Stars are born from enormous clouds of principally hydrogen gasoline floating in house. Astronomers like me research this gasoline as a result of it helps us perceive how stars and galaxies kind and develop.
Hydrogen gasoline offers off a faint glow that’s invisible to human eyes however will be noticed with a telescope tuned to detect radio waves.
Not too long ago, my colleagues and I have been utilizing a telescope like this – a radio telescope referred to as MeerKAT, in South Africa – to search for hydrogen gasoline in a selected galaxy. We have been solely observing for lower than three hours, which is kind of a brief period of time because the hydrogen glow is so faint.
Once we appeared on the outcomes, we have been in for an enormous shock. As an alternative of discovering hydrogen gasoline within the galaxy we geared toward, we noticed it in at least 49 beforehand unknown galaxies. Our findings are printed within the Month-to-month Notices of the Royal Astronomical Society.
Fuel in galaxiesThe big clouds of gasoline through which stars are born are referred to as nebulae. When stars ultimately die, they expel their gasoline into their surrounding surroundings, the place it will definitely cools and kinds new nebulae.
Galaxies are like enormous factories the place the life cycle of stars repeats itself time and again. To correctly perceive galaxies and the way they develop and evolve, astronomers want to think about each the celebs and the gasoline making up the galaxy.
One factor we’re notably interested by is “merger occasions”, when two galaxies collide and merge right into a single, bigger galaxy. These occasions may impression the gasoline, and kickstart star formation.
Finding out gasoline can usually assist us perceive a galaxy’s historical past. Fuel usually extends far additional out than the celebs in galaxies.
Once we see trails of disturbed gasoline, it’s a basic clue {that a} current galaxy merger or interplay has occurred.
However we do not see galactic gasoline simply with optical telescopes. Fortunately, radio telescopes are an excellent device for locating hydrogen gasoline.The MeerKAT radio telescope, made up of 64 radio dishes working collectively to behave as a bigger telescope.South African Radio Astronomy Observatory (SARAO)The MeerKAT radio telescopeThe MeerKAT radio telescope in South Africa not too long ago celebrated its fifth birthday. It is without doubt one of the “pathfinder” telescopes for the a lot bigger Sq. Kilometre Array (SKA), a undertaking underneath development in South Africa and Australia.
MeerKAT has already achieved some nice outcomes, from detecting big radio galaxies to learning the centre of our personal galaxy, the Milky Approach.
There are giant survey initiatives underway with MeerKAT to review the star-forming hydrogen gasoline in galaxies. These embody the MIGHTEE-HI and LADUMA surveys, the latter of which can use MeerKAT for greater than 3,000 hours looking one a part of the sky for hydrogen gasoline in very distant galaxies.
These surveys are particularly targeted on discovering hydrogen gasoline and are rigorously deliberate and carried out with that purpose in thoughts.
However that is not the one means MeerKAT can be utilized. Astronomers may pitch concepts for “open time” observations to deal with different science questions or targets.
That is how this discovery happened. I hoped to detect hydrogen gasoline in a single particular galaxy with MeerKAT, as it’s the most delicate telescope for these research.
We didn’t discover hydrogen gasoline in that galaxy, which was superb. We astronomers do not at all times discover what we’re searching for.
However once I inspected the MeerKAT knowledge, I noticed some gasoline positioned away from the goal galaxy. So we investigated additional.
By utilizing methods developed for the bigger MeerKAT science surveys reminiscent of LADUMA, we discovered much more gasoline. In complete, we had 49 detections.The 49 new gas-rich galaxies detected by the MeerKAT radio telescope in South Africa. Every detection is proven as colored contours, with redder colors indicating extra distant gasoline from us, and bluer colors as nearer gasoline. The background picture comes from the optical PanSTARRS survey. (Glowacki et al. 2024)Meet the 49ersEach detection of the gasoline in these galaxies was model new. In little greater than two hours of observing time, MeerKAT had revealed a number of collections of neighbouring galaxies.
A few of these neighbours are even interacting with one another, as their gasoline content material exhibits. This was by no means apparent from simply wanting on the optical photographs of their stars.
In a single case, a galaxy is stealing gasoline from two companion galaxies, and utilizing it to gas its personal star formation.Examples of particular person detections of the gasoline detected by MeerKAT (white contours) on prime of a three-colour optical picture from the DECaLS DR10 survey. The gasoline seen right here extends additional out than the celebs within the galaxies. (Glowacki et al. 2024)I’ve informally nicknamed this assortment of galaxies the 49ers, a reference to the miners of the 1849 California gold rush.
Whereas MeerKAT took the observations containing the 49 gold nuggets in simply a few hours, winnowing them out required a number of different instruments.
These included the ilifu cloud supercomputer, the place we decreased the MeerKAT observations (“knowledge discount” is a type of pre-processing that makes the uncooked observations helpful) and a knowledge visualisation device referred to as CARTA which we used for the preliminary discovery of the 49 new galaxies.
We additionally examined our knowledge with iDaVIE-v, a digital actuality software program for viewing astronomical datasets in 3D. This software program has already been used for brand spanking new discoveries reminiscent of polar ring galaxies. frameborder=”0″ enable=”accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share” referrerpolicy=”strict-origin-when-cross-origin” allowfullscreen> frameborder=”0″ enable=”accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share” referrerpolicy=”strict-origin-when-cross-origin” allowfullscreen>Extra gold nuggets to be foundFinding 49 new galaxies in such a brief quantity of statement time is kind of uncommon, even with a telescope as highly effective as MeerKAT. Nevertheless, we all know there are extra galaxies ready to be present in upcoming and current MeerKAT observations.
In another current work, our staff discovered traces of gasoline in additional than 80 galaxies (most model new) throughout three separate MeerKAT observations. Every of those observations was initially targeted on a single galaxy, just like the “open time” statement through which we discovered the 49ers.What’s going to we discover subsequent? We do not know, however with MeerKAT – and ultimately its extra highly effective successor, the SKA telescope – we’re assured astronomers will flip up loads extra items of gold.
Marcin Glowacki, Analysis Affiliate, Curtin UniversityThis article is republished from The Dialog underneath a Artistic Commons license. Learn the unique article.