There’s a area of the sky the place astronomers worry to look. Full of darkish clouds of mud, it hides an unseen mass. A mass so giant it’s pulling the Milky Means and different galaxies towards it…
Okay, possibly that’s overdramatic, however it’s true. The area is called the Zone of Avoidance, and it occurs to be within the common path of the galactic middle. Our view of the Universe isn’t as good as we’d like. The Solar is situated inside the galactic airplane of the Milky Means, about 30,000 light-years from its middle. So if we glance to the north or south of the galactic airplane, we get a reasonably regular view of the cosmos. We are able to peer deep into the sky and see distant galaxies. But when we glance towards the galactic middle, we don’t have a transparent view. As a substitute, we see a bunch of stars, gasoline, and mud. That is high quality if you wish to examine stars, gasoline, and mud, nevertheless it means our view of the distant Universe is obscured in that path. So if you wish to make an unbiased view of the cosmos, you keep away from that area, therefore the time period.
It’s additionally true that we’re being pulled in that path. There occurs to be a supercluster of galaxies that approach, referred to as the Nice Attractor. We are able to map it out a bit by learning the relative movement of close by galaxies, and we are able to observe X-rays from the supercluster, so we all know it’s on the market. However with all of the gasoline and mud within the Zone of Avoidance, we are able to’t examine it within the optical. One factor we all know to this point is that the Nice Attractor truly consists of a number of clusters. The closest one is called the Norma cluster, whereas a bigger and extra distant one known as the Vela supercluster. Nonetheless, there’s a lot we don’t know concerning the area.
Thankfully, radio mild can penetrate the mud of the Zone, so radio astronomers have tried to map the area. One draw back is that radio telescopes typically don’t have a big area of view, so it’s tough to map the area. However a brand new work is making progress.
The brand new examine makes use of knowledge from the MeerKAT array telescope in South Africa. MeerKAT is especially delicate to the radio emissions of impartial hydrogen, generally known as the HI or [21-centimeter line.](https://briankoberlein.com/weblog/dark-line/) Since hydrogen is so ample within the Universe, the distribution of hydrogen tells us the distribution of galaxies and clusters. The examine mapped the area of the Zone within the path of the Vela supercluster with sufficient decision to differentiate particular person pockets of impartial hydrogen, every surrounding a galaxy. On this approach, the group was capable of uncover 719 galaxies inside the Vela cluster. Lower than a 3rd of them had been identified beforehand.
This was simply the primary detailed survey of the Vela supercluster by MeerKAT, and it reveals the actual energy of this comparatively new observatory. Future research ought to give us a fair higher understanding of the zone astronomers so typically keep away from.
Reference: Sambatriniaina H. A. Rajohnson, et al. “Revealing hidden constructions within the Zone of Avoidance — a blind MeerKAT HI Survey of the Vela Supercluster.” arXiv preprint arXiv:2411.07084 (2024).
