THE STAR FORMATIONNEWSLETTER
No. 286 (#21-25)
塚越崇(茨城大)9 Dec. 2016

1. Photochemical-dynamical models of externally FUV irradiatedprotoplanetary discs
2. Seeding the Galactic Centre gas stream: gravitational instabilities
set the initial conditions for the formation of protocluster clouds
3. The Gaia-ESO Survey: Lithium depletion in the Gamma Velorum
cluster and inflated radii in low-mass pre-main-sequence stars
4. The Spatial Distribution of Complex Organic Molecules in theL1544 Pre-stellar Core
5. A correlation between chemistry, polarization and dust properties
in the Pipe Nebula starless core FeSt 1-457

Photochemical-dynamical models of externally FUV irradiated protoplanetary discs
T.J. Haworth et al.

• external FUVを入れたfull radiation hydrodynamic simulation• 円盤外側でのflowを真面目に計算• 新いアプローチの説明とsemi-analyticモデルの確認[Adams+2004, Facchini+2016]• 今後の研究の礎• flowのモデル• TORUS-3DPDRコード[Bisbas+2015b]を使用• 33 gas species and 330 chemical reactions (温度に~10% error)• UV場は遠方から一様にdisk edgeに入る• dust to gas ratio=1E-5 (small dustのみがflowに存在)• PDRの温度・化学はiterativeに解く、PDRと流体構造もiterativeに解く• 6つの構造モデルで計算(Model A~F)
• disk outer radius, FUV field, and optical thicknessなどを変化• 円盤物理構造は固定

50

Semi-analytic estimate
Numerical models

H
Simulation
H2
Semi-Analytic

0

1100

O
C
CO
+
HCO

30

-8

1000

CriticalRadius, AU
log10(Abundance)

20
-5

900

10
800
0

-9

700
-10

-10

-11

-12

A

B

C

Model

D

E

F

Figure 5. The mass loss rate for each model in this paper, both for the semi–
analytic estimates and numerical models. Note that in the case of model E
the mass loss rates are indistinguishable.

• semi-analyticモデルとconsistent• FUVに対し光学的に薄いモデルでは
100
80

0
Our critical radius
Semi-analytic critical radius(model C)、円盤外縁部でCOが多く残60

LHS of equation 14

40
1200

40

存。また回転がsub-Keplerとなる。
200=>irradiated diskのindicatorになるか

-20

も？

-40
-60
-80

200 400 600 800 1000 1200 1400 1600 1800 2000 2200

R, AU

3
r
st
t

-1

4
i
n
-1e
model C
b
c
w
-2
t
R,
AU
Model
a
Figure 8. The radial profile the abundances of some key species in our photochemic
H
Figure 7. A comparison of the semi–analytic critical radii and approximate
10
A, B, C and D. The left and right hand panels are models
in which the disc outer Ie
Keplerian velocity
estimates of the critical radius derived from our simulations.
C
left hand edge of each panel is the disc outer radius. Disc outerModelpradius600
Figure 9. The dust and gas temperature profiles for model A (without theimposed disc temperature structure discussed in section 3.3). The black ver500
tical line represents the disc outer edge and the red vertical line the location-15
400of the H–H2 transition. In model A, the disc outer edge is optically thickto the incident FUV and the H–H2 transition takes place at some point in300
the flow (at ∼ 380 AU). This transition marks the point at which the opticaldepth approaches unity, the temperature in the flow decreases substantially
-20
200
100
1000
B transitions
C occur.DEF
and a numberAof chemical

