The Contribution of Galaxies to the $3.4\mu \mathrm{m}$ Cosmic Infrared Background as Measured Using WISE

Abstract

The study of the extragalactic background light (EBL) in the optical and near infrared has received a lot of attention in the last decade, especially near a wavelength of $\lambda \approx 3.4\mathrm{\mu m}$, with remaining tension among different techniques for estimating the background. In this paper we present a measurement of the contribution of galaxies to the EBL at $3.4\mathrm{\mu m}$ that is based on the measurement of the luminosity function (LF) in Lake et al. (2018) and the mean spectral energy distribution of galaxies in Lake & Wright (2016). The mean and standard deviation of our most reliable Bayesian posterior chain gives a $3.4\mathrm{\mu m}$ background of $I_{\nu }=9.0\pm 0.5\mathrm{kJy}{\mathrm{sr}}^{-1}$ ($\nu I_{\nu }=8.0\pm 0.4\mathrm{nW}{m}^{-2}{\mathrm{sr}}^{-1}e{-fold}^{-1}$), with systematic uncertainties unlikely to be greater than $2\mathrm{kJy}{\mathrm{sr}}^{-1}$. This result is higher than most previous efforts to measure the contribution of galaxies to the $3.4\mathrm{\mu m}$ EBL, but is consistent with the upper limits placed by blazars and the most recent direct measurements of the total $3.4\mathrm{\mu m}$ EBL.

14 pages, 8 figures, 2 tables, submitted to ApJ. Table 1 data to be available from figshare under DOI 10.6084/m9.figshare.4245443, Table 2 under DOI 10.6084/m9.figshare.8142284, and the data behind Figure 5 under 10.6084/m9.figshare.4757131