Black hole in early cosmos seems to be feasting on matter at over 40 times its theoretical limit

It’s hard to understand how supermassive black holes were able to grow so big so rapidly. But with the discovery of a low-mass supermassive black hole (SMBH) consuming material at an extreme rate, seen merely 1.5 billion years after the Big Bang, astrophysicists now have valuable new insights into the mechanisms of hastily growing black holes in the early cosmos.

LID-568 was discovered by a cross-institutional team of astrophysicists led by International Gemini Observatory/NSF NOIRLab astrophysicist Hyewon Suh. They employed the James Webb Space Telescope (JWST) to observe a sample of galaxies from COSMOS legacy survey of the Chandra X-ray Observatory. This population of galaxies is quite bright in the X-ray part of the spectrum, but are invisible in the optical and near-infrared. James Webb Space Telescope’s unique infrared sensitivity lets it to detect these faint counterpart emissions.

LID-568 ostensibly stood out within the sample for its intense X-ray emission, but its exact location could not be determined from the X-ray observations alone, raising worries about properly centering the target in James Webb Space Telescope’s field of view. So, instead of using traditional slit spectroscopy, James Webb Space Telescope’s instrumentation support scientists suggested that Hyewon’s team use the integral field spectrograph on James Webb Space Telescope’s NIRSpec. This instrument can get a spectrum for each pixel in the instrument’s field of view instead of being restricted to a narrow slice.

JWST’s NIRSpec allowed Suh’s team to get a full view of their target and its surrounding area, leading to the unanticipated discovery of powerful outflows of gas around the central black hole. The speed and magnitude of these outflows led the team to conclude that a substantial fraction of the mass growth of LID-568 may have happened in a single episode of fast accretion.

“This serendipitous result added a new dimension to our understanding of the system and opened up exciting avenues for investigation,” says Hyewon Suh. In a spectacular discovery, Suh and her team found that LID-568 seems to be feeding on matter at a rate 40 times its Eddington limit. This limit relates to the maximum luminosity that a black hole can attain, besides how fast it can absorb matter, such that its inward gravitational force and outward pressure generated ostensibly from the heat of the compressed, infalling matter stay in balance. When LID-568’s luminosity was calculated to be much much higher than theoretically possible, Suh’s team knew they had something extraordinary in their data.