H-H2 transition

8 to critical radii a factor of a few times larger than the sonic raleadthin regime
if thetransition
not exactly
at could
the discouter edge
dius.
They also
foundthat theismass
loss rates
sometimes
be it
will notat somesignificantly
radius,since
oplowerthanoccur
Adams
et al. (2004)
predictsmaller
by up toan orderof themag6
tical depth
intothisthecould,
disc increases
The H–H2 intransition
nitude(thoughin part, berapidly.
due to diﬀerences
the PDR issignificant
in PDRmodelsbecauseit isassociatedwithincluding
large gracodeemployed).
Here,
we haveverifiedthat
the solutions
dientsin the thermal
andstructure.
In thewith
caseof ourthenon–isothermal
terms
arechemical
accurate whencomparedconsis4
models,radiallyinterior to the H–H2 transition, the temperature
tent
dynamical
models.
is muchlower
beyondwhich
illustrate using
the temFinallywethannotethat it,given
thewesemi–analytic
solutionsperature
profiletheyof models
A in useful
Figure benchmarks
9. For modelfor
A, exterior
arecan make
future2 accurate,
photochemical–dynamicalcodes(though due
is required
reto the H–H2 transition, thetemperature
onlycaredecreasesby about
garding
capturingofAU
the throughout
disc outer edge,
eitherhigh resolu20 K over
∼ 1800
the restof using
the modelled
flow
−1
tion
or forcing
there).
(∼0 0.01
K AU cells). Converselyinterior to the transition, from that
10
100
1000
point to the disc outer edge, theR,temperature
decreases by over 30 KAUin only 200 AU (0.15 K AU−1 , over an order of magnitude faster).

Azimuthal velocity, km/s

Mass loss rate, log10(Msol/year)

-7

n
s
t

R, AU

log10(Abundance)

T. J. Haworth et al.

Temperatur

10

A

W
m
c
a
F
w
3
2
M
b
b

Velocity Corrugations

0.0

-0.2

20 pc

0.8

0.6

0.4

0.2
0.0
Galactic Longitude (deg)

359.8

359.6

359.4

1000.10.01022 N(H2 ) (cm 2 )Dust Ridge

Residual Velocity (km s 1)

Galactic Latitude (deg)

0.2

Velocity (km s 1)

Galactic Latitude (deg)Seeding the Galactic Centre gas stream: gravitational instabilities set the initial conditions for theformation
J. D.
Henshaw etofal.protocluster clouds
0.2
A
J.D. Henshaw et al.

-0.1

10

-60.0
-80.0

1-100.0-120.0-0.1
ure 1. The Herschel-derived molecular hydrogen column density map of the CMZ (Battersby et al. in preparation). The black contours15.0
represent the+grated emission from N2 H J = 1 ! 0. Contour levels represent 1, 10, 50, and 90 per cent of peak emission. The orbital solution of Kruijssen et al. (2015)
10.0
ighlighted by the blue line. The portion relevant to this study is indicated by the solid line. The black dashed and black dot-dashed rectangle reflect the
5.0
on of interest to the present study and the dust ridge, respectively. The scale bar assumes a distance of 8.3 kpc (Reid et al. 2014).
0.0
-5.0
-10.0
1; Caswell et al. 2010), towards Sgr B2, which displays promiure 1 is a map of the inner CMZ. The colour-scale represents
thet star formation activity (see above). The coherency of the dust
Herschel-derived column density (Battersby et al. in -15.0
preparation).

• CMZのdust ridge cloudの初期状態を調べるため、上流にあるガスの運動を調べる• Mopra CMZ surveyのデータを使用[Jones+2012]•

