Herschel's Hidden Talent: Digging Up Magnified Galaxies

MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE 818-354-5011
http://www.jpl.nasa.gov

NEWS RELEASE: 2010-372 Nov. 4, 2010

HERSCHEL'S HIDDEN TALENT: DIGGING UP MAGNIFIED GALAXIES

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cfm?release=2010-372&cid=release_2010-372

PASADENA, Calif. -- It turns out the Herschel Space Observatory has a trick up its sleeve. The
telescope, a European Space Agency mission with important NASA contributions, has proven to
be excellent at finding magnified, faraway galaxies. Like little kids probing patches of dirt for
insects, astronomers can use these new cosmic magnifying lenses to study galaxies that are
hidden in dust.

"I was surprised to learn that Herschel is so good at finding these cosmic lenses," said Asantha
Cooray of the University of California, Irvine. "Locating new lenses is an arduous task that
involves slogging through tons of data. With Herschel, we can find a lot of them much more
efficiently." Cooray is a co-author of a paper about the discovery, appearing in the Nov. 5 issue
of the journal Science. The lead author is Mattia Negrello of the Open University in the United
Kingdom.

A cosmic magnifying lens occurs when a massive galaxy or cluster of galaxies bends light from a
more distant galaxy into a warped and magnified image. Sometimes, a galaxy is so warped that it
appears as a ring -- an object known as an Einstein ring after Albert Einstein who first predicted
the phenomenon, referred to as gravitational lensing. The effect is similar to what happens when
you look through the bottom of a soda bottle or into a funhouse mirror.

These lenses are incredibly powerful tools for studying the properties of distant galaxies as well
as the mysterious stuff -- dark matter and dark energy -- that makes up a whopping 96 percent of
our universe (see http://www.jpl.nasa.gov/news/news.cfm?release=2010-272 ).

"With these lenses, we can do cosmology and study galaxies that are too distant and faint to be
seen otherwise," said Cooray.

Cooray and a host of international researchers made the initial discovery using Herschel.
Launched in May 2009, this space mission is designed to see longer-wavelength light than that
we see with our eyes -- light in the far-infrared and submillimeter portion of the electromagnetic
spectrum. Scanning Herschel images of thousands of galaxies, the researchers noticed five never-
before-seen objects that jumped out as exceptionally bright.

At that time, the galaxies were suspected of being magnified by cosmic lenses, but careful and
extensive follow-up observations were required. Numerous ground-based telescopes around the
world participated in the campaign, including the National Radio Astronomy Observatory's
Green Bank Telescope in West Virginia, and three telescopes in Hawaii: the W.M. Keck
Observatory, the California Institute of Technology's Submillimeter Observatory, and the
Smithsonian Astrophysical Observatory's Submillimeter Array.

The results showed that all five of the bright galaxies were indeed being magnified by
foreground galaxies. The galaxies are really far away -- they are being viewed at a time when the
universe was only two to four billion years old, less than a third of its current age.

The Herschel astronomers suspect that they are just scratching the surface of a much larger
population of magnified galaxies to be uncovered. The images studied so far make up just two
percent of the entire planned survey, a program called the Herschel Astrophysical Terahertz
Large Area Survey, or Herschel-ATLAS.

"The fact that this Herschel team saw five lensed galaxies is very exciting," said Paul Goldsmith,
the U.S. project scientist for Herschel at NASA's Jet Propulsion Laboratory, Pasadena, Calif.
"This means that we can probably pick out hundreds of new lensed galaxies in the Herschel
data."

The five galaxies are young and bursting with dusty, new stars. The dust is so thick, the galaxies
cannot be seen at all with visible-light telescopes. Herschel can see the faint warmth of the dust,
however, because it glows at far-infrared and submillimeter wavelengths. Because the galaxies
are being magnified, astronomers can now dig deeper into these dusty, exotic places and learn
more about what makes them tick.

Herschel is a European Space Agency cornerstone mission, with science instruments provided by
consortia of European institutes and with important participation by NASA. NASA's Herschel
Project Office is based at NASA's Jet Propulsion Laboratory. JPL contributed mission-enabling
technology for two of Herschel's three science instruments. The NASA Herschel Science Center,
part of the Infrared Processing and Analysis Center at the California Institute of Technology in
Pasadena, supports the U.S. astronomical community. Caltech manages JPL for NASA.

More information and images are online at http://www.herschel.caltech.edu ,
http://www.nasa.gov/herschel and http://www.esa.int/SPECIALS/Herschel/index.html .

Whitney Clavin 818-354-4673
Jet Propulsion Laboratory, Pasadena, Calif.
whitney.clavin@jpl.nasa.gov

-end-

To remove yourself from this mailing, please go to http://www.kintera.org/TR.asp?a=ffIGKVNDKfIJL2K&s=ffISISNtHbLEKROzGpH&m=8fINLZPtGeLSI6K

To remove yourself from all mailings from NASA Jet Propulsion Laboratory, please go to http://www.kintera.org/TR.asp?a=isJMK4OPIiLQJcJ&s=ffISISNtHbLEKROzGpH&m=8fINLZPtGeLSI6K