English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Water and simple organic molecular ices dominate the mass of solid materialsavailable for planetesimal and planet formation beyond the water snow line.Here we analyze ALMA long baseline 2.9, 1.3 and 0.87 mm continuum images of theyoung star HL Tau, and suggest that the emission dips observed are due to rapidpebble growth around the condensation fronts of abundant volatile species.Specifically, we show that the prominent innermost dip at 13 AU is spatiallyresolved in the 0.87 mm image, and its center radius is coincident with theexpected mid-plane condensation front of water ice. In addition, two otherprominent dips, at distances of 32 and 63 AU, cover the mid-plane condensationfronts of pure ammonia or ammonia hydrates and clathrate hydrates (especiallywith CO and N$_2$) formed from amorphous water ice. The spectral index map ofHL Tau between 1.3 and 0.87 mm shows that the flux ratios inside the dips arestatistically larger than those of nearby regions in the disk. This variationcan be explained by a model with two dust populations, where most of solid massresides in a component that has grown into decimeter size scales inside thedips. Such growth is in accord with recent numerical simulations of volatilecondensation, dust coagulation and settling.

Evidence of fast pebble growth near condensation fronts in the HL Tau protoplanetary disk