星形成ゼミ
SFN #296 (41-45本目)
百瀬宗武（茨城大・理）41. Near-infrared time-series photometry in the field of
Cygnus OB2 association I - Rotational scenario
for candidate members
J. Roquette, J. Bouvier, S.H.P. Alencar et al. (A&A, 603, id.A106)
http://ads.nao.ac.jp/abs/2017A%26A...603A.106R【背景】中心星自転の角運動量(AM)に対して星周円盤が与える影響については，様々な論争あり。

【本研究の内容】Cyg OB2 に含まれる5000個以上のYSO候補の変光を
JHK 3バンドで調査，周期的変動を示すものを注意深い解析で抜き出【観測】• UKIRTを使い2007年4-7月と8-11月の計115夜(左下)でJHK撮像測光。
• 0.87平方度をカバー。領域中の対象となるYSOs候補は‥(i)円盤付随星(Guacello+ 2013)

1843個(ii)Chandra LagacyによるX線星(Guacello+ 2015他) 4864個• light curveの調査対象とし得たものは5083個（右下の赤点）- (i)から1272個，(ii)から4165個，重複が354個- O, B型星100個を含む，比較的大質量の星は飽和，1.4M⦿以下が対象- 視野中央にある42777個(右下グレー)をcontrol sampleとして使用
観測データ取得夜

し，信頼の置ける周期（2-30 daysの範囲をカバー）が導かれた894個にlight curve調査対象とコントロールサンプル分布

ついて，円盤有無や中心星質量，環境依存性を議論。

【主要な結論】D論の一部のようなので議論は多岐にわたるが。。。
• 円盤が付随している中心星の方が自転が遅い傾向がある（disk-locking
scenarioと整合的な結果）- high-UVの環境下に限ると影響はっきりしない【解析】• < 0.4 M⦿の中心星の方が，より大質量(0.4M⦿ < M < 1.4M⦿) のものよ• Lomb-Scargle 法による周期解析

り自転が遅い傾向がある• カタログとしての価値あり• 複数の指標による誤検出候補の注意深い除去• control sample を用いたCompletenessの考察
主に 2days < P < 20 daysの894個を議論の俎上に【主な結果】

別の見方• 円盤ありと円盤なしのP分布違い • Pごとのdisk fractionの違い• 中心星質量の依存性• 環境効果？（紫外線場の強弱）※下図はEUVの場合だが，J. Roquette et al.: Near-Infrared Time-Series Photometry in the Field of Cygnus OB2 Association※既出の可視光サーベイによるカラーからAvを
FUVでも同じ傾向

見積もり，1058個の中心星質量を推定した
log(F FUV )  3.7G0※ 2 days < P < 20 daysの数を下図に示した

log(F EUV )  11.42photons/s/cm2

89個

log(F FUV ) > 3.7G0log(F EUV ) > 11.42photons/s/cm2

少なくともP≲10daysの範囲では自転周期が長いものほど円盤存在
割合が高い

676個

（disk-lock scenarioと整合的）

dashed line がMedian
円盤ありの方がやや周期が長い

それよりPが長い範囲でdisk
fractionが落ちているのは，
field starの混入が効いている？
M < 0.4M⦿ の方が周期長い（disk-lock scenarioと整合的）※ ただし，この関係は環境紫外線場の強い領域では顕著でなくなる※UVが強い環境ではFig. 23: Same as Figure 20 but for periodic stars with low UV incident radiation (top). and stars
対流層の厚みと関係？
短時間で円盤散逸，with high UV incident radiation (bottom).

disk-lockがあまり
variability surveys sensitive to fainter stars may improve the size 働かない？
and completeness of the42. Signatures of rocky planet engulfment in HAT-P-4.
Implications for chemical tagging studies
C. Saﬀe, E. Jofre, E. Martioli et al. (A&A, 604, id.L4)
http://ads.nao.ac.jp/abs/2017A%26A...604L...4S【観測・解析】• GEMINIにCFHTの高分散分光器をつけるモード（λ=4500-8500Å，
Resolving power 〜 67500）• HAT-P-4A，4B，及び太陽のスペクトルの差から，重元素量の傾向を精密に読み取る。下のテーブルは基本的な諸量。
【背景】惑星を伴う星表面の重元素存在度の欠乏については論争あり
A&A proofs: manuscript
no. saﬀe• 太陽は 凝縮温度 Tc > 900Kの難揮発性元素が同スペクトルタイプの星に

