The outcome of protoplanetary dust growth: pebbles, boulders or planetesimals?

By C. Guttler, J. Blum, A. Zsom, C. Ormel, C. Dullemond. 2009

630 citations recorded by the source corpus.

Context. The evolution of dust particles in protoplanetary disks determines many observable and structural properties of the disk, such as the spectral energy distribution (SED), appearance of disks, temperature profile, and chemistry. Dust coagulation is also the first step towards planet formation. Aims. We investigate dust growth due to settling in a 1D vertical column of a disk. It is known from the ten micron feature in disk SEDs, that small micron-sized grains are present at the disk atmosphere throughout the lifetime of the disk. We hope to explain such questions as what process can keep the disk atmospheres dusty for the lifetime of the disk and how the particle properties change as a function of height above the midplane. Methods. We used a Monte Carlo code to follow the mass and porosity evolution of the particles in time. We gradually build up the complexity of the models by considering the effects of porosity, different collision models, turbulence, and different gas models, respectively. This way we can distinguish the effects of these physical processes on particle growth and motion. The collision model used is based on laboratory experiments performed on dust aggregates. As the experiments cannot cover all possible collision scenarios, the largest uncertainty of our model comes from the necessary extrapolations we had to perform. We simultaneously solved for the particle growth and motion. Particles can move vertically due to settling and turbulent mixing. We assumed that the vertical profile of the gas density is fixed in time and that only the solid component evolves. Results. We find that the used collision model strongly influences the masses and sizes of the particles. The laboratory-experiment based collision model greatly reduces the particle sizes compared to models that assume sticking at all collision velocities. We find that a turbulence parameter of α = 10−2 is needed to keep the dust atmospheres dusty, but such strong turbulence can produce only small particles at the midplane, which does not favor for planetesimal formation models. We also see that the particles are larger at the midplane and smaller at the upper layers of the disk. At 3–4 pressure-scale heights, micron-sized particles are produced. These particle sizes are needed to explain the ten micron feature of disk SEDs. Turbulence may therefore help keep small dust particles in the disk atmosphere.

Subfields: Astronomy and Astrophysics, Spectroscopy

View Paper: https://www.semanticscholar.org/paper/bb19878aea6e838aab96c695637586245cb069f7

