Researchers explain mystery of 'banging' galaxy clusters

June 6, 2017
Image of a galaxy cluster, which may contain hundreds or thousands of galaxies bound gravitationally. Credit: NASA

Two galaxy clusters in the process of merging created a layer of surprisingly hot gas between them that University of Colorado Boulder astronomers believe is from turbulence caused by banging into each other at supersonic speeds.

The two clusters, which are coming together to create the larger galaxy Abell 115, are located some 2.4 billion light years away. The turbulent area of hot gas sandwiched between the two clusters, which CU Boulder Professor Jack Burns likened to a wake behind a motorboat, is about 300 million degrees F. That is roughly three times as hot as the two smaller cluster cores and 10 times hotter than the core of the sun, said Burns, lead study author.

"We did not expect to see such very hot gas between the cluster components," said Burns. "We think the turbulence is like a big spoon stirring up gases, converting the energy of motion from the merging clusters into thermal energy. It is a manifestation of them banging together like two giant pots, something we have not really seen before."

Burns presented the new findings in a press briefing on Tuesday, June 6 at the 230th Meeting of the American Astronomical Society being held in Austin, Texas, June 4-8.

The two merging individually consist of hundreds of , each as large or larger than our own Milky Way galaxy, said Burns of CU Boulder's Center for Astrophysics and Space Astronomy. Individual galaxy clusters, which can include thousands of galaxies, are the largest gravitationally bound objects in the universe.

"Energetically speaking, galaxy cluster merging events are the biggest bangs in the universe since the Big Bang," said Burns. "These are massive, very dynamic systems that continue to evolve to this day."

The observations by the CU Boulder team were made using data from NASA's orbiting Chandra X-ray Observatory and the Karl G. Jansky Very Large Array, a radio- astronomy facility near Socorro, New Mexico, operated by the National Radio Astronomy Observatory and funded by the National Science Foundation.

The team's computer simulations show regions of relatively cool gas near the cores of each merging cluster, indicating the two objects have encountered each other before - perhaps circling a few times and stripping gas from one another before merging.

The study co-authors, all from CASA, include Research Associate Eric Hallman, doctoral student Brian Alden, NASA Senior Postdoctoral Fellow David Rapetti and senior collaborator Abhirup Datta. The new study was funded by NASA's Astrophysical Data Analysis Program.

To analyze temperatures within Abell 115 and other similar merging clusters, Burns and his team developed software to produce high-contrast temperature maps of all cluster regions in both the X-ray and radio portions of the electromagnetic spectrum. The new data pipeline uses the NASA Ames Research Center supercomputer to calculate 10,000 to 100,000 spectra in each cluster, said Burns.

The team is continuing to investigate the radio emissions stretching far outside Abell 115 into the intergalactic medium, including their relationship to the hot X-ray gas.

"These radio emissions are caused by electrons in the magnetic field of the galaxy cluster traveling at near the speed of light," said Burns. "Clearly something has energized the electrons, which we think is related to the cluster banging process."

As part of the project, the CU Boulder team is studying a sample of 50 other galaxy clusters for comparison, said Burns.

What's next for Abell 115? "Our computer simulations show these cluster mergers can be really complicated in terms of the accretion process, depending on the state we catch them in," said Burns. "We believe Abell 115 will eventually 'relax' and become centrally condensed, which is relatively boring compared to what we are seeing now."

Galaxy clusters form in what is known as the universe's cosmic web, said Burns. The cosmic web consists of long, narrow filaments of galaxies and intergalactic gas separated by enormous voids. Astronomers believe single filaments can stretch for hundreds of millions of light years, an astonishing length considering a single light-year is about 5.9 trillion miles.

Explore further: A lot of galaxies need guarding in this NASA Hubble view

Related Stories

A lot of galaxies need guarding in this NASA Hubble view

May 4, 2017

Much like the eclectic group of space rebels in the upcoming film Guardians of the Galaxy Vol. 2, NASA's Hubble Space Telescope has some amazing superpowers, specifically when it comes to observing innumerable galaxies flung ...

Astronomers discover powerful cosmic double whammy

January 5, 2017

Astronomers have discovered a cosmic one-two punch unlike any ever seen before. Two of the most powerful phenomena in the Universe, a supermassive black hole, and the collision of giant galaxy clusters, have combined to create ...

A peek into the merging galaxy cluster Abell 3888

February 17, 2016

(Phys.org)—Studying substructures of galaxy clusters can reveal important information about the morphology and evolution processes of these gravity-bound groups of galaxies. Optical spectroscopy is very helpful in this ...

Colliding galaxy clusters

December 5, 2016

Galaxy clusters contain a few to thousands of galaxies and are the largest bound structures in the universe. Most galaxies are members of a cluster. Our Milky Way, for example, is a member of the "Local Group," a set of about ...

Recommended for you

Bright areas on Ceres suggest geologic activity

December 13, 2017

If you could fly aboard NASA's Dawn spacecraft, the surface of dwarf planet Ceres would generally look quite dark, but with notable exceptions. These exceptions are the hundreds of bright areas that stand out in images Dawn ...

Stellar nursery blooms into view

December 13, 2017

The OmegaCAM camera on ESO's VLT Survey Telescope has captured this glittering view of the stellar nursery called Sharpless 29. Many astronomical phenomena can be seen in this giant image, including cosmic dust and gas clouds ...

