Dust in galaxies the next generation

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Dust in galaxies the next generation
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Dust

• Alters observed properties
• Intimately linked to cold ISM, star formation
• Easy and cheap to observe
• Traces energy input, modified by energetic
  processes in ISM

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AM0500-620 WFPC2
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AM1316-241 WFPC2
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And of course NGC 3314
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Dust in spiral arms is mostly like our local
sample with one exception so far.
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Dust within galaxies the reconstruction problem
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Extracting residual intensity

• Model galaxy light
• Divide into image
• Repeat with masking as needed
• Generate 3D model for galaxy light
• Solve pixel-by-pixel

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Example NGC 1316
Depth
t(v)
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Limitations

• Takes forever
• Requires detailed galaxy model, geometry
• Very sensitive to data S/N
• More applicable approaches replace physical
  depth by fraction of foreground starlight, or fit
  whole dust patches rather than pixels

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Fitting RAV/EB-V
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NGC 1316 R1.8
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NGC 2787
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R2.1
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NGC 3607 R4
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NGC 4278 R1.5
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R2
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R2.5
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R2.4
Note far side of annulus
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And closer to home
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Dust forms in the Crabs instability-driven
filaments. Here we can watch grain formation and
destruction in the synchrotron nebula.
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Dust loss and S0s?

• Dust in S0 systems restricted to annulus
• Dust can be destroyed by sputtering in a hot ISM
• Can a large bulge, hot ISM and low SFR destroy
  the dust from the edges of a disk, helping shut
  down star formation?

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Survival of acquired cold ISM and star formation
NGC 5866 S0 (ACS BVR, Hubble Heritage)
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Automated selection of E/S silhouettes from SDSS
spectra
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Chris Lintott, Anze Slosar, Alex Szlalay, Daniel
Thomas, Kevin Schawinski, Kate Land, Bob Nichol,
and a cast of 85,000 Sinh-mapped color images
(turns out to be important for this)
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