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)

302010011001150

12001250

13001350

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。
A&A 570, L9 (2014)

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/DDPD
PD
PD
PD
PD
PD

...
TD
pre-TD
...
PD
...
...
...
...
PD(6)
S 3.5 cm[µJy]
<180<60<60892 ± 79<45<120285 ± 10<60<60
181 ± 9(7)PB-corrected noise[µJy]
60202050154010202015(8)LX[erg s−1 ]1.03 × 1030...
4.28 × 1029
4.17 × 1030
2.21 × 1029...
7.7 × 1029
...
...
...

(9)
Spectraltype
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 4and 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
−1be 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
2hp2hd2hg?

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*)
RpThe 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 theproportional
to the Planetesimalsz | ⇠ (2⇡⌧sofFig.z/|v
8. Illustration
settling regime.
local with
Keplerianorbitalby km
the anddimensionlessa radius
Rp timescale
between divided
about 100
1000 km have a Bondi
stoppingtime⌧(seeSect.
2.4
hereafterforthedefinitionof ⌧s ).(see text). Fors
radius larger
than Rp but smaller than the Hill radius
Exceptthe smallest
particles,
can consider tothatdust has time equal totheforcriticalstopping
time ⌧s⇤wecorresponding
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⇣trajectoryofthedustfor⌧s = ⌧s is indicated by red lines. For⌘psmaller
dustparticles
with ⌧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 routdXfilter (s) ⌘drrin

Z Rp,maxRp,mindNp
PdRp
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 rout
drXfilter (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rrin

衝突せず、中心星に落下していく。

where xfilter (s, r) is the characteristic filtering efficieof 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⌃prxfilter,geo,circ = p8 ⇡ ⇢˜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⇥310たから？→だとすると、弱い乱流モデルがfavorされる ✓◆ 1✓◆ 1⇢˜pRp,mean
7/4
r
AU .
31 g cm
1 km

filtering efficiency ∝r-1/4 ~ r1/4

4
3
102-1-4-2

1-3-40-4-2

02

4Log(Xfilter)23

Slow ionized wind and rotating disklike system associated with thehigh-mass young stellar object G345.4938+01.4677
Guzman et al., ApJALMA 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

wingwing

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 thefield. Compact sources are identified by the number given in Table 2. All sources are within the→電子密度を求めた