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Star and Planet Formation with SOFIA

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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