TY - JOUR
T1 - Effect of Different Angular Momentum Transport Mechanisms on the Distribution of Water in Protoplanetary Disks
AU - Kalyaan, Anusha
AU - Desch, Steven J.
N1 - Publisher Copyright:
© 2019. The American Astronomical Society. All rights reserved.
PY - 2019/4/10
Y1 - 2019/4/10
N2 - The snow line in a protoplanetary disk demarcates regions with H2O ice from regions with H2O vapor. Where a planet forms relative to this location determines how much water and other volatiles it forms with. Giant-planet formation may be triggered at the water-snow line if vapor diffuses outward and is cold-trapped beyond the snow line faster than icy particles can drift inward. In this study, we investigate the distribution of water across the snow line, considering three different radial profiles of the turbulence parameter α(r), corresponding to three different angular momentum transport mechanisms. We consider the radial transport of water vapor and icy particles by diffusion, advection, and drift. We show that even for similar values of α, the gradient of α(r) across the snow line significantly changes the snow line location, the sharpness of the volatile gradient across the snow line, and the final water/rock ratio in planetary bodies. A profile of radially decreasing α, consistent with transport by hydrodynamic instabilities plus magnetic disk winds, appears consistent with the distribution of water in the solar nebula, with monotonically increasing radial water content and a diverse population of asteroids with different water content. We argue that Σ(r) and water abundance are likely a diagnostic of α(r) and thus of the mechanism for angular momentum transport in inner disks.
AB - The snow line in a protoplanetary disk demarcates regions with H2O ice from regions with H2O vapor. Where a planet forms relative to this location determines how much water and other volatiles it forms with. Giant-planet formation may be triggered at the water-snow line if vapor diffuses outward and is cold-trapped beyond the snow line faster than icy particles can drift inward. In this study, we investigate the distribution of water across the snow line, considering three different radial profiles of the turbulence parameter α(r), corresponding to three different angular momentum transport mechanisms. We consider the radial transport of water vapor and icy particles by diffusion, advection, and drift. We show that even for similar values of α, the gradient of α(r) across the snow line significantly changes the snow line location, the sharpness of the volatile gradient across the snow line, and the final water/rock ratio in planetary bodies. A profile of radially decreasing α, consistent with transport by hydrodynamic instabilities plus magnetic disk winds, appears consistent with the distribution of water in the solar nebula, with monotonically increasing radial water content and a diverse population of asteroids with different water content. We argue that Σ(r) and water abundance are likely a diagnostic of α(r) and thus of the mechanism for angular momentum transport in inner disks.
UR - http://www.scopus.com/inward/record.url?scp=85067307252&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85067307252&partnerID=8YFLogxK
U2 - 10.3847/1538-4357/ab0e6c
DO - 10.3847/1538-4357/ab0e6c
M3 - Article
AN - SCOPUS:85067307252
SN - 0004-637X
VL - 875
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1
M1 - 43
ER -