Near-infrared Extragalactic Background Light Fluctuations on Nonlinear Scales

TL;DR

This study uses simulated galaxy catalogs to analyze near-infrared EBL fluctuations, highlighting the significant role of satellite galaxy clustering and the potential of upcoming surveys to differentiate IHL models.

Contribution

It provides a detailed investigation of IGL and IHL contributions to EBL fluctuations, emphasizing the importance of one-halo clustering and biases in previous models.

Findings

One-halo clustering from satellite galaxies is significant at $\, ext{l}\, extasciitilde10^3$.

Upcoming SPHEREx survey can distinguish different IHL models.

Bias from mask-signal correlation affects power spectrum measurements.

Abstract

Several fluctuation studies on the near-infrared extragalactic background light (EBL) find an excess power at tens of arcminute scales ($\ell\sim10^3$). Emission from the intra-halo light (IHL) has been proposed as a possible explanation for the excess signal. In this work, we investigate the emission from the integrated galaxy light (IGL) and IHL in the power spectrum of EBL fluctuations using the simulated galaxy catalog MICECAT. We find that at $\ell\sim10^3$, the one-halo clustering from satellite galaxies has comparable power to the two-halo term in the IGL power spectrum. In some previous EBL analyses, the IGL model assumed a small one-halo clustering signal, which may result in overestimating the IHL contribution to the EBL. We also investigate the dependence of the IGL$+$IHL power spectrum on the IHL distribution as a function of redshift and halo mass, and the spatial profile within the halo. Our forecast suggests that the upcoming SPHEREx deep field survey can distinguish different IHL models considered in this work with high significance. Finally, we quantify the bias in the power spectrum from the correlation of the mask and the signal, which has not been accounted for in previous analyses.