Unified Simulations of Planetary Formation and Atmospheric Evolution: Effects of Pebble Accretion, Giant Impacts, and Stellar Irradiation on Super-Earth Formation

@article{Ogihara2020UnifiedSO,
  title={Unified Simulations of Planetary Formation and Atmospheric Evolution: Effects of Pebble Accretion, Giant Impacts, and Stellar Irradiation on Super-Earth Formation},
  author={Masahiro Ogihara and Yasunori Hori},
  journal={The Astrophysical Journal},
  year={2020}
}
A substantial number of super-Earths have been discovered, and atmospheres of transiting super-Earths have also been observed by transmission spectroscopy. Several lines of observational evidence indicate that most super-Earths do not possess massive H$_2$/He atmospheres. However, accretion and retention of less massive atmospheres on super-Earths challenge planet formation theory. We consider the following three mechanisms: (i) envelope heating by pebble accretion, (ii) mass loss during giant… 
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12 Citations
Background Citations
7
Results Citations
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12 Citations

Unified Simulations of Planetary Formation and Atmospheric Evolution. II. Rapid Disk Clearing by Photoevaporation Yields Low-mass Super-Earth Atmospheres
Super-Earths possess low-mass H$_2$/He atmospheres (typically less than 10% by mass). However, the origins of super-Earth atmospheres have not yet been ascertained. We investigate the role of rapid…
Size Evolution of Close-in Super-Earths through Giant Impacts and Photoevaporation
The Kepler transit survey with follow-up spectroscopic observations has discovered numerous super-Earth sized planets and revealed intriguing features of their sizes, orbital periods, and their…
Most super-Earths formed by dry pebble accretion are less massive than 5 Earth masses
Aims. The goal of this work is to study the formation of rocky planets by dry pebble accretion from self-consistent dust-growth models. In particular, we aim to compute the maximum core mass of a…
Hydrogen Dominated Atmospheres on Terrestrial Mass Planets: Evidence, Origin and Evolution
The discovery of thousands of highly irradiated, low-mass, exoplanets has led to the idea that atmospheric escape is an important process that can drive their evolution. Of particular interest is the…
Ejection of close-in super-Earths around low-mass stars in the giant impact stage
Context. Earth-sized planets were observed in close-in orbits around M dwarfs. While more and more planets are expected to be uncovered around M dwarfs, theories of their formation and dynamical…
Atmospheric Erosion by Giant Impacts onto Terrestrial Planets: A Scaling Law for any Speed, Angle, Mass, and Density
We present a new scaling law to predict the loss of atmosphere from planetary collisions for any speed, angle, impactor mass, target mass, and body compositions, in the regime of giant impacts onto…
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The characterization of exoplanets and their birth protoplanetary disks have enormously advanced in the last decade. Benefited from that, our global understanding of the planet formation has been…
The nature of the radius valley
The existence of a Radius Valley in the Kepler size distribution stands as one of the most important observational constraints to understand the origin and composition of exoplanets with radii…
Constraining the entropy of formation from young transiting planet
Recently K2 and TESS have discovered transiting planets with radii between $\sim$ 5-10 R$_\oplus$ around stars with ages $<100$ Myr. These young planets are likely to be the progenitors of the…
How dust fragmentation may be beneficial to planetary growth by pebble accretion
Context. Pebble accretion is an emerging paradigm for the fast growth of planetary cores. Pebble flux and pebble sizes are the key parameters used in the pebble accretion models. Aims. We aim to…
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