DEC 23, 2020

It's Not a Quasar, It's a Blazar

WRITTEN BY: Carmen Leitch

The National Science Foundation has a network of observing stations across the United States called the Very Long Baseline Array. There are ten stations in all, and each one has a 25-meter radio antenna dish and a building where the controls are housed. Each antenna collects radio signals that are amplified, digitized and recorded.

Now the VLBA has captured images of a jet of material that’s being ejected from the core of a galaxy. The material is racing out of the core, in the direction of the Earth, at three-quarters the speed of light. The galaxy, called PSO J0309+27 is estimated to be about 12.8 billion light years away from us, so we are seeing it as it appeared when the universe was under one billion years old, around seven percent of its age now.

PSO J0309+27 is a blazar. At the heart of most galaxies are black holes, whose gravitational pull takes in everything around it. As material is swallowed up by the black hole, gravitational energy could change into light, turning the system into what’s known as active galactic nuclei (AGN). Some of these AGNs produce massive jets, like the one observed in this research. While these objects might be named quasars, if a galaxy like this is oriented toward earth, shooting its material in our general direction, it’s known as a blazar. Blazars are some of the brightest objects in the universe.

The brightest radio emissions coming from the core of the galaxy can be seen in the bottom right of the image. This is the brightest blazar that’s ever been seen at this distance, and is the second-brightest X-ray-emitting blazar that’s been observed at this distance.

The core of the PSO J0309+27 galaxy holds a supermassive black hole, which is propelling the jet with gravitational energy.  The jet in the image is thought to extend for 1,600 light years.

This research has been reported in Astronomy & Astrophysics, and may help scientists understand why there aren’t that many blazars in the early universe.


Sources: AAAS/Eurekalert! via National Radio Astronomy Observatory, Astronomy & Astrophysics