A Cluster Too Far
Why is this galaxy cluster so red? Nearby
clusters have
galaxies with colors that are much more yellow and blue.
A leading explanation is that this
cluster of galaxies
lies so far across our universe (z~1) that cosmological
time dilation significantly reddens the light.
If true, this cluster might lie
too far
away to have formed in a dense universe,
implying that our universe is not very dense.
HST 035528+09435 is one of the reddest clusters found in the
Hubble Space Telescope's
Medium Deep Survey.
Astronomers will now work to confirm
the high distance to
this cluster,
and contemplate what it signifies about the
nature of our universe.