星形成ゼミ
SFN #309 (18-27本目)
百瀬宗武（茨城大・理）ハイライトは以下の３本• #21: The ALMA-PILS survey: Isotopic composition of oxygen-containing complex
organic molecules toward IRAS 16293‒2422B (J. K. Jørgensen et al. A&A in press)• #24: ZOOMING IN TO MASSIVE STAR BIRTH (S. Kong et al., ApJ in press)• #26: Transport of CO in Protoplanetary Disks: Consequences of Pebble Formation,
Settling, and Radial Drift (S. Krijt et al. ApJ in press)

These enhancements are thought to be a consequence of the servations of the THz ground state transitions of H2 D (Brünken
ativetohydrogen(e.g.,
van
Dishoeck
et
al.
1995;
Ceccarelli
et
al.
stars
is
the
Class
0
+ protostar IRAS 16293–2422. This source
A&A proofs: man
et
al.
2014)
and
D
H
(Harjuetal.
2017)
towardthecoldenveexothermic
reaction2【解析】
520. TheALMA-PILS
survey:Isotopic
compositionof oxygenいくつかの遷移の積分強度図
2001)
compared tothe cosmic
D/H ratioof 1.5 2.0⇥10(e.g,., lope
has aroundlong beenrecognisedashavinglarge
abundancesof deuterIRAS
16293–2422
suggestvery
similaramountofcontaining
complexorganic
molecules
towardIRASthe16293–++
Linsky2003;
Prodanović
etal.
2010).
In
particular,
deuteratedcations
speciesincomparedtohigh-mass
protostellar
sources(van
H3 + HD ⌧ H2 D + H2 + E(1) boththis source. Due to sensitivity limitations, how2422B
ated isotopologues of species
such as formaldehyde (H2 CO) and ever,
Dishoeck
et
al.
1995)
and
was
also
the
first
solar-type
protothe single-dish observations typically targeted the brightJ.
K.
Jørgensen
et
al.
A&A
in
press
methanolE (CH
arewhichfoundfollowed
to be significantly
enhanced
up est,starlow
for excitation,
which abundant
complexorganic
molecules
were
found
3 OH)
(where=232
K),bydissociative
recomtransitions that in some cases may be optihttps://arxiv.org/pdf/1808.08753.pdf
to levelsofofH⇠D10%
or electrons
above compared
toantheregular isotopo+(Cazauxetal.
2003).
Combiningthese
twoproperties,ithasbination
with
leads
to
enhancedatomiccally thick both for the main isotopologues as well as for the
2【内容】原始星
16293-2422Bに向けたALMABand et7のラインサー
loguesin IRAS
single-dish(e.g.,
Pariseal.
and deuterated
been a natural
targetfor deuteration
studies.observations
This is the source
D/H
ratio
that
can
be observationstransferred tograinswhen
the2006)
neutralvariants.
Furthermore,
single-dish
natusome ofthese sourceseven
showOtherdetectionsof systems
multiplysuch
deutertoward
which theabove protostellar
mentioned envelope
multi-deuterated
species,
13
ベイ。Oを含む有機分子およびそれらのD,
C同位体の遷移を系統的に調speciesfreeze-out(Tielens
1983).
isotopic
as rally
encompass
the entire
and are thusin(e.g., CD2 HOH
and CD3may
OH; also
Pariseet al.variations
2002 and trinsically
12ated species
13
as
well
as
some
deuterated
complexorganics,
e.g.,methylC
andC-containing
isotopologues
showbiasedtowardemissiononlargerscales
where
most
of
べ，柱密度・温度・同位体比を調べる。そして，これらの生成反応（特Parise et toal.the2004)
indicating
very
high
degrees of
deuteration
formate(CH
OCHO;andDemyk
et al.may
2010)
anddimethyl
ether
3located
compared
local
ISM
due
to
the
fractionation
processes
inthematerialismolecules
stillbelargelyfrozenにダスト表面反応）に制約をつける。
(seealsophases
overview
in Jørgensen
et al. 2016).
(CH
first detected. Recent ob3 ; Richard
thecoldalthoughthe variationsof those are expected to out
on3 OCH
dust grains
due etto al.
the2013),lower weretemperatures.
+servations
of
the
THz
groundstate
transitionsofH
D(BrünkenTheseenhancements
arethoughttobeaconsequence
of
the
2
【背景】
be at much smaller levels than those of deuterium vs. hydrogen.
Using ALMA we haverecently completed a large unbiased
+
et
al.
2014)
and
D
H
(Harjuetal.
2017)
towardthecoldenveexothermic
reaction2
Isotopeselective
photodissociationorion-molecule
reactionsinthe Protostellar Interferometric Line Survey (PILS), of a
• Dや13Cが関わる以下の反応は，低温環境下で同位体分別を引き起こす survey,
lopearoundIRAS
16293–2422
suggestvery
similaramountofthe+gas through the reaction:
key frequency window around 345 GHz (Jørgensen et al. 2016).
+(ΔE=232K)
H3 + HD ⌧ H2 D + H2 + E(1) These
both cationsin
thissource.
Duetosensitivity
limitations,howdata are up to two orders of magnitude more sensitive than
ever,
the
single-dishobservations
typicallytargetedthebright13 ++13(ΔE=35K)
C + CO ⌧ C + CO + E(2) previous single-dish studies and thus provide excellent opportu(where E = 232 K), which followed by dissociative recom- est, low excitation, transitions that in some cases may be optinities for systematic studies of complex organics and their iso+bination
of
H
D
with
electrons
leads
to
an
enhancedatomiccally thick In
bothfor the themainisotopologuesobservations
as well as forthe+への濃集→
12C/13Cの減少
2H以外の分子に伝播，COにおける
3
2
• DのH
(where E = 35 K; Langer et al. 1984; Furuya et al. 2011) may topologues.
particular,interferometric
make
D/H
ratio
that
can
be
transferredtograinswhentheneutraldeuterated
variants.
Furthermore,
single-dishobservations
natu1312enhancetheCOabundanceinthegas-phase
relativetoCO.
it possible to zoom in on the inner 30–60 AU around the cen（ただしCOは，FUVによる解離の影響も考慮する必要あり）
speciesfreeze-out(Tielens
1983).
Other
isotopic
systems
such
as
rally
encompasstheentireprotostellar
envelope
and
are
thus
in半ビーム分，１ビーム分
Isotopeselective
photodissociation
maydecreasetheamounttral protostars, i.e., Solar System scales, where the temperatures
1213• 両者の関係を分子種ごとで調べ，その起源に迫る。
C
andC-containing
isotopologues
may
also
show
variations
trinsicallybiasedtowardemissiononlargerscales
where
most
of
13
12
ずれた位置でのスペクトルof CO relative to CO, but at the same time enhancing the are high and the ices have sublimated and the complex organic
compared
to
the
local
ISM
due
to
the
fractionation
thematerialislocatedandmolecules
may
still
be
largelyfrozen13
13processes
13 inamount of C. Once on the grains, the enhanced CO or C molecules therefore are all present in the gas-phase. The initial【観測データのサマリー】
thecoldphasesalthoughthevariations
of
those
are
expected
to
out
on
dust
grains
due
to
the
lower
temperatures.
can then be incorporated
into the complex organic
molecules.
results presented the first detections of the deuterated isotopoをカバー，Δv=0.2km/s，ビームサイズ
0.5”(60au)• 329.1-362.9GHz
be
at
much
smallerlevels
than
those
of
deuterium
Using
ALMA werecently completed
unbiased
12 vs. hydrogen.
Other mechanisms, such as segregation between CO and 13 CO logues
of isocyanic
acidhaveand formamide(Coutensa etlarge
al. 2016)
as• 前例のない分解能と高感度を達成し，以下を星間空間で初検出
Isotopeselective
photodissociationorion-molecule
reactionsinsurvey,thedeuterated
Protostellar
Line ofSurvey(PILS), of a13
in the ices due to slight di↵erences in their binding energies (e.g., wellas theandInterferometricC-isotopologues
glycolaldehyde
13C体，エタノールのD体
thegas
throughthereaction:key frequency
aroundspecies
345 GHzet al. 2016).
ケテン，アセトアルデヒド，ギ酸のD,•Smithet al. 2015) may also a↵ect the amount of 12 C relative to (Jørgensen
et al.window
2016). Theseall (Jørgensen
show significant
deuTheseenhancements
data are up to twoorders ofnot
magnitude
morehinted
sensitivethan
13• 原始星の位置ドンピシャだとダスト連続波の光学的厚みが大きいので，
C
that
is
availableforincorporation
intolargermolecules.
terium–althoughonthelevels
by
the
13 +
+
13
previous
single-dishstudiesandthus
provideexcellent
opportuCSince
+ CO
⌧
C
+
CO
+
E
(2)
previous
single-dishobservations
–
but
also
indicationsof difall of these fractionation processes are very
sensitive to
１ビームずらした位置のスペクトルを解析（右のFigure
2,3）
nitiesforsystematicstudiesofcomplexorganics
and
theirisothe gas physics (density and temperature) it has therefore been ferences that may exactly reflect their chemistries. Specifically,es for the isotopologues of the complex organics and abundances relative to the main isotopologue at the position
AS16293B. As discussed in the text the uncertainties on the individual column densities are about 20%, while a
一番右のカラム（Ncorr/Nmain)
ertainties on the ratios between species are 30% from error propagation. Square brackets indicate tentative fits toN[cm 2 ]b

