The Resolved NIR Extragalactic Background

TL;DR

This paper provides updated estimates of the near-infrared extragalactic background light from resolved galaxies, using deep wide-field photometry and new ultradeep galaxy counts, aligning better with other measurement methods.

Contribution

It combines extensive galaxy counts with new ultradeep observations to refine the measurements of the NIR EBL, reducing previous uncertainties and discrepancies.

Findings

NIR EBL measurements are 10-20% higher than previous estimates.

Results are consistent with isotropy of the EBL across different fields.

New ultradeep Ks-band counts improve understanding of sources beyond detection limits.

Abstract

We present a current best estimate of the integrated near-infrared (NIR) extragalactic background light (EBL) attributable to resolved galaxies in J, H, and Ks . Our results for measurements of {\nu}I{\nu} in units of nW m-2 sr-1 are 11.7+5.6 -2.6 in J, 11.5+4 .5 -1.5 in H and 10.0+2 .8 -0.8 in Ks . We derive these new limits by combining our deep wide-field NIR photometry from five widely separated fields with other studies from the literature to create a galaxy counts sample that is highly complete and has good counting statistics out to J H Ks ~ 27 - 28. As part of this effort we present new ultradeep Ks -band galaxy counts from 22 hours of observations with the Multi Object Infrared Camera and Spectrograph (MOIRCS) instrument on the Subaru Telescope. We use this MOIRCS Ks -band mosaic to estimate the total missing flux from sources beyond our detection limits. Our new lim- its to the NIR EBL are in basic agreement with, but 10 - 20% higher than previous estimates, bringing them into better agreement with estimates of the total NIR EBL (resolved + unresolved sources) obtained from TeV {\gamma}-ray opacity measurements and recent direct measurements of the total NIR EBL, as well as recent model estimates for the total light from galaxies. We exam- ine field to field variations in our photometry to show that the integrated light from galaxies is isotropic to within uncertainties, consistent with the expected large-scale isotropy of the EBL.