N2H+(1-0), Dendrogramを使った構造抽出

B

-0.2

-0.3

-0.4

-0.5

-0.6

C

ge gas stream is supported by the comprehensive decomposition
The present investigation focuses on the region 0. 7 < l < 0. 0,
0.0 -0.1 -0.2 -0.3 -0.4 -0.5 -0.6 -0.7
he complex molecular gas kinematics performed by Henshaw
0. 1 < b < 0. 1, which is indicated by the black dashed rectanGalactic Longitude (deg)l. (2016). In this scenario, star formation is initiated at a comgle. The black contours highlight integrated emission of N2 H+ . Then zero point, triggered as the gas clouds are tidally compresseddata enclosed within the black dashed rectangle were analysed usFigure 2.
Galactic longitude versus: (A) Galactic latitude. A column dening their pericentre passage at ⇠ 60 pc from the bottom of theing the Semi-automated multi-COmponent Universal
Spectral-line
sity
map
of
the CMZ focusing on the region of interest (Battersby et al. in
1
actic gravitational potential (Kruijssen et al. 2015). Dynamical
fitting Engine (scouse ; Henshaw et al. 2016).
preparation).
The colour scale and blue solid line are equivalent to those inλ~22.5±0.1
pc(inclination補正後)でフィット
deling of the gas stream vel
performed by Kruijssen et al. (2015),
Fig.
1.
The
contours
refer to dendrogram-identified structures. The red condicts that G0.253+0.016 and Sgr B2 are separated by 0.43+0.22
tours are those spatially associated with the corrugated velocity field; (B)0.08r, which corresponds to a single free-fall time (t↵ ⇠ 0.34 Myr).
vLSR . The data points refer to the centroid velocities of spectral components
3 RESULTS
he context of the proposed evolutionary timeline, this result sugextracted using scouse (blue data points in panel A); (C) residual velocity
afterremoval of a linear velocity gradient (Equation 1 and § 3). The redts that once star formation
has been initiated, it happensは~8pc
rapidly.
A of Fig. 2 provides a close-up view of the
Herschel-derived
minimumな間隔λ≒λPanelsep
J(~6pc)dashed line represents the best-fitting solution to a sinusoidal model used
The question is whether it is reasonable to assume that thecolumn density map (Fig. 1). It focuses on the location of the upto describe the blue data points. Grey data points indicate those that are
uds have similar initial conditions, such that the tidal compresstream velocity field (depicted by the blue dots).
To identify
the process (see § 3).
excluded
from the fitting
最大波長λ
は~22
pc
~>
λ
~17pc
vel
T
n at pericentre causes them to evolve and form stars on simimain structures we use dendrograms (Rosolowsky et al. 2008).

• 速度パターンに揺らぎを発見=>ピークにガスが集積する様子•• ジーンズ長, Toomre lengthと比較••• 速度パターンがgas streamの重力不安定の要因か影響なのかは不明

gasのtraffic jamによって不安定となったのか、その逆か？

The Gaia-ESO Survey: Lithium depletion in the Gamma Velorum cluster and inflated radii in lowmass pre-main-sequence stars
R.D. Jeffries et al.

• 実際に観測される星の半径は理論より~10%ほど大きい=>温度や光度(質量や年齢)見積もりに影響を与える• dynamo-generated magnetic activityで説明できる• pre-main sequenceでも同じかもしれないので、radial inflationを調べる• Gaia-ESOサーベイのデータを使用• クラスターに対するunbiased survey, Gamma Vel. clusterのデータを使用• Prisinzano+2016で導出したPMS memberをターゲットに解析
Inflated radii in PMS stars• 測光データとLi spectrum(a)MV場なし)では、観測値のHR-diagramとEW(Li)を同時に説明することができないLithium EW (mÅ)• 従来の進化トラック(磁(b)Ages 7.5,14 and 30 Myr(V-I)0Ages 7.5,14 and 30 Myr(V-I)0• PMSが標準モデルより大きい半径を持ちTeffが小さくなっていれば？
=>Li depletionが遅くなり、より後期で生じる• Jackson&Jeffries(2014a)に乗っ取ってstarspotsの影響を考える• R*, L*, Teffが変化

6

R. D. Jeffries et al.

10% inflation(a)• inflationを入れた進化モデル

MV

Lithium EW (mÅ)(magnetic Dartmouth models)
だと、HR diagramもEW(Li)も両方を満たすことが可能。年齢はより後期に。
• beta pic moving groupに対しても同(b)

Uniform temperatureages of 18 and 21 Myr

Uniform temperatureages of 18 and 21 Myr

様の結果[Messina+2016](V-I)0• magnetic activityによるradius

(c)

MV

• バイナリ間の物理量の違い• ZAMSのturn-on/offによる年齢の違い• PMSとZAMSで見られるLi depletion(d)Lithium EW (mÅ)

inflationは、色々な問題を解決しうるかもしれないの違い(V-I)0Spotted surface
ages of 23 and 26 Myr(V-I)0Spotted surface
ages of 23 and 26 Myr(V-I)0

The Spatial Distribution of Complex Organic Molecules in the L1544 Pre-stellar Core
I. Jimenez-Serra et al.