CH3 OHCH2 DOH
CH3 OD

N/Nmain a

Ncorr /Nmain a

...
0.071
0.018

...
0.024
0.018

Methanol
1.0 ⇥ 1019
7.1 ⇥ 1017
1.8 ⇥ 1017

Ethanol
2.3 ⇥ 1017
2.7 ⇥ 1016
1.3 ⇥ 1016
2.3 ⇥ 1016
[1.1 ⇥ 1016 ]CH3 CH2 OH
a-a-CH2 DCH2 OH
a-s-CH2 DCH2 OH
a-CH3 CHDOH
a-CH3 CH2 OD)
13
a-CH3 CH2 OH[9.1 ⇥ 1015 ]13
a- CH3 CH2 OH
CH3 OCHO
CH3 OCDO
CH2 DOCHOCH3 O13 CHO
CH2 CO)
13
CH2 COCH2 13 CO
CHDCO
CH3 OCH313
CH3 OCH3
asym-CH2 DOCH3
sym-CH2 DOCH3CH3 CHOCH3 CDO)
13
CH3 CHOCH3 13 CHO
t-HCOOH
t-H13 COOH)
t-DCOOHt-HCOOD

...
0.12
0.057
0.10
[0.050]

0.059
0.057
0.050
[0.050][0.040 (1/25)]

Methyl formate
2.6 ⇥ 1017...
...
1.5 ⇥ 1016
0.057
0.057
16
4.8 ⇥ 100.18
0.061
[6.3 ⇥ 1015 ][0.024 (1/41)]
Ketenec
4.8 ⇥ 1016...

2.0 ⇥ 1015

0.042

7.1 ⇥ 1014...

0.015 (1/68)c
0.021

Dimethyl ether
2.4 ⇥ 1017...
...
1.4 ⇥ 1016
0.029 (1/34)d4.1 ⇥ 1016
0.17
0.043
16
1.2 ⇥ 10
0.050
0.025

Acetaldehyde
1.2 ⇥ 1017...
9.6 ⇥ 1015
0.080
1.8 ⇥ 1015

...
0.08

0.015 (1/67)

Formic acide
5.6 ⇥ 1016
8.3 ⇥ 1014...
...
0.015 (1/68)c

1.1 ⇥ 1015

0.020

同等の配位がある同位体について重みを調整した後でのMain spices に対する存在比(例えばCH2DOHはメチル基の同等なHの場所が3つあるので1/3する)(1) Ncorr/Nmainで比較すると，
D化物 2-3%のもの
D化物 4-8%のものに綺麗に分かれる.
(2)個々の分子種で異なるFunctionalgroups （官能基）にDが含まれている割合がかなり一様 → exchange
reactionが盛んな高温領域に速やかに輸送されたため？
(３) Texと氷表面での束縛エネルギーにも良い対応がある。
（右のFigure 4を参照）

