2024/01/07 by Loeb, Abraham
#Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences
paper · doi:10.48550/arxiv.2401.03592
Recently, Pandya et al. (2023) argued that the shapes of dwarf galaxies in JWST-CEERS observations show a prolate fraction that rises from ~25% at redshifts z=0.5-1 to ~50-80% at z=3-8. Here we suggest that this apparent change could result from a surface-brightness bias, favoring the detection of edge-on disks at low-luminosities and high-redshifts. Changing edge-on projections with an axis ratio of 10 to a face-on orientation reduces their apparent surface brightness by 2.5 magnitude per arcsec2 and could shift a substantial fraction of the observed galaxies below the detection limit.