CO/H2 ABUNDANCE RATIO ≈ 10−4 IN A PROTOPLANETARY DISKFrance et al., ApJ
目的：円盤でのCO/H2 ratio を求めたい
手法：HSTのCosmic Origins Spectrograph(COS)を使ってfar-UVでH2, COを観測する
今回の天体：RW Aur (K型原始星の連星, primary: 1.1-1.4Msun, secondary: 30-50%重い)
近赤超過から円盤はあると思われていて円盤質量は電波で4×10^(-3)Msun
今回の観測：HST, 波長帯は1064–1130 Å, resolutionはR>10^4 (=波長分解能0.1Å以下)
結果：
中心星付近の降着領域、円盤、アウトフローという多成分でできていそう(速度で分離)モデリングの結果、基本的に円盤上層部からの放射である。
この円盤表層（暖かい）では、H2の面密度は19.9 cm^-2 (Trot=440K),molecular fraction>0.47 COの面密度は16.1 cm^-2 (Trot=440K)
fractional abundance: CO/H2 = 1.6 * 10^-4 : 星間物質とほとんど同じ→余り化学変化がおきていない？(warm layerでは)

The Astrophysical Journal, 794:160 (12pp), 2014 October 20

Table 1RW Aur A H2 Parametersa

H2

J =1

!!
=2
J
<20.25+0.05
−0.21
!!
J =3
19.90+0.33
!!
−0.22
J =4
!!
16.1+0.3
J =5−0.5France et al.

20

10

20

!!

>0.24

18.76 ± 0.17
−5>3.717.61
× 10± 0.42
16.69 ± 0.20...
14.81 ± 0.12!!

N(J)/gJ (cm−2)

Hi

!!

J =0
log10 N(X)!!

France et al.

30−1
in the protoplanetary J"=0
disk around the bClassicalT Tauri Star
=
4
km
s
J"=1
10
log10 N(H2 , v = 0, J )RW Aurigae A. 18We have J"=3
demonstrated
use of a newly
fCOVthe= 0.9740J"=41019.13 ± 0.14acommissioned
observingmodeof the
HST to detect warm H2
N(X)/N(H
total )
1100
1150
1200
1250
1300
1350
19.61 ± 0.06
in this region for the firstJ"=2time. Spectral analyses of these data50
<0.53 . . .
J"=516
HST−COS10
revealthefollowing
major
findings.
J"=619.28 ± 0.07
40

Table 3RW Aur A DiskHAbundance
Ratiosa
2 LevelSpecies

Flux (10 −15 ergs cm−2 s−1 Å−1)