0.020

ogue relative to that of the main species given respectively without (N/Nmain ) and with the statistical
18

16

18

（次ページTable 3参照）

Species

氷表面での
束縛エネルギー【結果】

A&A
manuscript
no. msTable 2. Division of molecules into “hot” and “cold” fromtheproofs:
interferometricobservationsof IRAS16293 (this study) and high-mass hot cores(Bisschop et al. 2007), an indication of whether or not the species are detected in the single-dish study of IRAS16293 (Jaber et al. 2014) and theTable energies
2. Divisionof molecules
into “hot”
and “cold”
the 2013).
interferometric observations of IRAS16293 (this study) and high-mass hot coresbindingof eachspecies (fromthe tabulation
byfromGarrod(Bisschop et al. 2007), an indication of whether or not the species are detected in the single-dish study of IRAS16293 (Jaber et al. 2014) and thebinding energies of each species (from the tabulation by Garrod 2013).
aSpecies

IRAS16293
High-mass hot cores Binding energy
Interferometric Single-dish[K]Species
IRAS16293
High-mass hot cores Binding energya
Formaldehyde
H2 CO
Cold
+
Cold / Hot
2050
Interferometric Single-dish[K]
KeteneCH2 CO
Cold
+
Cold
2200
Formaldehyde
H2 CO
Cold
+
Cold / Hot2050
Acetaldehyde
CH3 CHO
Cold
+
Cold
2775
KeteneCH2 CO
Cold
+
Cold
2200
b
Dimethyl
ether
CH
OCH
Cold
+
Cold
/
Hot
3675
3
3
Acetaldehyde
CH3 CHO
Cold
+
Cold
2775
Methylformate CH
OCHO
Hot
++
Hot
5200
Dimethyl ether
CH3 3 OCH3
Cold
Cold / Hot b
3675
Methanol
Hot
++
Hot
5530
Methyl formate CH
CH3 OHHot
Hot
5200
3 OCHO
Formamide
NH
Hot
++
Hot
5560
Methanol
CH2 CHO
Hot
Hot
5530
3 OH
Formic
acid
HCOOH
Hot
-+
Cold
5570
Formamide
NH2 CHO
Hot
Hot
5560
Ethanol
CHCOOH
Hot
-Hot
6260
2 H5 OH
Formic acid
Hot
Cold
5570
Glycolaldehyde
CH
Hot
-6680
Ethanol
C22HOHCHO
Hot
Hot
6260
5 OH
Ethyleneglycol (CHHot-102002
Glycolaldehyde
CH22OH)
OHCHO
Hot
-6680
b
Notes: a TheEthylene
listed binding
for pure
ices(Garrod2013).
Although, dimethyl
ether is classified
as hot in Bisschop et al.
glycolenergies(CH2 OH)
Hot
10200
2
a
b
(2007),
temperaturesof 80–130
K areforfound
SgrB2(N)(Belloche
et al.dimethyl2013) andG327.30.6 (Bisschop
et al. 2013),
i.e.,
Notes:The listed binding
energies
puretoward
ices (Garrod2013).
Although,ether
is classified
as hot in Bisschop
et al.
relatively
compared
to other(2007), temperatures of 80–130 K are foundtoward “cold”
SgrB2(N)(Belloche
et al. species.
2013) and G327.3 0.6 (Bisschop et al. 2013), i.e.,
relatively “cold” compared to other species.

Table 3. Inferred abundances and deuterium fractionation (from interferometric and single-dish data, respectively) for di↵erent organic molecules.
ForTablethe deuterium
thedeuterium
numbers referto the inherent
D/H ratio (i.e.,andtakinginto accountthe statisticalfor
ratiosfor thefunctionalgroups
3. Inferredfractionation,
abundances andfractionation(from interferometric
single-dishdata, respectively)di↵erent
organic
molecules.
with
H-atoms)
for the singly
deuterated
species.
As notedD/H
in thetext
thetakinguncertainties
on theabundances,e.g.,functional
D/H ratios,
from
Formultiple
the deuterium
fractionation,
the numbers
refer
to the inherent
ratio(i.e.,
into accounttherelative
statisticalratios for thegroupsthewithALMAdata H-atoms)
are about for30%;
or 1.5percentage
pointsAsfor
ratiosor 5%,
multiplethe0.6
singlydeuterated
species.
noted
in of
the2 text
the respectively.
uncertainties on the relative abundances, e.g., D/H ratios, fromthe ALMA data are about 30%; 0.6 or 1.5 percentage points for ratios of 2 or 5%, respectively.

[D/H] ratios
Species[X/CH3 OH]
Single-dishInterferometric
Model (Taquet et al. 2014)[D/H] ratios
Species[X/CH3 OH]etal.⇥2014)(⇠Single-dish1000 AU) Interferometric(⇠ 50 AU)
1.1Model⇥ 105(Taquetyr
2.0
105 yra(⇠ 7.5%1000 fAU)
(⇠ 50
1.1 ⇥
105 yr2.0 ⇥105 yrFormaldehyde
H2 CO
19%
3%AU)
2.1%
0.21%
a
Formaldehyde CH
H23CO
19%
7.5% f f,g
3%
2.1%
0.21%
MethanolOH—
1.8–5.9%2%b3.5–1.8%
0.28–0.17%f,gbb
MethanolCHOH—
1.8–5.9%2%
3.5–1.8% m 0.090%–0.12%
0.28–0.17% m
3Ethanol
CH
CH
OH
2.3%
.
.
.
5%
0.63–9.7%32Ethanol ether
CH
3 CH 3
Dimethyl
CH
2.4%
3% j
4%b
3.7%
0.10%
3 OCH
Glycolaldehyde CH2 OHCHO
0.34%
...
5%c
6.5–13%0.22–0.38%
Methyl formate CH3 OCHO
2.6%
6%h
6%b
7–9%
0.25–0.22%
Acetaldehyde
CH3 CHO
1.2%
...
8%b
9.2%l
0.068%l
KeteneCH2 CO
0.48%
...
2%b
0.25%
0.015%
Formic acid
HCOOH
0.56%
...
2%b
2.3–1.0%k
0.58–0.66%k
Isocyanic acid
HNCO
0.27%
...
1%d
...
...
Formamide
NH2 CHO
0.10%
...
2%d
...
...
Water
H2 O
...
0.25%i
0.046%e1.2%
0.33%
Notes: a Persson et al. (2018). b This paper. c Jørgensen et al. (2016). d Coutens et al. (2016). e Persson et al. (2013) referring tofg

