Acknowledge:

Main Collaboratorsb) molecular cloud (gas and dust)c) dense cloud core星形成初期における円盤形成a) diffuse atomic cloudf) matured system(star and planetary system)d) protostar, protostellarenvelope/disk, and outflow/jete) protostar and protpplanetary disk

1/43
1/31

坂井南美(理化学研究所)

Disk
Disk: a flat, circular object
・Flattened structure?

→Could be “envelope” (Needs kinematics!)(→rotationallyor not??)
A disk is a flat,
circularsupported
device thathas a(→Pseudoor not?)magnetic coveringandis used forstoring
information
・”Kepler”motion?
→With infall or w/o ?
(→ Circular or elliptical orbit?)・(Mostly) circular orbit with Keplerian rotation≡“Keplerian disk”, “Rotationally supported disk”
2/31

Physical Evolution
ProtoplanetaryDisk

Protostellar
Envelope/Disk

Protostellar Core

Planetary System(Courtesy of JAXA)Class 0Class IClass II, Class III

When & how the “disk” is formed?
C → COConversion

CODepletion

MantleEvaporation?

Carbon Chains
N-Species
D-Species
Saturated COMs
3/31

Chemical Evolution

Chemical diversity in disks?

?

How to Find the “Disk Edge”?
L1527
Class 0
TaurusEdge-onInfant Disk

13CO J=2-1 (CARMA)

Beam:150x130 au
Disk size: ~90 au?
(Tobin et al. 2012, Natur, 492, 83)

C18O J=2-1 (ALMAc0)
Beam:130x100 au
Disk size: ~54 au?
(Ohashi et al. 2014, ApJ, 796, 131)

Disk size: ~74 au(Aso et al. 2017, ApJ, 849, 56)

C18O J=2-1 (ALMAc1)
Beam:82x69 au
Disk size: <200 au
4/31(Tuan-Anh et al. 2016, MNRAS, 465, 3563)

How to Find the “Disk Edge”?
L1527
Class 0
TaurusEdge-on
Infant Disk

(Ohashi et al. 2014, ApJ, 796, 131)

Centrifugal Barrier

5/31(Sakai et al. 2014, Nature, 507, 78)

First Identification of the “Centrifugal Barrier”(Sakai et al. 2014, Nature, 507, 78)

・First identification of centrifugal barrier (CB)
(Drastic chemical change at rCB=100 au)

・CB& is theinterface
betweenenvelope& diskxy
Parameter:
M, L/mAngular momentum
Vobserved = Vrot + Vinfall(e.g. Oya+2016, Oya+2017a,r Sakai+2017a)renergy conservation@Centrifugal barrier(CB)x of Chemistry!
PowerAll the kinetic energy is used for rot. motion
m 2GMm2y★
V +V=2(rotinfall)

mrVrot = L

6/31r

V =  L  1 , rot  m  r
Vinfall =2GM2 − Vrotr
rCB = 100±20 AU, M(star+disk) = 0.18±0.02 Mʘ

Identification of the “Centrifugal Barrier”

Toy model for the Infalling rotating enveloperCB L 1Vrot =  mr
Vinfall =2GM2− Vrotr

“Envelope” here means rCB<r<500-1,000
au~VrVθ

1 L
rCB = 2GM  m 2rCB, M → L/m →Vrot(r), Vinfall(r)

7/31
7/31

Assumed:i =5°, d =137 pc, beam size(for each line),
linewidth of 0.5 km/s, density profile r -1.5,
rout=1000 AU, thickness=20 AU(Sakai et al. 2014, ApJ, 791, L38)
(Oya et al. 2014, ApJ, 795, 152)
(Oya et al. 2015, ApJ, 812, 59)

Predictions by Stahler et al. 1994

Radial (z=0) motion/shock is not considered.
8/31(e.g. Stahler, S. W. et al. 1994, ApJ, 431, 341; Stahler, S. W. and Palla, F. 2004, The Formation of Stars)

Resolving Transition Zone: L1527

from Infalling-Rotating Envelope to Rotationally-Supported DiskCCH(Env.), SO(CB), CS(Outflow+Env.), H2CO(All)Beam:18x35 au, 25x40 au

Broadening

CentrifugalRadius(r~200 au)
Centrifugal
Barrier(r~100 au)

Snow line

Frozen Out(T~30 K)

SO (T~100 K)
CCH, c-C3H2, CS(T~20-30 K)
CCH, c-C3H2, CS

9/31(Sakai, N. et al. 2017, MNRAS, 467, L76)

