sources or ⇠ 1.00 5 Gaussian sources.
nents toward the southeast and west from the SMM4B
We ofalsotwo
performed
self-calibration
for the continposition. Main
The peakSMM4
intensity, total flux density, and de2. The Distinct Evolutionary NatureClass
0 Protostars
in Serpens
uum data using tasks in CASA (clean, gaincal, andconvolved size of the SMM4B continuum emission are
Yusuke Aso, Hirano Naomi, Yuri Aikawa,
et al.
25 mJy beam 1 , 173 mJy, and 0.00 70 ⇥ 0.00 53 (P.A.=95 ),applycal). Only
the phase was calibrated first with thetime bin of 3 scans (⇠ 18s). Then, using the derived
respectively. The peak intensity corresponds to a brighttable, the amplitude and the phase were calibrated toness temperature of Tb = 2.0 K. The total flux density
Serpens MainのSMM4をALMAで観測
gether. The self-calibration improved the rms noise level
corresponds to a gas mass of 0.29 M , while the peakof the continuum
maps by a factor of ⇠ 2. The obtained18
intensity corresponds to a gas mass column density of（Cycle 3、分解能~0.55ʼʼ(240 au)＠1.3
mm, 12CO
J=2-1, SO JN=65-54, C O J=2-1）
calibration tables for the continuum data were also ap0.04 M beam 1 under the same assumptions as above.
plied to the line data. The noise level of the line maps
were measured in emission-free channels. The parameT (K)● 1.3 mm continuum emission mapters of our observations mentioned above and others are
summarized in Table 1.
b

2つのコンパクトソース（SMM4A, SMM4B）、SMM4B周辺の広がった構造
3. RESULTS
輝度温度3.1. 1.3 mm continuum

Figure 1 shows a map of the 1.3 mm continuum emisSMM4A： 18 Kと高い
sion in the SMM4 condensation. The emission has two
local peaks. We label the stronger and the weaker
SMM4B： 2 Kと低い
peaks as SMM4A and SMM4B, respectively, in thispaper. SMM4A shows a size of ⇠ 200 (860 AU) at
the 3 noise level, while SMM4B shows a ⇠ 500 (2100
見た目からAU) size at the same noise level. The peak positionsof SMM4A and SMM4B measured by Gaussian fitting
SMM4A： r~240 auにシャープなエッジを持つ、disk状構造の存在
were ↵(J2000) = 18h 29m 56.s 718, (J2000) = 1 130 15.00 58
SMM4B： コンパクトな成分 or
and半径56↵(J2000) =auの小さなdisk?
18h 29m 56.s 526, (J2000) = 1 130 11.00 50,
respectively. The fitting uses emission within the 3
contour enclosing each peak after primary beam correction, providing peak intensities and deconvolved sizes(FWHM), as well as the positions. Total flux densities● 12COof the sources were measured by integrating the flux in6
the regions enclosed by the 3 contours after primary
SMM4A： ファン状のblueshiftした単極アウロフロー
beam correction.
CO (J=2–1): –13 - 9 kms–1
The emission around SMM4A shows a compact strucSMM4B： アウトフローは双極でcollimateしている
ture with extensions to the east and the south. Its
peak intensity, total flux density, and deconvolved
blueshiftとredshiftの軸は30ほどmisalignsize are 205 mJybeam 1 , 492 mJy, and 0.00 75 ⇥ 0.00 46(P.A.=145 ), respectively. The peak intensity corresponds to a brightness temperature of Tb = 18 K. The
dust temperature in Serpens Main was estimated by1000 au
Lee et al. (2014) to be ⇠ 20 K. Thus, the continuum
emission in SMM4A is thought to be optically thick.
A lower limit to the gas mass can be calculated fromthe total flux density to be 0.83 M by assuming opti(a)cal thinness, a dust temperature Tdust = 20 K, opacity21
coefficient (850 µm) = 0.035 cm g
(Andrews & –1
SO (JN=65–54): 2 - 14 kms

SMM4A

SMM4B

1000 auFigure 1. Continuum emission map of SMM4A and
SMM4B. Contour levels are 3, 6, 12, 24, . . . ⇥ , where 1
corresponds to 0.1 mJy beam 1 . The color map showsbrightness temperature in the unit of K. Yellow plus signs
and lines denote two peak positions and major axes derived
from 2D Gaussian fitting. Yellow circle denotes ALMA primary beam (FWHM⇠ 2700 ). A blue-filled ellipse at thebottom-left corner denotes the ALMA synthesized beam;
0.00 57 ⇥ 0.00 46, P.A. = 85 .
Aso et al.

