The complex puzzle of the objects known as little red dots (LRDs) has gradually become more complete since their initial discovery by the NASA/ESA/CSA James Webb Space Telescope in 2022. Now a particu...

Little Red Dots (LRDs) display singular properties unlike any known class of AGN or galaxies, motivating novel mass estimators for their central engines. Inspired by their similarities to stellar phen...

Observations from the JWST reveal an unexpectedly abundant population of little red dots and overmassive black holes in the early Universe, which are confirmed by their formation in fully cosmological...

Since it began sending observations back to Earth in summer 2022, the James Webb Space Telescope (JWST) has helped scientists create a much clearer picture of the universe, but it has also delivered some frustrating mysteries. Among these is the puzzle of the "Little Red Dots (LRDs)," strange compact cosmic objects that appear in the early universe but disappear before the cosmos is around 2 billion years old. To solve the mystery of the LRDs, a team of astronomers has looked at the bigger picture, not focusing on the objects themselves, but instead investigating the nature of the galaxies that surround them. "We hadn't seen anything like LRDs in the local universe," team member Jorge Zavala of the University of Massachusetts Amherst told Space.com. "This is a phase that we missed before. The question is: Is this an evolutionary phase related to the growth of galaxies and star formation activity or black hole growth? Do all galaxies [or] black holes go through this phase? We are not sure yet." The team set about answering these questions by studying JWST images of 217 LRDs. They found faint light surrounding the objects and theorized that these emissions represent dense, star-forming galaxies. "Most...

The James Webb Space Telescope (JWST) has observed mysterious tiny red objects known as 'Little Red Dots' (LRDs) in the early universe. New supercomputer simulations led by Sunmyon Chon of the Max Planck Institute for Astrophysics suggest these LRDs may be rapidly growing black holes from the universe's first few hundred million years. The simulations, conducted using Japan's ATERUI III supercomputer, reveal that intense far-ultraviolet (FUV) radiation from nearby galaxies prevented ordinary star formation in gas clouds, causing the gas to collapse into single supermassive stars that later formed black hole seeds. These black hole seeds then grew rapidly within dense gas disks that trapped radiation, allowing them to consume material up to dozens of times faster than black holes can today. The properties of these simulated black holes closely match the LRDs observed by JWST, suggesting they represent an early stage of extremely rapid black hole growth. This discovery could solve the longstanding mystery of how supermassive black holes, containing millions or billions of solar masses, appeared so soon after the Big Bang—less than 600 million years. The research, published in Nature, indicates that these conditions developed naturally in the early universe without requiring exotic physics or rare coincidences. JWST's ability to peer deeper into cosmic history than previous telescopes has provided unprecedented views of the young universe, revealing these LRDs that may hold the key to understanding early black hole formation. As JWST continues to discover more LRDs and future telescopes look even further back in time, this model could provide astronomers with a valuable framework for understanding how some of the universe's earliest black holes formed, grew, and influenced cosmic evolution.

Little red dots (LRDs) are a class of small, red-tinted cosmological objects discovered by the James Webb Space Telescope (JWST). Their most notable characteristics are their small size (less than a f...

arXiv abstract link

arXiv abstract link

We present a spectral test of the quasi-star hypothesis for Little Red Dots (LRDs) whereby a black hole grows inside a stellar-like envelope. We use \texttt{Prospector} to fit host galaxies and \textt...