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NASA Hubble Team Finds Monster “El Gordo” Galaxy Cluster Bigger Than Thought


Image Credit: NASA, ESA, and J. Jee (University of California, Davis)

Image Credit: NASA, ESA, and J. Jee (University of California, Davis)

NASA’s Hubble Space Telescope has weighed the largest known galaxy cluster in the distant universe, catalogued as ACT-CL J0102-4915, and found it definitely lives up to its nickname — El Gordo (Spanish for “the fat one”).

By measuring how much the cluster’s gravity warps images of galaxies in the distant background, a team of astronomers has calculated the cluster’s mass to be as much as 3 million billion times the mass of our sun. Hubble data show the galaxy cluster, which is 9.7 billion light-years away from Earth, is roughly 43 percent more massive than earlier estimates.

The team used Hubble to measure how strongly the mass of the cluster warped space. Hubble’s high resolution allowed measurements of so-called “weak lensing,” where the cluster’s immense gravity subtly distorts space like a funhouse mirror and warps images of background galaxies. The greater the warping, the more mass is locked up in the cluster.

“What I did is basically look at the shapes of the background galaxies that are farther away than the cluster itself,” explained lead author James Jee of the University of California at Davis. “It’s given us an even stronger probability that this is really an amazing system very early in the universe.”

A fraction of this mass is locked up in several hundred galaxies that inhabit the cluster and a larger fraction is in hot gas that fills the entire volume of the cluster. The rest is tied up in dark matter, an invisible form of matter that makes up the bulk of the mass of the universe.

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New Images of Solar Wind As It Impacts Earth

August 19, 2011 Leave a comment

CME Impacting WIND Spacecraft

Courtesy SwRI/NASA

Using data collected by NASA’s STEREO spacecraft, researchers at Southwest Research Institute and the National Solar Observatory have developed the first detailed images of solar wind structures as plasma and other particles from a coronal mass ejection (CME) traveled 93 million miles and impacted Earth.

Full Story: http://swri.org/9what/releases/2011/solarwind.htm

New Method Detects Emerging Sunspots Inside the Sun

August 19, 2011 Leave a comment

New Method Detects Emerging Sunspots Inside the Sun

A full disk image of the Sun showing the sunspot group in AR11158 after emergence, observed by SDO/HMI. Courtesy of NASA/SDO and the HMI science teams.

The first clear detection of emerging sunspot regions prior to any indication of the region in magnetograms was published in Science on 19 August 2011.

Sunspots, dark features in the solar photosphere with strong magnetic field, have been observed for more than 400 years. They are the most visible components of regions where solar flares and coronal mass ejections (CMEs) occur, and these eruptive events may cause power outages and interruptions of telecommunication and navigation services on the Earth. Although it is widely believed that sunspot regions are generated in the deep solar interior, the detection of these regions before they emerge from the convection zone into the photosphere has remained undetected until now.

Full Story: http://hmi.stanford.edu/Press/18Aug2011/