Sideline Quasars Spoilsports That Blocked Galaxy Formation
Did a gigantic quasar have so-called sideline quasars hanging around on the fringes to block the formation of new galaxies after the older one destroyed itself? That’s the intriguing suggestion put forward this week by University of Colorado (UC) Boulder astronomers, who have been studying one of the brightest objects known to humans — an enormous quasar located some 11 billion light-years away from earth.
Michael Shull and David Syphers, who published their results this week online in the Astrophysical Journal, used a $70 million UC-designed ultraviolet spectrograph on the Hubble Space telescope to figure out happened when a supermassive black hole devoured the central core of an ancient galaxy, causing it to spew out radiation that can be detected billions of miles away.
That’s called a quasar. The 50th anniversary of their discovery by Caltech astronomer Maarten Schmidt was celebrated on Saturday. He told The Los Angeles Times that he first thought it was a star. Only later did he realize that it was actually an extremely bright object located at an almost unimaginable distance.
By then the name quasar — short for “quasi-stellar radio source” — had stuck.
In the massive quasar studied by the UC-Boulder team, smaller sidelines quasars around the main object appear to have worked together to ionize the helium gas between galaxies. Neutral particles could have been attracted by gravity more quickly to collapse and form new galaxies. But the charged, overheated particles repelled each other, delaying the formation of new galaxies from the ruins of the old.
With the help of the sideline quasars, the gas between the galaxies could have been heated to as much as 40,000oF. Wowsers. You can see why it might take awhile to cool off and settle down.
Fortunately for us, the sideline quasars might delay but they can’t deny. Shull said that it’s possible that our Milky Way galaxy itself was once a quasar.
[artist’s rendition of a quasar courtesy NASA]