The Astrophysical Journal, 794:160 (12pp), 2014 October 20

G160M

1. The spectra are composed of emission from the accretion
14
10
regionnear
the stellar photosphere, the molecular
disk,
J"=8
J =6
20
!!
J =7
and several outflow components.
spatial disJ"=7Notes.
Trot(H2) = 440 KThe relative
!!
10
J =8
a The majority of the neutral atomic
12hydrogen on the RW Aur A
tribution of10thesecomponents can be inferred from their
0
T
(H
)
440
±
39
K
rot (McJunkin2
sightline is thought to be interstellar
et al. 2014), therefore −1
velocities.
0
6000
1400
1450
1500
1550
16002000 1650 4000
bH2
4 ± 1 km s
relative abundance ratios are lower
limits.
H2
2. Absorption
spectra(Å)
from H2T(HandCO(K)are observed and are
Wavelength
fcov
0.974 ± 0.027
2)exc
b N(H
)
=
N(H
i)
+
2N(H
).
total
2
Figure 1. Overview of the 2013 August 29 HST-COS observationsof RW Aur
The dataan
are displayed
the black
representative
shownAurconsistent
originas inthehistogram
upperwithlayersof errorthebars
RW
Figure
5. A.
Hwith
2 excitation diagram for the RW Aur disk absorption. As described
a
in
gray.
!!
Note. Column densities in each ground rotational
2 and 7 A
are poorly
fit due to line blends
and are not consideredin the text, J =disk.
circumstellar
low-ionization,
low-velocity
atomic!!
state, J , are in units of molecules cm−2 . Spectral
inthebest-fit
excitation
fit.
We
find
a
best-fitrotational
excitation
temperature!!
outflow
also detected in absorption.
We constrain the molecular fraction
atmo-by 3
fitting of J in
= 2 theand 7 warm
levels aredisk
compromisedof the His
2 of Trot = 440 ± 39 K.
COS
spectralblending Thisat the resolution
and S/N of the3.
Spectralmodelingthat the molecular(A color synthesis
version of this figure
is availableindicatesin the online journal.)
phere of RW Aur to be fH2! 0.47.
large molecularNorm
2
COS data.
H Fitabsorbers arise in a common parcel of disk gas, characraction is interesting because it has been suggested that cir5 19.90+0.33 cm−2 at Trot (H2 ) =terized
by
log
N(H
)
=
cumstellar material withlarge
molecular
fractionsmay
explain10
2
inthesubsequent
analysis.
The best-fit−0.22H2 model spectrum is
1structures must be derived from the spectra. The H2 absorption
blueainmolecular
Figures 2 and3. We ffind
a totalcolumn± 39 K,inwith
fraction
0.47.
The COhe discrepancy between
reddeningroutine
valuesandH2 !
linesoptical/IR-based
were fitted with an IDL-basedthatcombines the 440displayed+0.33−2 +0.3of log10 N(H2log) =1019.90
cm16.1. The uncertaintyon(CO)
the =−0.22 =hasN(CO)cm−2 at Trot
N(HI)-based reddening
valueswithout
invoke grain
H2 ools
opticaldepth having
templatesto(McCandliss2003)0 and the component−0.5
density determination is a combination of statistical+650
MPFIT ratios
least-squares
routines (Markwardt2009). 200column
populations or gas-to-dust
that minimizationdiffer significantly
from
K.
!!
errors−125 associated with the fitting process and systematic errors
inthegroundThecolumndensitiesofeachrotational
level
J
+4.7
he diffuse and translucent ISM (McJunkin et al.
2014).
Table 3on ourof continuum
errors!!
!!
= 1.6
4. We based
derivean choiceabundance
ratio normalization.
of CO/H2 These−1.3 ×electrovibrational level, N(H2 [v = 0, J ]) (in units of cm−2 ), aredistributed as ±0.05 statistical fitting uncertainties andummarizes the atomic
and molecular results from this work.1.5 levels 10−4arefor
the inner disk gas, consistent with the canonicalallowed to vary simultaneously. The first nine rotational+0.33/−0.21 systematic uncertainties on the normalization. The!!
!!
The combination of dense
cloud
CO/H
ratio
and
high
molecare considered (J = 20–8); lines originating in J ! 9 were interstellar
dense
value.
model finds
a bestcloud
fit b-valueof 4 ± 1 km s−1 , a radial velocity
ular fraction argue thatthe warm
surfaceof(H1.02 )/mH2 +not detected.
Themolecular
Doppler b-value(bH2 layers= (2kTrot
vH2abs = 5 ± 5 km s−1 , and a covering fraction consistent with
2
1/2
−1
H2
vturb ) ,somein unitsofofthe
km sphysical), the radial
velocity of the absorption
protoplanetary disks retain
characteristics
unity,presented
fcov= 0.974here± 0.027.
The
data
were obtained
through HST Guest
−1
!!
lines
(in
units
of
km
s
),
and
the
moleculargascovering
0.5
of the dense clouds out of which they formed, at least to thecritical densities
forthe low-J
levels of H2
ObservingThe
program
Initialdesignrotationaland characterization
fraction are also free parameters in the fit. The normalized
4 12876.
−3
are " 2 × 10 cm (Mandy & Martin 1993). At the expected∼1 Myr age of RW Aur.
spectra (Figures 2 and 3) are smoothed with a 3 pixel boxcarof the COS
G130M
λ1222
modedisk
waslayer
performed
part ofdensitiesof the warm
molecular(nH2 ∼106 ;asWoitke0.0
Finally, as describedintheIntroduction,observationsofH
average prior to H2 fitting. A synthetic normalized2 absorption
HST Guest
programWe
helpfulet al. Observing
2009; Bruderer
2013) we12505.
expect theH2 appreciatelevel populations
spectrumis createdfor eachcombination
free parameters
and CO UV fluorescencelines
suggestedhigh
CO/H2 ofratios
1092 1094 1096
1098
1100
1102
1104
1106
to be withdeterminedbycollisions.
such, the populationbediscussions
Eric(Å)Burgh,
EricAsSchindhelm,
and will
Christianandthistheoretical
spectrumisconvolved
with
the
COS
lineWavelength
0.1–1; e.g., France et al. 2011b;
2012). While we caution
described
by the Maxwell-Boltzmann
distribution
with a wasform
Schneiderduringcourseofsolidthis
work.
This
work
spread-function4 (Kriss 2011).
The process
until
the region, with the
Figure 2. HST-COS
spectra of iterates
the 1092–1106
Å spectral
continuum thefunctionshown as the
red line(top panel).
The bottom
panel shows theparhat the results presented
in the presentnormalized
studyfluxare
based onas the bluesupported
solid line (Sectionby
4.1).NASA
The strongest
H absorption
linesgwith
J ! 5 are labeledin purple.
The data
and the best-fit H absorption modeltially
best-fit parameters are found.
grant
NNX08AC146
to theUniversity!!
!!
J !! (−E!! /kTrot )with a 3 pixel boxcar
andthenormalized
spectraarebinnedby
4
pixelsandsmoothed
with
a
3
pixel
boxcaraveragefordisplay.
The
normalized
spectraaresmoothedJ
N (J )/N (J = 0) =e
(1)a sample size of one,Systematicthey suggest
that
theratiosuncertainties
onthe toCO/H
continuum
areColorado at Boulder
averageprior
H fitting.2 normalizationof
and K.F. acknowledges
support fromag0
derived from the emission
line
studies
werelikelymisleading
explicitly
takeninto accountduringthefitting,
and we(A color
version of
thisfigure is available
in theexecute
online journal.)
Nancy Grace Roman Fellowship during a portion of this work.
Flux
ergs cm−2 s−1 Å−1)

