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