Gas-assisted Growth of Protoplanets in a Turbulent Medium

Rosenthal, M. M.; Murray-Clay, Ruth; Perets, Hagai B.; Wolansky, Natania

doi:10.3847/1538-4357/aac4a1

Cited by 16 publications

(13 citation statements)

References 76 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A.4. Heavy Particle Regime -St 1 A well known expression for the RMS velocity (relative to inertial space) of a particle with St 1 is v p = v gas √ 1 + St (A12) This is derived in Youdin & Lithwick (2007) and Rosenthal et al (2018). In this regime particles receive many uncorrelated "kicks" from the largest scale eddies over a single stopping time, causing the particle to random walk in velocity.…”

Section: Acknowledgementsmentioning

confidence: 99%

New Constraints From Dust Lines on the Surface Densities of Protoplanetary Disks

Powell

Murray-Clay

Pérez

et al. 2019

ApJ

Self Cite

View full text Add to dashboard Cite

We present new determinations of disk surface density, independent of an assumed dust opacity, for a sample of 7 bright, diverse protoplanetary disks using measurements of disk dust lines. We develop a robust method for determining the location of dust lines by modeling disk interferometric visibilities at multiple wavelengths. The disks in our sample have newly derived masses that are 9-27% of their host stellar mass, substantially larger than the minimum mass solar nebula. All are stable to gravitational collapse except for one which approaches the limit of Toomre-Q stability. Our mass estimates are 2-15 times larger than estimates from integrated optically thin dust emission. We derive depleted dust-to-gas ratios with typical values of ∼10 −3 in the outer disk. Using coagulation models we derive dust surface density profiles that are consistent with millimeter dust observations. In these models, the disks formed with an initial dust mass that is a factor of ∼10 greater than is presently observed. Of the three disks in our sample with resolved CO line emission, the masses of HD 163296, AS 209, and TW Hya are roughly 3, 115, and 40 times more massive than estimates from CO respectively. This range indicates that CO depletion is not uniform across different disks and that dust is a more robust tracer of total disk mass. Our method of determining surface density using dust lines is robust even if particles form as aggregates and is useful even in the presence of dust substructure caused by pressure traps. The low Toomre-Q values observed in this sample indicate that at least some disks do not accrete efficiently.

show abstract

Section: Acknowledgementsmentioning

confidence: 99%

New Constraints From Dust Lines on the Surface Densities of Protoplanetary Disks

Powell

Murray-Clay

Pérez

et al. 2019

ApJ

Self Cite

View full text Add to dashboard Cite

show abstract

“…The extension of the Bondi crossing time of pebbles due to the recycling flow further promotes pebble accretion. Rosenthal et al (2018) introduced flow isolation mass, m R18 flow , as the solution of R Bondi = R Hill . In our dimensionless unit, the flow isolation mass is described by m R18 flow = 0.58.…”

Section: Comparison To Previous Studiesmentioning

confidence: 99%

“…19). When the planetary mass reaches the flow isolation mass (Rosenthal et al 2018), the planet-induced gas flow is in the flow-shear regime. In the flow-shear regime, we find that the accretion of pebbles with St 10 −3 is suppressed significantly when we assumed the Epstein gas drag regime, but the accretion probability of pebbles with St 10 −3 in the planet-induced gas flow is comparable to that of the unperturbed flow Paper (I).…”

Section: Comparison To Previous Studiesmentioning

confidence: 99%

“…In the flow-shear regime, we find that the accretion of pebbles with St 10 −3 is suppressed significantly when we assumed the Epstein gas drag regime, but the accretion probability of pebbles with St 10 −3 in the planet-induced gas flow is comparable to that of the unperturbed flow Paper (I). The difference is likely due to the smaller size of the bound atmosphere and complicated recycling flow patterns, both of which were not taken into account in Rosenthal et al (2018).…”