2
Table 1. Stellar parameters derived for each star.
etary
systemshavebeenreported
,
but
only
a
handful
of
these
比べ欠乏
(Star - Reference)
Te f flog g[Fe/H]
vturb
systems are binaries with similar components. Three of these−1- 形成途上に微惑星として難揮発性元素がロック，除去された？
[K]
[dex]
[dex]
[km
s
]
remarkable systems were studied in detail: 16 Cyg, HAT-P-1(A - Sun)
6036 ± 46
4.33 ± 0.13
0.277 ± 0.007
1.29 ± 0.07
• Galactic Chemical
Evolutionand HD80606 (GCE)や銀河スケールでの化学組成勾配に(Laws & Gonzalez 2001; Ramírez et al. 2011;(B - Sun)
6037 ± 37
4.38 ± 0.14
0.175 ± 0.006
1.21 ± 0.07
(B - A)
6035 ± 36
4.39 ± 0.10
-0.105 ± 0.006
1.22 ± 0.06
Schuler et al. 2011; Tucci Maia et al. 2014; Liu et al. 2014;
も起源を求めうるSaﬀe et al. 2015). There are also binary systems with circumstellar planets orbiting both stars of the system (e.g. Mack et al.【結果1：Feの存在比】
advantageofthehigh-resolution2014). These studies show that a Tc trend is probably present be- trograph). This device takes Saﬀe
et
al.:
Rocky
planetengulfmentin HAT-P-4【本研究の内容】惑星存在が確認されたHAT-P-4 AはBinaryで，その伴星
3・BとAで，[Fe/H]に0.1dexもの差が（Aの方がFeがアバンダント）
tween the stars of 16 Cyg but not in the case of HAT-P-1 nor HD ESPaDOnS spectrograph, located at the Canada-France-Hawaii
Bには惑星は確認されていない。両者はスペクトルタイプが似ており(ど80606. Notably, the binary system ζ 2 Ret (where one component Telescope (CFHT) and fed by an optical fiber connected to theどの遷移でも整合的結果，
8.1
mGeminiNorth
telescope
at
Mauna
Kea,
Hawaii.
We
usedisorbited
by
a
dust
disk
with
no
planetdetected),
also
shows
a
ちらも太陽型)，両者の化学組成を注意深く調べれば，誕生場所・時期のwhich provides an averTc trend between their stars, supporting the chemical signature of the 1-fiber object-only observing mode他の連星系では見られない
影響を除去し，惑星の有無が化学組成に与える影響を議論できるはず。
4
age
resolvingpowerof∼67500
between
4500
and
8500
Å
planet formation (Saﬀe et al. 2016). Then, there is a clear need
大きな差 . Theof additional systems to be studied through detailed abundance stellar spectra were obtained under a Fast Turnaround (FT) ob高分散分光（及び両者の差分）から，重元素存在度やLi存在度のserving mode requested to the Gemini Observatory (program ID:
analyses in order to reach more significant conclusions.
G型星の対流層=0.023M
were takenon ⦿
As a result違いを調べるof the planetary transit survey HATNet, GN-2016A-FT-25, PI: C. Saﬀe). The observations
immediately ⨁
after
the
A
Kovács et al. (2007) discovered a giant planet of 0.68 M Jup or- June 3, 2016, with the B star observed として，10Mの岩石（惑星）【HAT-P4系に関するキーパラメータ】
biting the star HAT-P-4 (=BD +36 2593) at a distance of 0.04 star, using for both the same spectrograph configuration. The ex−3
がAに余分に降着した？
posure
times
were
2
×
17
min
on
each
target,obtaining a finalAU.
They
estimatedadensity
of
0.41
g
cm
,
being
one
of
the
• HAT-P-4Aに付随する惑星：r=0.04 au, 0.68MJup, ρ=0.41 g cm-3
lowest density hot Jupiters known. Then, Mugrauer et al. (2014) signal-to-noise ratio of S/N ∼400 measured at ∼6000 Å in theFig. 1. Diﬀerential abundance vs excitation potential (upper panel) and• HAT-P-4A(Spshowed
type =G0V)とHAT-P-4B(G2V)の離隔
=
28644
au
that HAT-P-4 forms a wide binary system separated 91.8 combinedvs reduced EW spectra.
(lower panel)Thefor thefinal
case (Bspectral- A). Filled coverageand hollow
is 4050-10000 Å.
circles correspond to Fe i and Fe ii.
arcsec from its companion (TYC 2569-744-1, hereafter compo- The
Moon was also observed with the same Fig.
spectrographset- vs Tc for (A
2. Diﬀerential abundancesplanet engulfment in HAT-P-4

A&A proofs: manuscript no. saﬀe

δ Scuti stars are pulsating variables with ∼A6-F6 spectral【結果2：その他の重元素の存在比】
types and mass between 1.4 - 3.0 M⊙ (see e.g. the 【結果3：Liの存在比】
catalogsof Rodríguez et al. 2000; Liakos & Niarchos 2017). We determined the stellar masses through a Bayesian method using
the PARSEC9 isochrones (Bressan et al. 2012), obtaining 1.24
太陽とAの比較± 0.06 M⊙ and 1.17 ± 0.05 M⊙ for the stars A and B. Both thetemperatureand mass of A and TBcが高いもの
are lower than all δ Scuti stars
太陽はAに比べ，of these catalogs. One of the coolest δ Scuti stars with abundanceが欠乏しているdeterminationis CP Boo (6320 K, Galeev et al. 2012), which is∼300 K hotter than the A star. However, the A star is enhanced(! 0.20 dex) in Na i, Mg i, Al i, Sc ii, V i, and strongly enhanced(> 0.40 dex) in Sr ii and Y ii compared to CP Boo. Also, the stars
A and B lie out of the instability strip boundaries (e.g. Figures Fig. 4. Stellar spectra near the Lithium line 6707.8 Å for the A (blueand
6 and 7 of Liakos & Niarchos 2017) and no stellar pulsations dotted line) and B (black continuous line) stars.
llow
have been reported.
Fig. 2. Diﬀerential abundances vs Tc for (A - Sun). The Blue
long-dashedline
stragglers(BS) are stars significantly bluer than theisaweighted
linearfit
tothe
diﬀerential
abundance
values,whilethe• Liに関しても，Aの方がより豊富？（吸収が深い）We
main-sequence
continuous line shows the solar-twins trend of Meléndez
et al. (2009). turnoﬀ of the cluster (or population) to which
Figure 4 shows that the line Li i 6707.8 Å is stronger in thethey belong. There are binaries where one component is BS, •beA star (blue dotted line) compared to B (black continuous line),
降着の影響かもしれないが，AとBの質量のわずかな違いでもing impossible to fit both components with a single isochrone with abundances of 1.47 ± 0.05 and 1.17 ± 0.04 dex. In this bi説明可能かも(DesideraBとAの比較
et al. 2007). However, in our system the ages of bothnary system, the star which hosts the planet also presents thestars agree within the errors (2.7 ± 1.3 Gyr and 2.9 ± 1.8 Gyr), higher Li content, in contrast to the model that explains the
Aの方が，より難揮発性元素に富む
also derived
with the PARSEC isochrones (Bressan et al. 2012). Li depletion by the presence of planets. A similar rotational
BS stars 傾向にある（Feのオーバーアバンダ
present significant rotational velocities, intense activ- velocity (7.0 ± 0.9 and 6.1 ± 1.0 km s−1 estimated from our
the
ctral
ity and very low Li content (e.g. Fuhrmann & Bernkopf 1999; spectra), suggests that the rotational mixing is not the causence
ントと共に，難揮発性成分が後から
Schirbel etal. 2015; Ryan et al. 2001). None of these charac- for the diﬀerent Li content. The sligthly diﬀerent masses of0Å
【まとめ】
teristics are
seen
in
the
stars
A
or
B.
HFS
stars A and B suggest a diﬀerence of 0.2-0.3 dex in the Li
Aに加わったと考えて説明可能）
ocal
There are no firm reasons to identify any component of
the abundances, by fitting general literature trends (e.g. Figure 3•
Aが難揮発性元素に富むのは惑星の存在と密接に関係する可能性。
databinary system as peculiar. Then, a possible diﬀerent accretion of Delgado-Mena et al. (2015) and Figure 9 of Ramírez et al.
0.07• 岩石（微）惑星の降着が原因？
0.18
would be the most plausible explanation for the chemical diﬀer(2012)). This can explain (at least in part) the higher Li conthe
ences observed. We estimated the rocky mass of depleted matetent, in のMigrationが降着を促したのかもしれない。
agreement with the scenario proposed by Ramírez et al.
• Hot Jupitere torial in the A star following Chambers (2010). Adopting a con- (2011) for 16 Cyg. Another possible scenario is the accretion ofA)lines aretars Fig. 3. Diﬀerential abundances (B - A) vs Tc . Long-dashedvectionzone
similar to the present Sun (Mcz = 0.023 M⊙ ) we ob- material in the A star, which could increase its Li abundance andweighted linear fits to all species and to refractory species. The solartwins trend of Meléndez et al. (2009) is shown withline. M⊕ . However, adopting a higher Mcz value (e.g.
taina continuous
Mrock ∼10
agree with its higher metal content.
0.050 M⊙ ) at the time of planet formation, we derive Mrock ∼20