New eruptions detected in two luminous blue variables

December 12, 2017

(Phys.org)—Astronomers report the detection of new eruptions in two luminous blue variables, known as R 40 and R 110, located in the Magellanic Clouds. The finding, presented December 5 in a paper published on the arXiv ...

Juno probes the depths of Jupiter's great red spot

December 12, 2017

Data collected by NASA's Juno spacecraft during its first pass over Jupiter's Great Red Spot in July 2017 indicate that this iconic feature penetrates well below the clouds. Other revelations from the mission include that ...

10 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

HenryE
4.5 / 5 (4) Jun 06, 2017
While this is a great article, I was disappointed that the units of measurement were not metric. Ideally all reported measurements should be strictly metric but at the very least, science articles should have both metric and standard units of measurement. Continuing to use an outdated, overly cumbersome hodge-podge system of measurement does nothing to advance science.
Tuxford
1.4 / 5 (9) Jun 06, 2017
The cosmic web consists of long, narrow filaments of galaxies and intergalactic gas separated by enormous voids. Astronomers believe single cosmic web filaments can stretch for hundreds of millions of light years, an astonishing length considering a single light-year is about 5.9 trillion miles.

Nonsense again, merger maniac patching the fantasy model. Nope, the galaxies are larger with bigger more active cores therein that therefore eject even more newly formed gas therefrom within the central region of the cluster. No need to bang pots together. Embarrassing.
Tuxford
1.5 / 5 (8) Jun 06, 2017
"We did not expect to see such very hot gas between the cluster components," said Burns. "We think the turbulence is like a big spoon stirring up gases, converting the energy of motion from the merging clusters into thermal energy. It is a manifestation of them banging together like two giant pots, something we have not really seen before."

These guys would do better to bang a few of their own heads together. Maybe then they can jar loose the truth from more clear thinking!
RealScience
4.5 / 5 (4) Jun 06, 2017
While this is a great article, I was disappointed that the units of measurement were not metric. Ideally all reported measurements should be strictly metric but at the very least, science articles should have both metric and standard units of measurement. Continuing to use an outdated, overly cumbersome hodge-podge system of measurement does nothing to advance science.


Although I much prefer metric for most things, i I'm not fussy and have learned to convert most units freely as needed. It is good to be bilingual so that you can understand readily when others use units that they are comfortable with.

And astronomy is full of non-metric units - astronomical units for orbits, light-years, parsecs, solar mass for stellar masses, earth-mass and Jupiter-mass for planets... Do you object to those?
cantdrive85
1 / 5 (7) Jun 06, 2017
Two galaxy clusters in the process of merging created a layer of surprisingly hot gas between them that University of Colorado Boulder astronomers believe is from turbulence caused by banging into each other at supersonic speeds.

So the plasma ignoramuses are once again loudly announcing their ignorance from the rooftops! They are surprised by the presence of double layers between two adjacent plasmas, pathetic! It's as if they are proud of their wilful ignorance of over one hundred years of laboratory plasma research and well known real plasma physics. Instead they prefer their pseudoscientific thought experiments while they are missing 95% of their Universe.
Captain Stumpy
3.8 / 5 (4) Jun 07, 2017
@cd the nazi sympathizing anti-vaxx idiot pseudoscience cult peon
So the plasma ignoramuses
Ok idiot, lets do a test of eu stupidity

IF we take measurements of the magnetic field and plasma at the magnetopause - and using the following description:
Magnetic field line topology and electron anisotropy. Simple arrowheads denote electron flow along magnetic field. Solid arrowheads denote magnetic field direction. Open arrows denote flow of magnetized plasma
now, looking at the following images, which DO YOU PREDICT would be measured?

A - http://s1027.phot...&o=0

B - http://s1027.phot...&o=1

feel free to post your findings and then we can see what the science predicts
AGreatWhopper
5 / 5 (4) Jun 07, 2017
Amazing tucksturds and cantthink continually spew their adolescent fantasies here.

Do you not vote this spammy pseudo-science crap down every time??? Maybe the pimps running the site only want the hits from cranks.

"Home for cranks", "Serious physics site"...they don't go to together.

AGreatWhopper
5 / 5 (4) Jun 07, 2017
Tuxford1.4 /5 (9) 20 hours ago
Embarrassing.


You'll not react as you should to blatant "Trump Speak"??? There should be zero tolerance for this, "I haven't actually addressed a word you said, but I'll disparage you because all the tribal idiots that see this all as ego identity will be 'down with it'".

And any doubt we're over the carry capacity for the species in our environment... Total oxygen thieves.

Tucksturds, look in the mirror and you will see embarrassing like you cannot imagine. But that's it for y'all, isn't it. Only what you imagine- your private facts- are real. No, let's put it to you in your own language. You're a loser. Do something, then comment. Your puerile-ette fantasies are not "alternative facts".
HenryE
1 / 5 (1) Jun 07, 2017

And astronomy is full of non-metric units - astronomical units for orbits, light-years, parsecs, solar mass for stellar masses, earth-mass and Jupiter-mass for planets... Do you object to those?

Those are comparing one body or distance with another - the mass of Earth [or another astronomical body] versus the mass of Sol. That is not the same thing as providing measurements of actual units for an astronomical body or distance.. A light year is a light year regardless of metric or the old standard but if you wanted to know exactly how far that was, the metric system would be far far superior. Not to mention much easier to use as well.
Macksb
not rated yet Jun 14, 2017
Congratulations to the UC Boulder team. The merger of two galaxy clusters produces a wealth of information. The Boulder team is doing important work.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.