(Sakai et al. 2014, ApJ, 791, L38)
(Oya et al. 2015, ApJ, 812, 59)(CS)

Broadening

Infalling
Rotating
Envelope

Class I WCCC: TMC-1A
TMC-1A

CS(envelope)

infalling effectCS(outflow)

Velocity gradient→ infalling envelope

Infalling
motion continues to R~50 AU
10/31

L1527

Similar velocity structure
to the L1527 case

(Sakai+2014, ApJL, 791, L38; Sakai+2016, ApJL, 820, L34)

(Oya et al. 2016, ApJ, 824, 88)

Hot Corino: IRAS16293-2422A
Envelope

・ OCS (19-18)

Disk

Centrifugal
Barrier

Infalling-rotating envelope(Rout(OCS) = 180 AU)

・ CH3OH (110,11-101,10; A++)

Envelope Model

Disk

Rotating around CB(Rout(OCS) = 80 AU)

Envelope

・ HCOOCH3 (199,19-198,11; E)

All

Rotating around CB(Rout(OCS) = 55 AU)

RingRing

Envelope

I16293A・ H2CS (70,7-60,6)

Infalling-rotating envelope(Rout(OCS) = 150 AU)+ High velocity component

Tk : derived from H2CS (k=0,2) lines

M = 0.75 M⦿, rCB = 50 AU, i = 30º (Rout(OCS) = 180 AU)
H2COSOn (H2) = 107-109 cm-3
N (H2CS) = 1013-1015 cm-2
EnvelopeCBDiskRed

70-110110-140

70-90

Blue

70-110100-13070-120 (K)

11/31

L1527

・Edge of the disk is highlighted by chemical change
・At least two different chemical environments are recognizedCharacterized by unsaturated species(ex: L1527)

Characterized by saturated species(ex: IRAS16293-2422A/B)

Low-velocity outflow
Disk wind

Carbon-chain molecules

OCS
Saturated COMs

SO

H2CS

H2CO

protostardisk
centrifugal barrier gas stagnation
centrifugal radius

12/31(high temperature)
infalling gas(low temperature)(e.g. Sakai et al. 2014, Nature 507, 78; 2014, ApJ, 791, L38; 2017, MNRAS, 467, L76;
Oya et al. 2016, ApJ, 824, 88; 2018, ApJ, 854, 96)

Identification of Centrifugal Barrier
in Various Sources

Assumption: At the centrifugal barrier (rCB),all the kinetic energy is used for rot. motion→M (star+inner-disk) and j (=L/m) can be determined

2𝐺𝑀𝑗𝑗2𝑟𝐶𝐵 =2𝐺𝑀

L1527

IRAS
15398

IRAS 16293A/B

TMC-1A

L483

B335

HH212

NGC1333
IRAS4C

Evolutional
Stage

Class 0/I

Class 0/I

Class 0 binary

Class IClass 0Class 0Class IClass 0ChemicalComposition

WCCC

WCCC

Hot Corino

WCCC

WCCC+ HC

HC+WCCC

HC?

WCCC?

i (edge-on: 90º)

85º

70º

~ 60º/ ~5º~ 70º~ 40º~90º?

96°

75°-85°

M* [M⦿]0.18

0.007?

0.75 / 0.4

0.25

0.3

~0.02-0.06

0.250.2rCB [au]10040?

50 / 405050<544~50? (<140)

7.2

7.9--small--

76.3? (<10.5)

𝑚𝑎𝑥𝑉𝑟𝑜𝑡=Specific AngularMomentum: j[10-4 km/s･pc]

13/31

8.7
< 1.613 / 8.5
Sakai+ Oya+2014 A: Oya+2016
2014ab (Yen+2017) B: Oya+20182017 Okoda+2018

𝑗2cf; 𝑟𝐶𝑅(𝐹𝑔𝑟𝑎𝑣𝑖𝑡𝑦=𝐹𝑐𝑒𝑛𝑡𝑟𝑖𝑔𝑢𝑔𝑎𝑙 ) = 𝐺𝑀 = 2 𝑟𝐶𝐵(Composite)(Composite)

Sakai+ Oya+2017a (Yen+2015) Lee,C-F+2017 Zhang+2018
2016(Imai+2016) Podio+2015
Imai+2019 Codella+2018

8 sources: no clear trend → Importance of “environmental effect”.