43. Expelled grains from an unseen parent bodyaround AU Mic
E. Sezestre, J.-C. Augereau, A. Boccaletti, & P. Thebault (A&A, in press)
http://ads.nao.ac.jp/abs/2017arXiv170709761S【背景】AU Micに付随するデブリ円盤のここ７年の散乱光画像の中に，星から離れていくように動いていく成分が５つ同定された。
A&A proofs: manuscript no. AUMic_Sezestre
|

|

|

E

|

|

|

D

|

|

|

C

|

|

B

|

|

A

|

Fig. 1: 2010 and 2011 HST/STIS and 2014 VLT/SPHERE images of the debris disk of AU Mic. The five structures are identified in
the bottom panel.
with the constraints we derive on the dust properties and dynamics. We discuss our findings, the influence of the parameters, andthe implications in Section 4.

【本研究の内容】ダストのβ = (輻射圧 + 星風圧)/重力とダスト排出源の位置 R0をパラメータにしたモデルで時間変化を再現する。ダスト排出源
2. ModelWe develop a model that aims to investigate the dynamics ofは止まっている場合とケプラー回転している場合の二通りを考えるが，
dust particles released by a singular parent body and a↵ected bystrong stellar wind pressure force. Throughout this paper, we
そのメカニズムの詳細は考えない。 amake
the important assumption that the observed displacements
correspond to the actual proper motion of the particles, and not
to a wave pattern, which implies that the particles are supposed
to have the same projected speeds as the observed structures.
We seek to discuss if this assumption could yield to scenarii thatallow to reproduce the observed speeds in the AU Mic debris
disk, and which conditions must be fulfilled.

oftypicaTable 1: Documented stellar parameters of AU Microscopii
40
values(GJ803,
HD 197481)【AU
Micの基本パラメータ】
sion by s
A&A proofs: manuscript no. AUMic_Sezestre
been anaParameter
Value
Referencevalue of|||Spectral type |M1Ve
Torres et al. (2006)
Age
23 ± 3 Myr
Mamajek & Bell (2014) of Auger
this beha
Distance
9.94 ± 0.13 pc Perryman et al. (1997)
For
n
Mass (M? )0.3-0.6
M
Schüppleretal.
(2015)|||||
Wind speed (Vsw ) 4.5 ⇥ 105 m/s
Strubbe & Chiang (2006) and optim
The traje※ Windの質量放出率については，50M⦿ と300M⦿ の2通りを想定 the grid.
C
E
D
B
A
|
|
|
|
|
time-step
projection (structure
E).
Notingr
theapparent
positionoftheE
E（βをダストサイズに換算するに効く）
olution o
structure, the condition ra & rE yields a strict lower limit on :0.1 yearr E R0【説明すべき基本的な観測事実】
body.
Th
Fig.
1:
2010
and
2011
HST/STIS
and2014
VLT/SPHERE
imagesofthedebris
disk
of
AU
Mic.
The
five
>
.
(7)
the bottom
panel.
for
the
p
2r
E
（少なくとも外側のダストは）星から吹き出される運動をしている
bound traNevertheless, we anticipate unbound orbits withwith
highvalues 200onau
the constraints we derive
thefrdto best fit the observed speeds, and a power lawics.linking
andWe discuss our
findings,
the influen
with
resp
the implicationsin Section 4.
R0 can be approximated analytically. The trajectories
of grainsother parwith values much larger than 1 are almost radial
and
the
limit
between
割と大きなβが必要
speed reached by the particle is given by Eq. 6. The
data points to
2. ModelTwo
reproduce are apparent speeds at projected distances.
Let ustake that aims to inv
We develop
a modelthat
thepapdust
particles
releasedbyasingularthe pair (rD , vD ) for the D structure as an example, and note ↵is rotatina strong stellar wind pressure
force. T
the angle between the observer and the directionmakeof propagation
the important assumptionthdust thatpartiof the particle. For a given projected distance rDcorrespond, the greater
to the theactual proper motio
is static
w
to
a
wave
pattern,which
impliesthattreleased distance to the star R0 , the smaller the ↵ angle. In a
to have the same projectedasof speeds
Figuresimple approximation, we can write that sin ↵ We
= seekrD /(xR0 ) byto discuss
if this assumption cwith respallow
toreproducetheobservedspee
considering the right triangle where rD is the side opposed to thebyfultdisk, and which conditionsonly
must beangle
and assuming
thestructures
hypothenuse
x timesFig. 2: ↵Apparent
speeds of thein the AUisMic
de- R0 . Using Eq. 6
moves onbris
disk
derivedfromtheobservations(Tabs.
2
and
A.1).
The
and the above approximation, the apparent speed writes:
event. Thgray region shows the escape velocities for stellar masses rang- 2.1. Parent bodying from 0.3 to 0.6 M , thepdotted line corresponding
to pa massrD
3/2
To break the symmetry of dates
the disk,aswe
vofD0.4' Mv1. sin ↵ / v0 2
1·
/ R0
2
1.
(8)
cess of dust production. The
dust arrw
emittedR0
structures is thus assumed to be loca
from eac微惑星ベルト(星から35-40au)の内側に間欠的にダストを排出する源を置いて，(R0, β)
É. Sezestre et al.: Expelled grains from an unseen parent body around AU Micのグリッド上でパラメータを振りつつ，観測者が運動を見込む角度θを変えながら観測を再現するものを探す

