Due to computer simulations and new observations from Atacama Large Millimeter / submillimeter Array (ALMA), researchers have found that the…
Due to computer simulations and new observations from Atacama Large Millimeter / submillimeter Array (ALMA), researchers have found that the gas rings around active super massive black holes are not simple donuts. Instead, gas expelled from the center with incident gas switches to create a dynamic circulation pattern resembling a waterfountain in a city park.
Most galaxies host a super massive black hole, millions or billion times as heavy as the sun, in their centers. Some of these black holes swallow the material quite actively. But astronomers have thought that instead of falling directly into the black hole, matter instead will be built around the active black hole that forms a monk structure.
Takuma Izumi, a researcher at Japan’s National Astronomical Observatory (NAOJ), led a team of astronauts who used ALMA to observe the super massive black hole in Circinus Galaxy, located 1
4 million light years away from the Earth in the direction of the Circulus constellation. The team then compared their observations with a computer simulation of gas falling against a black hole made by the Cray XC30 ATERUI supercomputer powered by NAOJ. This comparison showed that the presumptive “donut” is not a rigid structure, but instead a complex combination of high-dynamic gaseous components. First of all, cold molecular gas falling against the black hole forms a disc near the rotational plane. As it approaches the black hole, this gas is heated until the molecules break down into component atoms and ions. Some of these atoms are then expanded over and under the counter, instead of being absorbed by the black hole. This hot atomic gas falls back onto the disc and creates a turbulent three-dimensional structure. These three components circulate continuously, resembling a water fountain in a city park.
“Previous theoretical models established previous assumptions about stupid monks,” explains Keiichi Wada, a theorist at Kagoshima University in Japan, who heads the simulation study and is a member of the research group. “Instead of starting with assumptions, our simulation started from the physical equations and showed for the first time that gas circulation naturally forms a monk. Our simulation can also explain different observation properties in the system.”
“By examining the motion and distribution of both the cold molecular gas and the hot atomic energy with ALMA, we showed the rise of the so-called” donut structure “around active black holes,” said Izumi. “Based on this discovery, we have to write about the astronomy books.”
Material provided by National Institutes of Natural Sciences . Note! Content can be edited for style and length.