• 低温コアにおけるCOMsのdepletionを調べる• pre-stellar core L1544– 16 –• IRAM30mによる3mm帯の高感度観測• コア中心と4000au離れた箇所(CH3OHでbright)のCOMsスペクトルを取得し比較• いくつかのCOMsを検出(次ページ)• アバンダンス導出• CH3OH-pでCH3O, CH3OCH3, CH3CHO増大,
他はほぼエラー範囲• モデル計算[Vasyunin&Herbst(2013)コード]• t~105yr あたりでgas phase COMのアバンダン
スピークはちょうど4000auになる=>CH3OH-pおよびCO depletionの半径(Caselli+1999)と同じ• モデルアバンダンスは観測を再現するが、CH3CHOのenhancementは小さめになる• O-bearingは. 1.— Sample of COM lines detected toward L1544’s dust continuum peak. Red lines show CH3OH-pで強いGaussian line fits derived for the COM transitions (see Table 1). The CH3 O spectrum
been extracted from the ASAI data (Vastel et al. 2014).

• N-bearingは中心で強い. 1.— Sample of COM lines detected toward L1544’s dust continuum peak. Red lines show
Gaussian line fits derived for the COM transitions (see Table 1). The CH3 O spectrum
been extracted from the ASAI data (Vastel et al. 2014).

• rotation diagram
によるTex導出• 5-6 K at center, 5-8 K
at CH3OH-p

τm , optical depth of the main component. (See Estalella 2016, for further details of the HfS fitting procedure.)Density (A correlation between chemistry, polarization
1e+05and dust properties in the Pipe Nebula starless core
Av bg=9.5FeSt
mag 1-457
50000 where
with
Aguti
et
al.
2007)
exceptatthesouthwestern
corner
C. Juarez et al.
the ratio seems to be more balanced.

10000
20000
0
15000
5000
1-457
(d~145pc)• FeStRadius
Juárezet al.: Juárez
Chemistry,polarization&
grain
growth
in
FeSt
1-457
(au)
et al.: Chemistry, polarization & grain growth in FeSt 1-457
0

5000

10000

Radius (au)

15000

20000

3.1.2. PdBI data

Fig. 7. Temperature profile (upper pannel) and Bonnor-Ebert density
globule, 4M pre-stellar core
•In BokA&A proofs:
Figure 3 we show a section of the channel map showing thenor-Ebert
fitIntensity
parametersfit
ofparameters
FeSt 1-457.
panel:
profilefromthe1-457.
1.2 ⦿mm dust conTable
4. Bonnor-Ebert
of FeSt

