Protostellar Disks Restless Atmosphere CL17-1261.pdf
- 1. Protostellar Disks’ Restless Atmospheres Neal Turner (JPL/Caltech) with M. Flock (JPL/Caltech), S. Fromang (Saclay), S. Hirose (JAMSTEC), C. Dullemond (Heidelberg), M. Benisty (Grenoble), J. Stauffer (IPAC/Caltech) Artwork by Robert Hurt (IPAC/Caltech) Copyright 2017. All rights reserved.
- 2. Spitzer National Aeronautics and Space Administration
- 3. CoRoT (ESA) CNES & European Space Agency
- 4. A. M. Cody et al. 2014 Uncorrelated Optical & IR Changes
- 5. Optical 4.5mm 3.6mm Uncorrelated Optical & IR Changes A. M. Cody et al. 2014
- 6. Erratic Dips Due to Variable Extinction A. M. Cody et al. 2014
- 7. urbulent mixing across the stellar mass range Mulders & Dominik 2012 Median CTTS Has NIR Excess Too Large
- 8. Wavelength / mm Flux lF l / erg cm -2 s -1 McClure et al. 2013 NIR Excess has T~Tsubl and L up to 0.17L*! Star Observed Excess Components
- 9. 1. Magnetic fields support an extended disk atmosphere, 1. Which absorbs enough starlight to cause the IR excess. 1. Fluctuating fields yield big-enough brightness changes. 1. The atmosphere can intermittently obscure the star. Outline
- 10. 1. Magnetic fields support an extended disk atmosphere, 1. Which absorbs enough starlight to cause the IR excess. 1. Fluctuating fields yield big-enough brightness changes. 1. The atmosphere can intermittently obscure the star. Outline
- 11. Hirose & Turner 2011
- 12. Hirose & Turner 2011 r = r0 exp(-z2/2h2) + (r0/79) exp(-z/1.57h)
- 13. Andrews et al. 2009
- 15. 1. Magnetic fields support an extended disk atmosphere, 1. Which absorbs enough starlight to cause the IR excess. 1. Fluctuating fields yield big-enough brightness changes. 1. The atmosphere can intermittently obscure the star. Outline
- 20. 1. Magnetic fields support an extended disk atmosphere, 1. Which absorbs enough starlight to cause the IR excess. 1. Fluctuating fields yield big-enough brightness changes. 1. The atmosphere can intermittently obscure the star. Outline
- 21. Hirose & Turner 2011 orbits
- 22. dust / gas = 10-4
- 23. dust / gas = 10-2
- 24. 1. Magnetic fields support an extended disk atmosphere, 1. Which absorbs enough starlight to cause the IR excess. 1. Fluctuating fields yield big-enough brightness changes. 1. The atmosphere can intermittently obscure the star. Outline
- 25. V J 3.6 70o 800 AU Outer disk dusty Outer disk dust-depleted
- 26. V J 3.6 70o 800 AU Outer disk dusty Outer disk dust-depleted
- 27. V J 3.6 70o 80 AU Outer disk dusty Outer disk dust-depleted
- 28. V J 3.6 70o 80 AU Outer disk dusty Outer disk dust-depleted
- 29. V J 3.6 70o 8 AU Outer disk dusty Outer disk dust-depleted
- 30. V J 3.6 70o 8 AU Outer disk dusty Outer disk dust-depleted
- 31. V J 3.6 70o 0.8 AU Outer disk dusty Outer disk dust-depleted
- 32. V J 3.6 70o 0.8 AU Outer disk dusty Outer disk dust-depleted
- 33. V J 3.6 70o 0.08 AU Outer disk dusty Outer disk dust-depleted
- 34. V J 3.6 70o 0.08 AU Tall atmosphere A=2 Nominal atmosphere A=1.5 Outer disk dust- depleted
- 35. V J 3.6 75o 0.08 AU Tall atmosphere A=2 Outer disk dust- depleted
- 36. Summary
- 39. 1. Magnetic fields support an extended disk atmosphere. 2. The atmosphere absorbs enough starlight to cause the IR excess. 3. Fluctuating fields yield brightness changes with amplitudes like those observed. 4. The atmosphere can intermittently obscure the star in systems seen near edge-on, if dust has settled in the disks’ outer reaches.
- 40. What does it all mean?
- 41. Radius / AU Midplane Temperature / K Water ice sublimates
- 42. 1. Most young stars with disks vary in the infrared, some because of starspots and accretion variability. 1. Cases with the optical steady while the IR varies are hard to understand unless the disk’s surface moves. 1. Such movements naturally arise in a magnetized disk atmosphere. 1. The atmosphere casts time-varying shadows. 2. The shadows move the snow line in and out.