24. ZOOMING IN TO MASSIVE STAR BIRTH【結果2（論文の順番とは前後するが）】S. Kong et al., ApJ in press
https://arxiv.org/pdf/1701.05953

Kong et al.
ALMA Band 6，CO(J=2-1)の高速度成分

16+00.0700【内容】IR Dark Clouds(IRDC) に付随するクランプのサーベイで見出さ
ト観測(2.3”)では分解できなかった構造を分解。原始星のほか，大質量原始星前段階 = Pre-protostellar coreの候補領域をN2D+輝線で特定。J-VLAのアンモニア観測も実施し，温度分布も推定している。

0.00280.00240.0020+00.0690

0.0016
Galactic Latitude

れたC1-Sコアを高分解能(0.2”, Cycle 2, B6)で観測。Cycle 0のパイロッ

0.1 pc0.0012+00.0680

0.0008+00.0670

0.0004+00.0660+00.0650
28.3240

28.3230

28.3220

28.321028.3200

0.0000Galactic Longitude

Zooming in to Massive Star Birth【結果1】ALMA Band 6ダスト連続波(a) color:Cycle 2 continuum compact
0.1 pc+00.0685

0.0075+00.0680
Galactic Latitude(b) color:Cycle 2 continuum extended
0.01350.01200.01050.00900.0060C1-Sa+00.0675
コンパク
ト配列 +00.0670

0.00450.0030Figure 12. CO(2-1) 0th-moment contours overlaid on the continuum images (grayscale with unit of Jy beam 1 , showing combined datafrom Figure 1). Blue contours show emission integrated from 33.8 to 72.8 km s 1 ; red contours show emission integrated from 85.8 to 124.8
km s 1 . The displayed contour levels are 5, 7.5, 10, 12.5 ... (a) Left panel: Outflow contours from extended-configuration only data (maxcontour level 25 with = 16 mJy beam 1 km s 1 ). (b) Right panel: Outflow contours from combined data (max contour level 45 with
with = 12 mJy beam 1 km s 1 ). The synthesized beams are shown in the lower left corners as filled gray ellipses.

3

0.1 pc0.00200
0.001750.001500.001250.00100
0.000750.000500.00150.000250.00000.00000

広がった配列+00.0665
C1-Sb(c) color:Cycle 2 continuum combined
0.1 pc+00.0685

0.0015Galactic Latitude+00.0680

0.0012

C1-Sa

全配列+00.0675+00.0670

0.00270.00240.00210.00180.0009
C1-S
C1-Sb

0.00060.0003+00.0665

28.3230 28.3225 28.3220 28.3215 28.3210
Galactic Longitude

0.0000

全配列＋
空間的に
スムージ
ング

the normal direction to the continuum elongation andthe outflow axis is approximately 30 . Also relevant isthat the origin of the outflow appears to be slightly o↵set
from the continuum peak (by one beam). The outflow is
only marginally resolved in the direction perpendicular
to the flow axis (by ⇠ 3 beams). An upper limit on thehalf opening angle of the outflow cavity is estimated to
be . 10 . One can see clumpy structures in both theblue and red lobes. The redshifted outflow appears tochange the orientation of its flow axis by a small angle,⇠ 10 , once it is about 0.1 pc away from the protostar.
The blueshifted side does not show evidence for such a
deflection, however, its overlap with the C1-Sb outflow
makes this harder to discern. The observed extent of
the outflow appears to be set by sensitivity, rather thanbeing a real, physical limit.
The outflow from C1-Sb shows a wider opening angle
at its base. The cavity walls, i.e., outflow lobe boundaries, are apparent in the extended configuration image.
The blue lobe overlaps with that from C1-Sa, but it is notclear if this involves a physical interaction or is simply a
projection e↵ect.
There appear to be some high-velocity CO(2-1) emission features in the wider region. However, some of thesefeatures may be artifacts resulting from imperfect cleaning of the image, given the strong sources of the C1-Sa
and C1-Sb outflows. Or these features could be outflows from other nearby protostars or other ambient highvelocity gas in the IRDC or projected along the line ofsight.

this is not included in these maps. C18 O(2-1) emission isnearly absent in C1-S (see also the spectra shown in Figure 6), but is rather mostly concentrated in C1-Sa andC1-Sb.
The lack of C18 O(2-1) emission in C1-S can be explained by CO depletion from the gas phase. In the C1S core and much of its clump envelope, we expect thatthe temperature is . 15 K (see, e.g., Figure 2). At suchtemperatures, CO is mostly frozen-out onto dust grains(Caselli & Ceccarelli 2012). As shown in Figure 6(3c),C1-S inner has no detected C18 O(2-1) flux (i.e., at velocities immediately around 79.4 km s 1 overlapping with
the N2 D+ (3-2) emission). We use the 3 0th-moment
C18 O(2-1) noise level (0.446 K km s 1 for C1-S inner) to calculate an upper limit of C18 O column denS innersity NCC1< 3.00 ⇥ 1014 cm 2 , assuming an ex18 O
citation temperature of 10 K and optically thin conditions. This corresponds to an abundance constraint of[C18 O]/[H]= 2.91 ⇥ 10 10 (using ⌃c,mm,tot from Table 3
and assuming 1.0 g cm 2 corresponds to NH = 4.27⇥1023
cm 2 . Assuming [12 CO/H] = 10 4 and [16 O/18 O] = 557(Wilson 1999), the above abundance constraint in C1-S
inner corresponds to a CO depletion factor of fD > 616.
Such high CO depletion factors have also been found toward the center of the lower-mass pre-stellar core L1544(Caselli et al. 1999, 2002), suggesting similarity of astrochemical properties of this source with C1-S.
C18 O(2-1) emission is observed towards the protostars
C1-Sa and C1-Sb. This is to be expected, since in the【結果4 ALMAのN2D+の観測結果】【結果3 J-VLAのNH3反転遷移の観測：温度の推定】