manuscript no. Juarez_et_al_2016
on map (Frau et al. 2010, 2012b). Black line and dots: profile (lower panel) used in this work (see Section
4.1).
+
N
H
(1−0)
emission
detected
with
the
PdB
interferometer.
Thebgb2bars Rdepicting Tthes with vertical±1-σξmax
range. ρGreen
Mass
AVMass Stable?
Agec
cξ/ρR
Model 3 ρc −3
ρ3out
Rout
Tb
ρ5cP
/ρoutR −3
Pout
Abg
Stable?
Agec
c
max
V
weak
emission(6σ)
isbetterdetectedinthesecondpanel
corre(10 cm Bonnor-Ebert) (10(103 cm
au)
(K)
(yr)
ine: isothermal
fit.
−3
3 Red (solid) line: fitted (10 K cm ) 5 (M⊙ ) −3 (mag)) (10 au)(K)
(10 K cm ) (M⊙ ) (mag)(yr)
to the strongest
line ofinthethe
threecentralhyperfinelines,
sensitive
tothecolumndensityandprofilethetemperature
profileshown
upa adding sponding
5 does not depend on temperhermalBE isothermal
200 ±•20a N2H+
20 ±
10.5
±
10.5
±0.1
0.7 10.547 ±±53mm連続波
0.6
2.7
9.52.7No
9.6No
× 10 9.6 × 105
3mm
line
200
± 120&of
20
± 0.1
1 km
10.5
0.7
47
±±Fig.
50.1 30.6± 0.1 the9.5
5
at afitting
velocity
5.80
sis−1±±ρ.survey,
The
last
panel
of
shows
d
5
ature.
Previous
studiesinstarlesscores(e.g., Crapsi et al. 2007)
gure
7.
The
best
centraldensity
=
2
×
10
200
±
20
20
±
1
12.0
±
0.1
9.8
0.7
40
±
5
0.8
±
0.1
2.7
9.5
No
9.6
× 10
d
c
profile BE + T
200 ± 2020 ± 112.0 ± 0.1
9.8 ± 0.7
40 ± 50.8 ± 0.1
2.7
9.5
No
9.6 × 105
profile5−3spectra
(in
red)
at
the
positionofthe6σ
detection.
The
IRAM
d core boundary radius, Rout = 20000 au is marked by show that those with nH2 > 10 cm may have an inner temersa fitted
for the•isothermal
model.
Theof the fitted
parameters
Rout weand ρTcan
wereandestimatedbyanalyzing
単一鏡+干渉計combineも
c ,and30m
spectra(in black)is alsoas comparison,
Parameters
fittedfortheBE
isothermal
BE uncertainties
model.
Theshown
uncertainties
ofthe fitted ρparameters
T wereestimatedbythe
analyzing
the center,A&A
c , Routedline.
2 Lower panel: AV profile from the dust extincproofs: manuscript no. Juarez_et_al_2016
gradient.
These
cores
are
colderat werethereaching
2by varying the parameters. The uncertainties of the peratureof theχresidualfitderivedphysicalparameters
ξ
,
ρ
/ρ
and
P
were
max
c manuscript
R ξmax , ρno.
out
A&A
proofs:Juarez_et_al_2016
increase of theχresidualfit
byvaryingtheparameters.
The
uncertainties
ofthederivedphysicalparameters/ρ
andP
A&A proofs: man
c
R
out
see
that
the
hyperfinestructure
is
also
seen
in
the
PdBI
spectrumán-Zúñiga
al. 2009,
2010). Black,green (long-dashed) + temperatures as low as 6 K, than atN2H+
througherroretpropagation
the outer shells, where theyassessedthrougherror analysis.
propagation
analysis.
indicatingthatindeedis acs .real
N2 H detection from theb usedature
to determine
thedetermine
sound
speed
value,
ctheres . boundary
lines
as in
upper
The
fittedcore
radius,Temperature
usedpanel.
to
the
sound
speed
value,
1.2mm
cont.
may
be
heatedthe=sphereinterstellar
radiationfield(e.g., Marsh et al.
cn Aikawaetal.
(2005)
results
followingtheevolutionofamarginally
Bonnor-Ebert
sphere10 K, (Tα ==1.1,
whereis where
PdBI.
The
emission
filteredtheoutbywithrespect
to bythe(Tbg theBased on Aikawa
et al.
(2005)
results following
evolutionof PdBIaunstable
marginallyunstable
Bonnor-Ebert
10 K,
α = α1.1,
α is
u,
and
A
value
of
the
surrounding
medium,A=
9.5
V pressure
nal gravity
toratio).
We tested
diﬀerent temperature profiles to check whetherVthe internal
gravity
to pressure
IRAM
30m
isratio).
estimated
to bethe∼upper
98%,
from
a2014).
comparisonof theisothermalではズレがあり、温度構造を入れるd•d Bonnor-Ebert
model
using
the temperaturepanel
of Fig.panel
7. Theuncertainties
are the sameareas thein theisothermaledandmarkedbya verticaldashedline ofand profile
horizontal
Modified Bonnor-Ebert
model
using
the profile
temperatureofthe upper
of
Fig.
7.
The
uncertainties
sameasin the isothermalprofile following:thefits itimproved.
We
found
that
aemission
temperature
PdBI
spectra(convolved
withaGaussian
toobtaintheIRAMecausethenewtemperature
profiledoes
notmodifythe
Bonnor-Ebert
density
profile,only
modifies
theresulting
1.2
mm
model because the new temperature profile does not modify the Bonnor-Ebert density profile, it only modifies the resulting
1.2 mm emission
pectively.
とよく合う
30m
beam size) and the IRAM 30m spectra at the peak position.
ion 4.1).
(see Section 4.1).
(T out −T in4.) Color scale: Moment-zero map of the IRAM 30m and PdBI
Fig.
Given the smallest antenna baseline of PdBI
observations,T (r)= T out − the combined
77, 88, 97, (4)99.5, 100 percent of
多様な分子分布2 ) data. Contours are 57, 67,
(1
+
(r/r
)
largestangularscale
detectable
by
the
PdBI
observations
is
∼
12
−1
−1
in
• コアの物理モデルとして使用
the peak, 1 Jy beam km s . The synthesized beam located at botor ∼ observations
1700 au (following
et al. 2010). tom right is 10.8 × 6.11 arcsec2 , with a P.A. of 10.79◦ . Black contours:
derived from arcsec
ammonia(9.5 ±Appendix
0.1 K;12 of(rPalauin =12 2500 au) with T in = 6 K at the center of the core andObservations
100
Observations
Thus,
about
98%
of
the
emission
detectedwiththe IRAM 30m MAMBO-II 1.2 mm dust continuum emission at an angular resolution
al. 2008).
The
value
obtainedforthederivedpaBE isothermal BE isothermal
10 increasing
10
until T out of=1512arcsec.
K at Contours
a radiusareof 59,
9000
aufittedmuch
80BE
fit + T profileBEfitscales+ T profile≥ 1700 au.
comes
from
structures
at
79,
89,
99
percentof the peak, 57 mJy
was 10.5 ± 0.7. The error was estimated through 8• IRAM30m & PdBIによる観測

