Oct 24, 2013 Unique Chemical Composition Surrounding Supermassive Black Hole—A Step toward Development of New Black Hole Exploration Method
An international research team led by Takuma Izumi, a second-year master's student of science at the University of Tokyo, and Kotaro Kohno, a professor at the University of Tokyo, successfully captured a detailed image of high-density molecular gas around an active supermassive black hole at the center of a galaxy called NGC 1097 at the highest sensitivity ever achieved. The observation result shows that there is a unique chemical composition characterized by enhancement of hydrogen cyanide (HCN) around the black hole, which would be caused by high temperature heating of the environment surrounding the black hole. It is expected that this new method focusing on the difference of emission frequencies from molecules uniquely found around black holes may open the way for "the search for a hidden black hole" which is overcast with dust particles and optically invisible.
The research findings are presented in the article "Submillimeter ALMA Observation of the Dense Gas in the Low-Luminosity Type-1 Active Nucleus of NGC 1097" published in the Publication of the Astronomical Society of Japan, Vol. 65, of October 25, 2013.
Figure 1. Spiral galaxy NGC 1097 observed with European Southern Observatory's Very large Telescope in optical wavelength (left) and the central 2100 light years observed with ALMA (right). The ALMA observations reveal intense emission from dust around the central black hole and in the circum-nuclear star burst ring. The star sign shows the location of the emission peak in near infrared, which reflects the star formation activity, whereas the central plus sign shows the location of the radio emission in the wavelength of 6 cm which comes from the active supermassive black hole. The emission peak position in the ALMA image agrees well with that of 6 cm emission. This ensures that ALMA detects the emission from the vicinity of the central black hole.
Credit:ESO, ALMA (ESO/NAOJ/NRAO), T. Izumi