J/MNRAS/488/L12 Runaway gas accretion and ALMA observations (Nayakshin+, 2019)
ALMA observations require slower Core Accretion runaway growth.
Nayakshin S., Dipierro G., Szulagyi J.
<Mon. Not. R. Astron. Soc., 488, L12-17 (2019)>
=2019MNRAS.488L..12N 2019MNRAS.488L..12N (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Exoplanets ; Stars, ages ;
Millimetric/submm sources ; YSOs
Keywords: planets and satellites: formation - protoplanetary discs
Abstract:
Due to recent high-resolution ALMA observations, there is an
accumulating evidence for presence of giant planets with masses from
∼0.01MJ to a few MJ with separations up to 100au in the annular
structures observed in young protoplanetary discs. We point out that
these observations set unique 'live' constraints on the process of gas
accretion on to sub-Jovian planets that were not previously available.
Accordingly, we use a population synthesis approach in a new way: we
build time-resolved models and compare the properties of the synthetic
planets with the ALMA data at the same age. Applying the widely used
gas accretion formulae leads to a deficit of sub-Jovian planets and an
overabundance of a few Jupiter mass planets compared to observations.
We find that gas accretion rate on to planets needs to be suppressed
by about an order of magnitude to match the observed planet mass
function. This slower gas giant growth predicts that the planet mass
should correlate positively with the age of the protoplanetary disc,
albeit with a large scatter. This effect is not clearly present in the
ALMA data but may be confirmed in the near future with more
observations.
Description:
Table 1 shows the masses, separation, and ages of the ALMA candidate
planets that we use here. Our two major data sources are Long et al.
(2018ApJ...869...17L 2018ApJ...869...17L) and the DSHARP (Andrews et al.
2018ApJ...869L..41A 2018ApJ...869L..41A, Cat. J/ApJ/869/L41; Huang et al.
2018ApJ...869L..42H 2018ApJ...869L..42H, Cat. J/ApJ/869/L42) survey. The former lists dust
gap widths W, separations, a, stellar masses, M*, and other relevant
information.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 29 39 Masses, separation, and ages of the ALMA
candidate planets that we use here
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See also:
J/ApJ/869/L41 : DSHARP I. Sample, ALMA obs. log and overview
(Andrews+, 2018)
J/ApJ/869/L42 : DSHARP. II. Annular substructures data (Huang+, 2018)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Name Star name
11- 15 F5.2 Myr Age Star age
17- 22 F6.2 AU Sep Gap location (1)
24- 29 F6.3 Mjup Mplanet Inferred planet mass (2)
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Note (1): Gap locations are mostly taken from Long et al. (2018ApJ...869...17L 2018ApJ...869...17L)
and Huang et al. (2018ApJ...869L..42H 2018ApJ...869L..42H)
Note (2): We use the relation RH=a(Mp/3M*)1/3 to compute the planet
mass Mp. Here, RH is the Hill's radius and we assume a reference
value of the gap width W=5.5RH to compute Mp. W, a and M* are
mostly taken from Long et al. (2018ApJ...869...17L 2018ApJ...869...17L), Andrews et al.
(2018ApJ...869L..41A 2018ApJ...869L..41A) and Huang et al. (2018ApJ...869L..42H 2018ApJ...869L..42H).
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History:
From electronic version of the journal
(End) Ana Fiallos [CDS] 23-Nov-2022