Observations of Water and other molecules in Protoplanetary Disk Atmospheres Colette Salyk UT Austin/McDonald Observatory Klaus Pontoppidan, Geoffrey Blake, Rowin Meijerink, Joan Najita, John Carr

Water vapor and organics detected in ‘typical’ circumstellar disks with Spitzer-IRS Spitzer IRS: Carr & Najita 2008; Salyk et al T~ K

Ground-based follow-up confirms origin in planet- forming region of disk Salyk et al Line profiles consistent with ~few AU emitting radii

What disk processes might water emission probe? Radial transport of water via diffusion (out) and icy- body migration (in) “snow line” e.g. Stevenson & Lunine 1988; Ciesla & Cuzzi 2006 vapor freezes out vapor diffuses outwards low vapor pressure high vapor pressure solids migrate inwards solids evaporate

What disk processes might water emission probe? Radial transport of water via diffusion (out) and icy- body migration (in) Water self-shielding Bethell & Bergin 2009

What disk processes might water emission probe? Radial transport of water via diffusion (out) and icy- body migration (in) Water self-shielding Radiative processes Condensation fronts and vertical transport Disk chemistry Small dust grain growth/settling Clearly a challenge to disentangle multiple effects

GO5 program: Water in Disks (PI: J. Carr) -52 class II disks in multiple star-forming regions -Designed to cover a range of stellar/disk parameters

GO5 program: Water in Disks (PI: J. Carr) -52 class II disks in multiple star-forming regions -Designed to cover a range of stellar/disk parameters -Subset of these disks + archived programs results in sample shown here

Sampled disks show significant variety

Pontoppidan et al., in prep

-Lines are actually spectrally uresolved line blends at the resolution of Spitzer-IRS -Lines probe a large range of excitation temperatures

Water vapor and organic emission is common around low-mass young stars Pontoppidan et al., in prep

Detection rates drop precipitously for SpT<G Pontoppidan et al., in prep

Transitional disks do not show emission

Emission of water correlates with CO emission

LTE models can be used to estimate density, T

But in general do a poor job of matching the data