Little Red Dots from Low-Spin Galaxies at High Redshifts

TL;DR

This paper introduces a new class of high-redshift galaxies called Little Red Dots (LRDs), characterized by their compactness, evolved stellar populations, and potential central black holes, suggesting they are low-spin galaxies with efficient gas feeding.

Contribution

It proposes that LRD galaxies are the low-spin tail of galaxy populations at high redshift, explaining their compactness, star formation, and black hole activity.

Findings

LRD galaxies are compact with evolved stellar populations.

They likely host overmassive central black holes.

LRDs are consistent with low-spin galaxy models.

Abstract

Recently, a new population of compact, high-redshift (z>7) galaxies appeared as little red dots (LRDs) in deep JWST observations. The latest spectroscopic data indicates that these galaxies contain an evolved stellar population, reflecting an early episode of high star-formation-rate. The appearance of broad emission lines suggests that a central overmassive black hole also powers these galaxies. I propose that LRD galaxies represent the low-spin tail of the galaxy population. Low-spin galaxies host a more compact gaseous disk with an enhanced star formation rate relative to typical galaxies at the same redshift. The compact disk feeds efficiently a central black hole, as predicted by Eisenstein & Loeb (1995).