SETI public: Fw: Cornell News: SIRTF Fellows Announced

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----- Original Message -----
From: cunews_at_cornell.edu
Sent: Wednesday, February 26, 2003 1:39 PM
To: CUNEWS-PHYSICAL_SCIENCE-L_at_cornell.edu; CUNEWS-SCIENCE-L_at_cornell.edu
Subject: Cornell News: SIRTF Fellows Announced

Dutch astrophysicist awarded NASA fellowship to study data from
orbiting observatory with Cornell instrument team

FOR RELEASE: Feb. 26, 2003

Contact: David Brand
Office: 607-255-3651
E-mail: deb27_at_cornell.edu

ITHACA, N.Y. -- This summer, NASA will sponsor four young scientists
who will work on analyzing data from the largest infrared telescope
to be sent into space. The telescope, called SIRTF, for Space
Infrared Telescope Facility, is scheduled for launch on April 15 and
will circle the sun in an orbit that trails just behind the Earth's.

One of the SIRTF fellows, Henrik Spoon, an astrophysicist at the
University of Groningen in the Netherlands, will work at Cornell
University as a postdoctoral researcher with James Houck, the K.A.
Wallace Professor of Astronomy.

Houck is the principal investigator on the infrared spectrograph, one
of three instruments to be carried aboard the orbiting observatory.
With data from SIRTF, Spoon will study the nature of heavily obscured
power sources in ultraluminous infrared galaxies (ULIGs), which are
many times brighter that most known galaxies at infrared wavelengths.

Spoon's fellowship comes with a precious commodity: 10 hours on the
new telescope dedicated solely to his research. He is excited, he
says, "to be part of the team of dedicated astronomers and engineers
pushing the limits of infrared astronomy, to chart the unknown
infrared universe beyond what previous infrared satellites could see."

The three other researchers to receive SIRTF fellowships are Michael
Cushing of the University of Hawaii, who will work at NASA-Ames
Research Center on the chemistry of low-mass stars and brown dwarfs;
Sarah Gallagher of Pennsylvania State University, who will work at
the University of California-Los Angeles on broad absorption line
quasars; and Jacqueline Kessler of the California Institute of
Technology (Caltech), who will do research at the University of Texas
on the evolution of grains and ices in low-mass stars. The
fellowships were awarded by the SIRTF Science Center at Caltech.

The ULIGs that Spoon will study were discovered in the early 1980s
with NASA's first infrared telescope, the Infrared Astronomical
Satellite (a mission in which Cornell astronomers played a key role).
Later, the European Space Agency's Infrared Space Observatory (ISO)
yielded a more detailed map of about a dozen of the galaxies, which
were found to be colliding galaxies. The source of their enormous
luminosity could be due to star formation or to the accretion of gas
onto a massive central black hole, hidden behind the thick layers of
enshrouding gas.

  "There are a couple of ways that these things can produce their
energy, and hence their luminosity," says Houck. "One of them is to
form stars very rapidly -- maybe 1,000 times faster than our galaxy.
Another is to harbor a large black hole in the center of the galaxy
that shreds stars as it swallows them. The gravitational energy that
these shredded stars release is converted into infrared light, and
that makes them luminous."

Still other ULIGs, says Houck, might be hybrids, fueled by a
combination of both black holes and superintense star formation. And,
since only a handful of the galaxies have been observed in detail,
there could be unknown processes driving still more types of bright
galaxies.

SIRTF's infrared detectors are 100 times more sensitive than those of
its predecessor, ISO. Spoon observes that until the 1950s astronomers
were able to observe the universe only in visible light. Now they can
conduct their surveys in "invisible colors" as well, including the
infrared and ultraviolet. But in order to study the universe in most
infrared colors, a telescope needs to be taken above the atmosphere.
"The SIRTF satellite will allow me to study the ULIGs in a very broad
range of infrared colors, without any missing color in between," says
Spoon. These colors could turn out to be critically important to
understanding the true nature of the ULIGs, he notes.

Houck says that trying to observe objects in deep space in the
infrared from a telescope on Earth is akin to "trying to look at a
distant mountain with a pair of binoculars that are on fire. That's
very close to what the situation is -- there's so much light from the
flaming binoculars, you can't see the mountain. The other problem is
that the Earth's atmosphere is opaque to almost all wavelengths of
infrared light."

SIRTF will be the fourth and last in NASA's Great Observatories
Program, joining the Hubble Space Telescope, the Compton Gamma Ray
Observatory and the Chandra X-Ray Observatory. The mission is managed
by NASA's Jet Propulsion Laboratory, and other participating
institutions include Caltech, the Smithsonian Astrophysical
Observatory and the University of Arizona.

This release was prepared by Lissa Harris, a Cornell graduate student
and Cornell News Service science-writing intern.

Related World Wide Web sites: The following site provide
additional information on this news release. It is not part of the
Cornell University community, and Cornell has no control over their
content or availability.

o SIRTF: <http://sirtf.caltech.edu>

-30-

The web version of this release may be found at
http://www.news.cornell.edu/releases/Feb03/SIRTF.fellows.lh.deb.html

Cornell University News Service
Surge 3
Cornell University
Ithaca, NY 14853
607-255-4206
cunews_at_cornell.edu
http://www.news.cornell.edu

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