UV Taper をかけた結果（下パネルを参照）から，C1-S領域

Tk = 13-16 K. ただし，臨界密度が割と低いので，エンにはN2D+が濃集している様子が見て取れる。Starless な領

ベロープ外側の低温領域の影響があるかもしれない
Zooming in to Massive Star Birth0.80+00.0740

0.1 pc+00.0720

Galactic Latitude+00.0700+00.0680

C1-S

C1-N

0.64

0.56

0.56

0.48

0.48
C1-S

C1-N

(a) color:N2 D+

0.40

0.32

0.32

0.24

0.24

0.1 pc+00.0685+00.0680+00.0620(c) color:Tk from NH3

0.08

0.08

0.00

0.00
(d) color:zoom in to C1-S region

20+00.0740

0.1 pc+00.0675

18+00.0680

C1-N

C1-S

0.0000(c) color:N2 D uvtaper
+

18

14

0.1 pcC1-S

12+00.0660

C1-Sb

10

12
10

+00.0640+00.0680

Galactic Latitude

Galactic Latitude

C1-Sa+00.0620

28.3300

28.3280

28.3260

28.3240

Galactic Longitude28.3220

28.3200

8

6

6
28.3230

28.3225

28.3220

28.3215

C1-S

C1-Sb

(d) color:1.3 mm continuum; contour:N2 D uvtaper
+

0.028

0.1 pc0.024

0.00080.0004+00.0675

0.00000.00280.00240.020

0.00200.016

0.0016
C1-Sa

0.012

0.0012
C1-S

0.008
0.004

+00.0670

80.0012+00.0665

16

14

C1-Sa

0.0025+00.0685+00.0700

0.00240.00160.0050+00.0720

160.00280.00200.007520

0.1 pc0.1 pc0.0100+00.0670

0.16

0.02000.01750.01500.0125+00.0640

0.167(b) color:1.3 mm continuum; contour:N2 D+

0.72

0.64

0.40

+00.0660

0.80
0.1 pc0.72域であるとする見方とconsistent

Zooming in to Massive Star Birth(b) color:MIREX; contour:NH3 (2, 2)

Galactic Latitude(a) color:MIREX; contour:NH3 (1, 1)

5

C1-Sb

0.00080.0004+00.0665

28.3210Galactic Longitude28.3230

28.3225

28.3220

28.3215

28.32100.000

28.3230

28.3225

28.3220

28.3215

28.32100.0000Galactic Longitude
Galactic Longitude
e 2. (a) Zeroth moment map of NH3 (1,1) integrated from 76.9 to 81.9 km s 1 (contours, shown from 3, 4, 5 , etc., with being
km s 1 ). The integration covers the main hyperfine structure. The background image shows the MIR+NIR extinction map (inFigure 3. N2 D+ observations: (a) Combined N2 D+ (3-2) 0th-moment map. The integration is from 76.9 to 81.9 km s 1 (i.e., centered2 ) from Butler et al. (2014). The white plus signs represent the C1-N and C1-S cores from T13. The red circle in the lower-righton 79.4 km s 1 velocity measured by T13). The color scale bar has a unit of Jy beam 1 km s 1 . The synthesized beam (⇠ 0.300 ) is shown
the resolution beam of the extinction map. The black ellipse in the lower-left shows the synthesized beam of the VLA observations.
as a red filled ellipse at lower-right. (b) N2 D+ (3-2) 0th-moment contours overlaid on the 1.3 mm continuum image. The continuum image

【議論1：C1-SのStarless 領域の柱密度構造（ダスト連続波）】
Zooming in to Massive Star Birth

エンベロープ差引無9エンベロープ差引有

no envelope subtraction200【議論2：N2D+に基づくC1-S のDynamical な性質の解析】

with envelope subtraction

(a)

(b)

S̄ (MJy sr 1 )150

動径輝度分布

100

14Kong et al.
2.0

data
model

C1-S inner

50
1.5

1.0

(c)

isothermal

Tdust = 7K
Tdust = 10K
Tdust = 13Kk⇢ = 1.5k⇢ = 0.215

6(g cm 2 )5(d)kρ＝-0.215

4

isothermal

Tdust = 7K
Tdust = 10K
Tdust = 13Kk⇢ = 1.5k⇢ = 0.283

Tmb (K)7

動径方向で等温を仮定したときkρ＝0.283

0.0

0.5のΣとΣ∝ r^{kρ}で

3

2.0

data
model

C1-S outer

のフィット

2

0.5

1.5

1
10

(e)

Tdust = (r/Rc )6K + 7K

Tdust (r), k⇢ = 1.5k⇢ = 1.5
Tdust (r), k⇢ = 0.414k⇢ = 0.414(g cm 2 )8kρ＝0.414

6

Tmb (K)1.0

0.0

内側ほど低温をkρ＝0.717

仮定したときのΣ4とΣ∝ r^{kρ}での
フィット

2

0

0

2000

4000
6000
R (AU)

8000

0.5

10000

密度分布は緩やか：infall 前の状態？

igure 5. (a) 1.3 mm continuum flux density S̄1.3mm as a function of projected radius, R, for C1-S outer. The measurement is averaged
ithin concentric annuli that have widths equal to the beam size. The error bars show uncertainties due to observational noise. (b) Sames panel (a), but after subtraction of the clump envelope, as evaluated from an annulus from Rc to 2Rc . (c) Mass surface density, ⌃, asfunction of projected radius R for C1-S outer assuming isothermal conditions. The fiducial dust temperature is 10 K (black dots). Also
k

0.5

1.0

4

2

0
vLSR (km s 1 )2

4

Figure 10. N2 D+ (3-2) core spectra (black) and their HFS fit
results (magenta). All spectra are in the rest frame of 79.4 km s 1 .
The spectral resolution is 0.05 km s 1 .

