Massive galaxy collision produces a 100-million degree shockwave

Proudly supported by

  Last updated June 26, 2019 at 12:47 pm

Topics:  

Two galaxy clusters have been discovered on the verge of collision, unleashing a monstrous 100-million degree shockwave.


galaxy cluster collision astronomy observation

Multi-wavelength view of galaxy clusters 1E2216 and 1E2215, which appear to come into first contact ahead of merging. Credit: NASA/CXC (X-rays); SDSS (optical); GMRT (radio); Liyi Gu et al. 2019


Two massive galaxy clusters have been discovered just before the point of collision, giving astronomers the best seats in the universe to watch the early stages of the cataclysmic event.


And in those first few moments as the galaxies approach each other they’ve seen massive shockwaves with temperatures up to 100-million degrees exploding from the collision.


That makes the shockwave around 17,000 times hotter than the surface of the Sun.


It is the first time clusters this close to smashing into each other have been seen. These collisions and mergers are one of the keys to understanding the structure of the universe, say the international team of researchers, including from Perth’s International Centre for Radio Astronomy Research.


Galaxy clusters on verge of collision


Clusters of galaxies are the largest known objects bound by gravity. Consisting of hundreds of galaxies that each contain hundreds of billions of stars, they’re surrounded by a halo of hot gas. Ever since the Big Bang, these objects have been growing by colliding and merging with each other.


The clusters, 1E2216 and 1E2215, are located over one billion light years away from the Earth. For billions of years they have been slowly drawn towards each other by gravity.





While astronomers have observed galaxy clusters mid-collision and post-collision, the early stages have remained elusive. Being able to see a collision from the very start will let astronomers test their theoretical models against an actual merger.


It is similar to seeing a raindrop that just touches the water surface in a photograph of a pond.


In particular, the researchers are expecting to see massive shockwaves spreading perpendicular to the axis of collision in the very first moments of collision.


Galaxy cluster collision shockwaves

Shocks during galaxy cluster merger. Credit: Courtesy of H. Akamatsu/SRON


“X-ray and radio images of these clusters show the first clear evidence for this type of merger shock”, says Liyi Gu, who led the research at RIKEN in Japan.


“The shock created a hot belt region of 100-million-degree gas between the clusters, which is expected to extend up to, or even go beyond the boundary of the giant clusters. Therefore, the observed shock has a huge impact on the evolution of galaxy clusters and large-scale structures.”


galaxy cluster collision temperatures

Temperature distribution of merging galaxy clusters IE2216 and IE2215. The colour scale ranges from 14 million °C (black) to 70 million °C (blue) to 80 million °C (red) to over 90 million °C (yellow). Credit: ESA/XMM-Newton; GMRT; Liyi Gu et al. 2019


Collecting snapshots to build a complete model of galaxy collisions


Spotting the impending collision required a huge amount of data. The team used three X-Ray satellites (ESA’s XMM-Newton, NASA’s Chandra, and JAXA’s Suzaku) combined with two ground-based radio telescopes (the Low-Frequency Array in Europe, and the Giant Metrewave Radio Telescope in India).


The team will continue to collect “snapshots” of the collision as it happens, allowing them to build a complete model of how galaxy clusters merge for the first time.


“This will help us to complete our understanding of the role of merger shocks in the formation of the largest structures in the Universe,” says Huib Intema from the ICRAR team who found the cluster.


With diameters of a few million light years, these galaxy cluster collisions can take about a billion years to complete. After the dust has settled, the two colliding clusters will have merged into one bigger cluster.


The research is published in Nature Astronomy.


Related


Astronomers find massive “ghost galaxy” near the Milky Way


Faint stellar glow reveals the location of dark matter in galaxy clusters


Massive gas jets seen streaming from early universe galaxy




About the Author

Ben Lewis
Ben Lewis is the Editor of Australia’s Science Channel, and a contributor to Cosmos Magazine. He has worked with scientists and science storytellers including Brian Cox, Chris Hadfield, Robert Llewellyn, astronauts, elite athletes, Antarctic explorers, chefs and comedians. Ben has also been involved in public events around Australia and was co-writer, producer and director of The Science of Doctor Who, which toured nationally in 2014 in association with BBC Worldwide Australia & New Zealand. Want more Ben? You can hear him on ABC and commercial radio in Adelaide, regional SA, across NSW, and the ACT. He also speaks at universities around Australia on communicating science to the public. Around the office he makes the worst jokes known to mankind.

