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Office of Public Information
Eberly College of Science
Pennsylvania State University
University Park, Pennsylvania

UNIVERSITY CONTACTS:

George Chartas, Penn State
(+1) 814-863-7946, gchartas{at}astro.psu.edu

Niel Brandt, Penn State
(+1) 814-865-3509, nbrandt{at}astro.psu.edu

Gordon Garmire, Penn State
(+1) 814-865-1117 or 863-9550, ggarmire{at}astro.psu.edu

Sarah Gallagher, MIT
(+1) 617-258-7348, scg{at}space.mit.edu

Barbara K. Kennedy, PIO, Penn State
(+1) 814-863-4682, science{at}psu.edu

25 March 2003

Doomed Matter Near Black Hole Gets Second Lease on Life

Supermassive black holes, notorious for ripping apart and
swallowing stars, might also help seed interstellar space
with the elements necessary for life, such as hydrogen,
carbon, oxygen and iron, scientists say.

Using NASA's Chandra X-ray Observatory and ESA's
XMM-Newton satellite, scientists at Penn State and the
Massachusetts Institute of Technology found evidence of
high-speed winds blowing away copious amounts of gas
from the cores of two quasar galaxies, which are thought
to be powered by black holes.

"The winds we measured imply that as much as a billion
suns' worth of material is blown away over the course
of a quasar's lifetime," said Dr. George Chartas of the
Penn State Astronomy and Astrophysics Department, who
led the observations.

The winds might also regulate black hole growth and
spur the creation of new stars, according to the
science team, which includes Drs. Niel Brandt and
Gordon Garmire of Penn State and Dr. Sarah Gallagher
of MIT.

These results are presented today in a press conference
at the meeting of the High Energy Astrophysics Division
of the American Astronomical Society at Mt. Tremblant,
Quebec. Different from high-speed jets shooting off
subatomic particles, the newly identified gusts arise
from the disk of matter orbiting the black hole, called
the accretion disk, once thought to be a one-way ticket
into the black hole.

Black holes are objects so dense that nothing, not even
light, can escape their gravitational attraction. But
this only applies once matter crosses the theoretical
border of a black hole, called the event horizon.
Outside the event horizon, the tug of gravity is
strong, but matter and light can escape.

Theorists have suggested that a wind could blow away
material from its accretion disk and pepper the
interstellar region with heavier elements. The wind
is created by radiation pressure, analogous to earthly
winds created by varying high and low air pressure
systems.

Chartas and his colleagues observed two quasars, which
are exceedingly distant star-like objects thought
to be the bright cores of galaxies fueled by a
supermassive black hole. With Chandra, the team observed
a quasar called APM 08279+5255; and with the European
Space Agency's XMM-Newton, they observed a quasar named
PG1115+080.

Both quasars are billions of light years away from Earth.
However, APM 08279+5255 was naturally magnified by a
factor of about 100 and PG1115+080 by a factor of about
25 through a process called gravitational lensing.
Essentially, their light, while en route to us, was
distorted and magnified by the gravity of intervening
galaxies acting like telescope lenses.

With the natural boost in magnification, coupled with
the X-ray observatories' abilities, the scientists
could ascertain several key properties in the quasar
light, such as the speed of the gas that absorbed the
light, as well as the material's proximity to the
black hole.

The team found the first observational evidence of a
wind component transporting a substantial amount of
carbon, oxygen and iron into the interstellar and
intergalactic medium. The wind was moving at 40 percent
light speed, considerably faster than predicted.

Brandt said the observation may spur new theoretical
work about black hole winds and their effect on their
environs. For example, Brandt said, "the wind might
provide insight to the relationship between black
hole mass and the central bulge of its host galaxy."

Chandra, launched in July 1999, is the third in NASA's
Great Observatory series, a sister craft to the Hubble
Space Telescope. ESA's XMM-Newton was launched from
French Guiana in December 1999 and carries three
advanced X-ray telescopes.

NASA's Marshall Space Flight Center in Huntsville, Ala.,
manages the Chandra program, and TRW, Inc., Redondo
Beach, Calif., is the prime contractor for the
spacecraft. The Smithsonian's Chandra X-ray Center
controls science and flight operations from Cambridge,
Mass., for the Office of Space Science at NASA
Headquarters, Washington.

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