An international team of astronomers from The University of Texas at Austin’s Cosmic Frontier Center has made a groundbreaking discovery by identifying the most distant black hole ever confirmed, located in the galaxy CAPERS-LRD-z9.
This remarkable black hole exists 500 million years after the Big Bang, which translates to roughly 13.3 billion years in the past, when the universe was merely 3% of its current age. The discovery opens new avenues for understanding the structure and evolution of the universe during this enigmatic period.
Lead researcher Anthony Taylor, a postdoctoral researcher at the Cosmic Frontier Center, emphasized, “When looking for black holes, this is about as far back as you can practically go. We’re really pushing the boundaries of what current technology can detect.”
Published on August 6 in the Astrophysical Journal, the research highlights not just the identification of the black hole but also the techniques used in its discovery.
Astronomers utilize spectroscopy to study celestial objects by splitting light into various wavelengths. This methodological approach enables them to detect the signature of fast-moving gas surrounding a black hole. As gas orbits and is drawn into the black hole, its light exhibits a distinct pattern—light emitted from gas moving away from us becomes redshifted, while light from gas moving toward us experiences blueshift.
Taylor elaborated, “There aren’t many other things that create this signature. And this galaxy has it!”
The data leading to this discovery was procured from the James Webb Space Telescope (JWST), specifically through the CAPERS (CANDELS-Area Prism Epoch of Reionization Survey) program. With its launch in 2021, JWST has offered unparalleled astronomical observations at unprecedented distances, significantly contributing to our understanding of the universe.
Mark Dickinson, a co-author and lead of the CAPERS team, pointed out that “the first goal of CAPERS is to confirm and study the most distant galaxies. JWST spectroscopy is the key to confirming their distances and understanding their physical properties.”
Initially identified as a minor feature in the imagery from the JWST, CAPERS-LRD-z9 is part of a newly recognized class of galaxies dubbed “Little Red Dots.” These compact, red, and unexpectedly bright galaxies emerged only during the first 1.5 billion years following the Big Bang, diverging significantly from the galaxies observed with the Hubble Space Telescope.
Steven Finkelstein, co-author on the paper and director of the Cosmic Frontier Center, remarked on the surprise found in the early JWST data: “The discovery of Little Red Dots was a major surprise; they looked nothing like galaxies seen with the Hubble Space Telescope. Now, we’re in the process of figuring out what they’re like and how they came to be.”
CAPERS-LRD-z9 contributes crucial evidence suggesting that supermassive black holes may play a key role in the unexpected brightness observed in Little Red Dots. While high brightness typically indicates a galaxy teeming with stars, such mass is unlikely to occur in galaxies this early in the universe.
Black holes themselves can also shine brightly by compressing and heating surrounding materials, producing tremendous light and energy. The confirmation of the black hole within CAPERS-LRD-z9 exemplifies this phenomenon.
Furthermore, astronomers are keen to investigate what causes the distinct red color characteristic of Little Red Dots. The phenomenon may be attributed to a dense cloud of gas enveloping the black hole, which skews its light into redder wavelengths. Taylor noted, “We’ve seen these clouds in other galaxies; when we compared this object to those other sources, it was a dead ringer.”
The mass of the black hole in CAPERS-LRD-z9 is estimated to be up to 300 million times that of the Sun, making it not only colossal but also accounting for nearly half the total mass of all stars in its galaxy. This extraordinary size raises intriguing questions about the formation and growth of supermassive black holes in the early universe.
Finkelstein commented on the implications of such a massive black hole existing at such an early stage, stating, “This adds to growing evidence that early black holes grew much faster than we thought possible, or they started out far more massive than our models predict.”
Looking ahead, the research team aims to gather additional, high-resolution observations using the JWST to deepen their understanding of CAPERS-LRD-z9 and explore the role of black holes within the context of Little Red Dots. “This is a good test object for us,” Taylor concluded, expressing excitement over the potential discoveries yet to come. “We haven’t been able to study early black hole evolution until recently, and we are excited to see what we can learn from this unique object.”
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