(via Galaxies swarm and light bends under dark matter’s sway | Bad Astronomy | Discover Magazine)
Holy mother…4.5 billion light years away from us is a galaxy cluster (MACS J1206) with a mass 1 quadrillion times the mass of the Sun. And it’s bending light. It’s bending light more than it should based on what we can see. Conclusion? Dark matter. You can tell how much and where it is based on how the galaxies behind the cluster are bent and smeared. It’s called gravitational lensing and it’s really nifty looking.
Phil’s got a great write-up, and this is a Hubble shot from the CLASH project, which is getting an unprecedented 524 orbits with Hubble. That’s 300 hours of continuous viewing. The Hubble data will also be used by this team to point the ESO’s VLT telescope in Chile at various targets to get spectrometry readings.
Interesting structures Phil would like to point out to you in the shot:
Galaxy being lensed by the cluster and, it would appear, also by the other two galaxies that you can see.
Very red galaxies which may be very small members of the same cluster (dust in the way) or very old (red-shifted).
Image credit: Credit: NASA, ESA, M. Postman (STScI) and the CLASH Survey Team