s.
bst
pal
ss
iof
ald
s,
ve
aat
ge
-S
ng
ce
le.
6)
a
rof

te
oeic
rld
er
ve
an
nd

Table 4
Dynamical properties of C1-S

26. Transport of CO in Protoplanetary Disks: Consequencesof Pebble Formation, Settling, and Radial Drift【モデルの概要】ガス円盤の物理構造
2009)

S. Krijt et al. (ApJ,in press)
https://arxiv.org/pdf/1808.01840.pdf@Ci@t【内容】円盤内でのCO分布のに対して，Pebble の形成，沈殿，動径移動が及ぼす影響をシミュレーションで調べた。Pebbleの形成なしだと，COの存在比に大きな変化はおきない。Pebbleが形成されて赤道面に沈殿すると，固相に取り込まれたCOが円盤上層から抜けるため，ガス円盤全体（上層部）
でCOがdeplete。実際はpebble が中心へと落下するはずで，その場合は，
CO snowline 内側でCOが再び気相に戻ってCO存在比が増えるはず。
実際の観測データでは，COの内側領域でのenhance は見えてないので，• Pebble の落下を妨げる機構？
• 固相に取り込まれたCOが別のより難揮発性化学種に変わっている？
可能性を考慮する必要がある。
（この論文のモデルでは，CO凍結・昇華やダストの成長とそれに伴うガス円盤中での移動は詳細に解いているが，化学反応は解いていない）

Figure 1. Bulk gas density and temperature for our standard disk model (see Sec. 2.1). The black contour denotes the ⌧UV = 1 surface (Eq. 7, and dashed lines showz/H = {1, 2, 3, 4}.

The analytical solution in Eq. 7 is only valid when the
dust-to-gas ratio is constant with height. During oursimulations, however, the small grain abundance willvary in time and space and we evaluate the integral in
Eq. 7 numerically.
In this paper, we focus exclusively on a disk modelwith rc = 100 au, p = 1, and Md = 0.05 M . Figure 1
shows the gas density (Eq. 4) and temperature structure
for these parameters. Dust is initially present at a dustto-gas ratio of 1/100, with all grains being s• = 0.1 µm
in size with a material density of ⇢• = 2 g/cm3 . For
these numbers, uv ⇡ 8 ⇥ 104 cm2 /g. The colored contours show various temperatures as well as the ⌧UV = 1

where
Di is
tion.
(Cv =
presensolve Evr =di↵usiothe Sc
Sc = 1disk wForradialArmitain whi10 3 rthe gavelocit

t).

2)

m-

3)

ng
es
by
a

=
th
is
ld
V
),

モデルのフレームワーク
COと小さなダストはグリッド点上で進化を追い，
ペブルはラグラジアン的に取り扱う

10【結果】シミュレーションの時間発展

初期 CO
存在度

（右）Pebbleの形成なしだと，COの存在比に大きな変化はおきない。

0.1Myr
変化分（中央）Pebbleが形成されて赤道面に沈殿すると，固相に取り込まれたCOが円盤上層から抜けるため，ガス円盤全体（上層部）でCOがdeplete。
（左）pebble が中心へと落下すると，
CO snowline 内側でCOが再び気相に戻ってCO存在比が増えるはず。

実際の観測では，内側でのCO plumeは0.3Myr
変化分

1Myr
変化分

1Myr CO存在度

見えてないので，さらに別の要素も考える必要あり（COの別の化学種への変化，落下を妨げる円盤不均一や微惑星からの影響）Figure 5. Time evolution (top-to-bottom) of the gas-phase CO number density in models M0a, M0b, and M1 (left-to-right).
Top and bottom rows show number densities while the middle three rows show number density relative to the initial conditions
at t = 0, with blue representing an enhancement and red a depletion in gas-phase CO density. Contours for ⌧UV = 1 andT = 22 K are also drawn and the faint dashed lines indicate z/H = {1, 2, 3, 4}.

18

for the projected gap size in diﬀerent orientations are consistent with the separation found by the geometrical model.

19 Accepted by ApJ
http://arxiv.org/pdf/1808.05052

19

The dependence of stellar properties on initial cloud density
Michael O. Jones1 and Matthew. R. Bate1
1

School of Physics and Astronomy, University of Exeter, Stocker Road, Exeter EX4 4QL, United Kingdom

E-mail contact: mbate at astro.ex.ac.uk
We investigate the dependence of stellar properties on the initial mean density of the molecular cloud in which stellar
clusters form using radiation hydrodynamical simulations that resolve the opacity limit for fragmentation. We havesimulated the formation of three star clusters from the gravitational collapse of molecular clouds whose densities varyby a factor of a hundred. As with previous calculations including radiative feedback, we find that the dependenceof the characteristic stellar mass, Mc , on the initial mean density of the cloud, ρ, is weaker than the dependence ofthe thermal Jeans mass. However, unlike previous calculations, which found no statistically significant variation in
the median mass with density, we find a weak dependence approximately of the form Mc ∝ ρ−1/5 . The distributionsof properties of multiple systems do not vary significantly between the calculations. We compare our results to theresult of observational surveys of star-forming regions, and suggest that the similarities between the properties of ourlowest density calculation and the nearby Taurus-Auriga region indicate that the apparent excess of solar-type stars
observed may be due to the region’s low density.
Accepted by MNRAS
https://arxiv.org/pdf/1806.01033

20

Sink particle radiative feedback in smoothed particle hydrodynamics models of starformationobserved may be due to the region’s low density.
Accepted by MNRAS

20 https://arxiv.org/pdf/1806.01033

20

Sink particle radiative feedback in smoothed particle hydrodynamics models of starformation
Michael O. Jones1 and Matthew R. Bate1
1

School of Physics and Astronomy, University of Exeter, Stocker Road, Exeter EX4 4QL, United Kingdom

