Is the Great Wall the largest galaxy cluster?
I could not find a picture of the Great Wall galaxy cluster on your site and was wondering if it was the largest galaxy cluster ever recorded. If you could send a picture of it and a ranking of its largeness that would be highly helpful. Thank you for taking the time to read this.
The Great Wall isn't a cluster. It's a feature that shows up on the Center for Astrophysics (CfA) Redshift Survey as an "overdensity" of galaxies. In this picture, each point of light represents a galaxy, and the Great Wall is the roughly horizontal band that stretches across the northern (top) part of the survey. The "wall" is more than 200 million light-years away, and stretches across roughly 600 million light-years from end to end (*much* bigger than clusters). But does that mean that galaxies are actually clustering on scales larger than superclusters? Not exactly. The CfA Redshift Survey consists of two slices of the sky that are each 36 degrees thick. Because the slice in the northern sky happens to be chose so that it intersects with several superclusters in a row, the "wall" shows up much more prominently than if the slice were oriented differently. Also, there's a geometric effect at work in the "cone diagram" plots that the Great Wall is typically presented in, which artificially boosts the apparent density of galaxies at the distance of the Great Wall. Considering these effects together, the Great Wall isn't quite as great.
Get More 'Curious?' with Our New PODCAST:
- Podcast? Subscribe? Tell me about the Ask an Astronomer Podcast
- Subscribe to our Podcast | Listen to our current Episode
- Cool! But I can't now. Send me a quick reminder now for later.
- What is the largest structure in the universe?
- How do we know that superclusters are the largest structures in the universe?
- What are collections of galaxies called?
How to ask a question:
If you have a follow-up question concerning the above subject, submit it here. If you have a question about another area of astronomy, find the topic you're interested in from the archive on our site menu, or go here for help.Table 'curious.Referrers' doesn't existTable 'curious.Referrers' doesn't exist
This page has been accessed 39063 times since January 24, 2004.
Last modified: January 24, 2004 8:46:05 PM
Ask an Astronomer is hosted by the Astronomy Department at Cornell University and is produced with PHP and MySQL.
Warning: Your browser is misbehaving! This page might look ugly. (Details)