30

2

2

2

(1−0)P(4)(1−0)R(5)(1−0)P(3)(1−0)R(4)(1−0)P(2)(1−0)R(3)(1−0)P(1)(1−0)R(2)(1−0)R(0)(1−0)R(1)

(10

−15

!!

Normalized Flux

CO

2

!!

Constraints on photoevaporation models from (lack of) radio
emission in the Corona Australis protoplanetary disks⋆
Galvan-Madrid et al., A&A
VLA3.5cmで円盤をたくさん観測した。その結果、10天体中7つでnon-detection→EUV photonの数に制限をつけた（EUV→電離→free freeが出るはずだから）→ΦEUV < 1−4 × 1041 s−1→これはかなり強い制限。

観測結果+モデル計算
A&A 570, L9 (2014)(freefree放射∝EUV)

Table 2. Comparison with Pascucci12.

Table 1. Disks in CrA within the VLA primary beam.
(1)
Name
G-95
G-87
G-85
V709
HBC-677
IRS8
R CrA
CrA-465
G-32
T CrA

(2)
RA
[h:m:s]19:01:28.72
19:01:32.32
19:01:33.85
19:01:34.84
19:01:41.62
19:01:51.11
19:01:53.67
19:01:53.74
19:01:58.33
19:01:58.79(3)Dec[deg:arcmin:arcsec]–36:59:31.7–36:58:03.0–36:57:44.8–37:00:56.7–36:59:53.1–36:54:12.5–36:57:08.3–37:00:33.9–37:00:26.7–36:57:50.1

