Active Supermassive Black Holes Revealed in Merging Galaxies

A team of astronomers has conducted infrared observations of luminous, gas-rich, merging galaxies with the Subaru Telescope to study active, mass-accreting supermassive black holes (SMBHs). They found that at least one SMBH almost always becomes active and luminous by accreting a large amount of material. However, only a small fraction of the observed merging galaxies show multiple, active SMBHs. These results suggest that local physical conditions near SMBHs rather than general properties of galaxies primarily determine the activation of SMBHs.

Examples of infrared K-band images of luminous, gas-rich, merging galaxies. The image size is 10 arc seconds. North is up, and east is to the left. The individual images clearly show aspects of the merging process, such as interacting double galaxy nuclei and extended/bridging faint emission structure.
Artist’s rendition of an active, mass-accreting black hole in a luminous, gas-rich merging galaxy.

The scientific paper on which this article is based appears in the Astrophysical Journal published on Jan., 2014.
Imanishi, M. & Saito, Y. 2014 “Subaru Adaptive-optics High-spatial-resolution Infrared K- and L’-band Imaging Search for Deeply Buried Dual AGNs in Merging Galaxies”, Astrophysical Journal, Volume 780, article id. 106.