A Near-Infrared Survey: Local Large-Scale Structure and The Near-Infrared Background.

摘要

I present a deep widefield Near-Infrared (NIR) survey and spectroscopy of bright galaxies over six fields on the sky. In collaboration with the research group of Dr. Amy Barger, I have used these data to study the large-scale structure of the local universe and the NIR background due to resolved galaxies.;With respect to local large-scale structure, we find that the slope of the galaxy counts curve above and below the supergalactic plane is significantly steeper than would be expected in a homogeneous universe. With our spectroscopic sample we find strong variability in the normalization of the NIR luminosity function of galaxies from field to field. We also find that the universe appears to be inhomogeneous on very large (> 500 megaparsec) scales. These results could pose a challenge to current cosmological models that require the universe to be homogeneous on large scales and invoke a vacuum energy to drive the apparent acceleration of the observed expansion of the universe.;With respect to the NIR background, we find the integrated light from galaxies (IGL) to be isotropic from field to field to within uncertainties. Our values for the IGL are 10--20% higher than previous measurements, bringing them into good agreement with new model IGL estimates, and into relative agreement with measurements of the total NIR background via gamma-ray opacity and recent direct photometric measurements. These results suggest that little or no NIR background excess may be required to reconcile resolved background measurements with total background measurements.