Black Holes Caught in a Galaxy Crash
National Radio Astronomy Observatory | ALMA | 2020 Jan 05
ALMA sees material around two growing supermassive black holes in unprecedented detail
An international team of astronomers used the Atacama Large Millimeter/submillimeter Array (ALMA) to create the most detailed image yet of the gas surrounding two supermassive black holes in a merging galaxy.
- NGC 6240 as seen with ALMA (top) and the Hubble Space Telescope (bottom). In the ALMA image, the molecular gas is blue and the black holes are the red dots. The ALMA image provides the sharpest view of the molecular gas around the black holes in this merging galaxy. Credit: ALMA (ESO/NAOJ/NRAO), E. Treister; NRAO/AUI/NSF, S. Dagnello; NASA/ESA Hubble
400 million light-years away from Earth, in the constellation of Ophiuchus, two galaxies are crashing into each other and forming a galaxy we know as NGC 6240. This peculiarly-shaped galaxy has been observed many times before, as it is relatively close by. But NGC 6240 is complex and chaotic. The collision between the two galaxies is still ongoing, bringing along in the crash two growing supermassive black holes that will likely merge as one larger black hole.
To understand what is happening within NGC 6240, astronomers want to observe the dust and gas surrounding the black holes in detail, but previous images have not been sharp enough to do that. New ALMA observations have increased the resolution of the images by a factor of ten – showing for the first time the structure of the cold gas in the galaxy, even within the sphere of influence of the black holes. ...
How to Fuel an AGN: Mapping Circumnuclear Gas in NGC 6240 with ALMA ~ Anne M. Medling et al
- Astrophysical Journal Letters 885(1):L21 (2019 Nov 01) DOI: 10.3847/2041-8213/ab4db7
- arXiv.org > astro-ph > arXiv:1910.12967 > 28 Oct 2019
at the Highest Spatial Resolution ~ Ezequiel Treister et al
- accepted by Astrophysical Journal (preprint)