NASA’s Hubble Space Telescope has captured a stunning image of a “space triangle” where two galaxies collide, resulting in a star-birth tsunami.
Collectively known as Arp 143, the duo consists of the bright and distorted star-forming galaxy NGC 2445 and the less luminous galaxy NGC 24444.
NGC 2445 has been distorted, to appear triangular in shape, with a wave of bright lights as stars are forming at a rapid rate from material shaken by the collision.
US-based astronomers, from the Flatiron Institute’s Center for Computational Astrophysics in New York and the University of Washington in Seattle, analyzed images taken by a 32-year-old observatory in low Earth orbit.
They explained that the galaxies passed through each other, igniting a firestorm of a unique shape, as thousands of stars burst into life.
The galaxy is drenched in stargazing because it is rich in gas, the fuel that makes stars, but it has yet to escape the attraction of partner NGC 2444, setting them up for a cosmic tug of war, which NGC 2444 appears to be winning.
NASA’s Hubble Space Telescope has captured a stunning image of the “space triangle” where two galaxies collide, triggering a star-birth tsunami.
The dancing galaxies were found in a catalog compiled by astronomer Halton Arp in 1966, consisting of 338 interacting eccentric galaxies.
It was believed that these strange galaxies were excellent laboratories for studying the physical processes that distort normal-looking elliptical and spiral galaxies.
He was one of the first to suggest that galactic encounters could form stars in bursts.
One of the Arp galaxies exploding with new stars is Arp 143, captured in these new images from the Hubble Space Telescope.
“The simulation shows that direct collisions between two galaxies is one way of forming rings of new stars,” said astronomer Julian Dalcanton.
Therefore, star formation rings are not uncommon. However, the strange thing about this system is that it is a triangle of star formation.
Part of the reason for this shape is that these galaxies are still very close to each other and that NGC 2444 is still gravitationally attached to the other galaxy.
NGC 2444 may also contain an invisible, hot gas halo that could help draw NGC 2445 gas away from its core. So, they are not completely free from each other yet and their unusual interaction distorts the ring in this triangle.
NGC 2445 has been distorted, to appear triangular in shape, with a wave of bright lights as stars are forming at a rapid rate from material shaken by the collision. Wide field width found for region Arp 143
The faintness of the two galaxies is also responsible for pulling “rope-like filaments of gas” from their partner, fanning the flow of young blue stars that seem to form a bridge between the two galaxies.
These rivers are among the first in what appears to be a wave of star formation that began on the fringes of NGC 2445 and continued inland when the two collided.
The team behind the study estimates that the streamers were born between 50 and 100 million years ago, and left behind, in the Triangle region, where NGC 2445 continues to slowly withdraw from NGC 2444.
According to the team, stars no older than 1 to 2 million years old are forming near the center of NGC 2445.
Hubble is so sharp that it is capable of resolving a few individual stars within the image, even though most of the bright blue masses are clumps of stars. Pink dots are young, giant star clusters still covered in dust and gas.
Although most of the events occur in NGC 2445, this does not mean that the other half of the interacting pair survived unharmed. The gravitational pull has stretched NGC 2444 into a strange shape.
The galaxy contains old stars and not a new stellar birth because it lost its gas long ago, long before this galactic encounter.
This is a close example of the types of interactions that occurred long ago. ‘It’s a great sandbox for understanding star formation and the interaction of galaxies,’ said Elena Sabi of the Space Telescope Science Institute in Baltimore, Maryland.