As a result of achieving high dynamic range imaging, a team of astronomers in Japan has detected for the first time a faint radio emission covering a giant galaxy with an active black hole at its center.
The radio emission is emitted by gas directly from the central black hole. The team expects to understand how the black hole interacts with its host galaxy by applying the same technology to other quasars.
The anomaly is called 3C273, a quasar located at the center of its host galaxy, at a distance of 2.4 billion light-years from Earth, and is the most studied quasar in the night sky.
A quasar, or quasar, or similar star, is the nucleus of a galaxy believed to contain a supermassive black hole at its center, which engulfs the surrounding material, producing massive radiation, but 3C273 is still very bright.
The quasar was first observed in 1963 and was the first quasar ever discovered.
Radio telescopes face challenges when focusing on bright objects like 3C273.
Phys.org said, “When you see a car’s headlight bulb, the dazzling brightness makes it difficult to see the darker surroundings. The same thing happens to telescopes when they spot bright objects.”
Scientists at the ALMA observatory developed techniques to study the dark host galaxy, and found that the structure of radio waves was placed over the galaxy for tens of thousands of light years, and this is the first discovery of its kind.
As a result of achieving the high dynamic range imaging, the team detected a faint radio emission extending for tens of thousands of light-years over the host galaxy 3C273.
Radio emission around quasars usually refers to synchrotron radiation, which comes from highly energetic events such as star-forming emissions or ultra-fast jets from the central core.
Synchrotron radiation is also found in 3C273. The primary characteristic of synchrotron radiation is that its brightness changes with frequency, but the faint radio emission the team discovered had a constant brightness regardless of radio frequency.
After considering alternative mechanisms, the team found that this faint, extended radio emission came from hydrogen gas (a key component of star formation) in the galaxy that is directly activated by 3C273’s core.
This is the first time that radio waves from such a mechanism have spanned tens of thousands of light years in the quasar host galaxy.
“By applying the same technique to other quasars, we expect to understand how the galaxy evolves through its interaction with the central core,” said one of the scientists involved in the study.