どちらの場合も，観測された固有運動は，同一ダストの群れが動いた結果であると仮定する。

y
Observer
Parent body

•

• !t
✓

•

M (tC ) •M (tB )• M (tE )

•
B

•

!tC

M (tD )••

Trajectory D

x

x

R0
Parent body
trajectory•

Position of releasefor structure D•

ケプラー回転する排出源で，観測を再現するいくつかの例のダスト軌道を上から見たところ。
É. Sezestre et al.: Expelled grains from an unseen parent body around AU Mic

M (tA )• Trajectory A

Fig. 5: Left: Sketch of the static case, seen from above. Right: Sketch of the orbiting case, seen from above. In this case, thestructure B is used as the reference structure. Note that the features are not necessarily emitted in the alphabetical order.
120

Table 2: Apparent separations from the star (in arcseconds) of the maximum elevation from midplane of the five arch-like structures,named A to 固定された排出源
E, observed in the AU Mic debris disk in 2010, 2011 and 2014.
In 2010, the A structure is angularly too close to the star
ケプラー回転する排出源
for being detectable. For consistency among all the features, the uncertainties on the positions of the features A and B in 2011 havebeen re-estimated to twice their values, as published in Boccaletti et al. (2015). The next four rows give the positions of brightness
enhancements (and not the maximum elevation positions) identified in 2004 and a posteriori associated to the D and E structures.
The last row shows the mean positions and uncertainties on the structures seen in 2004.
A
1.017 ± 0.025
0.750 ± 0.025-

B
1.714 ± 0.037
1.384 ± 0.025
1.259 ± 0.037-

C
2.961 ± 0.073
2.554 ± 0.025
2.459 ± 0.049-

D
4.096 ± 0.049
3.491 ± 0.025
3.369 ± 0.061
2.52
2.52
2.21
2.62
2.468 ± 0.154

E
5.508 ± 0.074
4.912 ± 0.208
4.658 ± 0.245
3.22
3.12
3.22
3.32
3.220 ± 0.071

Reference
Boccaletti et al. (2015)
Boccaletti et al. (2015)
Boccaletti et al. (2015)
Fitzgerald et al. (2007)
Liu (2004)
Metchev et al. (2005)
Krist et al. (2005)

論文中では，列状に連なっている排出源が一定の場所で連続的にダストを放出するケースなども議論。
この場合，排出源の軌道離心率が新たに加わる。

20

100

100
0

80

80
20

60

60
40

y (au)

Date
2014.69
2011.63
2010.69
2004.75
2004.58
2004.51
2004.34
2004.545 ± 0.147

120

40

3.1. Static parent body
3.1.1. Nominal case

The simplest case to consider is that of a static parent body withactive periods during which it releases dust particles. The re2

60

20

40
20

80

0

0
100

20

20
120

40

40
60

ture). For each fixed (R0 , ) pair, the code finds the position of
the parent body that best matches the observations documented
in Table 2 by adjusting the angle ✓ and the dust release dates.
This is done by minimizing a 2 value that takes into accountthe uncertainties on the positions, and also on the observing datey (au)

R0

Trajectory Ey (au)✓

Trajectory C

Particles trajectory•• Positionsof E•• Positionsof D•• Positionsof C•• Positionsof B••Positionsof A
Parent bodyyObserverTrajectory B

40
20x (au)

0(a) Model without constraint

20

140

60

40
20
x (au)

0(b) Particles going toward the observer

20

60

40
20
x (au)

020(c) Particles going away from the observer

Fig. 9: Orbiting parent body. Trajectories of the particles seen from above for the five structures in the case of a rotating parent
body (see Secs. 3.2.1 and 3.2.2 for details). For each structure, five similar trajectories, sometimes superimposed, are displayedcorresponding to best fits obtained when the reference structure is varied in the model. The color-coding is the same as in previous
figures. The solid black circle is the trajectory of the parent body. The crosses correspond to the observing dates.

A&A proofs: manuscript no. AUMic_Sezestre

固定された排出源の結果公転する排出源の結果

A&A proofs: manuscript no. AUMic_Sezestre

E

7

10

3

5

2
r

30

6

4
3

1

30

C

0
10

15

(a) Mean20

25

R0 (au)

30

35

30

A
1990

2000

2010

2020

2030

= 10.4, R0 = 12 au,

2
r = 0.92
r = 2.5

15120

Speed (km/s)

✓( )

150

60

0.5

5

10

15

20

25

R0 (au)

30

35

40

0

B

(c) Map of the angle of emission with respect to the observer.

