A pair of galaxies collide to form a brilliant ‘space triangle’ in a new Hubble Space Telescope image

 

 

Last week, NASA shared a stunning new photo captured by the venerable Hubble Space Telescope. The image showcases an ongoing head-on collision between two galaxies and a beautiful triangular-shaped frenzy of newly-born stars.

The interaction galaxies are collectively known as Arp 143. In the image below, NGC 2444 is shown at the left, and the glittery galaxy to the right is NGC 2445. NGC 2445 features thousands of newly-formed stars because the galaxy is rich in the gas that fuels starbirth. However, NGC 2445 remains in the gravitational pull of its counterpart, NGC 2444. As NASA puts it, there's a cosmic tug-of-war at play, and NGC 2444 is winning. The galaxy is pulling gas from NGC 2445, which has allowed for the formation of an 'oddball' triangle of new stars.

 

'The interacting galaxy duo is collectively called Arp 143. The pair contains the glittery, distorted, star-forming spiral galaxy NGC 2445 at right, along with its less flashy companion, NGC 2444 at left.' Image Credits: NASA, ESA, STScI, Julianne Dalcanton (Center for Computational Astrophysics / Flatiron Inst. and University of Washington); Image Processing: Joseph DePasquale (STScI). Click here to see the high-resolution version.

'Simulations show that head-on collisions between two galaxies is one way of making rings of new stars,' said astronomer Julianne Dalcanton of the Flatiron Institute's Center for Computational Astrophysics in New York and the University of Washington in Seattle. 'Therefore, rings of star formation are not uncommon. However, what's weird about this system is that it's a triangle of star formation. Part of the reason for that shape is that these galaxies are still so close to each other and NGC 2444 is still holding on to the other galaxy gravitationally. NGC 2444 may also have an invisible hot halo of gas that could help to pull NGC 2445's gas away from its nucleus. So they're not completely free of each other yet, and their unusual interaction is distorting the ring into this triangle.'

Beyond helping create the triangular-shaped collection of new stars, NGC 2444's gravitational pull is also 'yanking taffy-like strands of gas from its partner,' forming a sort of bridge of young blue stars. Despite being infant stars, researchers estimate that the streamer stars were born 50 to 100 million years ago – a long time to us but very little time in the universe. Closer to the center of NGC 2445, the stars are even younger, around 1 million to 2 million years old. In the image above, 'Most of the brilliant blue clumps are groupings of stars. The pink blobs are giant, young, star clusters still enshrouded in dust and gas.'

In addition to providing a spectacular image, the interacting galaxies shed important light on star formation and how different galaxies affect each other. 'This is a nearby example of the kinds of interactions that happened long ago. It's a fantastic sandbox to understand star formation and interacting galaxies,' said Elena Sabbi of the Space Telescope Science Institute in Baltimore, Maryland.

(Via PetaPixel)