Astrophysicist Honored with Goddard’s Highest Space Science Award

Scientific endeavors are rarely associated with the imagination. But for Dr.
Floyd Stecker, an astrophysicist at NASA’s Goddard Space Flight Center, the
two have much in common.

Stecker, a Silver Spring, Md., resident, was recently awarded Goddard’s
annual John C. Lindsay Award for Space Science for his innovative series of
papers that will help scientists study galaxy evolution in a new way.

“I feel honored to receive this award, not only because it’s the highest
award that Goddard gives for science, but also because it’s hardly ever
given to theorists,” said Stecker.

Stecker’s award-winning work provides a technique for scientists to measure
infrared-optical-ultraviolet (IR-O-UV) radiation from extragalactic space
that is emitted from stars and dust in galaxies.

Although the Cosmic Background Explorer (COBE) satellite has measured this
radiation at some infrared wavelengths, it is difficult to measure because
of interference by galactic foreground radiation and radiation from dust in
the solar system. So after the Compton Gamma Ray Observatory (CGRO)
discovered blazars (gamma-ray emitting active galaxies), Stecker and his
collaborators proposed an indirect way of taking these measurements.

The idea is to look at high-energy gamma radiation emitted by the blazars.
These gamma rays interact with the IR-O-UV radiation, converting some of
them into pairs of electrons and positrons (positive antimatter electrons)
and thus reducing the gamma rays’ intensity. By examining the shape and
absorption features of the resultant gamma ray spectrum, scientists can
learn about the characteristics of the IR-O-UV radiation.

This same technique can be used not only to explore the present IR-O-UV
background radiation, but also by looking at distant blazars, it can be used
to study the background radiation as it existed in the past. Because these
blazars are so far away, the gamma rays may have been emitted from galaxies
when they were young and are only reaching Earth now. The Large Area
Telescope (LAT), as part of the Gamma-ray Large Area Space Telescope (GLAST)
mission projected for September 2006,will use Stecker’s technique to help
scientists understand how galaxies form and evolve.

“This work provides a new mechanism to measure the presence of this diffuse
photon background and also explains previously puzzling facts about gamma
ray emission from blazars,” said Michael Salamon, one of Stecker’s
collaborators on the award-winning research and NASA Headquarters’
Discipline Scientist for Fundamental Physics. “Floyd clearly deserves this
award – it is overdue!”

Though the honor awards a decade of research, it is also a tribute to a
lifetime of passion for science. From the age of four, Stecker, who grew up
in New York City, never considered a career outside of science.

He earned a bachelor’s degree in physics from MIT and, as he jokingly
explains, after nearly electrocuting his advisor in a cosmic ray lab, he
decided a career in theory might be more appropriate. He got a doctorate in
astrophysics from Harvard University after writing a trailblazing thesis on
theory of the production of cosmic gamma rays. His subsequent book, “Cosmic
Gamma Rays” was the first book in the field.

When Stecker is not thinking about the problems of the cosmos in his office,
he likes to play tennis, chess, the piano and engage in horseback riding. In
addition to studying the early history of galaxies, Stecker occupies his
time outside of work reading about the early history of man, archeology and
paleontology. Had he not become a scientist, Stecker thinks he might have
become a science fiction writer.

“My job lets me take what may seem like science fiction and make it into
real science,” said Stecker. “Most people don’t realize that imagination is
very important to a scientist. It’s not just about analyzing data.”

The John C. Lindsay Award has celebrated this type of cutting-edge thinking
since 1966. It was named in honor of Dr. John C. Lindsay who contributed
greatly to exploration of the Sun via satellite and rocket-borne experiments
and who founded the Orbiting Solar Observatory Project.

In the past this honor has awarded research on topics like the spectrum of
gamma rays from supernovae, interstellar extinction and the development of
the Galileo probe’s Mass Spectrometer.

“Scientists at Goddard nominate each other, based on what they think is the
best real science that was done,” said Thomas Cline, Senior Scientist at
Goddard and John C. Lindsay award recipient in 1980. “The nominations are
judged by a panel of previous Lindsay winners. So this award is not some
sort of politically- or administratively- motivated award. It’s a genuine
honor.”