J/ApJS/188/242 Variations on debris disks. II. (Kenyon+, 2010)
Variations on debris disks. II.
Icy planet formation as a function of the bulk properties and initial sizes
of planetesimals.
Kenyon S.J., Bromley B.C.
<Astrophys. J. Suppl. Ser., 188, 242-279 (2010)>
=2010ApJS..188..242K 2010ApJS..188..242K
ADC_Keywords: Models, evolutionary
Keywords: circumstellar matter - planetary systems - protoplanetary disks -
planets and satellites: formation - stars: formation - zodiacal dust
Abstract:
We describe comprehensive calculations of the formation of icy planets
and debris disks at 30-150AU around 1-3M☉ stars. Disks composed
of large, strong planetesimals produce more massive planets than disks
composed of small, weak planetesimals. The maximum radius of icy
planets ranges from ∼1500km to 11500km. The formation rate of 1000km
objects-"Plutos"-is a useful proxy for the efficiency of icy planet
formation. Plutos form more efficiently in massive disks, in disks
with small planetesimals, and in disks with a range of planetesimal
sizes. Although Plutos form throughout massive disks, Pluto production
is usually concentrated in the inner disk. Despite the large number of
Plutos produced in many calculations, icy planet formation is
inefficient. At the end of the main sequence lifetime of the central
star, Plutos contain less than 10% of the initial mass in solid
material. This conclusion is independent of the initial mass in the
disk or the properties of the planetesimals. Debris disk formation
coincides with the formation of planetary systems containing Plutos.
As Plutos form, they stir leftover planetesimals to large velocities.
A cascade of collisions then grinds the leftovers to dust, forming an
observable debris disk. In disks with small (≲1-10km) planetesimals,
collisional cascades produce luminous debris disks with maximum
luminosity ∼10-2 times the stellar luminosity. Disks with larger
planetesimals produce debris disks with maximum luminosity ∼5x10-4
(10km) to 5x10-5 (100km) times the stellar luminosity. Following
peak luminosity, the evolution of the debris disk emission is roughly
a power law, f∝t-n with n∼0.6-0.8. Observations of debris
disks around A-type and G-type stars strongly favor models with small
planetesimals. In these models, our predictions for the time evolution
and detection frequency of debris disks agree with published
observations. We suggest several critical observations that can test
key features of our calculations.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table11.dat 39 150 Predicted excesses for disks around 1 solar
mass stars with Σ∝a-1 and
fS fragmentation parameters
table12.dat 39 132 Predicted excesses for disks around 1.5 solar
mass stars with Σ∝a-1 and
fS fragmentation parameters
table13.dat 39 120 Predicted excesses for disks around 2 solar
mass stars with Σ∝a-1 and
fS fragmentation parameters
table14.dat 39 105 Predicted excesses for disks around 3 solar
mass stars with Σ∝a-1 and
fS fragmentation parameters
table15.dat 39 150 Predicted excesses for disks around 1 solar
mass stars with Σ∝a-3/2 and
fW fragmentation parameters
table16.dat 39 132 Predicted excesses for disks around 1.5 solar
mass stars with Σ∝a-3/2 and
fW fragmentation parameters
table17.dat 39 120 Predicted excesses for disks around 2 solar
mass stars with Σ∝a-3/2 and
fW fragmentation parameters
table18.dat 39 105 Predicted excesses for disks around 3 solar
mass stars with Σ∝a-3/2 and
fW fragmentation parameters
table19.dat 39 100 Predicted excesses for disks around 1 solar
mass stars with Σ∝a-3/2 and
fS fragmentation parameters
table20.dat 39 88 Predicted excesses for disks around 1.5 solar
mass stars with Σ∝a-3/2 and
fS fragmentation parameters
table21.dat 39 80 Predicted excesses for disks around 2 solar
mass stars with Σ∝a-3/2 and
fS fragmentation parameters
table22.dat 39 70 Predicted excesses for disks around 3 solar
mass stars with Σ∝a-3/2 and
fS fragmentation parameters
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See also:
J/ApJ/636/1098 : Debris disks around solar-type stars (Bryden+, 2006)
J/ApJ/660/1556 : Characterization of dusty debris disks (Rhee+, 2007)
J/ApJS/179/451 : Predicted IR excesses for protoplanetary disks (Kenyon+, 2008)
Byte-by-byte Description of file: table*.dat
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Bytes Format Units Label Explanations
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1- 4 F4.2 --- xm Scaling factor
6- 9 F4.2 [yr] logt Log time (1)
11- 15 F5.2 [-] logLd Log total dust/stellar luminosity ratio
17- 21 F5.3 [-] logF24 Log of 24 micron flux excess
23- 27 F5.3 [-] logF70 Log of 70 micron flux excess
29- 33 F5.3 [-] logF160 Log of 160 micron flux excess
35- 39 F5.3 [-] logF850 Log of 850 micron flux excess
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Note (1): For calculations with Σ∝a-1 (for tables
11 to 14), or with Σ∝a-3/2 (for tables 15 to 22)
planetesimals with initial radii of 1m to 1km only, and the fS
(for table 11-14 and 19-22) or fW (for table 15-18) fragmentation
parameters. The typical inter-quartile range in the predicted fluxes
is ±5% to 10% at 24 microns and ±5% at 70-850 microns. The two
sets of fragmentation parameters are defined as follows:
Strong planetesimals have fS=(Qb=101, 103, or 105erg/g, βb=0,
Qg=2.25erg/g2xcm1.75, βg=1.25). Weaker planetesimals have
fW=(Qb=2x105erg/gxcm0.4, βb=-0.4, Qg=0.33erg/g2xcm1.7,
βg=1.3).
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History:
From electronic version of the journal
References:
Kenyon et al. 2008ApJS..179..451K 2008ApJS..179..451K. Paper I. Cat. J/ApJS/179/451.
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 14-Jun-2010