GIANT PLANET MIGRATION, DISK EVOLUTION, AND THE ORIGIN OF TRANSITIONAL DISKS

By Richard Alexander, Philip Armitage. 2009

140 citations recorded by the source corpus.

We present models of giant planet migration in evolving protoplanetary disks. Our disks evolve subject to viscous transport of angular momentum and photoevaporation, while planets undergo Type II migration. We use a Monte Carlo approach, running large numbers of models with a range in initial conditions. We find that relatively simple models can reproduce both the observed radial distribution of extrasolar giant planets, and the lifetimes and accretion histories of protoplanetary disks. The use of state-of-the-art photoevaporation models results in a degree of coupling between planet formation and disk clearing, which has not been found previously. Some accretion across planetary orbits is necessary if planets are to survive at radii ≲1.5 AU, and if planets of Jupiter mass or greater are to survive in our models they must be able to form at late times, when the disk surface density in the formation region is low. Our model forms two different types of “transitional” disks, embedded planets and clearing disks, which show markedly different properties. We find that the observable properties of these systems are broadly consistent with current observations, and highlight useful observational diagnostics. We predict that young transition disks are more likely to contain embedded giant planets, while older transition disks are more likely to be undergoing disk clearing.

Subfields: Astronomy and Astrophysics, Spectroscopy

View Paper: https://www.semanticscholar.org/paper/e5b2d72f49cd6369b60d4c28918d84b2130c405f

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Citations in the corpus

Accretion onto Pre-Main-Sequence Stars (2016, background): “Models of disk evolution through viscous accretion predict a decline in accretion rate with age (Hartmann et al. 1998, Alexander & Armitage 2009, Gorti & Hollenbach 2009).”
Observational Signatures of Planets in Protoplanetary Disks I: Gaps Opened by Single and Multiple Young Planets in Disks (2014, background): “…mechanisms can partially explain the observations, including grain growth (Dullemond & Dominik 2005; Birnstiel et al. 2012), photoevaporation (Alexander & Armitage 2007, 2009; Owen et al. 2012; Rosotti et al. 2013), infall from counterrotating external environments (Vorobyov et al. 2014),…”
Protoplanetary disc evolution and dispersal: the implications of X-ray photoevaporation (2010, background): “This clearly shows that a spread in accretion rates at late times > 1Myr does not necessary require a spread in initial conditions as some authors have suggested is necessary outside the XPE framework (e.g. Armitage et al. 2003; Alexander & Armitage, 2009).”
Characterization of exoplanets from their formation - II. The planetary mass-radius relationship (2012, background): “(21) This results in a total, constant mass loss rate due to internal photoevaporation of about 3 × 10−10 M /yr, a value similar to what was found by Alexander & Armitage (2009).”
YOUNG STELLAR OBJECTS IN THE GOULD BELT (2015, background): “Although the ages of young stars are highly uncertain, recent studies suggest a revised half-life for disk survival of 2.5 − 4 Myr on both observational (e.g., Kraus et al. 2012; Bell et al. 2013; Soderblom et al. 2014) and theoretical (e.g., Alexander & Armitage 2009) grounds.”
ALMA unveils rings and gaps in the protoplanetary system HD 169142: signatures of two giant protoplanets (2017, background): “For a lower planetary mass, the cavity is “porous” and gas from the outer disk could flow inward and fill the gap (e.g., Lubow & D’Angelo 2006; Alexander & Armitage 2009).”
RESOLVED IMAGES OF LARGE CAVITIES IN PROTOPLANETARY TRANSITION DISKS (2011, background): “Najita et al. (2007) suggested that transition disks exhibit low accretion rates compared to their normal counterparts with similar disk masses, consistent with a large reduction in the mass flow across a gap produced by a low-mass companion (see also Alexander & Armitage 2007, 2009).”
THE ROLE OF MULTIPLICITY IN DISK EVOLUTION AND PLANET FORMATION (2011, background): “For example, typical circumstellar disks seem to be affected by photoevaporation only at late stages of their evolution, after most of their mass has been accreted to the central star (e.g., Alexander & Armitage 2009; Alexander et al. 2006).”
WIDE-FIELD INFRARED SURVEY EXPLORER OBSERVATIONS OF THE EVOLUTION OF MASSIVE STAR-FORMING REGIONS (2012, background): “Photoevaporation of the disk may take a longer time to operate (for example, Alexander & Armitage 2009).”
Extrasolar planet population synthesis - IV. Correlations with disk metallicity, mass, and lifetime (2012, background): “…where the reduction of the type II migration rate due to the planet’s inertia is assumed to scale proportional to (Σa2/Mplanet)1/2 instead of linearly (cf. Alexander & Armitage 2009), the triangular envelope shape of the points is approximately retained, but shifted to larger extents of migration.”
TRANSITIONAL AND PRE-TRANSITIONAL DISKS: GAP OPENING BY MULTIPLE PLANETS? (2010, background): “Photoevaporation has been proposed as one gap/hole clearing mechanism (Alexander & Armitage 2007, 2009), but requires the mass loss rate by the photoevaporation to be comparable to the disk accretion rate.”
On the theory of disc photoevaporation (2011, background): “Unlike the previous EUV models (e.g. Alexander et al. 2006b; Alexander & Armitage 2009), the X-ray photoevaporation model can account for a large fraction of the observed ‘transition’ discs.”
Protoplanetary disk lifetimes vs stellar mass and possible implications for giant planet populations (2015, background): “The disk lifetime is a fundamental parameter to understand the interplay between a disk and its planets, since it determines the time available for the planets to form and migrate (e.g. Burkert & Ida 2007; Alexander & Armitage 2009).”
THE IMPRINT OF EXOPLANET FORMATION HISTORY ON OBSERVABLE PRESENT-DAY SPECTRA OF HOT JUPITERS (2016, methodology): “In the type II regime, the accretion rate can be written as (Alexander & Armitage 2009) da dt = min(1, 2Σa2/M) × vr,gas (A11) where vr,gas is the local radial velocity of the gas.”
Dynamics of Protoplanetary Disks (2010, background): “…& Pringle 2006b; Gorti, Dullemond & Hollenbach 2009; Matsuyama, Johnstone & Hartmann 2003; Owen et al. 2010), and how such models may be constrained by observations of transition disk sources (Owen, Ercolano & Clarke 2010) and by the statistics of extrasolar planets (Alexander & Armitage 2009).”