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Citations in the corpus

The Disk Substructures at High Angular Resolution Project (DSHARP). V. Interpreting ALMA Maps of Protoplanetary Disks in Terms of a Dust Model (2018, methodology): “Given the uncertainty in the details of collision models (see, Güttler et al. 2010; Windmark et al. 2012, for example), and for ease of reproduction, we will be using the B11S fits in the following.”
Trapping dust particles in the outer regions of protoplanetary disks (2011, methodology): “Recent collision experiments using silicates (Güttler et al. 2010) and numerical simulations (Zsom et al. 2010) show that there is an intermediate regime between fragmentation and sticking, where particles should bounce.”
Free collisions in a microgravity many-particle experiment. I. Dust aggregate sticking at low velocities (2011, methodology): “The model of Güttler et al. was implemented into a local growth simulation (Zsom et al., 2010), and the result was that the growth in a minimum mass solar nebula stalls at masses of approximately 1 mg.”
Pebble-isolation mass: Scaling law and implications for the formation of super-Earths and gas giants (2018, methodology): “The final pebble sizes in our model were determined by radial drift alone, where we did not take the effects of fragmentation (Brauer et al. 2008; Birnstiel et al. 2011), bouncing (Zsom et al. 2010), or condensation (Ros & Johansen 2013; Schoonenberg & Ormel 2017) into account.”
Concentrating small particles in protoplanetary disks through the streaming instability (2016, background): “On the other hand, when the dust coagulation is limited by the bouncing barrier, the distribution of the particle size tends to concentrate within about one order of magnitude near the barrier (Zsom et al. 2010).”
EVIDENCE OF FAST PEBBLE GROWTH NEAR CONDENSATION FRONTS IN THE HL TAU PROTOPLANETARY DISK (2015, background): “Lab experiments show that icy aggregates are significantly more ‘sticky’, and resistant to compaction than silicate aggregates (Güttler et al. 2010; Seizinger & Kley 2013; Kelling et al. 2014).”
Dust Evolution and the Formation of Planetesimals (2016, background): “Practically all particle size distributions have most of the mass in the largest grains (interstellar medium (ISM): Mathis et al. 1977, circumstellar disks: e.g., Brauer et al. 2008; Birnstiel et al. 2012b; Zsom et al. 2011; Okuzumi et al. 2012, debris disks: e.g., Dohnanyi 1969).”
Rubble Pile Asteroids (2018, background): “Furthermore models of grain growth confront other barriers to growth whereby small mm-sized grains may simply bounce or fragment instead of sticking, effectively limiting the maximum size of simple growth at cm-sizes (Zsom et al. 2010, Wurm et al. 2005, Blum and Wurm 2008, Johansen et al. 2015).”
THE MASS AND SIZE DISTRIBUTION OF PLANETESIMALS FORMED BY THE STREAMING INSTABILITY. I. THE ROLE OF SELF-GRAVITY (2015, background): “2 ing shows that particles within this size range do not easily stick together, and instead fragment or bounce (Brauer et al. 2008; Blum & Wurm 2008; Birnstiel et al. 2010; Zsom et al. 2010).”
Evidence for the formation of comet 67P/Churyumov-Gerasimenko through gravitational collapse of a bound clump of pebbles (2017, background): “…(“pebbles”) Radius a 1.58 × 10−4 m 5.00 × 10−4 m 1.58 × 10−3 m 5.00 × 10−3 m 1.58 × 10−2 m - Volume filling factor φpebble 0.4 Weidling et al. (2009); Güttler et al. (2010); Zsom et al. (2010) Young’s modulus Ypebble 8.1 × 103 Pa Weidling et al. (2012) Poisson ratio µpebble 0.17…”
The primordial nucleus of comet 67P/Churyumov-Gerasimenko (2015, background): “Weidenschilling (1997) did not consider bouncing of aggregates as a possible collisional outcome, which was however observed in many laboratory experiments (Blum & Wurm 2008; Güttler et al. 2010) and shown to be relevant under realistic conditions (Zsom et al. 2010).”
Astrochemistry and compositions of planetary systems (2020, background): “Third the material properties changes across snowlines, which may increase (or decease) stickiness and fragmentation thresholds, both of which aid (or quench) transforming initially sub-micron-sized particles into mm/cm-sized pebbles via coagulation (Güttler et al. 2010; Pinilla et al. 2017).”
THE STICKINESS OF MICROMETER-SIZED WATER-ICE PARTICLES (2014, background): “Dust coagulation plays an important role in the densest interstellar regions, i.e., in molecular clouds (Ossenkopf 1993; Weidenschilling & Ruzmaikina 1994; Ormel et al. 2009) and protoplanetary disks (Blum & Wurm 2008; Zsom et al. 2010; Testi et al. 2014).”
A simple model for the evolution of the dust population in protoplanetary disks (2012, background): “However there are several mechanisms that can limit collisional growth of dust particles: charging effects (Okuzumi 2009), bouncing (Güttler et al. 2010; Zsom et al. 2010), fragmentation and radial drift (Weidenschilling 1977a; Brauer et al. 2008a; Birnstiel et al. 2010).”
How to form planetesimals from mm-sized chondrules and chondrule aggregates (2015, methodology): “Particles of this size are inconsistent with coagulation experiments, which show that particles cannot grow beyond mm sizes (Zsom et al. 2010; Güttler et al. 2010).”
Planetesimal formation by sweep-up: how the bouncing barrier can be beneficial to growth (2012, background): “With the inclusion of a vertical structure,Zsom et al.(2011) still found the bouncing to be prominent, but also a number of other collision effects caused by the vertical mixing.”
The structure of protoplanetary discs around evolving young stars (2014, background): “In fact dust growth can be quite fast (Zsom et al. 2010), depleting the micro meter-sized dust grains to some level.”
Planetesimal formation near the snowline: in or out? (2017, background): “Although micron-sized grains can quite easily coagulate to mm-sized particles (Dominik & Tielens 1997; Ormel et al. 2007), typical relative velocities quickly become so large that particles fragment or bounce rather than stick (Blum & Wurm 2000; Zsom et al. 2010).”