Are Galaxies “Going Bananas” at Early Cosmic Times?

In a recent paper titled, “<a href="https://arxiv.org/pdf/2310.15232.pdf" rel="noopener ugc nofollow" target="_blank">Galaxies Going Bananas: Inferring the 3D Geometry of High-Redshift Galaxies with JWST-CEERS</a>”, Viraj Pandya and collaborators argued that the shapes of dwarf galaxies in Webb telescope data show an elongated banana-like fraction that increases from about 25% in the nearby Universe at redshifts 0.5–1 to about 50–80% in the early Universe within the redshift range of 3–8, about a billion years after the Big Bang. The data was taken from the Cosmic Evolution Early Release Science survey, abbreviated as CEERS. When saw this analysis, it occurred to me that the reported evolution might be the result of a selection bias, because galaxies must exceed a surface brightness threshold to be detectable against the background noise in the sky. As I subsequently showed in <a href="https://arxiv.org/pdf/2401.03592.pdf" rel="noopener ugc nofollow" target="_blank">a new paper</a>, this favors the detection of edge-on galactic disks for galaxies at low-luminosities and high-redshifts which are near the detection threshold. <a href="https://avi-loeb.medium.com/are-galaxies-going-bananas-at-early-cosmic-times-355cadc6f941">Learn More</a>