(4)
CSA11

(5)
SA13

TD
TD
PD
TD/DD
PD
PD
PD
PD
PD
PD

...
TD
pre-TD
...
PD
...
...
...
...
PD

(6)
S 3.5 cm
[µJy]
<180
<60
<60
892 ± 79<45<120285 ± 10<60<60
181 ± 9(7)
PB-corrected noise
[µJy]
60
20
20
50
15
40
10
20
20
15

(8)
LX
[erg s−1 ]1.03 × 1030...
4.28 × 1029
4.17 × 1030
2.21 × 1029...
7.7 × 1029
...
...
...

(9)
Spectral
type
M1
M1.5
M0.5
K1
M2
M2
A5
M5-M7.5
>M5
F0

(10)
Comments
...
...
...
a
...
...
b
...
...
c

Name
G-95
G-87
G-85
V709
HBC-677
IRS 8
R CrA
CrA-465
G-32
T CrA

ΦEUV,model[s−1 ]<4.0 × 1041
<1.3 × 1041
<1.3 × 1041
!1.1 × 1042
<1.0 × 1041
<2.7 × 1041
!4.1 × 1041
<1.3 × 1041
<1.3 × 1041
!3.8 × 1041

Notes. Columns 1 to 3: names and coordinates from CSA11 (who use the Chandra positions of Forbrich & Preibisch 2007) and SA13. Columns 4
and 5: classification in CSA11 and SA13. Primordial disk (PD), pre-transitional disk (pre-TD), transitional disk (TD), debris disk (DD). A blankfield means that the source is either not detected or not mentioned, or that the photometry was affected by extended nebulosity, mostly an issue inthe Herschel observations (SA13). Column 6: flux density at 3.5 cm or 3σ upper limits. For the detections, the VLA coordinates from Gaussian fits
are given as a comment, together with the estimation of the 3.5 cm flux due to free-free emission from the coadded nondetection epochs. Column 7:
primary-beam-corrected noise, measured individually around the position of each source. Column 8: X-ray luminosity in the 0.2–8 keV Notes.
band fromUpper limits using Eqs. (2) and (Forbrich & Preibisch (2007). A blank field means that only ∼101 counts were detected, and the X-ray spectral shape and luminositynondetections
could notare marked as simple uppe
29
−1
be derived. However, under typical assumptions, their measured count number would imply LX ∼ 1 × 10 erg s . Column 9: spectral types
the three detections, we list the estimatesreported by CSA11. Compiled from Forbrich & Preibisch (2007), Meyer & Wilking (2009), López Martí et al. (2005), and CSA11. Column 10:
nondetections, which are stilcomments. a) RA = 19:01:34.86, Dec = –37:00.55.8. S V709,ff ! 507 ± 88 µJy. b) RA = 19:01:53.68, Dec = –36:57:08.0. S RCrA,ff ! 183the± 20coaddedµJy.
Intermediate-mass YSO (Acke & van den Ancker 2004). c) RA = 19:01:58.79, Dec = –36:57:49.9. S TCrA,ff ! 170 ± 26 µJy. Intermediate-massfree-free emission from a photoevaporating
YSO (Acke & van den Ancker 2004).

them with a !symbol.

(e.g., Choi et al. 2008; Lindberg et al. 2014; Peterson et al. 2011;

Astrometric follow-up observations of directly imaged sub-stellar
companions to young stars and brown dwarfs⋆
Ginski et al., MNRAS＊アブストのみ
6つの星の伴星に対して、アストロメトリーを行った。
軌道要素をモンテカルロ法で制限
特にGQ Lupではseparation と position angleが両方変わった
エキセントリック or 傾いた円軌道
更にもう一点検出した（かも）On the filtering and processing of dust by planetesimals
1. Derivation of collision probabilities for non-drifting planetesimals
Guillot et al., A&A
円盤内の固体はダスト(ミクロン~cm~)から微惑星までサイズが多岐にわたる。
大きなダスト(mm~m)は動径方向に落ちていくもし、微惑星(km)が漂っていたら、落ちていく大きなダストは微惑星と衝突合体するだろうか？
この論文：ダストが微惑星に衝突する確率を導出・定式化
settling regimeb0
T. Guillot, S. Ida & C. W. Ormel: On the filtering of dust by planetesimals: 1. Derivation

gas disk
2hp

2hd

2hg

?

