1. Nov. 12 2007PALM 3000 Requirements Review Imaging of Protoplanetary and Debris Disks Karl Stapelfeldt Jet Propulsion Laboratory

2. Nov. 12 2007PALM 3000 Requirements Review What is Learned from High Resolution Disk Imaging? Confirms basic disk morphology of dust distribution –position angle –major and minor axes (outer radius of disk) Measurable disk parameters –Radial disk structure (gaps, rings) –Azimuthal disk structure (asymmetries) –Vertical thickness (if close to edge-on) Derivable disk parameters via image modeling –Inclination –Radial surface brightness profile  vertical flaring vs. radius –Vertical disk structure if nearly edge-on  scale height –Disk mass-opacity product –Dust properties : κ(λ), phase function, polarizability Some of the derivable properties are degenerate

3. Nov. 12 2007PALM 3000 Requirements Review “Transiting” Disks: The Orion Silhouettes HST/ACS Hα; N. Smith et al. 2005 Disks backlit by the M42 H II region, d= 450 pc Clearly seen in the optical (Hα, …), but difficult to study in the near-IR 26 clean examples to date; more coming ? Not seen towards other H II regions

4. Nov. 12 2007PALM 3000 Requirements Review Edge-on disks : 13 + 4 now imaged V 376 Cas Stapelfeldt et al. 2008 WFPC2 RI CB 26 Sauter et al. 2008 NICMOS JHK ‘Gomez Hamburger’- PPN Padgett et al. 2008 NICMOS JHK “Nature’s coronagraph”

5. Nov. 12 2007PALM 3000 Requirements Review Variable nebulosity in the HH 30 disk Stochastic flaring events ? Periodic disk illumination from hotspots on a rotating star ? (Wood & Whitney 1998). Moving inner disk inhomogeneities that shadow the outer disk ? 18 epochs 1994-2005 Watson & Stapelfeldt 2007 If asymmetry is periodic, few days < P < 300 days

6. Nov. 12 2007PALM 3000 Requirements Review Young disks detected against direct starlight PSF artifacts make these disks more difficult to analyze 3+5 T Tauri disks are detected 5 Ae star disks are detected Beware envelope nebulosity ! GG Tau I band Krist et al. 2005 GO Tau R bandGO Tau H band TW Hya H band Weinberger et al. 2002 AB Aur U  I bands Grady et al. 1999

7. Nov. 12 2007PALM 3000 Requirements Review Most YSO disks remain undetected in scattered light Only 1/3 have detectable nebulosity < 10 % have disk nebulosity Many resolvable CO disks not detected Some disks must be much darker than others: –Depletion of small grains ? –Dust settling ? Stapelfeldt et al. 2008 Disk detectability in WFPC2 images Noise floor

8. Nov. 12 2007PALM 3000 Requirements Review Imaging Comparison : HD 141569A (courtesy of John Krist) STIS Coronagraph (U → I) NICMOS Coronagraph (J)ACS Coronagraph (V) Important transition object between optically thick protoplanetary disks and optically thin debris disks Radial zones with decreased surface density – dynamical clearing by planets at r > 100 AU ? Spiral arm induced by stellar encounter ? (Weinberger et al. 1999; Mouillet et al. 2001; Clampin et al. 2003)

9. Nov. 12 2007PALM 3000 Requirements Review Recent debris disk discoveries: Rings HD 107146 ACS R band –Ardila et al. 2004 –Young G2 V star –Broad density peak at 130 AU radius –Micron-sized grains inferred HD 181327 NICMOS J band –Schneider et al. 2006 –Young F5 V star –R= 86 AU,  R= 36 AU –Faint optical dust halo extending out several hundred AU ?

10. Nov. 12 2007PALM 3000 Requirements Review Recent debris disk discoveries: edge-on systems HD 139664 ACS R band –Kalas et al. 2005 –Young F5 star 17 pc distant –110 AU measured outer radius –83 AU inferred inner radius HD 32297 NICMOS J band –Schneider et al. 2005 –A0 star at 113 pc distance –Detected radius ~ 300 AU –Optical groundbased images (Kalas et al. 2005) show much 1600 AU radius, “bent” disk

11. Nov. 12 2007PALM 3000 Requirements Review Fomalhaut’s Eccentric Ring A3V star, age 200 Myrs, distance 8 pc HST (Kalas et al. 2005) MIPS 70 μm deconvolved CSO (Marsh et al. 2005) 350 μ m 0.6 μ m New Spitzer (in prep)

12. Nov. 12 2007PALM 3000 Requirements Review Eccentric ring model (Wyatt et al. 1999) Outer ring is perturbed by eccentric interior planet Produces brightness asymmetry in thermal emission from the Fomalhaut disk Models predict mass of perturber: –0.06 to 0.3 M J, if located at ring inner edge (Quillen 2006) –Higher planet mass required if it is located well inside ring Spitzer imaging later this month could detect 1-2 M J planet at radii > 5″ (40 AU) * Sharpness of ring inner edge Kalas et al. 2005

13. Nov. 12 2007PALM 3000 Requirements Review Debris disks detected in scattered light 11 published detections; 3 more are coming Half of these have ring morphology Many other IRAS/Spitzer disks observed but not detected No object with Ld/Lstar < 10 -4 is detected in scattered light Effective contrast limit is ~ 1000x our own Kuiper Belt Source Name Sp Type Dis (pc)Ld/Lstar HD 141569B91000.008 HR 4796A0670.005 HD 32297A01130.003 HD 181327F5510.003 beta PicA5200.002 HD 107146G2280.001 AU MicM0100.0006 HD 15115F2450.0005 HD 53143K1180.0003 HD 139664F5180.0001 FomalhautA380.00008 Good AO imagesugly AO images

14. Nov. 12 2007PALM 3000 Requirements Review http://www.circumstellardisks.org http://www.circumstellardisks.org Online database for spatially resolved disks Built at JPL by Caer McCabe Catalogs peer- reviewed results on disks at optical, infrared, and (sub)millimeter wavelengths 100 disks in current working catalog Key references and images are included

15. Nov. 12 2007PALM 3000 Requirements Review PALM 3000 Disk Science Niches 1. Will achieve 2x better resolution & IWA than HST/NICMOS; more stochastic image residuals Bright NGS targets: V < 5 for 95% strehl at K band –Potential to exceed HST/NICMOS contrast floor by a factor of 10, down to L d /L star ~ 3x10 -5 –~4/17 stars with Spitzer-detected debris disks have a high enough dust content, and are bright enough & visible from Palomar –Debris disks will extend outside AO control radius –No YSOs are bright enough

16. Nov. 12 2007PALM 3000 Requirements Review PALM 3000 Disk Science Niches 2. Fainter NGS targets: V < 10 for 80% strehl at K band –Only 12 YSOs bright enough & visible from Palomar, primarily Ae stars –7 additional stars with existing debris disks images are bright enough and visible from Palomar 20 W LGS: Would open up huge near-IR sample; large surveys of Spitzer-selected YSOs in nearby molecular clouds Optical: low/variable strehl suitable only for discoveries of backlit or edge-on systems