Free Astronomy Magazine January-February 2025

39 JANUARY-FEBRUARY 2025 ASTRO PUBLISHING T his video sum- marizes the dis- covery made by Suh’s team observ- ing LID-568. [Im- ages and videos: NOIRLab/NSF/AURA/ J. da Silva/M. Za- mani/NASA/CXC/ J.Vaughan/A. M. Gutierrez/J. Dave- laar/Radboud Uni- versity/BlackHole- Cam/N. Bartmann (NSF NOIRLab) − Music: Stellardrone - Airglow] black hole. The speed and size of these outflows led the team to infer that a substantial fraction of the mass growth of LID-568 may have occurred in a single episode of rapid accretion. “This serendipitous result added a new dimension to our un- derstanding of the system and opened up exciting avenues for in- vestigation,” says Suh. In a stunning discovery, Suh and her team found that LID-568 appears 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 achieve, as well as how fast it can absorb matter, such that its inward gravitational force and outward pressure gener- ated from the heat of the com- pressed, infalling matter remain in balance. When LID-568’s luminosity was cal- culated to be so much higher than theoretically possible, the team knew they had something remark- able in their data. “This black hole is having a feast,” says International Gemini Observa- tory/NSF NOIRLab astronomer and co-author Julia Scharwächter. “This extreme case shows that a fast-feed- ing mechanism above the Edding- ton limit is one of the possible explanations for why we see these very heavy black holes so early in the Universe.” These results provide new insights into the formation of supermassive black holes from smaller black hole ‘seeds’, which current theories sug- gest arise either from the death of the Universe’s first stars (light seeds) or the direct collapse of gas clouds (heavy seeds). Until now, these the- ories lacked observational confir- mation. “The discovery of a super- Eddington accreting black hole sug- gests that a significant portion of mass growth can occur during a single episode of rapid feeding, re- gardless of whether the black hole originated from a light or heavy seed,” says Suh. The discovery of LID-568 also shows that it’s possible for a black hole to exceed its Eddington limit, and pro- vides the first opportunity for as- tronomers to study how this hap- pens. It’s possible that the powerful outflows observed in LID-568 may be acting as a release valve for the excess energy generated by the ex- treme accretion, preventing the sys- tem from becoming too unstable. To further investigate the mechanisms at play, the team is planning follow- up observations with JWST. !