Dust Transport and Processing in Centrifugally Driven Protoplanetary Disk Winds
AffiliationUniv Arizona, Dept Astron & Steward Observ
ISM: jets and outflows
ISM: magnetic fields
MetadataShow full item record
PublisherIOP PUBLISHING LTD
CitationSteven Giacalone et al 2019 ApJ 882 33
RightsCopyright © 2019. The American Astronomical Society. All rights reserved.
Collection InformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at email@example.com.
AbstractThere is evidence that protoplanetary disks including the protosolar one-contain crystalline dust grains on spatial scales where the dust temperature is lower than the threshold value for their formation through thermal annealing of amorphous interstellar silicates. We interpret these observations in terms of an extended, magnetocentrifugally driven disk wind that transports grains from the inner disk-where they are thermally processed by the stellar radiation after being uplifted from the disk surfaces-to the outer disk regions. For any disk radius r, there is a maximum grain size a(max)(r) that can be uplifted from that location: grains of size a << a(max) are carried away by the wind, whereas those with a less than or similar to a(max) reenter the disk at larger radii. A significant portion of the reentering grains converge to-and subsequently accumulate in-a narrow region just beyond r(max)(a), the maximum radius from which grains of size a can be uplifted. We show that this model can account for the inferred crystallinity fractions in classical T Tauri and Herbig Ae disks and for their indicated near constancy after being established early in the disk evolution. It is also consistent with the reported radial gradients in the mean grain size, crystallinity, and crystal composition. In addition, this model yields the properties of the grains that remain embedded in the outflows from protoplanetary disks and naturally explains the inferred persistence of small grains in the surface layers of these disks.
VersionFinal published version
SponsorsNASA ATP grant [NNX13AH56G]; Hubble Fellowship Program by NASA through Space Telescope Science Institute [HST-HF2-51394.002-A]; NASANational Aeronautics & Space Administration (NASA) [NAS 5-26555]