Rotational Disruption of Porous Dust Aggregates due to Gas Flow in Protoplanetary Disks

Abstract

We introduce a possible disruption mechanism of dust grains in planet formation by their spinning motion. This mechanism has been discussed as rotational disruption for the interstellar dust grains. We theoretically calculate whether porous dust aggregates can be disrupted by their spinning motion and if it prohibits dust growth in protoplanetary disks. We assume radiative torque and gas-flow torque as driving sources of the spinning motion, assume that dust aggregates reach a steady-state rigid rotation, and compare the obtained tensile stress due to the centrifugal force with their tensile strength. We model the irregularly-shaped dust aggregates by introducing a parameter, ${\gamma }_{\mathrm{ft}}$, that mimics the conversion efficiency from force to torque. As a result, we find that porous dust aggregates are rotationally disrupted by their spinning motion induced by gas flow when their mass is larger than $\sim 10^8$ g and their volume filling factor is smaller than $\sim 0.01$ in our fiducial model, while relatively compact dust aggregates with volume filling factor more than 0.01 do not face this problem. If we assume the dust porosity evolution, we find that dust aggregates whose Stokes number is $\sim 0.1$ can be rotationally disrupted in their growth and compression process. Our results suggest that the growth of dust aggregates may be halted due to rotational disruption or that other compression mechanisms are needed to avoid it. We also note that dust aggregates are not rotationally disrupted when ${\gamma }_{\mathrm{ft}}\le 0.02$ in our fiducial model and the modeling of irregularly-shaped dust aggregates is essential in future work.

16 pages, 16 figures, accepted for publication in ApJ

References in corpus (15)

• Closed-form expressions for particle relative velocities induced by turbulence
• Radiative torques: Analytical Model and Basic Properties
• A Three-Dimensional View of Turbulence: Constraints on Turbulent Motions in the HD 163296 Protoplanetary Disk using DCO${}^{+}$
• Dust size distributions in coagulation/fragmentation equilibrium: Numerical solutions and analytical fits
• Radiative torque alignment: Essential Physical Processes
• The evidence of radio polarization induced by the radiative grain alignment and self-scattering of dust grains in a protoplanetary disk
• ALMA Reveals Transition of Polarization Pattern with Wavelength in HL Tau's Disk
• Grain Alignment by Radiative Torques in Special Conditions and Implications
• Submillimeter polarization observation of the protoplanetary disk around HD 142527
• Subsonic Mechanical Alignment of Irregular Grains
• Radiative torques alignment in the presence of pinwheel torques
• Radial variations in grain sizes and dust scale heights in the protoplanetary disk around HD 163296 revealed by ALMA polarization observation
• Tensile Strength of Porous Dust Aggregates
• Intrinsic polarisation of elongated porous dust grains
• Millimeter-wave polarization due to grain alignment by the gas flow in protoplanetary disks

Cited by in corpus (8)

• On Internal and External Alignment of Dust Grains in Protostellar Environments
• Effects of grain alignment with magnetic fields on grain growth and the structure of dust aggregates
• Compaction during fragmentation and bouncing produces realistic dust grain porosities in protoplanetary discs
• Self-scattering on large, porous grains in protoplanetary disks with dust settling
• Dust grain shattering in protoplanetary discs: collisional fragmentation or rotational disruption?
• The rotational disruption of porous dust aggregates from ab-initio kinematic calculations
• The radiative torque spin-up efficiency of ballistic dust grain aggregates
• Aeolian erosion in protoplanetary discs: How impactful it is on dust evolution?