October 1 What
did the first galaxies look like?
To help answer this question, the Hubble Space Telescope has just
finished taking the eXtreme
Deep Field (XDF), the deepest
image of the universe ever taken in visible
light. Pictured above, the XDF
shows a sampling of some of the oldest
ever seen, galaxies that formed just after the dark
ages, 13 billion years ago, when
the universe was only a few percent of its present age. The Hubble
camera and the infrared channel of the WFPC3
camera took the
image. Combining efforts spread
over 10 years, the XDF
is more sensitive, in some colors, than the original Hubble Deep Field
(HDF), the Hubble
Ultra Deep Field (HUDF)
completed in 2004, and the HUDF
completed in 2009.
Astronomers the world over will likely study the XDF
for years to come to
better understand how stars and galaxies formed in the early universe.
2012 Oct 1
Image Credit: NASA,
Illingworth, D. Magee, and P.
R. Bouwens (Leiden Obs.),
and the XDF Team
STScI-2012-37 Like photographers assembling a portfolio of best shots, astronomers have assembled a new, improved portrait of mankind's deepest-ever view of the universe. Called the eXtreme Deep Field, or XDF, the photo was assembled by combining 10 years of NASA Hubble Space Telescope photographs taken of a patch of sky at the center of the original Hubble Ultra Deep Field. The XDF is a small fraction of the angular diameter of the full Moon. The Hubble Ultra Deep Field is an image of a small area of space in the constellation Fornax, created using Hubble Space Telescope data from 2003 and 2004. By collecting faint light over many hours of observation, it revealed thousands of galaxies, both nearby and very distant, making it the deepest image of the universe ever taken at that time. The new full-color XDF image reaches much fainter galaxies and includes very deep exposures in red light from Hubble's new infrared camera, enabling new studies of the earliest galaxies in the universe. The XDF contains about 5,500 galaxies even within its smaller field of view. The faintest galaxies are one ten-billionth the brightness of what the human eye can see.
Text: NASA News Release
sizes of this image print acceptably, however the pervious generation
of this image the HUDF, Hubble
Ultra Deep Field
has a larger
pixel count and produces slightly higher resolution prints,
only detectable at sizes greater than 16"x20".