PASADENA, Calif.– NASA’s Spitzer Space Telescope has imaged a wild creature of
the dark — a coiled galaxy with an eye-like object at its center.
The galaxy, called NGC 1097, is located 50 million light-years away. It isspiral-shaped
like our Milky Way, with long, spindly arms of stars. The “eye” atthe center of the galaxy
is actually a monstrous black hole surrounded by a ring of stars. In thiscolor-coded
infrared view from Spitzer, the area around the invisible black hole is blueand the ring of
The black hole is huge, about 100 million times the mass of our sun, and isfeeding off gas
and dust along with the occasional unlucky star. Our Milky Way’s central blackhole is
tame by comparison, with a mass of a few million suns.
“The fate of this black hole and others like it is an active area ofresearch,” said George
Helou, deputy director of NASA’s SpitzerScience Centerat the California Institute of
Technology in Pasadena.”Some theories hold that the black hole might quiet down and
eventually enter a more dormant state like our Milky Way black hole.”
The ring around the black hole is bursting with new star formation. An inflowof material
toward the central bar of the galaxy is causing the ring to light up with newstars.
“The ring itself is a fascinating object worthy of study because it isforming stars at a very
high rate,” said Kartik Sheth, an astronomer at NASA’s Spitzer Science Center. Sheth and
Helou are part of a team that made the observations.
In the Spitzer image, infrared light with shorter wavelengths is blue, whilelonger-
wavelength light is red. The galaxy’s red spiral arms and the swirling spokesseen between
the arms show dust heated by newborn stars. Older populations of starsscattered through
the galaxy are blue. The fuzzy blue dot to the left, which appears to fitsnuggly between
the arms, is a companion galaxy.
“The companion galaxy that looks as if it’s playing peek-a-boo through thelarger galaxy
could have plunged through, poking a hole,” said Helou. “But we don’tknow this for
sure. It could also just happen to be aligned with a gap in the arms.”
Other dots in the picture are either nearby stars in our galaxy, or distantgalaxies.
This image was taken during Spitzer’s “cold mission,” which lastedmore than five-and-a-
half years. The telescope ran out of coolant needed to chill its infraredinstruments on
May 15, 2009. Two of its infrared channels will still work perfectly during thenew
“warm mission,” which is expected to begin in a week or so, once theobservatory has
been recalibrated and warms to its new temperature of around 30 Kelvin (aboutminus
406 degrees Fahrenheit).
NASA’s Jet Propulsion Laboratory, Pasadena, Calif., manages the Spitzer Space
Telescope mission for NASA’s Science Mission Directorate, Washington. Science
operations are conducted at the SpitzerScience Centerat the California Institute of
Technology, also in Pasadena.Caltech manages JPL for NASA. Spitzer’s infrared array
camera, which made the observations, was built by NASA’s GoddardSpace Flight
Center, Greenbelt, Md.The instrument’s principal investigator is Giovanni Fazio of the
Harvard-Smithsonian Center for Astrophysics.
(No Ratings Yet)