Temperature (K)Temperature (K)-1

Iv (mJy beam )• BE球による1.2mm連続波のフィット

better 8the data. The secondbeam−1 . row of Table 4 shows the best fit pa6
tion analysis,
being
ρ
and
R
the
main
contribc
outrameters of the Bonnor-Ebert+temperature gradient model. Fig40
4
4
3.1.3.
IRAM
30m+PdBI
ncertainty
(see
Table
4).
This
value
is
significantly20
ure 7 shows
the Bonnor-Ebert density and temperature profiles +22nitrogen-bearing molecules (e.g., HNC and N2 H ; panels (a) tohe critical0 value (6.5), thus the core is gravitation- that appear
tofit best(f))
the thedata.
Inemission
addition,isthe
redcompactline in Figure
6 peak coincides
In Figure 4 we show the moment-zero map0 of the merged
IRAM
0
gas
very
and the2e+05
in accordance
withKandorietal.
(2005)
results.
2e+05=20000 (seeau R =20000
au 2.3), overlapped
shows withthe predicted
1.2 with
mm thedust
intensity
andmm
extinction
ra- emission. A
30m and PdBIR data
Section
IRAM well40
peakof the 1.2
dust continuum
1,5e+05
1,5e+0530m
mapsignal-to-noiseof the dust continuum
emission
at 1.2
7 is observed
withMAMBO-II
an excellent
to dialprofile fromthis similar
Bonnor-Ebert+temperaturemodel.
behavior is seen in C3 Hgradient
2 (panels (g) and (h)). However,
30
−1
−1
mm.
The
peak
is
1
Jy
beam
km
s
and
the
arc
structurehintedor-Ebert20scenario. By using the isothermal Bonnoret al. (2015)foralso
clear decreaseof theeﬀective
C4 Hfindandamolecules
containing
oxygenin our sample (e.g.,
1e+05 Forbrich
1e+05
+
at
the
column-density
single-dishmap(panel(b)ofFig.1)
is
now
HCO
,
CH
OH;
panels
(i)
to
(k))
the
emissionis shifted ∼ 44′′
we
found
a
good
fit
for
the
A
map
but
nondusttemperature
towards
thecenter
of
FeSt
1-457
from
Herschel
A =9.5 mag A =9.5 mag
3
V
50000
50000
10
clearly
seen.
towards
southwest
withvalue
respectattothe
thecenterdust. An extreme caseﬀerences in thedustemission profile (see green observations. However,theythefindthe lowest
18
13
0
0
ofthanthis kinetic
wouldbe
C O and derived
CO molecules,
010000 be interpreted
20000
0
10000
20000
5000This 15000
15000
5000
15000
10000
20000
10000
20000
15000
line in5000
Figure6).
canas a de- 00 to be 5000
13.5
K, Radius
highergasthetemperaturefrom which present′′
Radius (au)
Radius (au) Radius (au)(au)strong
emissionpeakingthan
to theat ∼ 120
3.2.approximation
Chemical survey(FTS) the extinc- ammonia (9.5 K; Rathborneextended
the isothermal
becauseet al. 2008)
and higher
thesouthwest,
temAV (mag)

