Speaker
Description
With the advent of the James Webb Space Telescope (JWST), observational probes of the structure of objects in the early universe are more readily available. In particular, the discovery of high-redshift (z ~ 10) Supermassive Black Holes (SMBHs) challenges the typical formation channels of these objects which cannot form sufficiently massive seeds or grow them within these timescales without significant periods of Super-Eddington accretion. Similarly, in the past few years, a brand new class of high-redshift objects has been discovered, called “Little Red Dots” (LRDs) - thought to be heavily dust enshrouded SMBHs ($10^{6}$ - $10^{8}$ $M_{\odot}$) hosted in a highly compact galaxy approximately 50 parsecs in size.
To address the potential formation of these objects, we have introduced a model of self-interacting dark matter (SIDM), where a small fraction of the SIDM is ultra-strongly self-interacting (uSIDM). The typical cross-sections of SIDM are on the order of 0.1-10 $\text{cm}^{2}/\text{g}$, whereas uSIDM cross-sections are on the order of $10^{3}$-$10^{4}$ $\text{cm}^{2}/\text{g}$. With such high cross-sections, the uSIDM undergoes rapid gravothermal evolution leading to a full core-collapse of the innermost portion of the dark matter halo. The rapid timescale for this collapse allows for the formation of a heavy SMBH seed well within the observed formation times; thus uSIDM is a prime candidate for the creation of LRDs. Subsequent sub-Eddington accretion grows the seeds to match the observed SMBH masses, LRD mass function, and predicts a testable clustering bias for LRDs at z ~ 5.