Optimizing Roman's High Latitude Wide Area Survey for Low Surface Brightness Astronomy

TL;DR

This paper discusses optimizing the Roman Space Telescope's High Latitude Wide Area Survey to explore the low surface brightness universe, aiming to uncover faint structures and improve understanding of galaxy formation, dark matter, and stellar populations.

Contribution

It proposes a survey strategy to reach unprecedented depths in low surface brightness regions, enabling new scientific insights into faint galaxies and cosmic structures.

Findings

Potential to detect structures below 30 AB mag/arcsec^2 surface brightness

Enhanced characterization of low surface brightness galaxies and halos

Synergy with other observatories for multi-wavelength analysis

Abstract

One of the last remaining frontiers in optical/near-infrared observational astronomy is the low surface brightness regime (LSB, V-band surface brightness, $\mu_V>$ 27 AB mag/arcsec$^2$). These are the structures at very low stellar surface densities, largely unseen by even current wide-field surveys such as the Legacy Survey. Studying this domain promises to be transformative for our understanding of star formation in low-mass galaxies, the hierarchical assembly of galaxies and galaxy clusters, and the nature of dark matter. It is thus essential to reach depths beyond $\mu_V$ = 30 AB mag/arcsec$^2$ to detect the faintest extragalactic sources, such as dwarf galaxies and the stellar halos around galaxies and within galaxy clusters. The High Latitude Wide Area Survey offers a unique opportunity to statistically study the LSB universe at unprecedented depths in the IR over an area of $\sim$2000 square degrees. The high spatial resolution will minimize source confusion, allowing an unbiased characterization of LSB structures, including the identification of stars in nearby LSB galaxies and globular clusters. In addition, the combination of Roman with other upcoming deep imaging observatories (such as Rubin) will provide multi-wavelength coverage to derive photometric redshifts and infer the stellar populations of LSB objects.