v bg

v bg

6

-3

Density (cm )

out

-3

out

Density (cm )60

diﬀerence could be related to the eﬀect of averaging the emission from Herschel along the line of sight which would take into+
account
dust from the cloud at higher temperatures. Note that
N2H (1-0)
ARTISTによる放射輸送計算
the temperature profile we found fits well the FeSt 1-457 core is
1,5similar to the
one
found
for
the
L1544
core
(Crapsietal.
2007),• Tdust=Tgas, no velocity fielda core with significantly higher density, but also to core 16 fromMarsh et al.
(2014), which has a density similar to that of FeSt1分子分布を再現するには~8000au,14500auで•
1457.
アバンダンスを変化させる必要がある
Even though
we did not modify the Bonnor-Ebert density
profile (lower panel of Figure 7), which assumes a constant tem多くの分子はコア中心でアバンダンス低perature, we•finallyconsidered the temperature profile shown in
0,5
the upper panel=>コア中心でダストに吸着
of Figure 7 to generate the synthetic maps. This+apparent inconsistency is not important in our case. Sipilä et al.
N2H VESPA data
(2011) •showthat the isothermal and non-isothermal
Bonnor-10-10
アバンダンス変化の半径はgrain
growthの半ARTIST X=2.5x10 , 1.5x100-10Ebert density profiles are fairly similar. In addition, as the gas
ARTIST X=2.5x10径[Forbrich+2015]とconsistentpressure is proportional to the temperature, reducing the tem0
10000
5000
15000
A&A proofs: manuscript no. Juarez_et_al_2016
perature by half, reduces the pressure by half as well, which
Radius (au)makes分子分布の非対称性
the core even more unstable against gravity. Therefore,+
this model is good enough to say that FeSt 1-457 has a density Fig. 8. N2 H ARTIST abundance estimate. Annuli averaged integrated
profile •of C4H,
a very HCO+,CH3OHは南東にピーク
young core, it is gravitationally unstable and intensity vs. annuli radius. Black line: IRAM 30m VESPA data. Bluedashed line: ARTIST radial integrated intensity profile for a constantseems to becolder at the center than in the outer parts.
=>南東からのUV照射による可能性(PDR)−10-1

Annuli averaged integrated intensity (K km s )••4.2. ARTIST••

西~北西側にθ-Oph(B2)がある

abundance of 2.5 × 10 . Red line: ARTIST radial integrated intensity
profile with a step function abundance of 2.5 × 10−10 and 1.5 × 10−10 for
smaller and larger radius than ∼ 8000 au (55 arcsec; indicated by thebrown vertical dotted line), respectively.

磁場との比較
Once thephysical model of temperature and density of the core
was determined (see previous section), we estimated the abundataと比較
dances •forAlves+2014によるpol.
the molecular lines detected with
the IRAM 30m obfirst computed integrated intensity maps (moment-zero) using
servations.
南西側で偏光度が高い
We • used
the Adaptable Radiative Transfer Innovations the moment task over a velocity range that included all the emisfor Submillimeter
Telescopes(ARTIST; Brinch & Hogerheijde sion. Then, we used the ellint task for the integrated intensity=>radiative
torqueによるダスト整列ならFUV
2010; Padovani et al. 2011, 2012; Jørgensen et al. 2014) soft- maps to compute the line radial profiles with annuli of 10 arcsec
照射とconsistentware to generate
a synthetic spectral cube of the molecular lines width, which is a value between one third and one fifth of thedetected. We assume that the source is spherically symmetric angular resolution of the observed molecular lines.
Figures 8 and 9 show the annuli averaged integrated intentorque的• コア中心で偏光度↓もradiativewith the density
and temperature radial profiles derived fromthesity (moment-zero) vs. the annuli radius for the observed (open
Bonnor-Ebert model derived in the previous section.
circles) and ARTIST produced data.