Galaxy Cluster in Cosmic Free-for-All (NASA, Chandra, 4/28/09)


Galaxy Cluster in Cosmic Free-for-All (NASA, Chandra, 4/28/09)
Originally uploaded by nasa1fan.

This composite image shows the massive galaxy cluster MACSJ0717.5+3745 (MACSJ0717, for short) where four separate galaxy clusters have been involved in a collision, the first time such a phenomenon has been documented. Hot gas is shown in an image from NASA’s Chandra X-ray Observatory and galaxies are shown in an optical image from NASA’s Hubble Space Telescope. The hot gas is color-coded to show temperature, where the coolest gas is reddish purple, the hottest gas is blue, and the temperatures in between are purple.

The repeated collisions in MACSJ0717 are caused by a 13-million-light- year-long stream of galaxies, gas, and dark matter – known as a filament — pouring into a region already full of matter. A collision between gas in two or more clusters causes the hot gas to slow down.

However, the galaxies, which are mainly empty space, do not slow down as much and so they move ahead of the gas. Therefore, the speed and direction of each cluster’s motion — perpendicular to the line of sight — can be estimated by studying the offset between the average position of the galaxies and the peak in the hot gas.

Learn more:
www.nasa.gov/mission_pages/chandra/multimedia/photo09-031…

Credits: X-ray: NASA/CXC/IfA/C. Ma et al. Optical: NASA/STScI/IfA/C. Ma et al.

p.s. You can see all of our Chandra photos in the Chandra Group in Flickr at: www.flickr.com/groups/chandranasa/ We’d love to have you as a member!

Reblog this post [with Zemanta]

Author: rjbailey

"I have no idea what I'm doing, but I know I'm doing it really, really well." - Andy Dwyer

One thought on “Galaxy Cluster in Cosmic Free-for-All (NASA, Chandra, 4/28/09)”

So, Whattaya Think?

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.