Transcript Document

A Galaxy Revealed in Multiple
Wavelengths
Topic:
Multiwavelength observations
Concepts:
Infrared observations, X-ray
observations, Optical
observations, EM spectrum
Missions:
“Great Observatories”: Hubble,
Chandra, Spitzer;
GALEX
Coordinated by
the NASA Astrophysics Forum
An Instructor’s Guide for using
the slide sets is available at the
ASP website
http://www.astrosociety.org/e
ducation/astronomy-resource0
guides/
The Four Space Observatories Provide New
Insights into M101
• In 2012, GALEX ultraviolet
observations added new
insights into the structure of
the Pinwheel Galaxy, M101.
• Combined with previous
Spitzer, Hubble, and
Chandra observations, they
produced a new
multiwavelength view of the
galaxy M101 combining
infrared, visible, ultraviolet,
and X-ray images,
respectively, into a single
picture.
Credit: NASA/CXC/SAO, NASA/JPLCaltech, NASA/STScI
Messier 101 (M101) is a face-on spiral
galaxy 22 million light years distant in
the direction of the constellation Ursa
Major and is 70% larger than our own
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Milky Way.
How do Astronomers Learn
More about M101?
Investigations across multiple wavelengths provides a
more complete view of galaxies like M101:
• Spitzer’s infrared view can show lanes of
dust that congeal into stars—the brightest
areas warmed by young, hot stars.
• Hubble’s visible light view can reveal a
galaxy’s stars and star clusters, and
brownish dust lanes silhouetted against
their glow.
• GALEX’s ultraviolet view can locate hot,
young stars that formed about 1 million
years ago.
• Chandra’s x-ray view can unveil the
emission from supernova remnants, diffuse
hot gas, and where gas spiraling into black
holes is heated to extremes.
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The Big Picture
Large Magellanic
Cloud
• Galaxies are made of various
objects that emit in different
wavelengths:
•
•
•
•
Types of stars: young and old, big
and small
Diffuse gas
Interstellar dust
Exotic, high-energetic objects (e.g.
black holes or neutron stars)
Spitzer Image:
Hubble
Image:
M51
• A complete understanding of how
galaxies form and evolve with time,
requires understanding all of these
components
• Some of them must be studied at
These three galaxies
different wavelengths.
have been studied
extensively in
various wavelengths
to help astronomers
better understand
their evolutions.
Chandra
Image:
Centaurus A
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How Does this Change our View?
Composite
Ultraviolet
Infrared
X-ray
Visible
Animated slide: click through to compare the
images.
Credit: NASA/CXC/SAO, NASA/JPL-Caltech,
NASA/STScI
•
Adding the GALEX UV view of
M101reveals the true extent of the
galaxy and shows us how many
young, hot stars have recently
formed in the outskirts of the
galaxy’s disk!
•
Images taken in different
wavelengths reveal different
aspects and processes of galaxies
like M101 and of the universe at
large, allowing us to build a
complete picture and
understanding of the cosmos.
•
NASA’s science missions range
across the electromagnetic
spectrum to reveal this larger,
deeper, and more fundamental
view.
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Resources
Press release:
http://chandra.harvard.edu/photo/2012/m101/
Activities:
Hubble’s Composite Images
http://amazing-space.stsci.edu/resources/print/lithos/n90_nebula_litho.pdf
Multimedia:
Video – combining the Hubble, Chandra, and Spitzer observations:
http://hubblesite.org/newscenter/archive/releases/2009/07/video/b/
EM spectrum tour:
http://missionscience.nasa.gov/ems/index.html
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A Galaxy Revealed in
Multiple Wavelengths
BONUS CONTENT
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NASA leverages the EM Spectrum
Credit:
Goddard
Space Flight
Center
• NASA has a fleet of telescopes that cover the electromagnetic (EM)
spectrum, in order to observe the universe in different wavelengths.
• Because Earth’s atmosphere blocks certain wavelengths of light,
space-based (and stratospheric) observatories often complement
the work of ground-based observatories.
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What do the Colors Mean?
Spitzer
Hubble
GALEX
Chandra
Infrared
Visible
Ultraviolet
X-ray
• Because human eyes cannot see in Infrared, Ultraviolet or Xray, scientists assigned red, yellow, blue, and purple colors to
Spitzer, Hubble, GALEX, and Chandra images, respectively.
• Combining the four colors produces the final multiwavelength
image that traces various astrophysical processes occurring in
the M101 galaxy.
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