SMA Observations of the Orion proplyds Jonathan Williams (IfA) Sean Andrews (IfA) David Wilner (CfA)

VLA  mass loss rate ~ 10-7 M/yr HST  radii ~ 20-100 AU VLA  mass loss rate ~ 10-7 M/yr  tevap ~ 105 yr for MMSN (10-2 M)

Most solar mass stars form in Orion type environments. But if tevap ~ 105 yr, what are the prospects for planet formation? What is the mass of the inner (< 30 AU) disk that is bound to the star?

Need to get to shorter wavelengths! Mundy et al. 1995 BIMA Previous millimeter array observations - isolate individual objects filter out cloud emission OVRO Bally et al. 1998 Need to get to shorter wavelengths! PdBI Lada 2000

SMA Observations November 2004 Compact array, 341 GHz, 1.5’’ beam Two tracks  2.7 mJy/beam

0.019 M 0.016 M 0.024 M 0.013 M

bremsstrahlung + greybody (ionized gas + dust) Submillimeter wavelengths essential to get the dust

What about the 18 non-detections? Average mass ~ 8x10-4 M

Odd detection statistics  abrupt mass loss event? Circular or elliptical orbits? (Störzer & Hollenbach 2000)

An SMA survey of Orion?

An SMA survey of Orion? 10 tracks  ~ 20-30 detections? Disk mass function Environmental influence Gas content?

David Aguilar