Astronomers using the James Webb Space Telescope (JWST) might have found the most distant supermassive black hole ever spotted. This massive black hole is in the galaxy called GHZ2, which exists just 350 million years after the Big Bang.
Recent research, published on arXiv, combines data from JWST’s Near Infrared Spectrograph and Mid-Infrared Instrument. These tools can observe light shifted to infrared by the universe’s expansion. According to Oscar Chavez Ortiz, a doctoral candidate at the University of Texas at Austin and lead researcher, GHZ2 raises questions about how black holes can grow rapidly so early in the universe’s history.
Chavez Ortiz shared that researchers have two main thoughts on how these ancient black holes formed: either they started as “light seeds” that grew quickly or as “heavy seeds” that began with a large mass. This debate can help us understand the evolution of galaxies and black holes.
GHZ2 is intriguing because of its bright “emission lines.” These lines emerge when certain atoms in the galaxy are heated up, releasing energy at specific wavelengths. According to Jorge Zavala, an assistant professor at the University of Massachusetts Amherst, some of these lines indicate a lot of energy, which hints at powerful processes going on in GHZ2.
A key observation was the detection of the C IV λ1548 emission line, linked to triply ionized carbon. Chavez Ortiz points out that the energy needed to ionize carbon this way suggests a strong radiation field typically produced by active galactic nuclei (AGN), indicating that this galaxy may host a black hole actively feeding on surrounding material.
The findings suggest GHZ2 is unique. While the spectrum from visible light seems to show star formation, the carbon emission strongly hints at the presence of an AGN. However, Zavala noted that the galaxy may not show all characteristics of an AGN, which suggests it could be primarily fueled by stars, possibly of enormous mass, or it might have a mixed source of light from both normal stars and an AGN.
To confirm these findings, researchers plan further observations using JWST to get more detailed spectra and additional data from the Atacama Large Millimeter/submillimeter Array. If they indeed confirm AGN activity in GHZ2, it would solidify its status as the most distant supermassive black hole known. This presents a rare chance to test theories about how such black holes formed just a few hundred million years after the Big Bang.