0

10

20

30

40

50

60

Position (au)(d) Best fits to the velocities as a function of apparent position

β=10.4, R =28auが most likely（だが，ある程度広い範囲で再現可能：左上がχ 分布，右上がTime vs. 見か

け位置。右下は見かけ位置とspeedの間の関係。左下
each of the dimensions of the parameter space (see for example It could nevertheless correspond to a high density region of
はその時のθの値。

10

15

20

25

R0 (au)

30

35

0

0

10
1980

40

1990

2000

2010

2020

2030

Date (yr)2r of the fit to five structures

A

Fig. 6: Static parent body. Modeling results in the case of a static parent body. Upper left: Map of the reduced 2 ( 2r ) obtained byfitting the position of the five structures. The solid and dashed black lines show the expected power law trends (Eq. 9) along thetwo families of solutions, each scaled to go through the best fits identified by the black crosses. The branch of largest R0 values
corresponds to trajectories going
0 away from the observer, while the other branch identifies the solutions pointing to the observer(see also Fig. A.1). The area under the dotted white line are solutions excluded by Eq. 7. Bottom left: Map of the angle of emission,
taking with respect to the observer. Upper Right: Projected positions as a function of time. The solid lines correspond to trajectories
2
going away from the observer, while the dashed lines are trajectories pointing toward the observer (see also deprojected trajectories
seen from above in Fig. A.1). Bottom right: Same as Fig. 2, overlaid with the best fit solutions (black crosses in panel (a)).

Figs. A.2 and A.3 in the orbiting case). This gives = 10.5+21.6
4.5 ,R0 = 28.4+7.9
6.8 au and ✓ = 165 ± 6 (1 uncertainties). The simulation closest to these values in the grid of models (right black
cross in Fig. 6a, 2r = 0.9) is shown in figures 6b and 6d, and therelease dates of particles are documented in Table 3. It shows aquasi-periodic behaviour of about 7 years, with the structures the1(b) Best fits to the apparent positions as a function of observing date

D

A

0

A

β=6.4, R =7.7auが χ minimum.

C

30

0.3

B

Table 3: Release dates (in years) of the structures A2to E for the best fit for all the models considered. The last row shows the average0over the five reference structures.
Uncertainties are derived from the dispersion of the results.

10

5

20

Fig. 8: Orbiting parent body. Modeling results of the position adjustement of all the structures in the case of an orbiting parent body(nominal case, see Sec. 3.2.1). Left: 2r map averaged over the five references (see text). Right: projected trajectories for the fivestructures assuming each of the structure is a reference for the fit. This shows that the fits are essentially independent of the assumed
reference structure. The black lines are the apparent positions of the parent body.

E

90
1

30

0.3
5

180

3

30
30

(a) Mean= 10.4, R0 = 28 au,

210

C

30

10

0.5

20

240

10

D

3

(b) Best fits to the apparent positions as a function of observing date
270

40

2

Time (year)2
r map of the fit to five structures

4

1

B

6
5

3

20

0
1980

40

20

E

30

30

0.3

7

10

10

1

20

30

5

D

60
50

10

40

reference A
reference B
reference C
reference D
reference E

8

50

2

0.5

9

Separation (au)10Apparent position (au)

8

20

70

30

= 10.4, R0 = 12 au,60

2r = 0.92
r = 2.510

2r= 10.4, R0 = 28 au,

9

30

10

30

70

20 30

10

large velocity dispersion in the aftermath of a giant collision.
As shown by Jackson et al. (2014) for example, the collision
produces a swarm of large objects, passing through the same position in space, that will in turn become the parent bodies of theobserved dust grains. This could mimic a static parent body, but
importantly, the grains may be released from parent bodies on【主な考察】
Structure A as a reference
Structure B as a reference
Structure C as a reference
Structure D as a reference
Structure E as a reference⦿
Average

B

C

Static: = 10.4, R0 = 28 au
2011.6 ± 0.1 2005.0 ± 0.1 1996.2 ± 0.1
2011.6 ± 0.1 2005.0 ± 0.1 1996.2 ± 0.1
2011.6 ± 0.1 2005.0 ± 0.1 1996.1 ± 0.1
2011.5 ± 0.1 2004.9 ± 0.1 1996.1 ± 0.1
2011.4 ± 0.1 2004.8 ± 0.1 1996.0 ± 0.1
2011.6 ± 0.1 2005.0 ± 0.1 1996.1 ± 0.1

DE

1990.3 ± 0.1
1990.3 ± 0.1
1990.2 ± 0.1
1990.1 ± 0.1
1990.0 ± 0.1
⦿1990.2 ± 0.1

1982.2 ± 0.1
1982.2 ± 0.1
1982.1 ± 0.1
1982.0 ± 0.1
1981.9 ± 0.1
1982.1 ± 0.1• いずれにせよβ > 6がもっともらしい。質量放出率が300M であれば0.1μmスケール，50M なら < 20nmス
Orbiting free: = 6.4, R = 8 au
ケールのダストに相当
Structure A as a reference 2004.2 ± 0.6 2003.3 ± 0.9 1989.0 ± 0.7 1989.6 ± 0.7 1990.6 ± 0.7
0Structure B as a reference
Structure C as a reference
Structure D as a reference
Structure E as a reference
Average2003.7 ± 0.8
2003.4 ± 0.6
2004.9 ± 0.6
2004.0 ± 0.6
2004.1 ± 0.7

2002.9 ± 0.4
2002.5 ± 0.6
2003.9 ± 0.5
2003.1 ± 0.5
2003.1 ± 0.6

1988.4 ± 0.6
1988.0 ± 0.3
1989.8 ± 0.1
1988.8 ± 0.2
1989.1 ± 0.5

1989.0 ± 0.5
1988.6 ± 0.1
1990.5 ± 0.2
1989.4 ± 0.2
1989.3 ± 0.4

1990.0 ± 0.5
1989.6 ± 0.2
1991.6 ± 0.1
1990.4 ± 0.2
1990.6 ± 0.4

Structure A as a reference
Structure B as a reference
Structure C as a reference
Structure D as a reference

