A rare triple-merger galaxy, known as J121/1219+1035, hosts three actively feeding radio-bright supermassive black holes, as revealed by a team of American astronomers.
Artist’s impression of J121/1219+1035, a rare trio of merging galaxies, featuring three radioactively bright supermassive black holes actively feeding, with jets illuminating the surrounding gas. Image credit: NSF/AUI/NRAO/P. Vosteen.
The J1218/1219+1035 system is located approximately 1.2 billion light-years from Earth.
This unique galaxy system contains three interacting galaxies, each harboring supermassive black holes at their centers that are actively accreting material and shining brightly in radio frequencies.
Dr. Emma Schwartzman, a research scientist at the US Naval Research Laboratory, states: “Triple active galaxies like J1218/1219+1035 are incredibly rare, and observing them during a merger allows us a front-row seat to the growth of supermassive galaxies and their black holes.”
“Our observations confirmed that all three black holes in J1218/1219+1035 are emitting bright radiation and actively firing jets. This supports the theory of active galactic nuclei (AGN) and provides insight into the life cycle of supermassive black holes.”
Schwartzman and colleagues utilized NSF’s Very Large Array (VLA) and Very Long Baseline Array (VLBA) to study J1218/1219+1035.
The findings confirmed that each galaxy hosts a compact synchrotron-emitting radio core, indicating that all three harbor AGNs powered by growing black holes.
This discovery makes J1218/1219+1035 the first confirmed triple radio AGN and only the third known triple AGN system in nearby space.
“The three galaxies within J1218/1219+1035, located about 22,000 to 97,000 light-years apart, are in the process of merging, resulting in a dynamically connected group with tidal signatures indicative of their interactions,” the astronomers noted.
“Such triple systems are crucial in the context of hierarchical galactic evolution, wherein large galaxies like the Milky Way grow through successive collisions and mergers with smaller galaxies, yet they are seldom observed.”
“By capturing three actively feeding black holes within the same merging group, our new observations create an excellent laboratory for testing how galactic encounters funnel gas into centers and stimulate black hole growth.”
J1218/1219+1035 was initially flagged as an anomalous system through mid-infrared data from NASA’s Wide-Field Infrared Surveyor (WISE), which suggested the presence of at least two obscured AGNs within the interacting galaxies.
Optical spectroscopy confirmed one AGN in a core while revealing complex signatures in another, although the nature of the third galaxy remained uncertain due to the possibility of emissions from star formation.
“Only through new ultra-sharp radio imaging with VLA at frequencies of 3, 10, and 15 GHz did we uncover compact radio cores aligned with all three optical galaxies, confirming that each hosts an AGN bright in radio emissions and likely fueling small-scale jets and outflows,” the researchers explained.
“The radio spectra of the three cores exhibited traits consistent with non-thermal synchrotron radiation from the AGNs, featuring two sources with typical steep spectra and a third with an even steeper spectrum potentially indicative of unresolved jet activity.”
Source: www.sci.news
