NASA Announces Dark Matter Discovery
August 15th, 2006 by WaltPhysics weblogs are all abuzz over a mysterious press release put by NASA entitled NASA Announces Dark Matter Discovery. The main body of the announcement reads:
Astronomers who used NASA’s Chandra X-ray Observatory will host a media teleconference at 1 p.m. EDT Monday, Aug. 21, to announce how dark and normal matter have been forced apart in an extraordinarily energetic collision.
Via Backreaction.
Update. John Baez has been on the case, and he’s deduced the meat of the announcement: a collision of two clusters of galaxies has apparently pulled galaxies and their dark matter halos apart. This provides compelling evidence in favor of the actual existence of dark matter. He has more in the comments, and at his website.
August 16th, 2006 at 2:07 am
Since one of the folks at the teleconference is Maxim Markevitch, I bet this is about the Bullet Cluster 1E0657-56 - he used Chandra to study this. These are some colliding galaxies where the gas crashed to a halt and got really hot, while the dark matter kept going straight through! The Chandra observatory shows the X-rays from the hot gas. They can see the dark matter with gravitational lensing - it bends the light from galaxies further back.
This is not completely new, since Markevitch spoke about it in November last year. Also last year people found signs of galaxies made almost entirely of dark matter.
August 16th, 2006 at 9:28 pm
For more information, including a picture of the Bullet Cluster, see week238 of This Week’s Finds.
In fact what’s colliding are not galaxies but two whole clusters of galaxies.
August 17th, 2006 at 10:33 pm
So-called Dark Matter is extremal black holes, and therefore they will have some nice pictures.
August 21st, 2006 at 8:55 pm
[...] Well, John Baez was right, the mysterious NASA press release about a dark matter discovery was about the Bullet Cluster. [...]