Keplerian  Disk  形成に至るまでの  原始星エンベロープの進化  の観測的描像	

高桑繁久	 (ASIAA)

基調論文	
[1]  Yen,  Hsi-­‐‑Wei;  Takakuwa,  Shigehisa;  Ohashi,  Nagayoshi;  Ho,  Paul  T.  P.,  2013,	
``Unveiling  the  Evolutionary  Sequence  from  Infalling  Envelopes  to  Keplerian  Disks  around  Low-­‐‑mass  Protostars’’,  ApJ,  772,  22	[2]  Takakuwa,  Shigehisa;  Saito,  Masao;  Lim,  Jeremy;  Saigo,  Kazuya;  Sridharan,  T.  
K.;  Patel,  Nimesh  A.,  2012,	
``A  Keplerian  Circumbinary  Disk  around  the  Protostellar  System  L1551  NE’’,	
ApJ,  754,  52	[3]  Takakuwa,  Shigehisa;  Saito,  Masao;  Lim,  Jeremy;  Saigo,  Kazuya,  2013,``Evidence  for  Infalling  Gas  of  Low  Angular  Momentum  towards	
the  L1551  NE  Keplerian  Circumbinary  Disk’’,  ApJ,  in  press			

これらの論文の共著者のみなさま＝本講演の共同研究者	

0.  Introduction	
Keplerian Disk:�
Class II (T Tauri) Stars では�
普遍的に観測.�
�
惑星系形成の母体�
 ̀̀Protoplanetary Diskʼʼ��Outer Radii ˜ 100 – 800 AU�
Disk Mass ˜ 0.0001 – 0.1 M�

Simon,  Dutrey,  &  Guilloteau  2001	

最近の観測では	 Class  I  においても  Keplerian  Disk  が見つかってきている	• Class I protostars(L1551 NE, IRS 63, Elias 29, IRS 43…)
Outer Radii ~ 100 – 300 AU• Keplerian  disks  around  Disk Mass ~ 0.004 – 0.06 M
Class  0/I  protostars  • Class 0 protostars
No unambiguous detectionof Keplerian disks

B59#11  Rd  <  350  AU    (Hara  et  al.  2013)  L1527  IRS  Rd  <  90  AU    (Tobin  et  al.  2012)	

Keplerian  Disk  の形成は  Class  0    I  の間で起こる	

Keplerian  Disk  は原始星エンベロープから  どのように形成されるのか？  –  理論	• 磁場なし�
エンベロープのガスが角運動量を保存して重力収縮、��遠心力が釣り合う半径で Keplerian Disk 形成�
(e.g.,  Terebey  et  al.  1984;  Basu  1998)	
�• 磁場あり��̀̀magnetic brakingʼʼ が角運動量を抜く� 大きな (> 10 AU) の Keplerian Disk はできない�(Mellon  &  Li  2008,  2009;  Li  et  al.  2011;  Dapp  et  al.  2012)	

 あるいは円盤の質量が中心星の質量より重い�(Machida  et  al.  2011a,  b)  	Keplerian  Disk  形成過程の観測的研究	
1. Early Class 0 から Late Class I 原始星までの100 – 1000 AU スケールのエンベロープの回転運動の観測(基調論文[1])2. エンベロープからKeplerian Disk への遷移を直接観測(基調論文[2],[3])1. Early Class 0 から Late Class I 原始星までの100 – 1000 AU スケールのエンベロープの回転運動の観測	
Source	Class	

Lbol  (L)	

Tbol  (K)	D  (pc)	

Region	B335	

0	

1.5  	31	150	

Isolated	

NGC  1333  IRAS  4B	

0	

1.6	

54	

250	

Perseus	

L1448-­‐‑mm	

0	7.5	

69	250	

Perseus	

L1527  IRS	

0/I	

2.8	

59	

140	

Taurus	

TMC-­‐‑1A	I	

2.4	

172	

140	

Taurus	

L1489  IRS	

I	

3.7	

238	

140	

Taurus	• Known  inclination  angles,  position  angles  of  outﬂows,  protostellar  envelopes,  and  large-­‐‑scale  rotation	

