Featured Research

from universities, journals, and other organizations

El Gordo: A 'fat' distant galaxy cluster

Date:
January 11, 2012
Source:
ESO
Summary:
An extremely hot, massive young galaxy cluster is the largest ever seen in the distant universe. The newly discovered galaxy cluster has been nicknamed El Gordo -- the "big" or "fat one" in Spanish. It consists of two separate galaxy subclusters colliding at several million kilometres per hour, and is so far away that its light has travelled for seven billion years to reach Earth.

El Gordo: a massive distant merging galaxy cluster.
Credit: ESO

An extremely hot, massive young galaxy cluster -- the largest ever seen in the distant Universe -- has been studied by an international team using ESO's Very Large Telescope (VLT) in the Atacama Desert in Chile along with NASA's Chandra X-ray Observatory and the Atacama Cosmology Telescope. The new results are being announced on 10 January 2012 at the 219th meeting of the American Astronomical Society in Austin, Texas.

The newly discovered galaxy cluster [1] has been nicknamed El Gordo -- the "big" or "fat one" in Spanish. It consists of two separate galaxy subclusters colliding at several million kilometres per hour, and is so far away that its light has travelled for seven billion years to reach Earth.

"This cluster is the most massive, the hottest, and gives off the most X-rays of any cluster found so far at this distance or beyond," said Felipe Menanteau of Rutgers University, who led the study. "We devoted a lot of our observing time to El Gordo, and I'm glad our bet paid off and we found an amazing cluster collision."

Clusters of galaxies are the largest objects in the Universe held together by gravity. The process of their formation, when smaller groups of galaxies merge together, very much depends on the amount of dark matter and dark energy in the Universe at that time -- so studying clusters can shed some light on these mysterious components of the cosmos.

"Gigantic galaxy clusters like this one are just what we were aiming to find," said team member Jack Hughes, also of Rutgers. "We want to see if we understand how these extreme objects form, using the best models of cosmology that are currently available."

The team, led by Chilean and Rutgers astronomers, found El Gordo by detecting a distortion of the cosmic microwave background radiation. This faint glow is the remnant of the first light from the Big Bang, the extremely hot and dense origin of the Universe about 13.7 billion years ago. This radiation left over from the Big Bang interacts with electrons in the hot gas in galaxy clusters, distorting the appearance of the background glow seen from Earth [2]. The denser and bigger the cluster, the bigger this effect. El Gordo was picked up in a survey of the microwave background with the Atacama Cosmology Telescope [3].

ESO's Very Large Telescope was used by the team to measure the velocities of the galaxies in this huge cluster collision and also to measure its distance from Earth. In addition NASA's Chandra X-ray Observatory was used to study the hot gas in the cluster.

Although a cluster of El Gordo's size and distance is very rare, the authors say that the new results are still consistent with astronomers' current understanding of a Universe that started with a Big Bang and is mostly made of dark matter and dark energy.

El Gordo most probably formed just like the Bullet Cluster, a spectacular interacting cluster of galaxies that is almost four billion light-years closer to Earth. In both clusters there is evidence that normal matter, mainly composed of hot, X-ray-bright gas, has been wrenched apart from the dark matter. The hot gas was slowed down by the collision, but the dark matter was not.

"This is the first time we've found a system like the Bullet Cluster at such a large distance," said Cristóbal Sifón, student at the Pontificia Universidad Católica de Chile (PUC) in Santiago. "It's like the old saying: If you want to understand where you're going, you have to know where you've been."

Notes

[1] The formal name of the cluster is ACT-CL J0102-4915, the first part of the name shows that it is a galaxy cluster found using data from the Atacama Cosmology Telescope and the second part indicates the location of the object on the sky, in the southern constellation of Phoenix.

[2] The effect is called the Sunyaev-Zel'dovich (SZ) effect after the Russian astronomers, Rashid Sunyaev and Yakov Zel'dovich who predicted it in the late 1960s.

[3] The Atacama Cosmology Telescope (ACT) is a six-metre telescope on Cerro Toco in the Atacama Desert in the north of Chile and close to the site of ALMA. It is designed to make high-resolution surveys of the microwave sky to study the cosmic microwave background radiation.

These results on El Gordo are being announced on 10 January 2012 at the 219th meeting of the American Astronomical Society in Austin, Texas.


Story Source:

The above story is based on materials provided by ESO. Note: Materials may be edited for content and length.


Journal Reference:

  1. Felipe Menanteau, John P. Hughes, Cristobal Sifon, Matt Hilton, Jorge Gonzalez, Leopoldo Infante, L. Felipe Barrientos, Andrew J. Baker, John R. Bond, Sudeep Das, Mark J. Devlin, Joanna Dunkley, Amir Hajian, Adam D. Hincks, Arthur Kosowsky, Danica Marsden, Tobias A. Marriage, Kavilan Moodley, Michael D. Niemack, Michael R. Nolta, Lyman A. Page, Erik D. Reese, Neelima Sehgal, Jon Sievers, David N. Spergel, Suzanne T. Staggs, Edward Wollack. The Atacama Cosmology Telescope: ACT-CL J0102-4915 'El Gordo,' a Massive Merging Cluster at Redshift 0.87. The Astrophysical Journal, 2012; (accepted) [link]

Cite This Page:

ESO. "El Gordo: A 'fat' distant galaxy cluster." ScienceDaily. ScienceDaily, 11 January 2012. <www.sciencedaily.com/releases/2012/01/120110140423.htm>.
ESO. (2012, January 11). El Gordo: A 'fat' distant galaxy cluster. ScienceDaily. Retrieved July 31, 2014 from www.sciencedaily.com/releases/2012/01/120110140423.htm
ESO. "El Gordo: A 'fat' distant galaxy cluster." ScienceDaily. www.sciencedaily.com/releases/2012/01/120110140423.htm (accessed July 31, 2014).

Share This




More Space & Time News

Thursday, July 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Supply Ship Takes Off for International Space Station

Supply Ship Takes Off for International Space Station

AFP (July 30, 2014) — The European Space Agency's fifth Automated Transfer Vehicle (ATV-5) is takes off to the International Space Station on an Ariane 5 rocket from French Guiana. Duration: 00:34 Video provided by AFP
Powered by NewsLook.com
Raw: Rocket Launches Into Space With Cargo Ship

Raw: Rocket Launches Into Space With Cargo Ship

AP (July 30, 2014) — Arianespace launched a rocket Tuesday from French Guiana carrying a robotic cargo ship to deliver provisions to the International Space Station. (July 30) Video provided by AP
Powered by NewsLook.com
In Virginia, the Rise of a New Space Coast

In Virginia, the Rise of a New Space Coast

AP (July 30, 2014) — Every summer, tourists make the pilgrimage to Chincoteague Island, Va. to see wild ponies cross the Assateague Channel. But, it's the rockets sending to supplies to the International Space Station that are making this a year-round destination. (July 30) Video provided by AP
Powered by NewsLook.com
Russia Saves Gecko Sex Satellite, Media Has Some Fun With It

Russia Saves Gecko Sex Satellite, Media Has Some Fun With It

Newsy (July 27, 2014) — The satellite is back under ground control after a tense few days, but with a gecko sex experiment on board, the media just couldn't help themselves. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

    Environment News

    Technology News



      Save/Print:
      Share:  

      Free Subscriptions


      Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

      Get Social & Mobile


      Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

      Have Feedback?


      Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
      Mobile iPhone Android Web
      Follow Facebook Twitter Google+
      Subscribe RSS Feeds Email Newsletters
      Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins