Transcript CloudsToSolarSystems_EXES

From large clouds to solar
systems ... How do we get there?
Keely Finkelstein
Sept. 22, 2012
Molecular Cloud seen in visible &
IR wavelengths:
2
Horsehead Nebula - Molecular
Cloud
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A star forming region will
look different depending on
what wavelength of like you
are observing it with.
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Different wavelength
regimes, probe different
parts of the cloud.
Horsehead Nebula - in optical - dust obscures star-forming activity
Horsehead Nebula - Molecular
Cloud
✤
A star forming region will
look different depending on
what wavelength of like you
are observing it with.
✤
Different wavelength
regimes, probe different
parts of the cloud.
Horsehead Nebula - in infrared - a hot thin layer of dust on edge of cloud
glows
Horsehead Nebula - Molecular
Cloud
✤
A star forming region will
look different depending on
what wavelength of like you
are observing it with.
✤
Different wavelength
regimes, probe different
parts of the cloud.
Horsehead Nebula - in sub mm - both cooler dust & molecules glow
Horsehead Nebula - Molecular
Cloud
✤
A star forming region will
look different depending on
what wavelength of like you
are observing it with.
✤
Different wavelength
regimes, probe different
parts of the cloud.
Horsehead Nebula - in radio - also see cold dust & molecules glowing
An example - the Orion Molecular Cloud Complex
belt stars
Horsehead Nebula
M42, Orion Nebula
Horsehead is just one small part of the larger molecular cloud
complex and the Orion Nebula
Orion Molecular Cloud Complex
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The previous image of the Orion molecular cloud complex spans a region that
is 75 light years across
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Molecular gas (as mapped by CO emission) extends over even more of the
space mapped out in previous image.
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The Orion molecular cloud complex is the nearest site of massive star
formation to the Sun (at a distance of 1500 light years) & is considered a giant
molecular cloud complex
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Other molecular cloud sites are closer to us, such as the Taurus Molecular
Cloud complex at 300 light years away - but it is smaller and only lowmass stars are produced in it. Orion is the nearest site that is large
enough to produce massive stars.
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The whole Orion complex has a mass of ~ 200,000 solar masses
Orion GMC in CO emission (at
millimeter wavelengths)
belt stars
CO emission in
Horsehead Nebula
CO emission in
Orion Nebula
QuickTime™ and a
GIF decompressor
are needed to see this picture.
Full Extended CO map overlaid on Orion Constellation
Structures of Molecular Clouds
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Clouds are complex structures Clumps of varying sizes, often connected
by filaments and surrounded by more tenuous material
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The clumps can be very large and dense and often when we look at them
in visible light they look uniformly dark
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But observing them at other wavelengths, such as millimeter
wavelengths, reveals that the insides of these clumps can be very
structured & can contain one or more very dense cores
It is out of these cores that stars are born
So how do we go from these
Giant Molecular clouds to this . . .
?
Star Formation Role Play - You
are the experts:
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You are all at a conference and your are the world’s experts in star and planet
formation
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8 teams of experts - divide into teams and each group of you are the world
experts in some branch of astrophysics.
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You are all gathered together at a conference to determine how these giant
molecular clouds can turn into multiple solar systems.
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After you have debriefed and discussed with your team, and you are confident
in your area of expertise - go out and exchange information with other groups.
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Anything goes - you are allowed to form consortia with other teams, you can
withhold info from other teams, you can mislead them . . . its the real research
world out there.
Star Formation Role Play - You
are the experts:
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But just remember that unless you are willing to share information with other
groups, they will not share with you!
You can’t show other teams your briefing papers, but must explain and to them
what is on it verbally.
Your goal is to make a coherent theory of star and planet formation.
You don’t know enough to figure this out for yourselves! Go out and talk to some
other groups to see if that helps fill in the gaps in your story!
Once you think you have a theory, complete with timescales, and numbers, write
it down and then teams will present to the whole group.
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But keep in mind, there’s not just one correct ranking with only the 8 expert
areas - ideas and concepts may be interwoven and used in multiple steps.
Try to come up with the best coherent theory!