The mass of a supermassive black hole at the centre of an elliptical galaxy is enormous.
Astronomers found a giant black hole which is 660 million times bigger than the sun.
They determined the speed of a disk of cold molecular gas and dust orbiting the supermassive black hole.
Astronomers found that the mass of the giant black hole is 660 million times bigger than the sun. The scientist said, “This is among the most precise measurements of the mass of a galaxy’s central black hole.”
Astronomers studied the gravitational pull of a giant black hole.
Aaron Barth from UCI explained, “This is the first time that ALMA has probed the orbital motion of cold molecular gas well inside the gravitational sphere of influence of a supermassive black hole. We are directly viewing the region where the cold gas is responding to the black hole’s gravitational pull.”
The mass of the black hole was determined by cold molecular gas and dust orbiting around it in the galaxy NGC 1332.
Barth further explained, “For a precise measurement, we need to zoom in to the very centre of a galaxy where the black hole’s gravitational pull is the dominant force. ALMA is a fantastic new tool for carrying out these observations.”
Cold molecular gas and dust orbiting around black hole don’t emit visible light.
ALMA observes the wavelength at which the molecules glow brightly.
ALMA studied the supermassive black hole present in the elliptical galaxy NGC 1332.
NGC 1332 is a giant elliptical galaxy in the southern sky 73 million light-years from Earth. The scientist explained, “About one in 10 elliptical galaxies contain disks of cold molecular gas and dust that orbit their centers.”
Astronomers use Doppler Effect to map the motion of the gas surrounding black holes.
Doppler Effect is a change in the frequency of sound, light or other waves due to the movement of source away from observers.
In this case, astronomers studied radio waves emitted from carbon monoxide molecules.
The emissions caused due to CO molecules are usually bright and thus can be easily detected with ALMA.
This study is published in the Astrophysical Journal Letters.
Benjamin Boizelle from UCI explained, “This observation demonstrates a technique that can be applied to many other galaxies to measure the masses of supermassive black holes to remarkable precision.”