Astronomers had to reclassify a bright radio galaxy in the sky after it was found to have redirected a jet of radiation straight toward Earth. shows the first observation of a reorientation of
At the center of most galaxies is a supermassive black hole, and in some cases these monsters are busy eating matter and emitting higher levels of radiation. Regions undergoing this process are called active galactic nuclei (AGNs) or quasars. Some of them eat so disorderly that they are spitting out huge jets of charged particles that move at near the speed of light. These jets can be aimed in any direction from your home galaxy, and if they happen to be pointed at Earth, they will appear as very bright objects called blazers.
Now astronomers have discovered a strange galaxy that seems to have switched from quasars to blazers. At some point in the past, the Galactic Jet seems to have changed direction by as much as 90 degrees, flipping from running across the sky to pointing directly at Earth.
Known as PBC J2333.9-2343, the galaxy lies 656.8 million light-years away, and when viewed at large scale with certain types of instruments, you can see what appear to be jets moving across the sky. You can see it growing. Because of this, it was originally classified as a radio galaxy with an AGN at its center.
But the galaxy seemed to have some other strange properties, so astronomers used radio, optical, infrared, X-ray, ultraviolet, and gamma-ray telescopes to take a closer look at the galaxy. These comprehensive studies have revealed a blazer at the center of the galaxy. This is a characteristic of the jet seen from the front. So what about old jets? The astronomer also saw two lobes of matter, relics of these old jets no longer being fed by AGN activity.
This study allowed the team to more accurately estimate the size of the galaxy, which turned out to be a massive galaxy with a diameter of about 4 million light-years. For reference, our Milky Way is only 100,000 light years wide.
The team says they’ve seen other AGNs redirect jets in the past, but this was always directed from one vertical part of the sky to another. PBC J2333.9-2343 was the first record of a jet traveling in a straight line with the Earth, changing the classification of the object. But in a similar event, a supposedly stationary galaxy was seen to suddenly ignite into a quasar.
The exact cause of the shift has not yet been explained, but the researchers say it could have merged with another galaxy, collided with another large object, or the black hole may have been dormant for some time before exploding again. I’m assuming there is.
A study was published in a journal Monthly Notices of the Royal Astronomical Society.
Source: Royal Astronomical Society
