The vast cosmos is a thing of beauty and wonder. Star systems, planetary movements, even comets hurtling through the vacuum of space make for sights beyond awe and marvel. Thanks to modern technology, we don’t need to sit and wonder what these celestial events must look like hundreds and thousands of light-years away from us. The Hubble Space Telescope recently shared breath-taking images of galaxies colliding on the microblogging site Twitter and people cannot hold their amazement.
Galaxy collision is a very rare merging event where dramatic changes occur in their appearance as well as stellar content. The physical conditions can be extreme but the resulting view is phenomenal.
They published 59 images of such collisions with the earliest being 2008 and the latest from October 2020.
The official website of NASA-ESA Hubble (the Hubble Telescope is a NASA endeavour but jointly run with contributions from the ESA or European Space Agency) explained this phenomenon in a post accompanying these photographs. According to them, most star clusters in the Milky Way galaxy (our corner of the vast universe) have masses that can be 10 thousand times the mass of our Sun. But when the galaxies collide, the star clusters formed there can be more than millions of times greater than the mass of our sun.
These stellar systems have excellent luminosity. Their shine isn’t limited to the collision itself. When they go into a quieter phase after the collision, their gleam persists in their host galaxy for a long, long time. These long-lasting shining signatures are proof of past collision events.
In a 2008 release of a similar space event, Hubble had dubbed this incident as “galaxies gone wild” and they couldn’t be more right.
The new Twitter post features six galaxy mergers. They are from Hubble imaging Probe of Extreme Environments and Clusters (HiPEEC) survey. This survey had been investigating how these collisions impact star clusters. These events induce physical changes to the system and raise the rate of star formation.
Witnessing something like this may have been impossible a few decades ago, but thanks to Hubble such far off and fascinating events can now be documented. They observed through the ultraviolet and near-infrared study that these star clusters go through very rapid and large variations in their properties during the collision. They also observed that the larger clusters seem to form towards the end of the merger.
When galaxies collide, they go through dramatic changes in appearance and stellar content. Each of these merging systems was studied as part of a recent Hubble survey to investigate the rate of new star formation within such systems.
The first set of these images launched in 2008 were to mark the 18th anniversary of Hubble Telescope’s operation in the Earth’s lower orbit. Now it has been nearly three decades since it was launched and it continues to awe scientists and enthusiasts alike with its magnificent and simply stunning discoveries.