SMA observations with the compact and subcompact configurationsin the C18O (2-1) line (θ ~ 3”-8” & ΔV ~ 0.1-0.3 km s-1)

SMA  C18O  (2-­‐‑1)  Survey	

Contour:  total  integrated  intensity  Color:  mean  velocity  	L1448-mm
B335 (Class 0)

L1489
L1527 IRS (Class 0/I)

TMC-1A (Class I)

500 AU
500 AU

500 AU

TMC-1ANGC 1333 4B (Class 0)

L1448-mm (Class 0)

L1489 IRS (Class I)
500 AU

500 AU
1000 AU

500 AU

Velocity  gradient  perpendicular  to  the  outﬂow  direction	
Less  clear	

Clear	

θ  ~  3”-­‐‑5”  dV  ~  0.3  km  s-­‐‑1	

SMA  C18O  (2-­‐‑1)  Survey	
•P-­‐‑Vs  perpendicular  to  the  outﬂow  directions	

B335  (Class  0)	L1527  IRS  (Class  0/I)	

TMC-­‐‑1A  (Class  I)	IRAS  4B  (Class  0)	L1448-­‐‑mm  (Class  0)	L1489  IRS  (Class  I)	Velocity  gradient  perpendicular  to  the  outﬂow  direction	
Less  clear	

Clear	

Rotational  Proﬁles	
p=-1.02p=-0.62+/- 0.14+/- 0.07

COM  +  SUB	L1448-mm

L1527 IRS

TMC-1A
p=-1.02p=-0.49+/- 0.17+/- 0.05

L1489 IRS

Rotational  Proﬁles	p=-1.02

p=-0.62+/- 0.14+/- 0.07

COM  +  SUB	L1448-mm

TMC-1A
p=-1.02p=-0.49+/- 0.17+/- 0.05

L1527 IRS

Less  evolved	
• Slower  rotation  with  a  conserved  angular  momentum  in  an  infalling  envelope  	L1489 IRS

More  evolved	

• Keplerian  rotation  with  higher  rotational  velocities	Three  Categories  of  Envelope  Kinematics	
Class  0	Class  I	
IRS 63

HH 211Elias 29

HH 111
HH 212
L1551 IRS5

L1489 IRS
TMC-1A
B335	
L1448-mm
IRAS  4B	L1527 IRS

B335	IRAS  4B	HH 211

L1157

Detection  limit  of  the  SMA  observations	Three  Categories  of  Envelope  Kinematics	
Class  0	Class  I	
IRS 63

HH 211Elias 29

HH 111
HH 212
L1551 IRS5

L1489 IRS
TMC-1A
L1448-mm
L1527 IRS

B335	
IRAS  4B	(1)  Class  0  	Infalling  motion  without  clear  rotational  motion  (e.g.,  B335  &  IRAS  4B)	HH 211

L1157

Three  Categories  of  Envelope  Kinematics	
Class  0	Class  I	IRS 63

HH 211Elias 29

HH 111
HH 212
L1551 IRS5

L1489 IRS
TMC-1A
L1448-mm
L1527 IRS

B335	
IRAS  4B	(1)  Class  0  	Infalling  motion  without  clear  rotational  motion  (e.g.,  B335  &  IRAS  4B)	HH 211

L1157(2)  Class  0  and  I	
Infalling  and  rotating  motions	r  -­‐‑1  rotation  	(e.g.,  L1527  IRS,  L1448-­‐‑mm,  L1551  IRS,  HH  212…)	

Three  Categories  of  Envelope  Kinematics	
Class  0	Class  I	(3)  Class  I	
Keplerian  rotation	
(e.g.,  TMC-­‐‑1A,  L1489  IRS,  IRS  63,  L1551  NE,  HH111…)	

IRS 63
HH 211Elias 29

HH 111
HH 212
L1551 IRS5

L1489 IRS
TMC-1AL1448-mm
L1527 IRS

B335	
IRAS  4B	(1)  Class  0  	Infalling  motion  without  clear  rotational  motion  (e.g.,  B335  &  IRAS  4B)	HH 211

L1157(2)  Class  0  and  I	
Infalling  and  rotating  motions	r  -­‐‑1  rotation  	(e.g.,  L1527  IRS,  L1448-­‐‑mm,  L1551  IRS,  HH  212…)	