Orbiting frontward: = 24.4, R0 = 17 au
2000.8 ± 0.2 1999.4 ± 0.1 1997.2 ± 0.1
2000.2 ± 0.1 1998.9 ± 0.1 1996.8 ± 0.1
2000.4 ± 0.1 1999.1 ± 0.1 1996.9 ± 0.1
2000.4 ± 0.2 1999.1 ± 0.1 1996.9 ± 0.1

1995.8 ± 0.2
1995.4 ± 0.1
1995.5 ± 0.1
1995.5 ± 0.1

1994.1 ± 0.2
1993.7 ± 0.2
1993.8 ± 0.1
1993.8 ± 0.1• 数年後の位置変化に関して異なる予言← 将来の観測で検証可能

44. Species-to-species rate coeﬃcientsfor the H3+ + H2 reacting system
O. Sipila, J. Harju and P. Caselli (A&A, in press)
http://ads.nao.ac.jp/abs/2017arXiv170703170S【背景】低温環境下での（H2以外の分子への）重水素濃集は，prestellar coreや原始星エンベロープの物理化学進化を捉える上で重要• ChemistryをドライブするのはH3+とそのD化物であり，それらの正確な存在比や，輝線を出すH2D+, D2H+のo/p比の正確な予言が大事（o/pは，
H3 + HD → H2D+ + H2の逆反応の進み方も違う）• これまでの化学反応計算では，H3+のisotopologues が全て基底状態にあると仮定して計算されていたが，実際は回転励起状態ごとで化学反応係数が異なることを考慮に入れた場合，存在比やo/p比が変わりうる。

【本研究の内容と大まかな結果】• H3+のisotopologues の励起を考慮に入れた化学反応係数を様々な温度・密度領域で算出。基底状態にあると考えた場合との差異を調べる。
• H2D+, D2H+については輻射輸送に基づくnon-LTE効果も考慮。
• 原始星エンベロープのように高温(T≳20K)・高密度領域(n(H2) ≳ 106 cc-1)
で差が大きくなりうる。最近のIRAS16293に対する観測結果とも合うセンス。

sidered in Hugo et al. (2009) are the rotational levels of the H3
present paper.
isotopologs and H2 in their ground vibrational states. The ground thRate
coeﬃcientsassumingthat
higherrotational
levelscanprstate-to-species coeﬃcients pertain to the reaction【具体的な計算内容】
be populated – the so-called species-to-species rate coeﬃcientsca
k00state-to-state rate coeﬃcients calst–今まで：
can be constructedAfrom
the
+
B
→
C
+
D
,
0
0
culated by Hugo et al. (2009). Below, we show how this is ac-as
where
the AとBの状態が基底状態だと思って計算していた
species
A and B are in their ground states and C and sicomplishedin practice.
leD canWhenenter into
any
state
upon
formation.
The
coeﬃcientkisthequantum
statesofthereactants
andproducts
are00(ground-state-to-species coeﬃcients)mobtainedthroughsummationoverthebepossible
states:resolved,a chemical
reactioncanwrittenproductas!
cuki jmnk=k
00
00mn .
th
A
+
B
→
C
+
D
,
i
j
m
n
本研究：
m,n
th
where the states are labeled with i, j, m, and n. The states con-ou
The
species-to-species
rate coeﬃcient,k̄, is definedin terms of +AとBの励起状態i,jの違いを考慮(state-to-state
rate coeﬃcients)
sidered in Hugo et al. (2009) are the rotational levels of the H3
thetotal formation rates of C and D in rate
reactions
between A andこれらを平均化し，species-to-species
coeﬃcientsにする
deisotopologs
and
H
in
their
groundvibrational
states.
The
ground2
B:Hstate-to-species!
coeﬃcients
pertain to !
the reaction!
blk̄[A][B] =ki jmn [Ai ][B j ] =ki j [Ai ][B j ] ,k00• すでに状態ごとの化学反応係数のリストは先行研究あり(Hugo+2009) lei j mn A0 + B0 → C + D
ij ,• 励起状態の分布が得られれば，それを考慮した平均化をすることで， ha
−3
where
[A
]
is
the
numberdensity
(in
units
of
cm
) of species
where
the
species
A
and
B
are
in
their
groundstatesand C andshi
より現実的な化学反応係数が得られる。
ADincanstateenteri, etc.,is theupon
sumformation.
over all theThe
productstates m
intoandanyki jstate
coeﬃcient
k00 isn(++• 励起計算としては，(i)LTEの場合(method
1)と(ii)
H2 D,and
D2HBについてandn.
The
populationsoftheenergylevelsofA
dependobtained through summation over the possible productstates: roon the gas density
and temperature,
non-LTE(method2)を考慮した場合とで比較。
! the cross-sections for col- w
lisional transitions, and thek00
Einsteinof the radiative ro=
kcoeﬃcients
00mn .
transitions between the energy levels.
m,n For example, if we have areason, based on these parameters, to believe that only the two pe
The species-to-species
rateonlycoeﬃcient,k̄, isdefinedin terms※励起状態の臨界密度を超えたときに，これまでの計算との差異が生じる。
lowestenergy levels of A andthe groundstateof B arepop- ofpa
the total
rates of C
and
D in reactions
A andclulated,the formation
species-to-species
rate
coeﬃcientcan bebetween
calculated※本来はそれぞれの励起状態の臨界密度は当該種のアバンダンスにも依存するが，B:
from
それは固定して考えている。
2!
!
k00 [A0 ][B0 ] + k10 [A1 ][B!
0]=.ki j [Ai ][B j ] ,k̄[A][B]k̄ =ki jmn
[A
][B
]
=
lo
i
j
[A][B]ijmnij

【結果1：単一温度・密度のモデル】【結果2：ソースモデル IRAS 16293】• ダッシュ: method 1，実線: method 2，点線：基底状態を仮定• 原始星エンベロープを模した温度・密度構造で計算• 高温・高密度になるほど差が顕著になる（臨界密度を超えたところ）• 実線：method 1，ダッシュ：基底状態を仮定
A&A proofs: manuscript no. h3+• D3+などは特に（放射は観測できないが）A&A proofs: manuscript no. h3+

