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

Axisymmetric dust rings are a ubiquitous feature of young protoplanetarydisks. These rings are likely caused by pressure bumps in the gas profile; asmall bump can induce a traffic jam-like pattern in the dust density, while alarge bump may halt radial dust drift entirely. The resulting increase in dustconcentration may trigger planetesimal formation by the streaming instability(SI), as the SI itself requires some initial concentration. Here we present thefirst 3D simulations of planetesimal formation in the presence of a pressurebump modeled specifically after those observed by ALMA. In particular, we placea pressure bump at the center of a large 3D shearing box, along with an initialsolid-to-gas ratio of $Z = 0.01$, and we include both particle back-reactionand particle self-gravity. We consider both mm-sized and cm-sized particlesseparately. For simulations with cm-sized particles, we find that even a smallpressure bump leads to the formation of planetesimals via the streaminginstability; a pressure bump does {\it not} need to fully halt radial particledrift for the SI to become efficient. Furthermore, pure gravitational collapsevia concentration in pressure bumps (such as would occur at sufficiently highconcentrations and without the streaming instability) is not responsible forplanetesimal formation. For mm-sized particles, we find tentative evidence thatplanetesimal formation does not occur. This result, if it holds up at higherresolution and for a broader range of parameters, could put strong constraintson where in protoplanetary disks planetesimals can form. Ultimately, however,our results suggest that for cm-sized particles, planetesimal formation inpressure bumps is an extremely robust process.

Protoplanetary Disk Rings as Sites for Planetesimal Formation