MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIFORNIA 91109. TELEPHONE (818) 354-5011
http://www.jpl.nasa.gov
Contacts: Jane Platt/JPL (818) 354-0880
Ray Villard/Space Telescope Science Institute (410) 338-4514
Richard de Grijs/University of Cambridge 44(0)1223-337528
Lars Lindberg Christensen/European Space Agency 49(0)8932-006306
IMAGE ADVISORY March 7, 2001
HUBBLE SPIES ANCIENT STAR CLUSTERS WITH A VIOLENT PAST
A colorful image showing violent star formation triggered
when two galaxies bumped into each other has been captured by
NASA's Hubble Space Telescope.
In the image, the starburst galaxy M82 has a disturbed
appearance caused by violent activity after an ancient encounter
with its large galactic neighbor, M81. The image, taken by
Hubble's Wide Field and Planetary Camera 2, designed and built by
NASA's Jet Propulsion Laboratory, Pasadena, Calif., is online at
http://www.jpl.nasa.gov/pictures/wfpc .
The huge lanes of dust that crisscross M82's disk are
another telltale sign of the flurry of star formation. Below the
center and to the right, a strong galactic wind is spewing knotty
filaments of hydrogen and nitrogen gas. More than 100 super
star clusters -- very bright, compact groupings of about 100,000
stars -- appear as white dots sprinkled throughout the galaxy's
central area. The dark area just above center is a huge dust
cloud.
A collaboration of European and American scientists used
these clusters to date the interaction between M82 and M81 to
about 600 million years ago, when a region called M82 B (the
bright area just below and to the left of the central dust cloud)
exploded with new stars. Scientists have found that this ancient
starburst was triggered by the encounter with M81. The results
are published in the February 2001 issue of the Astronomical
Journal.
This discovery provides evidence linking the birth of super
star clusters to violent interaction between galaxies. These
clusters also provide insight into the rough-and-tumble universe
of long ago, when galaxies bumped into each other more
frequently.
M82 is located 12 million light-years from Earth in the
constellation Ursa Major. The picture was taken Sept. 15, 1997.
The natural-color composite was constructed from three exposures
taken with blue, green and red filters.
The Space Telescope Science Institute, Baltimore, Md.,
manages space operations for the Hubble Space Telescope for
NASA's Office of Space Science, Washington, D.C. The Institute
is operated by the Association of Universities for Research in
Astronomy Inc., for NASA under contract with NASA's Goddard Space
Flight Center, Greenbelt, Md. The Hubble Space Telescope is a
project of international cooperation between NASA and the
European Space Agency. JPL is a division of the California
Institute of Technology in Pasadena.
Additional information about the Hubble Space Telescope is
available at http://www.stsci.edu . More information about the
Wide Field and Planetary Camera 2 is available at
http://wfpc2.jpl.nasa.gov .
#####
Image credit: NASA, ESA, R. de Grijs (Institute of Astronomy,
Cambridge, UK)
03/06/01 JP
#2001-048
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