planetesimals
dust subdisk

Fig. 1. Geometry of the problem considered in this study. The gas disk
has a characteristic height hg and is accreting onto the star thus yielding a small but non-negligible inflow velocity. Dust particles grow bymechanisms not modeled in this study. They settle to the mid-plane andbset(τ*)bset(τs<τ*)Rp
The dust grains settle onto the midplane because of friction
Bondiwith the gas and the vertical componentof the star’s gravitationalgas ⌧flow
force, yielding a sedimentation
terminal velocity vz =s ⌦K z
Hill(Nakagawa et al. 1981). The sedimentation timescale is thus
⌧sed ⌘) 1dust⌦K1capture, i.e., itinis the
proportional
to the Planetesimalsz | ⇠ (2⇡⌧sof
Fig.z/|v
8. Illustration
settling regime.
local with
Keplerianorbitalby km
the anddimensionlessa radius
Rp timescale
between divided
about 100
1000 km have a Bondi
stopping
time
⌧
(see
Sect.
2.4
hereafterforthedefinitionof ⌧s ).(see text). Forsradius larger
than Rp but smaller than the Hill radius
Exceptthe smallest
particles,
can consider tothat
dust has time equal totheforcriticalstopping
time ⌧s⇤we
corresponding
a stopping
fully sedimented and has a scale height that is determined by its
the time necessary for the unperturbed dust particle to cross the Bondi
stopping time and turbulent stirring. Dubrulle et al. (1995) show
sphere, the effective cross section for capture is bset ⇠ RB . The approxthat⇤
imate⇣trajectory
of
the
dust
for
⌧
s = ⌧s is indicated by red lines. For⌘psmallerdust
particleswith ⌧s < ⌧s⇤ (dashed green lines),
hd = min 1, ↵/⌧(7) the deflections hg ,
by the gravitational pull of the planetesimal is smaller, hence a smaller
radius.
whereeffective↵ is the capture
traditional
turbulence parameter(Shakura & Sunyaev 1973). (We note that Youdin & Lithwick (2007) extend this設定：

dust of size s as
Z routd
Xfilter (s) ⌘drrin

Z Rp,max
Rp,min

dNp
P
dRp
dRp

!

dr.

微惑星が0.1AU-35AUに分布しているとする

Using the distribution of planetesimal sizes defined
Xfilter>1 効率よく微惑星に食べられるand the surface density of planetesimals ⌃p (r)integrated filtering efficiency can be written in the fo
結果:
Z routdr
Xfilter (s) =2xfilter (s, r) ,乱流が典型的な値の場合(α=10^-2)、filtering efficiencyは低い（ダストは微惑星にあまりr
rin

衝突せず、中心星に落下していく。

where xfilter (s, r) is the characteristic filtering efficie
of size s at orbital distance r,

乱流が弱い場合(α=10^-4)、微惑星サイズに依存してfilteringが変わる
1)微惑星が10kmよりも小さい時⇡r2 ⌃p (r)xfilter (s, r) =,Mfilter (s, r)

幾何断面積での衝突

where Mfilter is defined by eq. (50). The quantity
measures the filtering efficiency at each orbital dista
filtering efficiency ∝r-7/4
ing us to estimate where the dust is mostly absorbed
2)微惑星(原始惑星)が1000kmより大きく、そのスケールハイトがガスの1/10以下で、かIn the geometrical, circular limit, eq. (51) leads u

つダストがmmより大きい時、沈殿regimeで衝突

3⌃pr
xfilter,geo,circ = p
8 ⇡ ⇢˜p Rp,mean hg↵,⌧s .

