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Star and Planet Formation with SOFIA

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Star and Planet Formation with SOFIA. Neal Evans, John Bally, Jim De Buizer, Murad Hamidouche, Thomas Henning, Goran Sandell, Floris van der Tak, Ewine van Dishoeck. Sub-Themes and Membership. The formation of massive stars

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Star and Planet Formation with SOFIA

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  1. Star and Planet Formation with SOFIA Neal Evans, John Bally, Jim De Buizer, Murad Hamidouche, Thomas Henning, Goran Sandell, Floris van der Tak, Ewine van Dishoeck

  2. Sub-Themes and Membership • The formation of massive stars • Membership: Jim De Buizer (SOFIA), John Bally (U. Colorado), Floris van der Tak (SRON), Göran Sandell (SOFIA) • Astrochemistry of star formation • Membership: Ewine van Dishoek (Leiden Obs), Thomas Henning (MPIfA), Floris van der Tak • The formation and evolution of disks • Membership: Murad Hamidouche (SOFIA), Thomas Henning, Neal Evans, Jim De Buizer, John Bally

  3. Activities Since Last Meeting June 18 - First telecon of whole working group • Establishment of subthemes, membership to work on those subthemes June 18 to July 07 – Subgroups exchanged ideas and text via email, leads collated and wrote (~5pg) summaries July 09 – I distilled the three texts into a zero-th order (~10pg) draft, released to subthemes for further iteration via email

  4. The Importance of Massive Stars

  5. The Richness of Astrochemistry

  6. Disk Structure SAFIRE, HAWC,FORCAST Disk SED model of the T Tauri star LkCa15 (Chiang et a. 2001).

  7. SOFIA’s Niche • After IRAS, ISO, KAO, Spitzer • Contemporary with Herschel, JWST, ALMA • The wavelength region 28-60 microns • Between JWST and Herschel • Lack of saturation problems • High Spectral Resolution (MIR to FIR) • Flexibility, long operating timebase • Most projects use SOFIA as complement to other telescopes

  8. Massive Star Formation in Galactic Context • Surveys in mm continuum finding 1000’s of dense clumps • Bolocam Galactic Plane Survey • Complementary survey from APEX • Infrared Dark Clouds (IRDC) • MSX, GLIMPSE, MIPSGAL • New models of Galaxy, VLBA distances, … • Provide link to extragalactic star formation

  9. The New Milky Way

  10. A Piece of the Plane A very small piece of the BGPS showing the wealth of sources. Many, but not all, will be IRDCs

  11. IRDCs

  12. Need for SOFIA • Massive stars are distant, form in clusters, produce copious PAH emission, high L, heavy extinction • Need better spatial resolution, imaging between PAH bands, avoid saturation • Imaging from 28-60 microns to separate L sources • High-R spectroscopy to study dynamics

  13. Nebulosity Hides Stars CS contours of dense core overlaid on GLIMPSE image of W51W (blue is 3.6 micron, green 4.5, red 8.0)

  14. High-R Observations • Complementary to ALMA • Tracers of higher temperature, density • CASIMIR, GREAT, EXES • TEXES has shown that MIR absorption probes different gas, very close to the star, perhaps in a disk.

  15. Other Ideas • Use HAWC-Pol • constrain location and nature of aligned grains • Test importance of magnetic fields vs. turbulence • Time variable phenomena • Outbursts due to stellar mergers, major accretion events • Occultations

  16. Astrochemistry • Central Ideas • Trace the Oxygen • Trace the Water • Chemical Effects of outflows and shocks

  17. Where are the Oxygen Atoms? • About 1/3 of the O is unaccounted for. • OI 63 micron emission “ubiquitous” from ISO • But abundances not well constrained • Apparently optically thick and subthermal • Need the line profile: GREAT is unique.

  18. Follow the Water • Herschel has major programs • SOFIA can add complementary information • Some H218O lines at THz • EXES ro-vibrational lines • Can trace water evaporation region

  19. Shock Chemistry • Theory expects shocks to drive O into water • Not well tested • Water, OH, O I lines, all with high-R

  20. Disks • Very interesting, but hard to find unique niche • Origin of the disk • Separating disk from infalling envelope • 28-60 micron is key region • Need a well-sampled SED in this region • Later stages • Residual envelope may confuse disk models • Use SOFIA resolution to see if FIR resolved

  21. Disk-Envelope Separation Disk with intrinsic L Passive Disks Points and red line are data; blue line is model. Model with passive disk inside envelope cannot fit 20-70 micron Need to add “disk emission”, but could be inner envelope.

  22. Evolution of Materials for Planet Building • Multiwavelength data probe grain growth • Ice is key to forming giant planets • 45 micron ice feature (Unique to SOFIA) • 6 micron MIR lines indicate evaporation • Evidence from Spitzer and TEXES

  23. Status and Schedule for Writing • Current status: “zero-th order” draft with ongoing changes by working group • Schedule: • Present to Aug 1: Further edits and address feasibility with SOFIA • Aug 1: Official first draft distributed by Neal • Aug 18: Deadline for all comments from group • Aug 22: Full draft to SOFIA Vision Group

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