Fig. 4. Left: Radial distributions of the fractional abundances of selected species at t = 5 × 105 yr in a protostellar core resembling IRAS 16293
according to the model of Crimier et al. (2010). Solid lines correspond to the species-to-species model (method 1), while dashed lines correspondto the ground state-to-species model. Middle: Radial distributions of the o/p ratios of selected species, and the meta/ortho ratio of D+3 . The thinsolid lines show the thermal spin-state ratios of the plotted species. Right: Density and temperature distributions of the IRAS 16293 core model.
The blue and red horizontal lines mark the critical densities of the first excited rotational transitions of oH2 D+ and pD2 H+ , respectively.

oH2D+の第一励起状態とpD2H+の第一励起状態の臨界密度（一番右の青線と赤線）を横切る半径で，両者のo/p比の結果が変わる

Fig. 2. Total abundances (sums over spin states) of the various H+3 isotopologs as functions of time. The medium density is n(H2 ) = 106 cm−3 (upperrow) or n(H2 ) = 107 cm−3 (lower row). From left to right, the panels show calculations assuming T gas = T dust = 10 , 15, or 20 K. Species-to-species
rate coeﬃcients are adopted in two of the models (method 1, dashed lines; method 2, solid lines). The dotted lines show the results of calculations
using the ground state-to-species rate coeﬃcients.

ここでは割愛するが，o/p比の比較についても
We consider first a scheme where all of the excited rotational
states are accessible as long as the medium
density is higher
論文には結果が載っている。
2.3.1. Local thermal equilibrium

than the critical density of the first excited rotational state of(o,p)H2D+ or (o,p)D2H+ . This situation corresponds to local
thermodynamic equilibrium (LTE). One great advantage of thisaccessible owing to our assumptions (see Table 1). However, for
H+3 and D+3 we again assume that all levels can be populated regardless of the medium density.
Because the values of the rate coeﬃcients are now strictlytied to the density, the rate coeﬃcients need to be calculated ona case-by-case basis and the construction of a ready-made reaction set is not practical. Instead, the calculation of the rate coeﬃ-

新しい計算は，最近のSOPIA (Harju+ 2017)のoD2H+観測をよりよく説明
ここでは割愛するが，pre-stellar core(L1544)を模したFig. 5. Left: Radial distributions of the fractional abundances of the spin states of H D and D H at t = 1 × 10 yr in the innermost 10000 AUof the L1544 model. Solid lines correspond to the species-to-species model (method 1), while dashed lines correspond to the ground state-to温度・密度構造の場合は大きな差は生じない
species model. Middle: Radial distributions of the o/p ratios of H D and D H . Linestyles are the same as in the left panel. Right: Density andtemperature distributions of the L1544 core model. The blue and red horizontal lines mark the critical densities of the first excited rotationaltransitions of oH D and pD H ,（より低温で，高密度領域が狭いため）
respectively.
2

2

2

+

2

+

+

2

+

+

2

+

6

Spezzano, S., Caselli, P., Bizzocchi, L. et al. (A&A, in press)
http://ads.nao.ac.jp/abs/2017arXiv170706015S
A&A proofs: manuscript no. Maps_L1544【背景】星なしコアの内部では，ダスト連続波分布（H2柱密度をトレース）と分子輝線分布が異なる（CO凍結など）他，分子種ごとで異なる分布を示すことが明らかになってきている。
【本研究の内容】
星なしコアの１つL1544を22の異なる分子種，39の遷移によりIRAM30m望遠鏡でマッピング。積分強度分布の違いを定量化するべく，主成分分析（PCA）を施し，分布の違いやグルーピングの定量化を試みた。

【結果：５つのグループ】

Table 1: Spectroscopic parameters of the observed lines, divided depending on the position of their emission peaks.
Molecule
c-C3 H2 peakc-13 C3 H2 *c-C3 H2 *c-C3 H2
H2 CCCH2 CCC*C3 H* (2 ⇧1/2 ⇤ = bb )C3 H (2 ⇧1/2 ⇤ = bb )C4 H*
H2 CCO*H2 CCOHCCNC*
H2 CS*HCS+*
C34 S*
CCS
CCS
CCS
CCS*
CH3 CN*
HCC13 CN*
Dust peak
13
CN*
13
H CN*
N2 H+*
Methanol peak
CH3 OH*
CH3 OH
SO*
SO
34
SO*
SO2 *
OCS*
HCO*
HNCO peak
CH2 DCCH*
CH3 CCD*
CH3 CCH*
CH3 CCH
HNCO*
HNCO
Other
13
CS*
HC18 O+*(⇥10 5 s 1 )

rmsa
(mK)

2.17
1.04
1.89
9.32
4.82
6.12
5.95
0.63
1.03
1.09
3.38
1.48
0.11
1.60
4.40
2.78
3.29
5.48
11.11
5.74

6
21
17
16
13
7
7
10
7
18
16
16
15
32
11
14
15
16
17
10

5.25
4.14
4.47

1.05
2.25
2.01

4
20
20

96739.362
108 893.963
86093.950
109252.220
97715.317
104029.418
85139.103
86670.760

12.53c13.12c
19.31
21.05
9.09
7.74
16.34
4.18

0.26
1.47
0.52
1.08
1.07
1.01
0.17
0.47

37
9
27
23
10
18
14
14

JKa ,Kc = 60,6 - 50,5
J K = 61 - 5 1
J K = 50 - 4 0
J K = 61 - 5 1
JKa ,Kc = 40,4 - 30,3
JKa ,Kc = 50,5 - 40,497080.728
93454.331
102546.024
85457.300
87925.237
109905.749

16.31
22.92
17.30
24.45
10.55
15.82

0.30
0.26
0.20
0.35
0.88
1.75

7
7
32
20
20
6

J= 2 - 1
J =1-092494.308
85162.223

6.66
4.09

1.41
3.64

18
15

Transition

Rest frequency
(MHz)

