The viscous evoluton of circumstellar disks in young star clusters

Transcription

1 The viscous evoluton of circumstellar disks in young star clusters Francisca Concha-Ramírez Leiden Observatory MODEST18 Firá, Greece 28 June 2018

2 Clarke, Bonnell, Hillenbrand 2000 Lada & Lada 2003 De Wit et al 2005 Parker & Goodwin 2007 HST

3 Motvaton Understand mechanisms afectng the evoluton and fnal distributon of protoplanetary disks inside star clusters Find inital conditons that generate simulated clusters consistent with observatons Ultmately: Solar System formaton

4 Disk truncaton Ram pressure stripping (Chevarlier 2000, Wijnen & 2016,...) Dynamical interactons (Breslau+ 2014, Vincke+ 2015, Portegies Zwart 2016,...) ESO NASA/ESA External photoevaporaton (Fang+ 2012, Facchini+ 2016, Guarcello ) NASA/JPL-Caltech/Z. Balog (Univ. of Ariz./Univ. of Szeged)

5 Physical processes Viscous evoluton of the disks Truncatons due to close encounters External photoevaporaton Ram pressure stripping Stellar feedback from winds and/or supernovae

6 Physical processes Viscous evoluton of the disks Truncatons due to close encounters External photoevaporaton Ram pressure stripping Stellar feedback from winds and/or supernovae

7 Model

8 Viscous growth of disks Based of the similarity solutons of Lynden-Bell and Pringle (1974) and Hartmann et al (1998) 1. Disk characteristc radius, inside which of the disk mass originally resides 2. Disk mass 3. Accreton rate onto central star

9 Viscous growth of disks Viscous tmescale: Viscosity: : radial viscosity dependence : turbulence parameter : isothermal soundspeed : keplerian frequency

10 Viscous growth of disks Viscous tmescale: Viscosity: : radial viscosity dependence : turbulence parameter : isothermal soundspeed : keplerian frequency

11 Viscous growth of disks Assumptons (from observatons): (Hartmann+ 1998, Sicilia-Aguilar 2010, Antoniucci+ 2014,...) (Isella+ 2009, Andrews+ 2010, Mulders & Dominik 2012,...)

12 Viscous tmescales

13 Viscous growth of disks Assumptons (from observatons): (Hartmann+ 1998, Sicilia-Aguilar 2010, Antoniucci+ 2014,...) (Isella+ 2009, Andrews+ 2010, Mulders & Dominik 2012,...) fast slow

14 Disk propertes inital Inital characteristc radius: Inital disk mass:

15 Disk propertes afer truncaton Truncaton radius: Disk mass afer encounter: New viscous tmescale:

16 Cluster inital conditons ph4 for star cluster simulatons 1500 stars Kroupa inital mass distributon, Plummer sphere distributon, Evolved for No gas, constant gas, gas expulsion at

17 Disk size afer 2 Myr Concha-Ramírez, Vaher, Portegies Zwart 2018 (subm.)

18 Disk mass afer 2 Myr Concha-Ramírez, Vaher, Portegies Zwart 2018 (subm.)

19 Accreton rate afer 2 Myr Concha-Ramírez, Vaher, Portegies Zwart 2018 (subm.)

20 Validatng the model Ansdell+ 2016

21 Comparison with observatons Disk size, disk mass, and accreton rate data available for diferent star forming regions Caveat: gas vs dust disks

22 Comparison with observatons Sets of simulatons For each observed region, chose sets where Performed Kolmogorov Smirnov test to fnd

23 Disk sizes Trapezium (dust): Vicente & Alves 2005 Lupus clouds (gas): Ansdell Orionis (dust): Maucó Upper Scorpio (gas): Barenfeld Chamaeleon I (dust): Pascucci Concha-Ramírez, Vaher, Portegies Zwart 2018 (subm.)

24 Disk masses Trapezium (dust): Mann & Williams 2009 Lupus clouds (dust): Ansdell Orionis (dust): Ansdell Upper Scorpio (dust): Barenfeld Chamaeleon I (dust): Mulders Concha-Ramírez, Vaher, Portegies Zwart 2018 (subm.)

25 Accreton rates Trapezium: Robberto Lupus clouds: Alcalá Orionis: Maucó Chamaeleon I: Manara Concha-Ramírez, Vaher, Portegies Zwart 2018 (subm.)

26 Results Simulaton results within observatonal ranges Observatonal values are under and overestmated by simulaton results

27 Why? More physical processes needed in simulatons Inital conditons not representatve of observed star forming regions Observatonal data is not homogeneously defned

28 Why? More physical processes needed in simulatons Inital conditons not representatve of observed star forming regions Observatonal data is not homogeneously defned

29 The viscous evoluton of circumstellar disks in young star clusters Francisca Concha-Ramírez Leiden Observatory MODEST18 Firá, Greece 28 June 2018

30 Viscous growth of disks Based of the similarity solutons of Lynden-Bell and Pringle (1974) and Hartmann et al (1998) 1. : radial viscosity dependence exponent 2. : inital disk mass 3. : inital characteristc disk radius, inside which of the mass initally resides 4. : viscous tme scale at R c (0)

31 Viscous growth of disks Disk characteristc radius: Disk mass in tme: Accreton rate:

32 Viscous growth of disks Surface density: Accreton rate onto central star:

33 Viscous growth of disks Viscous tmescale: Viscosity:

34 Gas in the cluster No gas Constant gas Gas expulsion: with, is the gas expulsion onset, and

35