Astronomers have detected two big, unexplained objects erupting from the Universe's brightest black hole.
The supermassive black hole 3C 273 was discovered in a 1959 study of cosmic radio-wave sources as a quasar – short for "quasi-stellar object," since the light emitted by these behemoths is brilliant enough to be mistaken for starlight.
While black holes do not produce light, they are surrounded by massive swirls of gas known as accretion disks. As gas falls into the black hole at near-light speed, friction warms the disk, causing it to flame with radiation, which is normally detected as radio waves.
The first quasar to be discovered was 3C 273. It's also the brightest, glowing more than 4 trillion times brighter than Earth's Sun despite being more than 2.4 billion light-years away.
Scientists have spent decades researching the flaming black hole core, but analyzing the surrounding galaxy that contains it has been nearly impossible due to the quasar's brightness. Ironically, quasars' extraordinary brightness has kept scientists largely in the dark about how they affect their host galaxies.
A new research published in The Astrophysical Journal on April 28 might finally change that.
A team of astronomers used the Atacama Large Millimeter/submillimeter Array (ALMA) radio telescope in Chile to calibrate it so that it could distinguish the radiant glow of quasar 3C 273 from the light generated by its host galaxy.
They were left with just the quasar's galaxy's radio waves, which revealed two gigantic and enigmatic radio structures that had never been observed before.
One structure appears to be a massive smear of radio light that envelops the whole galaxy and extends hundreds of light-years to the southwest. This radio fog collides with the second structure, a massive energy jet known as an astrophysical jet that reaches for tens of thousands of light-years as well.
Astrophysical jets are a mystery to scientists. They don't know how or why they arise. They do know that jets are prevalent near quasars and other supermassive black holes, and that they are most likely caused by interactions between the black hole and its dusty accretion disk. Ionized (electrically charged) matter is used to make jets, which fly at near-light speed.
The radiation emitted by these jets can look brighter or darker depending on the radio frequency at which it is seen; nevertheless, the huge radio structure orbiting galaxy 3C 273 had a consistent brightness regardless of frequency. This shows that the two radio structures are formed by independent, unconnected events, according to the researchers.
After putting numerous possibilities to the test, the researchers came to the conclusion that the huge radio fog seen around the galaxy is caused by star-forming hydrogen gas being ionized directly by the quasar. According to the researchers, this is the first time ionized gas has been discovered reaching tens of thousands of light-years around a supermassive black hole.
This finding sheds light on a long-standing astronomical puzzle: can a quasar ionize enough gas in its host galaxy to prevent new stars from forming? To get an answer, the researchers compared the estimated gas mass of the galaxy to that of other galaxies of similar kind and size.
They discovered that, while the quasar had ionized a massive amount of gas, leaving it unusable for star formation, star formation in the galaxy as a whole had not been repressed. This shows that galaxies with radiation-belching quasars at their cores can nonetheless be healthy and expanding.
"This discovery provides a new avenue to studying problems previously tackled using observations by optical light," lead study author Shinya Komugi, an associate professor at Kogakuin University in Tokyo, said in a statement.
"By applying the same technique to other quasars, we expect to understand how a galaxy evolves through its interaction with the central nucleus."
Reviewed by Lilit
on
June 10, 2022
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