T H E D I S P E R S A L O F P L A N E T- F O R M I N G D I S C S

A N E W G E N E R AT I O N O F X - R AY P H O T O - E VA P O R AT I O N M O D E L S

G I O VA N N I P I C O G N A - L M U M U N I C H O S S E R VAT O R I O A S T R O N O M I C O D I R O M A - J U N E 2 7 T H , 2 0 1 8

C O L L A B O R AT O R S : - B A R B A R A E R C O L A N O - J A M E S O W E N - T O M M A S O G R A S S I - M I C H A E L W E B E R - L I S A W Ö L F E R - L Á S Z L Ó S ZŰC S - K R I S T I N A M O N S C H

1 . D I S C W I N D SD R I V E R S O F A N G U L A R M O M E N T U M A N D M A S S L O S S

D I S C E V O L U T I O N

Bai et al., 2016

Extract angular momentum

Mass-loss rate becomes greater than accretion rate after few Myr

D I S C D I S P E R S A L

2 . T R A N S I T I O N D I S K SB A S I C C O N C E P T S

• firstly defined observationally (Strom+, 1989)

• stars with significantly reduced NIR excess emission in their SED

• the fraction of protoplanetary discs that are Transition Discs is ∼13% (Luhman+, 2010)

Pascucci et al., 2010

D E F I N I T I O N

Type I - X-F(E)UV photoevaporation (i.e. see Elisabetta's talk)

• when photo-evaporation opens a gap in the disc, it removes it on a short time-scale the disc

F O R M AT I O N

Alexander et al., 2014

Type II - Planetary (binary) sculpting (i.e. Daniel Price's view )

• systems of 3–6 giant planets are needed, binary (misaligned) companion

F O R M AT I O N

planet sculpting

photoevaporation

D ATA S E T

3 . R E S E A R C H U N I TA TA S K F O R C E T O U N D E R S TA N D T D S

1. solid/gas evolution in discs (PI: Testi) 2. relation accretion rate/ X-ray activity (PI: Preibisch)

see next slide

1. trapping the dust in TDs (PI: Birnstiel) 2. dust entrainment in photo-evaporative winds (PI: Ercolano)

1. TDs and planetary systems (PI: Kley) 2. origin of non-axysimmetric features in TD (PI: Duellemond)

P L A N E T F O R M AT I O N W I T N E S S E S A N D P R O B E S : T R A N S I T I O N D I S C S

P R O J E C T B

1. radiation-hydrodynamics models of photo-evaporative discs + chemistry (PI: Ercolano)

2. astrochemistry in the atmospheres and winds of TDs (PI: Caselli)

TgasMOCASSIN

(Radiative Transfer)+ column density

NEW!

T E M P E R AT U R E

Picogna et al., in submission

PA R A M E T E R VA L U E

C O D EP L U T O

( M I G N O N E + 2 0 0 7 )

R A D I A L R A N G E 0 . 3 3 - 1 0 0 0 A U

V E R T I C A L R A N G E 0 . 0 0 5 - P I / 2

L O G ( L X )2 8 . 3 , 2 9 . 3 , 2 9 . 8 , 3 0 . 3 ,

3 1 . 3 , 3 1 . 8 E R G / S

I N N E R H O L E 0 , 4 . 6 , 1 4 . 1 , 2 1 . 2 , 3 0 . 3 A U

C A R B O N D E P L E T I O N C / 3 , C / 1 0 , C / 1 0 0

S TA R M A S S0 . 3 - 2 . 0 S O L A R

M A S S E S

PA R A M E T E R S PA C E

Disc without hole

density temperature radial velocity

R E S U LT S

Picogna et al., in submission

density temperature radial velocity

Disc with 15 AU hole

R E S U LT S

Picogna et al., in submission

Total Mass-loss rate is more than 2 times larger than in the old prescription: > 2*10^(-8) solar masses/year

NEW

OLD

W I N D P R O F I L E S

Picogna et al., in

submission

Cum

ulat

ive

Mas

s-lo

ss ra

te

X-ray luminosities

W I N D D E P E N D E N C E

Picogna et al., in submission

Cum

ulat

ive

Mas

s-lo

ss ra

te

Hole radius

W I N D D E P E N D E N C E

Picogna et al., in submission

4 . O B S E R VAT I O N A L C O N S T R A I N T S

O B S E R VA B L E S

MOCA

SSIN

(Radia

tive T

ransfe

r)

SPOCK

(1D viscous evolution)

Disc wind profiles

PLUTO Hydro simulations

Disc demographics

Synthetic line profiles

streamlines

OBSERVABLES

integrate

• we applied the wind profiles to a 1D viscous evolution code (SPOCK)

• we run a parameter space analysis finding the probability to observe a transition disc with a specific accretion rate and inner radius

Pro

bab

ility

[%]

ol

ne

log(R hole) [AU]

log

(Acc

retio

n Ra

te) [

Sun

mas

s/yr

]

Picogna et al., in submission

D I S C D E M O G R A P H I C S

new

old

[NeII] purple

[OI] yellow

Picogna et al., in submission

a

a

aa

a

a

z [A

U]

norm

. lin

e st

r.no

rm. l

ine

str.

velocity [km/s] velocity [km/s]

E M I S S I O N L I N E S

• Carbon and Oxygen seems to be depleted in the outer disc due to freez-out (Anna/Cecile's talk)

• C/3 extend the area affected by disc photoevaporation

ol

ne

log(R hole) [AU]

log

(Acc

retio

n Ra

te) [

Sun

mas

s/yr

]

Pro

bab

ility

[%]

sola

C/3 @ >15

Wölfer et al., in preparation

M E TA L D E P L E T I O N

solar

A N E W D ATA B A S E

Monsch et al., submitted

• there is not a clear cut between Transition Discs (TD) explainable by photo-evaporation and planet sculpting

• TDs contain a wide range of different protoplanetary discs not exaplainable by a single model

• new improved models predict a higher mass loss rate

• this database of hydro models will be the backbone for our Research Unit on TDs

• stay tuned (more info at transitiondiscs.com)

C O N C L U S I O N S