Astronomers propose 'BBQ sauce' phase to link red dot galaxies to quasars

An international team of astronomers has proposed a theoretical “BBQ sauce” phase that may link early-universe “little red dot” galaxies to quasars [1, 2].

This discovery provides a potential physical explanation for how the compact, red galaxies identified by the James Webb Space Telescope evolve into the extremely luminous quasars observed in later stages of the universe [1, 2]. Understanding this transition helps scientists map the growth of supermassive black holes during the cosmic dawn.

The researchers used a new instrument on the Subaru Telescope in Hawaii to gather the data necessary for this proposal [1, 2]. The “little red dot” objects have been a subject of intense study and debate since their discovery. Some theories suggest these objects are “black hole stars,” which are essentially clouds of gas energized by a hidden supermassive black hole ^[3].

The new “BBQ sauce” theory suggests a different evolutionary path. By identifying this intermediate phase, astronomers believe they can bridge the gap between the smaller, redder galaxies and the high-energy output of quasars [1, 2]. This process describes the transformation of a galaxy's appearance and energy signature as its central black hole grows and clears surrounding material.

Supporting evidence for the nature of these distant objects continues to emerge from other observatories. For example, the Chandra X-ray Observatory detected a galaxy matching a JWST “little red dot” located 11.8 billion light-years away ^[4]. The detection of X-rays from such a distant source supports the presence of high-energy processes, such as those found in black hole accretion disks, within these red dots ^[4].

The study was released this month, offering a new framework for interpreting the deep-field images captured by the latest generation of space and ground-based telescopes [1, 2].