Replacing ⌃p and hg by their MMSN scaling relation
filtering efficiency of a swarm of planetesimals witotal mass as the present solar system:⇣⌘
応用例：例えば、地球付近が水浸しにならないのは、氷ダストが途中で微惑星に食べられ⌧s ,↵xfilter,geo,circ,MMSN = 1.1⇥
3
10
たから？→だとすると、弱い乱流モデルがfavorされる ✓
◆ 1✓
◆ 1
⇢˜p
Rp,mean
7/4
r
AU .
3
1 g cm
1 km

filtering efficiency ∝r-1/4 ~ r1/4

-1
-4

-2
0

-4

0

-2

-2

0

2

4
30

10.0

5

2
0.1

0.3

4

Fig. 21. Filtering efficiency of dust of 1 micron to 100 meters by a
MMSN planetesimal belt with planetesimals of 1 to 10,000 km in raダストが大きくないとfilterされない
dius extending
from 0.1 to 35 AU for a turbulent parameter ↵ = 10 2
and assuming monodisperse size distributions for planetesimals anddust grains.
Top panel: Contours of the disk-integrated filtering fac0.1-1AUというとても内側
tor Xfilter . Bottom panel: Orbital distance at which Xfilter (r) = 1 fordust particles drifting in from beyond 35 AU. (The integration thus starts
from 35 AU and goes inwards.)

-2

-2

1

-3
-4

0 0
-4
4

-2

0

2

4
30

1.0

10

3

5
0.1

2

3
1
0.5

1

0.3

0.1

0.1

-2
0
2
Log(Dust size) [cm]

-1

0.1

0
-4

1.0

0
-4

1
0.5

1.0

1

3

rXfilter=1 [AU]

10

3

0

2

0

0
-4
4

-3

1

0

2

1

0.1 to 35 AU

Log(Xfilter)

02

Log(Planetesimal size) [km]1

Log(Xfilter)

0.1 to 35 AU

2

-2

-2

MMSN

3

rXfilter=1 [AU]

2

3

10.0

MMSN

0

α=10-4

3

2

Log(Planetesimal size) [km]α=10-2

0

3

4

0

4

0.1

0.1
1.0

-2
0
2
Log(Dust size) [cm]4

Fig. 22. Same as Fig. 21, but for a turbulent parameter ↵ = 10 4 .

This is exemplified by Fig. 22 which shows the integrated
filtering coefficient as a function of planetesimal and dust sizesfor ↵ = 10 4 . The two islands of efficient filtering previously
observed in Fig. 21 are now much wider and more pronounced.

Slow ionized wind and rotating disklike system associated with thehigh-mass young stellar object G345.4938+01.4677
Guzman et al., ApJ
ALMA 85-99GHzの連続波で、大質量星形成クランプIRAS16562−3959を観測中に大質量YSOのG345.49+1.47. (~15Msun)がある。ionized windがふいている
1.7kpc, cluster: ~900Msun
結果：
H40α, H42α, H50β の水素再結合線を検出。
低速アウトフローモデルで結果を再現した。
Lorentzian wingから電子密度を求めると5 × 107 cm−3
SOとSO2も検出(~3000AU)：回転構造も検出→遅い電離ウインドを伴った大質量原始星の描像

source10からHRL–9–(水素再結合線)
linear

–9–

log

wing

wing

source10(G345.49+1.47)
Stark効果によるブロードニング
Fig. 1.— Continuum emission detected at 92.3 GHz toward IRAS 16562 3959. Bottom panel: Contours shown correspond to 15, 15, 30, 60, 120, 250, 500, 1000, and 2000 , with = 50 µJy beam 1 .
represents the r.m.s. variations of the dynamic range limited image measured at the edge of the
field. Compact sources are identified by the number given in Table 2. All sources are within the→電子密度を求めた