Gas Pressure Driven Screening Forces and Pebble Aggregation: A Pathway for Growth in Planet Formation

Fuente: arXiv
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Autor principal: Vyas, Mukesh Kumar
Formato: Preprint
Publicado: 2025
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author Vyas, Mukesh Kumar
author_facet Vyas, Mukesh Kumar
contents The formation of planetesimals from cm-sized pebbles in protoplanetary disks faces significant barriers, including fragmentation and radial drift. We identify a previously unaccounted screening force, arising from mutual shielding of thermal gas particles between pebbles when their separation falls below the gas mean free path. This force facilitates pebble binding, overcoming key growth barriers under turbulent disk conditions. Unlike conventional mechanisms, screening forces operate independently of surface adhesion and complement streaming instability and pressure traps by enhancing aggregation in high-density regions. Our analysis predicts that screening interactions are most effective in the {middle disk regions ($ \sim 0.3$ to few AU),} consistent with ALMA observations (e.g., TW Hya) of enhanced dust concentrations. {Furthermore, we find that screening-induced pebble growth from centimeter to kilometer scales can occur on timescales significantly shorter than the disk lifetime ($\sim 10^5$ years). Importantly, this growth naturally terminates when particles smaller than the local gas mean free path are depleted, thereby avoiding runaway accretion.} Beyond planetary science, the screening forces have {potential} implications for high-energy astrophysics, dusty plasmas, confined particle suspensions and other relevant areas, suggesting a broader fundamental significance.
format Preprint
id arxiv_https___arxiv_org_abs_2507_02570
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Gas Pressure Driven Screening Forces and Pebble Aggregation: A Pathway for Growth in Planet Formation
Vyas, Mukesh Kumar
Earth and Planetary Astrophysics
High Energy Astrophysical Phenomena
Classical Physics
The formation of planetesimals from cm-sized pebbles in protoplanetary disks faces significant barriers, including fragmentation and radial drift. We identify a previously unaccounted screening force, arising from mutual shielding of thermal gas particles between pebbles when their separation falls below the gas mean free path. This force facilitates pebble binding, overcoming key growth barriers under turbulent disk conditions. Unlike conventional mechanisms, screening forces operate independently of surface adhesion and complement streaming instability and pressure traps by enhancing aggregation in high-density regions. Our analysis predicts that screening interactions are most effective in the {middle disk regions ($ \sim 0.3$ to few AU),} consistent with ALMA observations (e.g., TW Hya) of enhanced dust concentrations. {Furthermore, we find that screening-induced pebble growth from centimeter to kilometer scales can occur on timescales significantly shorter than the disk lifetime ($\sim 10^5$ years). Importantly, this growth naturally terminates when particles smaller than the local gas mean free path are depleted, thereby avoiding runaway accretion.} Beyond planetary science, the screening forces have {potential} implications for high-energy astrophysics, dusty plasmas, confined particle suspensions and other relevant areas, suggesting a broader fundamental significance.
title Gas Pressure Driven Screening Forces and Pebble Aggregation: A Pathway for Growth in Planet Formation
topic Earth and Planetary Astrophysics
High Energy Astrophysical Phenomena
Classical Physics
url https://arxiv.org/abs/2507.02570