#qasars

The Shocking Truth About Active Galaxies

Supermassive black holes at the centre of galaxies can be fairly quiet, like Sag A* at our centre, it fairly silently goes on about it's business without much ado, while other galaxies are significantly more active.

One of the interesting features about very active galaxies is the jet of particles sped to near the speed of light that emits from the poles of the black hole.

But what causes these jets ?

There are two potential theories, either the black hole behaves similar to our own Sun, where magnetic connections and disconnections fire out plasma, or a shock wave fires out particles at the speed of light.

Thankfully we don't need to visit a black hole to find out, IXPE is in orbit and has been busy looking at these jets in detail to see what is making them.

As particles hit the shockwave and are sped up to near the speed of light, they move from a turbulent magnetic field into a more ordered one, and start by emitting X-Rays, further along the beam, visible light is emitted, finally as the beam breaks down (which you can see in the above image of M87), infrared and radio waves.

If the shockwave theory is correct, we should see polarization not present in the later light, and that's exactly what IXPE has found, confirming that a shock wave at the polar regions is responsible for the firing of these jets.

What the scientists are not so sure about yet, is what exactly is causing the shock wave in the first instance.

Source :

Astronomers think they have found a galaxy that existed just 300 million years after the big bang. The galaxy named HD1 is so old, it likely only exists of what are known as population iii stars, the very first stars that ever came into existence, made of mostly hydrogen, helium and a small amount of beryllium and lithium.

We have never seen any population iii stars, and according to the theories of the early universe, most of these stars would have been colossal blue giant stars that wouldn't have lived very long at all, a few million years at most before going supernova and collapsing into black holes.

One thing that really stands out about this galaxy is it's unusually powerful in ultra violet light, a common feature of massive blue giant stars, but the amount seen in this galaxy may indicate the presence of a supermassive black hole behaving as a quasar, if this is correct, it will be the earliest example of a blackhole too.

If supermassive black holes were present just 300 million years after the big bang, it may be evidence that black holes were being created much earlier than previously thought.

The next step is to turn the James Webb Telescope towards it, and while it is more focused on the Infra Red, it will be able to resolve much more detail than Hubble, and maybe begin to see if indeed, this was a Qasar just 300 million years into the Universe's existence, or if the galaxy was producing far more stars than even the most prolific starburst galaxy would do today.

NGC 1058 

Some spiral galaxies have incredibly active and bright cores, so much so, they are in a classification similar to Quasars, a supermassive black hole at the centre of the galaxy, being fed enormous amounts of material and amongst the brightest objects in terms of EM output. Known as Seyfert galaxies, they are closer than most Quasars and as a result, have a visible galaxy. 

They are amongst the most studied objects in our sky, mostly because of their similarity to Qasars, and are thought to have some of the same processes with the central black hole that exist in them.