Image: A. Angelich (NRAO/AUI/NSF)/ALMA (ESO/NAOJ/NRAO) The behaviour of pebbles around the snowline in protoplanetary disks University of Amsterdam Djoeke Schoonenberg SPF2, Biosphere, 15 March 2018 with Chris Ormel, Beibei Liu, Sebastiaan Krijt
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Image: A. Angelich (NRAO/AUI/NSF)/ALMA (ESO/NAOJ/NRAO)
Thebehaviourofpebblesaroundthesnowlineinprotoplanetarydisks
University of AmsterdamDjoekeSchoonenberg
SPF2, Biosphere, 15 March 2018
withChrisOrmel,BeibeiLiu,SebastiaanKrijt
Water snowline around V883 Ori
Cieza et al., Nature, 535, 2016 Schoonenberg, Okuzumi, & Ormel, A&A, 605, L2 (2017)
Outline• Planetesimalformationbystreaminginstabilityaroundthesnowline
• FormationoftheTRAPPIST-1planets
Fromdusttoplanets
Nottoscale!(noteventolog-scale)
µm
km
dust
planetesimal
planet
1e3km
Streaminginstability• Mechanismtodirectlyformplanetesimalsfrompebbles
• Requireslocalsolids-to-gasratiooforderunity
Johansen,Youdin,&MacLow2009(seealsoYoudin&Goodman2005;Johansen,Henning,&Klahr2006;
Johansen&Youdin2007;Simonetal.2016;Yangetal.2017)
Krijtetal.2016(seealsoBirnstieletal.2012,Lambrechts&Johansen2014)
Schoonenberg&Ormel,A&A,602,A21(2017)
Planetesimalformationoutsidethesnowline:alocaltransportmodel
constantmassfluxoficypebbles
snowline
↵ = 3 · 10�3
⌧ = 3 · 10�2
Mgas = 10�8M�yr�1
Mpeb/Mgas = 0.8
e-foldingtimescale≈(rpeak-rsnow)/vgas
Schoonenberg&Ormel,A&A,602,A21(2017)
Icypebbledesigns
‘single-seed’
‘many-seeds’
evaporationfront
Icypebbledesigns
MichaelHammer,Astrobites
‘single-seed’
‘many-seeds’
evaporationfront
↵ = 3 · 10�3
⌧ = 3 · 10�2
Mgas = 10�8M�yr�1
Mpeb/Mgas = 0.8
Schoonenberg&Ormel,A&A,602,A21(2017)‘dirt’‘freesilicates’
Many-seedsmodelenhances‘bump’andleadstoplanetesimalicefractionof~0.5
FormationscenariofortheTRAPPIST-1planets
Ormel,Liu,andSchoonenberg,A&A,604,A1(2017)
Grimmetal.,A&A,inpress
Jack Cook/WHOI/USGS
WaterfractionofTRAPPIST-1planetsdictatedbyratiooficypebbleaccretiontowater-poorpebbleaccretion
Ormel,Liu,andSchoonenberg,A&A,604,A1(2017)
planetesimalformation+pebbleaccretion (nomigration/planetesimalmergers)
�16
Planetesimalmergersandmigration
UsingMERCURY(Chambers1999)
�17
Planetesimalmergersandmigration
UsingMERCURY(Chambers1999)
�18
Planetesimalmergersandmigration
UsingMERCURY(Chambers1999)
firstplanetaryembryohascrossedsnowline
↵ = 10�3
Mgas = 10�10M� yr�1
Z = 0.02
b c d e f g h
• PlanetesimalformationinourTRAPPIST-1modelstartsafterafew10^3years
• Firstplanetembryomigratesacrossthesnowlineafterafew10^4years
• Withoutmigration,planetesimalformationisaself-limitingprocess(becausepebblefluxgoesdownduetopebbleaccretionasplanetesimalmassgrows)
• Icypebbleaccretionversusrockypebbleaccretionaftericeline-crossingdeterminesbulkcompositionofTRAPPIST-1planets
• PRELIMINARY:waterfractionsofafewpercentseemtobefeasible
Takehomemessages
Related Documents