Possible  Interpretation  of    the  Three  Categories  of  Envelope  Kinematics	
Assumption:	

Empirical  radial  proﬁle:      Increasing  angular  momenta  as  radii  increase	 e.g.,  NH   cores	3(Goodman+  93)	j	r	

Rigid-body rotation: w ~ 6.5 x 10-14 s-1	Inside-­‐‑out  collapse  of  a  singular  isothermal  (10  K)  unmagnetized  dense  core  where  the  angular  momentum  is  conserved	

Early  Collapse  Stage	

Expansion  wave	

j	Expansion  wave	r	• LiEle  amount  of  angular  momenta  is  carried  toward  the  inner  region  by  infalling  material    slow  rotation	

Later  Collapse  Stage	

Expansion  wave	

j	

Expansion  wave	r	• More  angular  momenta  are  carried  toward  the  inner  region  by  infalling  material    increase  rotation  velocities	Evolution  of  Rotational  Proﬁles	
radius M(r) is given by
2cwhere cs is the sound speed (Shu 1977). The enclosed mass as a function ofs2M(r)= massr. as a function of(4.4)
where cs is the sound speed (Shu 1977). The
enclosedGradius M(r) Theis given
by distribution of the specific angular momenta j(r) is
initial2cs 2M(r) =(4.4)
Local of the expansion
waveG(cr.sj(r)*t)= ωr2,(4.5)
The initial distribution of the specific angular momenta j(r) is amountof angular momentum has been carried
where ω is the angular velocity of the rigid-body rotation. On the assumptionj(r) = ωr 2,(4.5)
into the centralregion.
that the angularmomentum is conserved during the collapse, the Keplerian

Inside-out collapse model•(rdvelocity) of eachofmass
shell initiallyat a radiusr can be expressed as,
ω is theradiusangularthe rigid-bodyrotation.
On theofassumption• whereConstantmass
infalling
rate
that the angular momentum is conserved during
collapse, the Keplerianj(r)2 theGM(r)=.
(4.6)
Mass of the central protostar+disksystem
2rd 3radius (r ) of each mass shell initially at a radiusof rrdcan be expressed as,
dof the specific angular momentum becomes constant asymptotically toward
On the assumptionof2the GM(r)steady mass accretion (≡ Ṁ ), the Keplerian radiusj(r)the inner radii (see3 Figure
2 in .Terebey et al. 1984), and the=(4.6)rotational profile
as a function of timerd t can berd 2derived from Equation 4.6 asof the infalling material becomes Vrot ∝ r −1 as derived from Equation 4.1 and3
2
On the assumption of the steady massaccretion
Ṁ ), theKeplerianω 2(≡G3 M(r)
ω 2G3 Ṁ 3 radiusj(r)= profile as=t3 . can be described(4.7)= rotational
4.2. Therefore,rdthe
a functionof time
88GM(r)16cs 4.6 as 16cs
as a function of time t can be derived
from Equationas! 3 et al.2
This is thej(r)solutionby2
3 r 3−0.5 Basu et al. (1998) performed
2 Terebey3
ω G M(r)ωG(1984).
Ṁ) 3 r ≤ rd(GṀ
trd t .
==(4.7) ,rd =8 initial×rotation
8= the(4.8)
the same calculation
withof a constant velocity,and theirGM(r) Vrot (r)16c16css2rd
( r )−1.0 rd ≤ r < rinfall
rdsolutionby
is rTerebey
4.7 implies
a central
protostar + diskd ∝ t. Equation
This is the solution
et al. (1984).
Basu that
etal.when(1998)
performed
whereincreases
rd is evaluatedbytoEquation
4.7 aandrinfallis theoflocationof thesystem
its massM(r)timeinterval
t = M(r)/Ṁ ,expanthe
the same calculation
withthe initialrotationof aafter
constant
velocity,
and theirsion wave(= catt; aShu
1977).
that the andmaterial
locatedcloser moto theinitially
radiusof whenr Notehasacollapsed
carriedan angularsolution is rdmaterial∝ t. Equation
4.7s implies
thatcentral protostar+ diskpolar axis
possesses athesmaller angularand theofcalculated
rotamentumof j(r)themomentum,rotational
velocity
system increases
its mass
to towardM(r) after center,a time andintervalof t = M(r)/Ṁ , the the material
tionalitsprofile
is applied
to theplane. that
Alsothenotereaches
Keplerianvelocity
at amaterial
radiusofonrd .theOnequatorial
the assumption
material initiallyat a radiusof r hascollapsedand carriedanangular
mo-Keplerian radius & rotational profile as function of time

