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 Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Abundances and partitioning of ices and gases produced by gas-grain chemistryare governed by adsorption and desorption on grains. Understandingastrophysical observations rely on laboratory measurements of adsorption anddesorption rates on dust grains analogs. On flat surfaces, gas adsorptionprobabilities (or sticking coefficients) have been found close to unity formost gases. Here we report a strong decrease of the sticking coefficients ofH2O and CO2 on substrates more akin to cosmic dust, such as submicrometer-sizedparticles of carbon and olivine, bare or covered with ice. This effect resultsfrom the local curvature of the grains, and then extends to larger grains madeof aggregated small particles, such as fluffy or porous dust in more evolvedmedia (e.g. circumstellar disks). The main astrophysical implication is thataccretion rates of gases are reduced accordingly, slowing the growth of cosmicices. Furthermore, volatile species that are not adsorbed on a grain at theirfreeze-out temperature will pertain in the gas phase, which will impact gas-icepartitions. We also found that thermal desorption of H2O is not modified bygrains size, and thus the snowlines temperature should be independent on thedust size distribution.

Laboratory-based sticking coefficients for ices on a variety of small grains analogs