Published By

ICRAR is an institute of astronomers, engineers and big data specialists supporting the Square Kilometre Array, the world’s largest radio telescope. ICRAR is an equal joint venture between Curtin University and The University of Western Australia, with funding support from the State Government of Western Australia.


Featured Videos

Placeholder
Sausages, SPHERE, and Mother's Day: Astro Morning Tea with ICRAR
Placeholder
Space junk, Einstein, and star colours: Astro Morning Tea with ICRAR
Placeholder
Space junk, Einstein, & star colours: Astro Morning Tea with ICRAR (Captioned)
Placeholder
IceCube blazar neutrino detection: Astro Morning Tea with ICRAR
Placeholder
IceCube blazar neutrino detection: Astro Morning Tea with ICRAR (Captioned)
Placeholder
What are black holes?
Placeholder
How will the Universe end?
Placeholder
Introducing the Starfox Telescope
Placeholder
What happens when Cosmic Giants meet Galactic Dwarfs?
Placeholder
Spinning supermassive black hole rips a star apart
Placeholder
Supernovae, the Moon, & our Universe: Astro Morning Tea with ICRAR
Placeholder
Supernovae, the Moon, & our Universe: Astro Morning Tea (Captioned)
Placeholder
The SKA - An international affair
Placeholder
Space junk, galaxy shapes, and cheese: Astro Morning Tea with ICRAR
Placeholder
Space junk and galaxy shapes: Astro Morning Tea (Captioned)
Placeholder
Simulation of the cataclysmic supernova SN1987A
Placeholder
Fumes, dark energy, and black death: Astro Morning Tea with ICRAR
Placeholder
Fumes & dark energy: Astro Morning Tea with ICRAR (Captioned)
Placeholder
Hidden Galaxies: in the zone of avoidance
Placeholder
Galaxies, black holes, and turkeys: Astro Morning Tea with ICRAR
Placeholder
Galaxies and black holes: Astro Morning Tea with ICRAR (Captioned)
Placeholder
Discover the GLEAM galactic survey
Placeholder
Discover the GLEAM galactic survey (Captioned)
Placeholder
NASA tests & data storage: Astro Morning Tea (Captioned)
Placeholder
NASA tests, Matter & Data storage: Astro Morning Tea with ICRAR
Placeholder
The 'missing satellite problem'
Placeholder
Christmas is in the air at Astro Morning Tea
Placeholder
Christmas is in the air: Astro Morning Tea (Captioned)
Placeholder
Particles and moon caves: Astro Morning Tea with ICRAR (Captioned)
Placeholder
Particles, moon cave, and bombs: Astro Morning Tea with ICRAR
Placeholder
Fly though the Universe with the GAMA survey
Placeholder
Fly though the Universe with the GAMA survey (captioned)
Placeholder
The number zero, a vanished star, & going batty: Astro Morning Tea with ICRAR
Placeholder
Zeroes and vanished stars: Astro Morning Tea (Captioned)
Placeholder
Columbus, Caterpillars and WASP: Astro Morning Tea with ICRAR
Placeholder
How does a radio telescope work?
Placeholder
ISS, Illegal activity and Pineapples: Astro Morning Tea with ICRAR
Placeholder
ISS and Pineapples: Astro Morning Tea (Captioned)
Placeholder
Gravity, Plutomania and the Day Comedy Dies: Astro Morning Tea with ICRAR
Placeholder
Gravity and Plutomania: Astro Morning Tea (Captioned)
Placeholder
Explore Murchison - Australia's SKA site
Placeholder
Astro Morning Tea: Environmentalism and everything is Dutch! (Captioned)
Placeholder
Astro Morning Tea with ICRAR: Environmentalism, Missing things and everything is Dutch!
Placeholder
Foreign Correspondent: USA Total Solar Eclipse
Placeholder
Astro Morning Tea with ICRAR: Moon Landings, Scary Accordions and Smart Animals
Placeholder
The Square Kilometre Array: Telescope of the Future
Placeholder
Astro Morning Tea with ICRAR: Space Weather, Extra Dimensions, and Pringles
Placeholder
Astro Morning Tea with ICRAR: Secret Space Station, Drones and Fresh Milk
Placeholder
The Electromagnetic Spectrum