We present preliminary results on 24 mum detections of luminous infrared galaxies at z greater than or similar to 1 with the Multiband Imaging Photometer for Spitzer (MIPS). Observations were performed in the Lockman Hole and the Extended Groth Strip (EGS) and were supplemented by data obtained with the Infrared Array Camera (IRAC) between 3 and 9 mum. The positional accuracy of less than or similar to2" for most MIPS/IRAC detections provides unambiguous identifications of their optical counterparts. Using spectroscopic redshifts from the Deep Extragalactic Evolutionary Probe survey, we identify 24 mum sources at z greater than or similar to 1 in the EGS, while the combination of the MIPS/IRAC observations with BVRIJHK ancillary data in the Lockman Hole also shows very clear cases of galaxies with photometric redshifts at 1 less than or similar to z less than or similar to 2.5. The observed 24 mum fluxes indicate infrared luminosities greater than 10(11) L-circle dot, while the data at shorter wavelengths reveal rather red and probably massive (M greater than or similar to M*) galaxy counterparts. It is the first time that this population of luminous objects is detected up to z similar to 2.5 in the infrared. Our work demonstrates the ability of the MIPS instrument to probe the dusty universe at very high redshift and illustrates how the forthcoming Spitzer deep surveys will offer a unique opportunity to illuminate a dark side of cosmic history not explored by previous infrared experiments.

We present the K-band local luminosity function derived from a sample of 1056 bright (K < 15) K-selected galaxies from the Hawaii+Anglo-Australian Observatory (AAO) K-band redshift survey. The Hawaii+AAO K-band redshift survey covers four equatorial fields with a total area of 8.22 deg2. We derive both the nonparametric and Schechter luminosity function from our data and determine M*(K) = -23.70 ± 0.08 + 5 log10(h), α = -1.37 ± 0.10, and ϕ* = 0.013 ± 0.003 h3 Mpc-3 for a universe with Ωm = 0.3 and ΩΛ = 0.7. We also measure the K-band luminosity function for the early- and later type galaxies from our morphologically classified subsample. It appears that later type galaxies have a fainter M* and a steep slope, while early-type galaxies have a much brighter M* and a quite flat slope in their K-band luminosity functions. This is consistent with what has been found in optical-type dependent luminosity function. The K-band luminosity density derived using our luminosity function is now measured at a similar redshift depth to optical luminosity densities in the Sloan Digital Sky Survey redshift survey. It is 2 times higher than the previous measurement from the shallower 2MASS sample and resolves the previously reported discrepancies between optical and near-infrared luminosity densities.