (Oberlin College), J.P. Huchra (Harvard-Smithsonian CfA), T. Jarrett (IPAC), L. Macri (NOAO), J. Mader (McDonald Observatory), N. Martimbeau (Harvard-Smithsonian CfA)

We present a study of the Virgo cluster using a sample of galaxies from the Two Micron All-Sky Survey (2MASS) with complete photometry and redshift information, within the survey region, to a limiting magnitude m\mathrm{K} = 12.0 mag. We use the infrared Tully-Fisher relation to determine distances to spiral galaxies in the cluster. Combined with distances obtained by surface brightness fluctuations (compiled from the literature), we establish distances to seven sub-clumps near the Virgo cluster, one of which (the W cloud) is probably background. Using these distances, we construct the K-band galaxy luminosity function of the cluster.

We estimate the mass of the individual sub-clumps and the cluster as a whole, using the virial theorem. Using the luminosity function, we calculate the integral luminosity density in the core of the cluster. We compare the cluster luminosity function to field luminosity functions and calculate the luminosity over-density of the cluster versus the field.

This work was supported in part by NSF grant AST-9731923 to the SAO Summer Intern program.