Spitzer Mid-IR Extinction

Short science presentation for the STScI MIRI Team.

Transcript

1. Spitzer mid-IR Extinction Karl D. Gordon Astronomer MIRI Inst. Scientist MIRI Tagup 5 Oct 2021 kgordon@stsci.edu @karllark2000 karllark@github Gordon et al. 2021, ApJ, 916, 33
2. Pair Method for Extinction I Github: measure_extinction
3. Pair Method for Extinction I
4. Diffuse Extinction Curve
5. Sample of OB stars
7. Analytic Fit
9. Dense = 3 micron ice feature not by A(V) threshold
10. Two Dense Curves
11. Lower than most literature results
12. Higher than dust grain models
13. Selected correlations (or not)
14. No other features
15. G21 in dust_extinction Github: dust_extinction
16. NIR Extinction work by Marjorie Decleir (ISM* postdoc)
17. Challenging from the ground
18. JWST cycle 1 programs • S. Zeegers: 12 sightlines (ID:2183) – Galactic plane, 3 different regions • M. Decleir: 9 sightlines (ID:2459) – All also have HST UV depletions (current cycle), FUSE H2, IUE HI, FUSE/IUE extinctions • Both use NIRCam TSO grism and MIRI MRS – cover 2.4-28 microns – measure the 3.4 micron HAC feature and 10 & 20 micron silicate features (and any other features) – measure the continuum extinction over the full range