Inside-out planet formation. IV. Pebble evolution and planet formation timescales
File(s)Hu_2018_ApJ_857_20.pdf (3.42 MB)
Published version
Author(s)
Type
Journal Article
Abstract
Systems with tightly packed inner planets (STIPs) are very common. Chatterjee & Tan proposed Inside-out Planet Formation (IOPF), an in situ formation theory, to explain these planets. IOPF involves sequential planet formation from pebble-rich rings that are fed from the outer disk and trapped at the pressure maximum associated with the dead zone inner boundary (DZIB). Planet masses are set by their ability to open a gap and cause the DZIB to retreat outwards. We present models for the disk density and temperature structures that are relevant to the conditions of IOPF. For a wide range of DZIB conditions, we evaluate the gap-opening masses of planets in these disks that are expected to lead to the truncation of pebble accretion onto the forming planet. We then consider the evolution of dust and pebbles in the disk, estimating that pebbles typically grow to sizes of a few centimeters during their radial drift from several tens of astronomical units to the inner, lesssim1 au scale disk. A large fraction of the accretion flux of solids is expected to be in such pebbles. This allows us to estimate the timescales for individual planet formation and the entire planetary system formation in the IOPF scenario. We find that to produce realistic STIPs within reasonable timescales similar to disk lifetimes requires disk accretion rates of ~10−9 M ⊙ yr−1 and relatively low viscosity conditions in the DZIB region, i.e., a Shakura–Sunyaev parameter of α ~ 10−4.
Date Issued
2018-04-10
Date Acceptance
2018-02-01
Citation
Astrophysical Journal, 2018, 857 (1)
ISSN
0004-637X
Publisher
American Astronomical Society
Journal / Book Title
Astrophysical Journal
Volume
857
Issue
1
Copyright Statement
© 2018. The American Astronomical Society. All rights reserved.
Sponsor
Science and Technology Facilities Council
Science and Technology Facilities Council (STFC)
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000429557800010&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Grant Number
ST-N000838
ST/N000838/1
Subjects
Science & Technology
Physical Sciences
Astronomy & Astrophysics
accretion, accretion disks
planet-disk interactions
planetary systems
planets and satellites: formation
protoplanetary disks
PROTOPLANETARY DISKS
SUPER-EARTHS
STARS
DISTRIBUTIONS
COAGULATION
ACCRETION
SYSTEMS
TAURI
MASS
Publication Status
Published
Article Number
20
Date Publish Online
2018-04-09