Evolution  of  Rotational  Proﬁles	
L1489 IRS
TMC-1A
L1448-mm
L1527 IRS
1e6 yr5e5 yr

2.5e5 yr

1.5e5 yr

B335	
IRAS  4B	

1e5 yr
5e4 yr

Detection  limit  of  the  SMA  observations	Caveat:  actual  time  scales  depend  on  initial  conditions.	

Evolution  of  Rotational  Proﬁles	
L1489 IRS
TMC-1AL1448-mm
L1527 IRS
1e6 yr5e5 yr

2.5e5 yr

1.5e5 yr

B335	
IRAS  4B	

1e5 yr
5e4 yr

At  t  <  5  x  104  yr,    slow  rotation  that  cannot  be  detected.	
Caveat:  actual  time  scales  depend  on  initial  conditions.	

Evolution  of  Rotational  Proﬁles	
L1489 IRS
TMC-1A
L1448-mm
L1527 IRS
1e6 yr5e5 yr

2.5e5 yr

1.5e5 yr

B335	
IRAS  4B	

1e5 yr
5e4 yr

At  t  <  5  x  104  yr,    slow  rotation  that  cannot  be  detected.	

At  t  ~  1.5  x  105  yr,    faster  rotation  with  r  -­‐‑1  proﬁles	

Caveat:  actual  time  scales  depend  on  initial  conditions.	

Evolution  of  Rotational  Proﬁles	
At  t  >  5  x  105  yr,    L1489 IRS
TMC-1Alarge-­‐‑scale  Keplerian  rotation	
L1448-mm
L1527 IRS
1e6 yr5e5 yr

2.5e5 yr

1.5e5 yr

B335	
IRAS  4B	

1e5 yr
5e4 yr

At  t  <  5  x  104  yr,    slow  rotation  that  cannot  be  detected.	

At  t  ~  1.5  x  105  yr,    faster  rotation  with  r  -­‐‑1  proﬁles	

Caveat:  actual  time  scales  depend  on  initial  conditions.	

まとめ:  原始星エンベロープの  100  –  1000  AU  スケールでの回転運動の進化	
• ３つの分類分け(1) Class 0 (e.g., B335 & IRAS 4B)
infalling motion with little rotational rotation(2) Class 0-I (e.g., L1527 IRS & L1448-mm)
infalling and rotating motions (r -1 rotation)(3) Class I (e.g., TMC-1A & L1489 IRS)
large-scale Keplerian rotation (r -0.5 rotation)• 角運動量保存のinside-out collapse + 剛体回転的
初期角運動量分布で再現可能回転速度の増大	

2. エンベロープからKeplerian Disk への遷移を直接観測
観測天体  L1551  NE	Tbol  ~91  K,  Lbol  ~  4.2  Lsun	
エンベロープの質量  ~0.39  Msun	
(Moriarty-­‐‑Schieven+  2006)	

Class  I  Binary  System	

Close  (~  70  AU)	protostellar  binary	

VLA  3.6  cm;	Reipurth  et  al.  2002	

SMA  Observations  of  L1551  NE	in  0.9-­‐‑mm  Continuum  and	
C18O  (3-­‐‑2)  Emission	

Fe  II  Jet  Driven	
by  Source  A	

L1551  NE	Hayashi  &  Pyo  2009	

70 AU700.9-­‐‑mm  Continuum	
70  AU	70  AU	

Compact  Component	
associated  with  Source  A	
(0.9”  x  0.5”,  0.7  Jy)	+  Protrusion  to  Source  B		
+  North  and  South  Comp.	
Rim-­‐‑Brightening	Circumbinary  Disk  +	Circumstellar  Disks		Total  Mass  ~  0.046  Msolar	Right  ascension  (J2000)	