Section: Comparison To Previous Studiesmentioning

confidence: 99%

See 1 more Smart Citation

Influences of protoplanet-induced three-dimensional gas flow on pebble accretion

Kuwahara

Kurokawa

2020

A&A

View full text Add to dashboard Cite

Context. Pebble accretion is among the major theories of planet formation. Aerodynamically small particles, called pebbles, are highly affected by the gas flow. A growing planet embedded in a protoplanetary disk induces three-dimensional (3D) gas flow. In our previous work, Paper I, we focused on the shear regime of pebble accretion and investigated the influence of planet-induced gas flow on pebble accretion. In Paper I, we found that pebble accretion is inefficient in the planet-induced gas flow compared to that of the unperturbed flow, particularly when St ≲ 10−3, where St is the Stokes number. Aims. Following on the findings of Paper I, we investigate the influence of planet-induced gas flow on pebble accretion. We did not consider the headwind of the gas in Paper I. Here, we extend our study to the headwind regime of pebble accretion. Methods. Assuming a nonisothermal, inviscid sub-Keplerian gas disk, we performed 3D hydrodynamical simulations on the spherical polar grid hosting a planet with the dimensionless mass, m = RBondi∕H, located at its center, where RBondi and H are the Bondi radius and the disk scale height, respectively. We then numerically integrated the equation of motion for pebbles in 3D using hydrodynamical simulation data. Results. We first divided the planet-induced gas flow into two regimes: flow-shear and flow-headwind. In the flow-shear regime, where the planet-induced gas flow has a vertically rotational symmetric structure, we find that the outcome is identical to what we obtained in Paper I. In the flow-headwind regime, the strong headwind of the gas breaks the symmetric structure of the planet-induced gas flow. In the flow-headwind regime, we find that the trajectories of pebbles with St ≲ 10−3 in the planet-induced gas flow differ significantly from those of the unperturbed flow. The recycling flow, where gas from the disk enters the gravitational sphere at low latitudes and exits at high latitudes, gathers pebbles around the planet. We derive the flow transition mass analytically, mt, flow, which discriminates between the flow-headwind and flow-shear regimes. From the relation between m, mt, flow and mt, peb, where mt, peb is the transition mass of the accretion regime of pebbles, we classify the results obtained in both Paper I and this study into four groups. In particular, only when the Stokes gas drag law is adopted and m < min(mt, peb, mt, flow), where the accretion and flow regime are both in the headwind regime, the accretion probability of pebbles with St ≲ 10−3 is enhanced in the planet-induced gas flow compared to that of the unperturbed flow. Conclusions. Combining our results with the spacial variety of turbulence strength and pebble size in a disk, we conclude that the planet-induced gas flow still allows for pebble accretion in the early stage of planet formation. The suppression of pebble accretion due to the planet-induced gas flow occurs only in the late stage of planet formation, more specifically, in the inner region of the disk. This may be helpful for explaining the distribution of exoplanets and the architecture of the Solar System, both of which have small inner and large outer planets.

show abstract

“…The particular scaling law (8) was derived for the case of classic planetesimal accretion. For the competing picture wherein pebble accretion accounts for the formation of giant planet cores (e.g., Ormel & Klahr 2010;Lambrechts & Johansen 2012;Lin et al 2018;Rosenthal et al 2018), the scaling exponent can be different. For example, Lambrechts & Johansen (2014) find that the pebble accretion rate depends on stellar mass according to Ṁ ∼ M −11/36 * , which coresponds to the alternate scaling law t onset ∼ m 11/36 ∼ m 1/3 (compare with equation [8]).…”

Section: Empirical Considerationsmentioning

confidence: 99%

A Theoretical Framework for the Mass Distribution of Gas Giant Planets forming through the Core Accretion Paradigm

Adams,

Meyer,

Adams

2021

Preprint

View full text Add to dashboard Cite

This paper constructs a theoretical framework for calculating the distribution of masses for gas giant planets forming via the core accretion paradigm. Starting with known properties of circumstellar disks, we present models for the planetary mass distribution over the range 0.1M J ≤ M p < 10M J . If the circumstellar disk lifetime is solely responsible for the end of planetary mass accretion, the observed (nearly) exponential distribution of disk lifetime would imprint an exponential fall-off in the planetary mass function. This result is in apparent conflict with observations, which suggest that the mass distribution has a (nearly) power-law form dF/dM p ∼ M −p p , with index p ≈ 1.3, over the relevant planetary mass range (and for stellar masses ∼ 0.5 − 2M ). The mass accretion rate onto the planet depends on the fraction of the (circumstellar) disk accretion flow that enters the Hill sphere, and on the efficiency with which the planet captures the incoming material. Models for the planetary mass function that include distributions for these efficiencies, with uninformed priors, can produce nearly power-law behavior, consistent with current observations. The disk lifetimes, accretion rates, and other input parameters depend on the mass of the host star. We show how these variations lead to different forms for the planetary mass function for different stellar masses. Compared to stars with masses M * = 0.5 − 2M , stars with smaller masses are predicted to have a steeper planetary mass function (fewer large planets).

show abstract

Gas-assisted Growth of Protoplanets in a Turbulent Medium

Cited by 16 publications

References 76 publications

New Constraints From Dust Lines on the Surface Densities of Protoplanetary Disks

New Constraints From Dust Lines on the Surface Densities of Protoplanetary Disks

Influences of protoplanet-induced three-dimensional gas flow on pebble accretion

A Theoretical Framework for the Mass Distribution of Gas Giant Planets forming through the Core Accretion Paradigm

Contact Info

Product

Resources

About