Pasadena, CA. Astronomers have found distant red galaxies–very massive
and very old–in the universe when it was only 2.5 billion years post Big

“Previous observations suggested that the universe at this age was home to
young, small clumps of galaxies long before they merged into massive
structures we see today,” remarked Carnegie Observatories Ivo Labbé, who
led the group of astronomers in the study.* “We are really amazed — these
are the earliest, oldest galaxies found to date. Their existence was not
predicted by theory and it pushes back the formation epoch of some of the
most massive galaxies we see today.”

About two years ago, astronomers from Leiden (The Netherlands) using the
European ground-based Very Large Telescope found a population of distant
red galaxies in the near infrared. But the images could not ascertain what
made the galaxies red: Were they old and “dead” and no longer forming
stars, or were massive amounts of dust obscuring star-forming regions?

The Labbé-led group used the infrared-imaging Spitzer Space Telescope to
analyze the content of the new galactic population to address the
questions of age, stellar mass, and activity. Giovanni Fazio
(Harvard-Smithsonian Center for Astrophysics), a co-author on the study,
said,” Spitzer offers capabilities that the Hubble Space Telescope and
other instruments don’t, giving us a unique way to study very distant
galaxies long ago that eventually became the galaxies we see around us

The team was particularly surprised to find very old, red galaxies that
had stopped forming new stars altogether. They had rapidly formed massive
amounts of stars out of gas much earlier in the universe’s history, but
then suddenly starved to death, raising the question of what caused them
to die so early. Such “red and dead” galaxies may be the forefathers of
some of the old and giant elliptical galaxies seen in the local universe

In addition to the old “dead” galaxies long past star formation, there
were other red, dusty galaxies still vigorously producing stars. Jiasheng
Huang (Harvard-Smithsonian Center for Astrophysics) said, “We’re detecting
galaxies we never expected to find, having a wide range of properties we
never expected to see.” Apparently, the early universe was already a
wildly complex place. “It’s becoming more and more clear that the young
universe was a big zoo with animals of all sorts,” continued Labbé.
“There’s as much variety in the early universe as we see around us today.”

Ultimately, these studies will help to unravel how galaxies like our Milky
Way assembled and how they got to look the way they appear today. The
research will be published in an upcoming issue of The Astrophysical
Journal (Letters).

Carnegie Observatories:

More information on Spitzer can be found at:

* Researchers on the project were Ivo Labbé, Carnegie Observatories;
Jiasheng Huang, Harvard-Smithsonian Center for Astrophysics; Marijn Franx,
Leiden Observatory; Gregory Rudnick, NOAO; Pauline Barmby,
Harvard-Smithsonian Center for Astrophysics, Emanuele Daddi, NOAO; Pieter
G. van Dokkum, Yale University; Giovanni G. Fazio, Harvard-Smithsonian
Center for Astrophysics; Natascha Forster Schreiber Max Plank-Institute
für extraterrestrische Physik; Alan Moorwood, ESO;Hans-Walter Rix,
Max-Plank-Institute für Astronomie; Huub Röttgering NOAO; Ignaciao
Trujillo,Max-Plank-Institute für Astronomie; Paul van der Werf, Leiden

The Carnegie Observatories is part of the Carnegie Institution
(, which has been a pioneering force in basic
scientific research since 1902. It is a private, nonprofit organization
with six research departments throughout the U.S. Carnegie scientists are
leaders in plant biology, developmental biology, astronomy, materials
science, global ecology, and Earth and planetary science.

The Spitzer Space Telescope was launched in August 2003 for a 5-year
mission. It detects energy from celestial objects in the infrared part of
the spectrum, which is able to penetrate areas in space not visible in the
optical spectrum such as dense clouds of gas and dust where stars form,
new extrasolar planetary systems, and galactic centers. JPL manages the
Spitzer Space Telescope for NASA.