Low-Velocity Outflow/Disk Wind・Drastic Chemical Change・Broadened Thickness
・Temporal T Rise⇔

Shock between rCB & rCR

Embedded sources:
During the infalling motion,
PDynamic > PStatic ≥ PMagnetic(e.g. Machida+2016)

Snow line

Infalling Gas(Low T, Mid n)

Disk Mid-plane(Low T, High n)
Gas-Stagnation(Weak-Shock: HighT , High n)

14/31

ex; @L1527
dVdyn~0.9 km/s
dVstat~Cs~0.2 km/s

→ Gas can go beyond therCR (= 2 x rCB).
AM extraction throughB-field would not beso effective until the gasgetting close to the CB.

BHB07-11(B59)
TMC-1A

NGC1333 IRAS4C(See Postar #98)

rfootpoint~5-15 au(Zhang, Y. et al. 2018, ApJ, 864, 76)rfootpoint~25 au(Bjerkeli et al. 2016, Nature, 540, 406)

AM extraction around & inside RCB→ disk wind &/or narrow-range-flow?
“How it is extracted?”→ stable disk-system
or unstable system....?
15/31

rfootpoint~90-130 au(Alves, F. O. et al. 2017, A&A, 603, L3)

B335: A Small Disk or No Disk?

100 aurCB<5 au, Mstar~0.04 M.

50 au(Imai et al. 2019, ApJ, 873, L21)

(Imai et al. 2016, ApJ, 830, L37)

rdisk < 10 au(Yen et al. 2015, ApJ, 812, 129)

Mdisk~7.5x10-4 M.

(Evans et al. 2015, ApJ, 814, 22)
16/31

Centrifugal barrier would be the key: Ring -> Spiral arms-> Fragmentation -> Binary/Triplet/Giant-Planets(Zhao, B. et al. 2017, MNRAS, 473, 4868)

17/31

Identification of Centrifugal Barrier
in Various Sources

Assumption: At the centrifugal barrier (rCB),
all the kinetic energy is used for rot. motion→M (star+inner-disk) and j (=L/m) can be determined

2𝐺𝑀𝑗𝑗2𝑟𝐶𝐵 =2𝐺𝑀

L1527

IRAS
15398

IRAS 16293A/B

TMC-1A

L483

B335

HH212

NGC1333
IRAS4C

Evolutional
Stage

Class 0/I

Class 0/I

Class 0 binary

Class IClass 0Class 0Class IClass 0ChemicalComposition

WCCC

WCCC

Hot Corino

WCCC

WCCC+ HC

HC+WCCC

HC?

WCCC?

i (edge-on: 90º)

85º

70º

~ 60º/ ~5º

~ 70º

~ 40º

~90º?

96°

75°-85°

M* [M⦿]0.18

0.007?

0.75 / 0.4

0.25

0.3

~0.02-0.06

0.25

0.2

rCB [au]

10040?

50 / 405050<544~50? (<140)

7.2

7.9--small--

76.3? (<10.5)

𝑚𝑎𝑥
𝑉𝑟𝑜𝑡
=Specific AngularMomentum: j[10-4 km/s･pc]

18/31

8.7
< 1.613 / 8.5
Sakai+ Oya+2014 A: Oya+2016
2014ab (Yen+2017) B: Oya+20182017 Okoda+2018

𝑗2cf; 𝑟𝐶𝑅(𝐹𝑔𝑟𝑎𝑣𝑖𝑡𝑦=𝐹𝑐𝑒𝑛𝑡𝑟𝑖𝑔𝑢𝑔𝑎𝑙 ) = 𝐺𝑀 = 2 𝑟𝐶𝐵(Composite)(Composite)

Sakai+ Oya+2017a (Yen+2015) Lee,C-F+2017 Zhang+2018
2016(Imai+2016) Podio+2015
Imai+2018 Codella+2018

8 sources: no clear trend → Importance of “environmental effect”.

Volatile-Rings with Larger Radius
L1489 IRS (Taurus)
HH111 (Orion)

SO (56-45)
CH3OH Ring

SO Ring?

rCB~450 au ??
(Lee et al. 2016, ApJ, 826, 213)

G328.2551-0.5321
rCB~300 au ??
(Yen et al. 2014, ApJ, 793, 1)
19/31

Disk formation around a high-mass protostar?
rCB~300-800 au
M~11-16 M.
(Csengeri, T. et al. 2018, A&A, 617, A89)

High-Mass Cases:
How it looks?
G339.88-1.26

Outflow

Outflow

envelope/disk

rCB=530 au (dV~6 km/s)
M=11 M.
Innermost Disk: SiO
Centrifugal Barrier(Ring): H2S/SO2 (Clumpy)
Envelope→CB: CH3OH/H2CO (Clumpy)
20/31(Zhang, Y. et al. 2019, ApJ. 873, 73)

High-Mass Cases:
How it looks?

