| The measurement of the the Extragalactic Background Light (EBL) has seen some controversy in recent works, with direct and indirect measures conflicting. Specifi- cally, upper limits based on analyzing the plausible opacity obscuring TeV spectra of blazars suggests that the density of radiation with wavelengths near 3.4 mum is onethirdtoonehalfasintenseasdirectmeasuresofthesame(forexample: Aharonian et al., 2006; Levenson et al., 2007; Matsumoto et al., 2005). The dominant contributor of the EBL at 3.4mum is expected to be ordinary starlight from relatively local, z < 1, galaxies, so an estimate of the amount of light emitted by galaxies based on the galaxy Luminosity Function (LF) should provide a useful lower limit to the EBL. While analyses of this sort have been done by others (Dominguez et al., 2011; Helgason et al., 2012), the full sky coverage of the AllWISE database has made it possible for us to improve the measurement of both the LF at 2.4 mum and the EBL using the large public spectroscopic redshift surveys. In order to do so, we had to develop a mathematical model for the measurement of a generalization of the LF, which is the density of galaxies per unit comoving volume per unit luminosity, to the Spectro-Luminosity Functional (SLF), which replaces the density per unit single luminosity, dL, with the density per luminosi- ii ties at all frequencies, DL nu. Our best combined analysis of the data yields present day Shechter Function LF parameters of: L☆ = 6.4+/-[0.1 stat, 0.3sys]x1010 L2.4mum [solar mass](M☆ = --21.67+/-[0.02 stat, 0.05sys] AB mag), &phis;☆ = 5.8+/-[0.3stat, 0.3sys]x10 --3 Mpc--3, and alpha = --1.050 +/- [0.004stat, 0.03sys]; this implies a present day density of galaxies of 0.08 Mpc--3 brighter that 106 L2.4mum [solar mass] (10--3 Mpc--3 brighter than L☆) and a luminosity density equivalent to 3.8 x 108 L2.4mum [solar mass] Mpc--3. The net EBL at 3.4mum that our synthesis model produces from galaxies closer than z = 5 is Inu = 9.0 +/- 0.5 kJy sr--1 (nuInu = 8.0 +/- 0.4 nW m--2 sr --1), largely in agreement with similar LF based estimates of the EBL. |
