LGS-AO OBSERVATIONS OF THE HV TAU C EDGE-ON PROTOPLANETARY DISK

G. Duchêne (UCB)A.M. Ghez (UCLA), C.E. McCabe (IPAC)

C. Pinte, F. Menard, G. Duvert, K. Stapelfeldt,

D. Padgett, M. Perrin, H. Bouy, D. Barrado,

A. Noriega-Crespo, T. Brooke

Keck Science Meeting – Sept 18 2008

Protoplanetary disks Key questions for planet formation:

Processes? Timescales? Initial conditions? Map disk structure/content through time A complementary set of observations

G. Duchêne – Keck Science Meeting – Sept 18 2008

Corder et al.(2005) Fukagawa et

al. (2004)

Tannirkulam et al. (2008)Mariñas et al. (2006)

Keck adaptive optics vs HST

HST

Keck AO

McCabe et al. (2002)Duchêne et al. (2004)

Krist et al. (2004)

G. Duchêne – Keck Science Meeting – Sept 18 2008

The HV Tau triple system PMS system in Taurus (~1 Myr, ~0.5 M) Tertiary has an opaque 50AU edge-on disk V=14.5, R=13.0 Limited NGS correction

Stapelfeldt et al. (2003)

HST/WFPC2DSS2 blue

1”

G. Duchêne – Keck Science Meeting – Sept 18 2008

Keck AO images New images in NGS (55 Hz) and LGS mode

L’ (3.78 μm) and Ms (4.67 μm) filtersStrehl ratios of 70-80%LGS AO dataset deeper and sharper

HST/WFPC2 Keck LGS-AO Keck NGS-AO

4.7 μm3.8 μm0.6-0.8 μm

G. Duchêne – Keck Science Meeting – Sept 18 2008

Additional AO images JHK images obtained at VLT with NAOS

Continuous 0.6-4.7 μm coverage at uniform resolution (~0.1” or better)

2.2 μm

G. Duchêne – Keck Science Meeting – Sept 18 2008

Major features From 0.6 to 4.7 μm, distance

between nebulae decreases Over same range, nebulae

flux ratio decreases as well Both phenomena are typical of “small” dust

grains (not much larger than 1 μm) Persistent shear-like asymmetry (warp?)

Structural feature on scales of many AUs

1.6μm0.8μm 3.8μm

0.1”

G. Duchêne – Keck Science Meeting – Sept 18 2008

Modeling strategy Panchromatic fit to broad dataset to constrain

the disk main propertiesDisk mass, overall structureGrain size distribution (amax)Spatial variations in dust properties

MCFOST(multi-purpose RT code)

Scattered light images (0.8 – 3.8 μm)

Thermal emission map (1.3 mm)

Overall SED (0.5 μm – 2.7 mm)

Grid of ~106 independent models; 50,000h of CPU time

G. Duchêne – Keck Science Meeting – Sept 18 2008

Pinte et al. (2006)

Preliminary results Each dataset has its own

“best fit”Objective is to find the best

compromise in the grid

Best overall model

ISM-like dust model

Summary Keck LGS-AO offers

Comparable 3-5 μm resolution as HST (optical)Great sensitivity to disks, even in thermal IR

Detailed model for HV Tau C still needs work Need to expand sample to find trends!

G. Duchêne – Keck Science Meeting – Sept 18 2008

HV Tau C HK Tau B