Remember the big black hole announcement last year about this time? A group called the “Event Horizon Consortium” (EHC) announced the first-ever “picture” of a black hole at the heart of the distant galaxy M87. It was made by linking up the highest-powered radio telescopes around the world. They focused on the galaxy and provided incredibly high-resolution information about the region at the event horizon.
Now, astronomers are talking about black hole activity at the heart of another object, called 3C 279. It’s a powerful quasar at the core of a distant galaxy, some five billion light-years away. The radio signals and light that we see from it today show it as it looked before our Sun and planets had even begun to form.
Quasars are galaxies in the distant (and younger) universe with energetic activities at their hearts. In visible light, they are incredibly bright, but they also radiate in many other forms of light. What is happening inside these galaxies? Astronomers long searched for ways to explain these incredibly bright objects.
I remember one researcher musing about the engines powering quasars. They said that if a black hole wasn’t a good explanation for quasars, then it had to be something MUCH weirder. Imagine what could be stranger? Black holes certainly provide that “engine”. It’s powerful enough to cause quasars to emit across the electromagnetic spectrum. So, the comment seemed prophetic.
A Twisted Pair of Jets
The quasar 3C 279 has a pair of twin jets. In the area where the jet originates, superheated gases swirl around in a disk surrounding the black hole’s event horizon. Incredibly strong magnetic fields also exist there. They channel some of the hot material to create energetic outflows. Based on EHT observations, the jets send material out at something like 99.5% of the speed of light. That indicates a very active and powerful “push” caused as matter funnels into the black hole’s gravity well.
The collection of radio telescopes used by the EHT zeroed in on the area where the jet activity originates. Astronomers used observations of this quasar as a “pathfinder” and calibration object in 2017.
The data show the base of the jet as it twists over time. Could it be that accretion disk’s rotation and shredding of infalling material are affecting the shape of the jet? Are the incredibly strong magnetic fields playing a role? It’s all part of figuring out how black holes accrete material around them. In addition, it gives more insight into how strong magnetic fields cause the jets to form in the first place.
More observations will help fill in the story of this jet at 3C 279, once EHT is up and running again. At the moment, the world-wide array is shut down due to the CoVID-19 pandemic. EHT scientists are busy analyzing data from the most recent observations.
Here’s an animated look at the activity in 3C 279 over the course of a week, taken in April 2017.