C18O  (3-­‐‑2)	
Moment 0 map"

High velocity

280 AU

Right ascension (J2000.0)

Declination (J2000.0)

Declination (J2000.0)-2.59 ~ -0.37 km s-1+0.74 ~ +2.96 km s-1

Low velocity-0.37 ~ +0.0 km s-1+0.0 ~ +0.74 km s-1~800 AU scale, elongated"circumbinary feature"
Right ascension (J2000.0)@High-Velocity  North-South Vel. Grad., along the major axis"@Low-Velocity  Redshifted Emission to the North too"Low-­‐‑Velocity  C18O  (3-­‐‑2)  Channel  Maps  with  the  SMA  compact  and  subcompact  conﬁg.	

Declination (J2000.0)

Vsys~  6.9  km  s-­‐‑1	

Right ascension (J2000.0)@Low-Velocity East-West 速度勾配、短軸方向�
High, Low-Velocity 成分で速度勾配の方向が垂直、�それぞれ異なったガスの運動	χ2  model  ﬁving  to  the  High-­‐‑Velocity  Components    Keplerian  Circumbinary  Disk          with  (M*,  i,  θ)  =  (0.8  Msolar,  -­‐‑62°,  167°)  Obs.

Obs	  	.

ResModel	odelM.

Res	Contours	in  steps  of  2σ	Right  ascension  (J2000.0)	

See Takakuwa et al. (2012) for details."

Obs

Low-­‐‑Velocity  成分    Infalling  Gas  toward  the  Keplerian  Circumbinary  disk  ??	

Observed & Model P-Vs along the major and minor axes"
Observations

Keplerian Only Model

Infall --> Keplerian Model

Major

Keplerian-only model cannot"
explain the vel. grad. along the"minor axis, nor the northern"redshifted component."

4Position (arcsec)

2-2

Infalling ``ringʼʼ component,"
rkep ~300 AU"
vinf ~0.6 km s-1"
No rotation"-44Minor

2-2-4468468LSR Velocity (km s-1)

468

議論:  Low-­‐‑Velocity  成分の	 Infalling  Motion	
短軸方向の速度勾配	 infall  速度  ~0.6  km  s-­‐‑1  @半径=  300  AU	Keplerian  Disk  から出した中心星の質量	 =  0.8  Msolar	  @半径	 =  300  AU,  Free-­‐‑fall  速度は  2.2  km  s-­‐‑1  	Infall  速度が	 Keplerian  Disk  に向かって減速している？？	
Low-­‐‑Velocity  Infall  成分では回転がみえない	r-­‐‑1  で内側の	 Keplerian  Disk  とつなごうとすると、	低速度の北側  Red  成分を説明できない		
急激に角運動量の輸送が変わっている？？		

Machida  et  al.  2011	

Keplerian  Disk  の内外でのプラズマ  β  =  8  pi  P  /  B2  の違い？	
Diﬀuse  Infall  成分  magnetic  braking  が効いている？		

まとめ:  L1551  NE  における  SMA  観測	
• 0.9-mm Continuum Circumbinary Disk + Circumstellar Disks• C18O (3-2) 高速度成分は半径 ~300 AU, 中心星 0.8 Msun の	 
Keplerian Circumbinary Disk
• 低速度成分は	 infall ~0.6 km s-1(<< free-fall 速度 = 2.2 km s-1)、
無回転で Disk に落ち込むガス Infalling 速度の減速？
 Magnetic braking がこの成分のみ効いている？

本講演のまとめ:  円盤形成の観測的研究の現況	
• Class I 天体での	 Keplerian Disk は普遍的になりつつある エンベロープに埋もれた Class 0  I の段階で円盤形成• 原始星の進化段階に沿ったエンベロープの回転速度、回転則の系統的な進化も見えてきている• 一天体内での	 Infall  Keplerian Disk の遷移もみえつつある 今後の観測のメインの課題
これらを説明するモデルをつくってほしい	

Machida  v.s.  Li  ??	
どっちが正しいのか教えて欲しい。
私、双方から話を聞いているので。。。。。