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Session 19 - Source Surveys, Galaxy Surveys, Distance Scale II.
Display session, Wednesday, January 07
Exhibit Hall,

[19.07] The Radio and Infrared Luminosity Functions

N. A. Reddy (U. Texas at Austin), M. S. Yun (NRAO)

The luminosity function (LF) for radio sources was determined at \nu=1.4 GHz and \lambda=60\mu by correlating infrared sources from the Strauss 1.2 Jy IRAS Redshift Survey with their radio counterparts in the NRAO VLA Sky Survey (NVSS). The sample was limited to those galaxies with known redshift and S_60\mu > 2.00 Jy within two regions of the completed NVSS Sky Survey given by the following coordinates: 4h\leq\alpha<16h, \delta\geq30^\circ and -40^\circ\leq\delta\leq-10^\circ. The radio-far-infrared correlation was derived and accurate positions for IRAS Redshift Survey sources were obtained through the correlation process. Luminosity distributions for \nu=1.4 GHz and \lambda=60\mu were then constructed. A determination of the characteristic volume for a given distance and luminosity interval was used to construct the luminosity functions corresponding to the distributions. A \chi^2 analysis of the observed distributions and functions yields the Schechter parameters corresponding to the analytic distributions and functions. The analytic distribution at 1.4 GHz is well described by the sum of two Schechter functions with L_1^*=(3.98\pm0.31)\times 10^22 W Hz^-1 and L_2^*=(24.78\pm3.84)\times 10^22 W Hz^-1, respectively. The analytic distribution at \lambda=60\mu is also given by two best-fit curves with L_1^*=(14.00\pm1.20)\times 10^9 L_ødot and L_2^*=(79.75\pm9.78)\times 10^9 L_ødot. The 1.4 GHz luminosity function is fitted with one curve with L^*=(2.80\pm0.15)\times 10^22 W Hz^-1 and the 60\mu luminosity function is fitted with two curves with L_1^*=(9.16\pm0.84)\times 10^9 L_ødot and L_2^*=(46.57\pm3.08)\times 10^9 L_ødot, respectively. Two distinct populations are identified in the radio and far-infrared luminosity functions: 1) normal late-type galaxies; and 2) starburst/AGN population of galaxies. The former matches the spiral population of Condon. The latter can be identified with Condon's but is not identical (Note: all calculation use a Hubble constant value of H_o = 75 km s^-1 Mpc^-1).

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