E-mail contact: mbate at astro.ex.ac.uk
We present a new method for including radiative feedback from sink particles in smoothed particle hydrodynamics
simulations of low-mass star formation, and investigate its eﬀects on the formation of small stellar groups. We findthat including radiative feedback from sink particles suppresses fragmentation even further than calculations that
only include radiative transfer within the gas. This reduces the star-formation rate following the formation of theinitial protostars, leading to fewer objects being produced and a lower total stellar mass. The luminosities of sinkparticles vary due to changes in the accretion rate driven by the dynamics of the cluster gas, leading to diﬀerent
luminosities for protostars of similar mass. Including feedback from sinks also raises the median stellar mass. The
median masses of the groups are higher than typically observed values. This may be due to the lack of dynamicalinteractions and ejections in small groups of protostars compared to those that occur in richer groups. We also find thatthe temperature distributions in our calculations are in qualitative agreement with recent observations of protostellar
heating in Galactic star-forming regions.
Accepted by MNRAS
https://arxiv.org/pdf/1807.09849

21

The ALMA-PILS survey: Isotopic composition of oxygen-containing complex organic
molecules toward IRAS 16293–2422B

https://arxiv.org/pdf/1808.08753.pdf

22

22

Distortion of Magnetic Fields in a Starless Core IV: Magnetic Field Scaling on Density
and Mass-to-flux Ratio Distribution in FeSt 1-457
Ryo Kandori1 , Kohji Tomisaka2 , Motohide Tamura1,2,3 , Masao Saito2 , Nobuhiko Kusakabe1 , Yasushi
Nakajima4 , Jungmi Kwon5 , Takahiro Nagayama6 , Tetsuya Nagata7 and Ken’ichi Tatematsu2
1

Astrobiology Center of NINS, 2-21-1, Osawa, Mitaka, Tokyo 181-8588, Japan; 2 National Astronomical Observatoryof Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan; 3 Department of Astronomy, The University of Tokyo, 7-3-1,
Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan; 4 Hitotsubashi University, 2-1 Naka, Kunitachi, Tokyo 186-8601, Japan;
5Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku,
Sagamihara, Kanagawa 252-5210, Japan; 6 Kagoshima University, 1-21-35 Korimoto, Kagoshima 890-0065, Japan; 7
Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan
E-mail contact: r.kandori at nao.ac.jp
κIn the present study, the magnetic field scaling on density,|B|∝ρ, was revealed in a single starless core for the first15
time. The κ index of 0.78 ± 0.10 was obtained toward the starless dense core FeSt 1-457 based on the analysis of theradial distribution of the polarization angle dispersion of background stars measured at the near-infrared wavelengths.
The result prefers κ = 2/3 for the case of isotropic contraction, and the diﬀerence of the observed value from κ = 1/2 is
2.8 sigma. The distribution of the ratio of mass to magnetic flux was evaluated. FeSt 1-457 was found to be magneticallysupercritical near the center (λ ≈ 2), whereas nearly critical or slightly subcritical at the core boundary (λ ≈ 0.98).
Ambipolar-diﬀusion-regulated star formation models for the case of moderate magnetic field strength may explain
the physical status of FeSt 1-457. The mass-to-flux ratio distribution for typical dense cores (critical Bonnor–Ebert
sphere with central λ = 2 and κ = 1/2–2/3) was calculated and found to be magnetically critical/subcritical at thecore edge, which indicates that typical dense cores are embedded in and evolve from magnetically critical/subcritical
diﬀuse surrounding medium.

Accepted by ApJ
https://arxiv.org/pdf/1808.05327

The JCMT Gould Belt Survey: SCUBA-2 Data-Reduction Methods and Gaussian

23

The JCMT Gould Belt Survey: SCUBA-2 Data-Reduction Methods and Gaussian
23 Source
Recovery Analysis
Helen Kirk1,2 , Jennifer Hatchell3 , Doug Johnstone1,2 , David Berry4 , Tim Jenness5,6 , Jane Buckle7,8 ,Steve Mairs4 , Erik Rosolowsky9 , James Di Francesco1,2 , Sarah Sadavoy10 , Malcolm Curry5,11 , Hannah
Broekhoven-Fiene2 , Joseph C. Mottram12,13 , Kate Pattle14,15 , Brenda Matthews1,2 , Lewis Knee1 , Gerald
Moriarty-Schieven1 , Ana Duarte-Cabral16 , Sam Tisi17 and Derek Ward-Thompson14
1

NRC Herzberg Astronomy and Astrophysics Research Centre, 5071 West Saanich Rd, Victoria, BC, V9E 2E7,
Canada; 2 Department of Physics and Astronomy, University of Victoria, 3800 Finnerty Road, Victoria, BC, Canada
V8P 5C2; 3 Physics and Astronomy, University of Exeter, Stocker Road, Exeter EX4 4QL, UK; 4 East Asian Observatory, 660 N. Aohoku Place, University Park, Hilo, Hawaii 96720, USA; 5 Joint Astronomy Centre, 660 N. Aohoku
Place, University Park, Hilo, Hawaii 96720, USA; 6 LSST Project Oﬃce, 933 N. Cherry Ave, Tucson, AZ 85719,
USA; 7 Astrophysics Group, Cavendish Laboratory, J J Thomson Avenue, Cambridge, CB3 0HE, UK; 8 Kavli Institute for Cosmology, Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge, CB3 0HA, UK;
9
Department of Physics, University of Alberta, Edmonton, AB T6G 2E1, Canada; 10 Harvard-Smithsonian Center
for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA; 11 RAL Space, Rutherford Appleton Laboratory,
Harwell Oxford, Didcot, Oxfordshire, OX11 0QX, UK; 12 Leiden Observatory, Leiden University, PO Box 9513, 2300
RA Leiden, The Netherlands; 13 Max-Planck Institute for Astronomy, Konigstuhl 17, 69117 Heidelberg, Germany;
14
Jeremiah Horrocks Institute, University of Central Lancashire, Preston, Lancashire, PR1 2HE, UK; 15 Institute of
Astronomy and Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan; 16 School of Physics
and Astronomy, Cardiﬀ University, The Parade, Cardiﬀ, CF24 3AA, UK; 17 Department of Physics and Astronomy,
University of Waterloo, Waterloo, Ontario, Canada N2L 3G1
E-mail contact: helenkirkastro at gmail.com
The JCMT Gould Belt Survey was one of the first Legacy Surveys with the James Clerk Maxwell Telescope in Hawaii,
mapping 47 square degrees of nearby (< 500 pc) molecular clouds in both dust continuum emission at 850 µm and450 µm, as well as a more-limited area in lines of various CO isotopologues. While molecular clouds and the material
that forms stars have structures on many size scales, their larger-scale structures are diﬃcult to observe reliably in thesubmillimetre regime using ground-based facilities. In this paper, we quantify the extent to which three subsequentdata-reduction methods employed by the JCMT GBS accurately recover emission structures of various size scales,in particular, dense cores which are the focus of many GBS science goals. With our current best data-reduction
procedure, we expect to recover 100% of structures with Gaussian sigma sizes of ≤30′′ and intensity peaks of at least
five times the local noise for isolated peaks of emission. The measured sizes and peak fluxes of these compact structures
are reliable (within 15% of the input values), but source recovery and reliability both decrease significantly for larger
emission structures and for fainter peaks. Additional factors such as source crowding have not been tested in our
analysis. The most recent JCMT GBS data release includes pointing corrections, and we demonstrate that these tend
to decrease the sizes and increase the peak intensities of compact sources in our dataset, mostly at a low level (several
percent), but occasionally with notable improvement.
Accepted by ApJS
https://arxiv.org/pdf/1808.07952

