Compact, AGN-hosting Dwarf Galaxies with "Little Red Dots"-like SEDs in the Local Universe

TL;DR

This study compares local AGN-hosting dwarf galaxies with high-redshift 'Little Red Dots', revealing differences in physical properties and suggesting different formation pathways for these compact, red galaxies.

Contribution

The paper provides a statistical analysis of local AGN-hosting dwarf galaxies with 'V-shaped' SEDs, comparing them to high-redshift LRDs, and highlights their physical differences and distinct evolutionary paths.

Findings

Approximately half of the local ADGs exhibit 'V-shaped' SEDs.

Local 'V-shaped' ADGs are more evolved with larger effective radii.

Physical differences suggest different formation pathways from high-z LRDs.

Abstract

Local active galactic nuclei (AGNs) in dwarf galaxies are often considered as analogs for the earliest supermassive black holes, although their connections require more comprehensive examinations. Motivated by finding the local analogs of "Little Red Dots" (LRDs), the compact, red galaxies discovered by JWST at z > 5 characterized by "V-shaped" SEDs, we compile a sample of local AGN-hosting dwarf galaxies (ADGs) with comparable luminosities to statistically evaluate this connection. By applying K-means clustering to SED shapes and morphological sizes, we classified four groups which trace a sequence in physical properties, including metallicity, star formation rate, and dust emission, mainly driven by their distinct UV-optical slopes. Within these groups, we find that about half of the ADGs exhibit "V-shaped" SEDs and relatively compact morphologies. However, a direct comparison reveals fundamental physical differences: local "V-shaped", compact ADGs appear significantly more evolved than high-z LRDs, characterized by systematically larger effective radii and distinct ionization states. Our results suggest that local compact ADGs likely follow a different formation pathway from LRDs, highlighting the complexity of black hole-galaxy co-evolution across cosmic time.