Eup
(K)

JKa ,Kc = 21,2 - 10,1
JKa ,Kc = 32,2 - 31,3
JKa ,Kc = 20,2 - 11,1
JKa ,Kc = 51,5 - 41,4
JKa ,Kc = 41,3 - 31,2
J = 9/2 - 7/2 F = 5 - 4
J = 9/2 - 7/2 F = 4 - 3
N = 12 - 11 J = 25/2 - 23/2 F = 12 - 11 & 13 - 12
JKa ,Kc = 51,5 - 41,4
JKa ,Kc = 51,4 - 41,3
J =9-8JKa ,Kc = 30,3 - 20,2
J =2-1J =2-1
N, J = 8, 7 - 7, 6
N, J = 7, 6 - 6, 5
N, J = 7, 7 - 6, 6
N, J = 8, 9 - 7, 8
J K = 60 - 5 0
J= 10 - 984185.634
84727.688
82093.544
102992.379
83933.699
97995.166
97995.913
114182.510
100094.514
101981.429
89419.300
103040.452
85347.890
96412.949
99866.521
86181.391
90686.381
106347.726
110383.500
90601.777

6.30
16.10
6.40
28.19
23.43
12.54
12.54
35.62
27.46
27.73
21.46
9.89
6.14
6.94
28.14
23.34
26.12
25.00
18.54
23.92

N = 1 - 0 F 1 = 2 - 1 F2 = 2 - 1 F = 3 - 2
J= 1 - 0 F = 2 - 1
J= 1 - 0 F1 = 0 - 1 F = 1 - 2

108780.201
86340.168
93176.265

JKa ,Kc = 21,2 - 11,1 (E2 )JKa ,Kc = 00,0 - 11,1 (E1 -E2 )N, J = 2, 2 - 1, 1
N, J = 3, 2 - 2, 1
N, J = 2, 3 - 1, 2
JKa ,Kc = 31,3 - 20,2
J=7 - 6
NKa ,Kc = 10,1 - 00,0 J = 3/2 - 1/2 F = 2 - 1

A

Notes. (*) Molecular transitions included in the principal component analysis; (a) Average rms of the map; (b) A transition between
lambda doublets of lower energy is designated as an a component and between upper doublets as a b component (Brown et al.
1975); (c) Energy relative to the ground 00,0 , A rotational state.

(1) c-C3H2 peak（炭素鎖分子）(2) Dust Peak (N系分子)2.5’ = 21,000au

S. Spezzano et al.: The observed chemical structure of L1544
グループの代表的分布，黒コントアがダスト連続波，▼がそのピーク

45. The observed chemical structure of L1544(3) メタノール peak（O系分子）

more abundant towards the c-C3 H2 peak. Sulfur-bearing
molecules here all contain oxygen (unlike those toward
the c-C3 H2 peak). Jiménez-Serra et al. (2016) show that
O-bearing complex molecules (COM) like methyl formate
and dimethyl ether are also more abundant towards themethanol peak while N-bearing COM like HCCNC, CH3 CN

(1)

(2)

(3)

(4)

(5)

less abundant towards the south where the C/O atomic ratio is quite large, because of the photodissociation
Fig. of
1: CO,
Sample of maps belonging to the diﬀerent families observed towards L1544. The full dataset is shown in theand the formation rate of carbon chains is very
fast (e.g.A. The black dashed lines represent the 90%, 50%, and 30% of the H2 column density peak value derived from
Appendix
Herbst & Leung 1989).
Herschel maps (Spezzano et al. 2016), 2.8⇥1022 cm 2 . The solid lines represent contours of the molecular integrated
emission starting with 3 with steps of 3 (the rms of each map is reported in Table 1). The dust peak (Ward-Thompson
et al. 1999) is indicated by the black triangle. The white circles represent the HPBW of the 30 m telescope.
3.4. HNCO peak(4) HNCO Peak （pre-bio ?）(5) そのほか(1)

【PCA解析結果】３つの有意なコンポーネント• PC1：ダスト分布に似た形で，そのピークを挟むように，炭素鎖分子
ピーク（南）と HNCOピークをカバー：基本物理量である「柱密度」「温度」（右コラム下）と強い相関• PC2：炭素鎖分子ピークが −，CH3OHピークが+：C-rich chemistry（CO解離領域）と飽和有機分子領域（輻射影響小）の反相関？
• PC3：ダストピーク種とHCNOピーク間の分子の関連を示唆？：新たなS. Spezzano et al.: The observed chemical structure of L1544
発見（理由の解明は今後の課題），物理量との相関はない【議論】• 概ね，これまで言われていた傾向を定量的に再確認• 南側の炭素鎖分子ピークはダスト柱密度の急勾配部分（コアの縁）に相当，ISRFでCOが解離したことによるC-richな環境で化学がドライブ• 北側のCH3OHピーク：Oを含むComplex Organic Molecules (COM)が中心。より光が弱い環境。
• HNCOピーク：D化物の輝線複数受かっている(CH3CCD, CH2DCCH)ので，光学的厚みなどの効果ではなく，確かな第３の分子ピーク• PC3：ダストピークの化学種と，HNCOピーク(Pre-bio molecules ?)に関連を示唆？

S. Spezzano et al.: The observed chemical structure of L1544

同じ領域のHerschel データから求めたH2柱密度とTdust map

Fig. 2: Maps of the first four principal components obtained by performing the PCA on the standardised data. The maps
are constructed by summing for each pixel the contribution of each molecular transition scaled by the values reported
in Table 2, i.e. they represent each pixel projected in the space of the principal components. The percentages represent
the amount of correlation that can be reproduced by the single principal component. The blue, black, white and grey
diamonds indicate the dust, the HNCO, the c-C3 H2 , and the methanol peaks respectively.

Fig. 5: Maps of the H2 column density and the dust temperature in L1544.
L1544. The first PC map, a weighted mean of all molecular transitions included in the analysis, correlates very wellwith the H2 column density maps of L1544. The second

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