16https://arxiv.org/pdf/1701.05953

25

25

Dust segregation in Hall-dominated turbulent protoplanetary disks
Leonardo Krapp1 , Oliver Gressel1,2 , Pablo Benı́tes Llambay1 , Turlough P. Downes3 ,Gopakumar Mohandas1,2 and Martin E. Pessah1
1

Niels Bohr International Academy, The Niels Bohr Institute, Blegdamsvej 17, DK-2100, Copenhagen Ø, Denmark
2
Kavli Institute for Theoretical Physics, University of California, Santa Barbara 93106, USA
3
Centre for Astrophysics & Relativity, School of Mathematical Sciences, Dublin City University (DCU), IrelandE-mail contact: krappleo@nbi.ku.dk
Imaging of dust continuum emitted from disks around nearby protostars reveals diverse substructure. In recent years,
theoretical eﬀorts have been intensified to investigate in how far the intrinsic dynamics of protoplanetary disks (PPDs)
can lead to such features. Turbulence in the realm of non-ideal magnetohydrodynamics (MHD) is one candidate for
explaining the generation of zonal flows which can lead to local dust enhancements. Adopting a radially-varying
cylindrical disk model, and considering combinations of vertical and azimuthal initial net flux, we perform 3D nonideal MHD simulations aimed at studying self-organization induced by the Hall eﬀect in turbulent PPDs. To this end,
new modules have been incorporated into the Nirvana-iii and fargo3d codes. We moreover include dust grains,treated in the fluid approximation, in order to study their evolution subject to the emerging zonal flows. In the regimeof a dominant Hall eﬀect, we robustly obtain large-scale organized concentrations in the vertical magnetic field thatremain stable for hundreds of orbits. For disks with vertical initial net flux alone, we confirm the presence of zonal
flows and vortices that introduce regions of super-Keplerian gas flow. Including a moderately strong net-azimuthal
magnetic flux can significantly alter the dynamics, partially preventing the self-organization of zonal flows. For plasmabeta-parameters < 50, large-scale near-axisymmetric structures develop in the vertical magnetic flux. In all cases, wedemonstrate that the emerging features are capable of accumulating dust grains for a range of Stokes numbers.
Accepted by ApJ.
http://arxiv.org/pdf/1808.07660

27

27

Revisiting the pre-main-sequence evolution of stars II. Consequences of planet formation
on stellar surface composition
Masanobu Kunitomo1,2, Tristan Guillot3 , Shigeru Ida4 and Taku Takeuchi5
1

Department of Earth and Planetary Science, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113- 0033,
Japan; 2 Department of Physics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8602, Japan; 3 Laboratoire Lagrange, UMR 7293, Université Côte d’Azur, CNRS, Observatoire de la Côte d’Azur, 06304 Nice CEDEX 04,
France; 4 Earth-Life Science Institute, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8551,
Japan; 5 Department of Earth and Planetary Sciences, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku,
Tokyo 152-8551, Japan
E-mail contact: kunitomo at eps.s.u-tokyo.ac.jp
We want to investigate how planet formation is imprinted on stellar surface composition using up-to-date stellar
evolution models. We simulate the evolution of pre-main-sequence stars as a function of the eﬃciency of heat injection
during accretion, the deuterium mass fraction, and the stellar mass. For simplicity, we assume that planet formation
leads to the late accretion of zero-metallicity gas, diluting the surface stellar composition as a function of the massof the stellar outer convective zone. We adopt 150M⊕(M⋆ /M⊙ )(Z/Z⊙ ) as an uncertain but plausible estimate of themass of heavy elements that is not accreted by stars with giant planets, including our Sun. By combining our stellar
evolution models to these estimates, we evaluate the consequences of planet formation on stellar surface composition.
We show that after the first ∼0.1 Myr, the evolution of the convective zone follows classical evolutionary tracks withina factor of two in age. We find that planet formation should lead to a scatter in stellar surface composition that islarger for high-mass stars than for low-mass stars. We predict a spread in [Fe/H] of approximately 0.02 dex for stars
with Teﬀ ∼ 5500 K, marginally compatible with diﬀerences in metallicities observed in some binary stars with planets.
Stars with Teﬀ ≥ 7000 K may show much larger [Fe/H] deficits, by 0.6 dex or more, compatible with the existence ofrefractory-poor λ Boo stars. We also find that planet formation may explain the lack of refractory elements seen in
the Sun as compared to solar twins, but only if the ice-to-rock ratio in the solar-system planets is less than ≈0.4 andplanet formation began less than ≈1.3 Myr after the beginning of the formation of the Sun.
Accepted by A&A
http://arxiv.org/pdf/1808.07396