G16.59-0.05
CH3OH traces
inner rot-envelope & disk?
(Moscadelli, L. et al. 2019, A&A, 622, A206)

Massive binary source
IRAS07299-1651

H30α recombination line emission traces the disk kinematics!
21/31(Zhang, Y. et al. 2019, Natur. Astron. 3, 517)

Chemical Model Calc. for Acc. Shocks
Difference in Desorption Temperature
C < CO < SO < CH3OH, H2O,,,,

Dust size distribution: a-3.5
Main carrier~0.01um(Miura et al. 2017, ApJ, 839, 47)Dust(Main carrier)~0.1um(Aota et al. 2015, ApJ, 799, 141)
22/31

SO, CH3OH can be desorbed from dustby the “weak” accretion shocks inL1527 and IRAS16293, respectively

Disk Evolution
When & How Disk Substructures Are Formed?
Ring&Gaps?
Spirals?
Multiple-System or Giant-Planets?
Disk + Spirals?
Warped Structure?
When, Where, & How Dust-Growth Starts?

23/31

Vertical Structure of the Infant Disk
ALMA Cycle2 Band 7, Disk in L1527 Class 0 Protostar
0.9

Doubly Flared Disk?

Inflection Point !

24/31(Sakai, N. et al. 2017, MNRAS, 467, L76)Doubly-Flared Disk Structure ?
ALMA Cycle2

Doubly Flared Disk?

25/31

White Contours: 10σ x 100.25n
beam: 18x35 au

Centrifugal
BarrierWhite Contours: 10σ x 100.25n
beam: 22x36 au

Centrifugal
Barrier

Inflection Point !

(Sakai, N. et al. 2019 Nature, 565, 206)

Warp Structure Found in the Infant Disk

White Contours: 10σ x 100.25n
beam: 18x35 au

0.9 mm
CB3-5°tilt
1.3 mmWhite Contours: 10σ x 100.25n
beam: 22x36 au

26/31(Sakai, N. et al. 2019 Nature, 565, 206)

Spiral?
Far from us

NorthSouth5°inclination

NorthSouth

Close to us

No
27/31

40<r<60 au(transition?)

Kepler56 system ©NASA

28/31

Disk Formation around the Solar Type Protostar in L1527<2010
1000 au:
Before ALMA2014
100 au:ALMA Cycle 0

2017<50 au:Cycle 22019<30 au:Cycle 4Outerdisk
Innerdisk

Dust Growth
Spiral/Ring Structure

T ~ 10K
Density>105cm-3・ Depletion
・ Surface reactions
e.g. CO → CH3OH
Hydrogenationice(dust)surface
29/31

20K < T< 100K, Density>107cm-3
Surface reactions of heavy elements
cosmic ray induced UV
gas-phase reactions➔ Complex organic molecules

T>100 K, Evaporation
Gas-phase reactions

ice(dust)surface

dust surface(Sketch provided by Y. Aikawa)(Sakai+2010, ApJ, 722, 1633;+2014, Natur. 507, 78; +2014, ApJ, 791, L38; +2017, MNRAS, 467, L76; +2019, Natur.. 565, 206)

Disk Substructure Formation in Class 0 Stage

Preliminary data

30/31

(Nakatani, R. et al. 2019, submitted)

Key Issues to be Studied Further
・Role of Transition Zone (z-broadening point to rCB & rCB to rRSD)
How is it connected to low-velocity-outflow/disk-wind?
(@L1527 z-broadening~150 au rCB=100 au rRSD~80 au⇒Transition-Zone: 150>r >80 au)

・Relation to Magnetic Field

It can be wrapped around the CB. But, can we observe it?
*MHD Simulations & Ionization Degree....
Constant coupling ratio to gas/dust ×
Careful treatment of the ionization degree ○・Characterization of (Slow) Accretion through the RSD

Can the warped structure be remained or not?
(If yes, it could be one of the reason of misaligned orbit found in
exoplanetary systems....)・ Disk Substructure Formation could be Started in Class 0 Stage!
31/31