3.2. Spectral Energy Distribution

CO (J=2–1): –43 - –13, 9 - 46 kms–1

Figure 2a and 2b show Spitzer 24 µm and Herschel
70 µm images of the SMM4 region. SMM4A and
SMM4B are not detected by Spitzer and only marginallywith Herschel where they are much fainter than a neighboring Class 0 protostar. Figure 2c shows the SED of
the overall submillimeter condensation SMM4 as definedby the JCMT and derived from Spizter IRAC (3.6, 4.5,1000 au
5.8, 8.0 µm), Spizter MIPS 24 µm, Herschel PACS
70 µm observations, ALMA 1.3 mm (this work), andthe literature: CSO SHARK-II 350 µm (Suresh et al.
2016), JCMT SCUBA 450 µm and 850 µm (Davis et al.
(b)1999), and CARMA 3 mm (Lee et al. 2014).
The upper
limits in the SED, which are set to be the flux densities–1
SO (JN=65–54): –21 - 2, 14 - 25 kms

SO

SO (JN=65–54): –21 - 2, 14 - 25 kms–1

SMM4B：アウトフローの端と、SMM4B付近のショック領域

1000 au10(d)

Aso et al.

mean velocity (moment 1; color) maps in (a) 12 CO lower, (b) 12 CO
nts of SMM4A and SMM4B. The integrated velocity range of eachb2 of 20 , (b) from 10 in steps
ntour levels are: (a) from 20 in steps
eps of 3 , where 1 corresponds tob1(a) 20, (b) 35, (c) 16, andb2 (d)
b1
b0
he same as in Figure 1. Blue-filled ellipses
at the bottom-left corners
b0
r0
12
00
00
= 82 for CO emission and 0. 65 ⇥ 0. 52, P.A. = 85 for SOr1
r0
and 150 , which is used to make a position-velocity diagram (Figurer2

s1
,
s
t
s

s

d
ae
)
B,
d-

12COのlobeに沿ったPV図：これらのペアが同じmomentを持っていると仮定

blueやred lobesの傾きは、ib ~36 とir ~70

r1

shifted lobes of ther2 SMM4B outflow, P.A.= 15 , and(d) the direction perpendicular to the outflow direction,
P.A.=75 . The direction(a) is also along the main(b)ve(a)(c)
locity gradient seen in the mean velocity map (Figure
Figure 8. (a) Integrated intensity maps of blue- and redshifted components of the 12 CO emission. The integrated velocity
4). Inaddition
systemicrange
is 15 km tos 1this< |Vgradient
Vsys | < around
50 km s 1the. Contour
levelsveare from 3 to 24 in steps of 3 and then in steps of 6 ,1
where
1 corresponds
38 mJy beam
km s 1 .component
The black dashedofpthe integrated intensity maps. (b)locity,Figure6a alsoto shows
a compactat curve traces peaks
palong the curve shown in panel (a). Contour levels are 2 2, 4, 4 2, 8 . . . ⇥ , where 1 corresponds
VLSRPosition-velocity= 7 km s 1diagram.1 These
two components are also seen
to 2.6 mJy beam . Color also shows the same PV diagram in logarithmic scale. The rectangular frame denotes the velocity
in allof thediagrams
6b-d).
range|V other
Vsys | < PV
15 km
s 1 . Solid (Figureand dashedlines trace Hubble-law motions derived by visual inspection; solid (dashed)lines are6b
considered
be a pair (seethe text in at
moredetail).
(c) Momentum profiles along the dashed and solid lines shown in
Figureshows tonegative
intensities
the
SMM4A
00
panel (b). The width
00 of cut is 0.55 (1 beam) along the positional direction. Blue and red lines show the profiles of the blueposition(o↵set=5 ). Therespectively.
negative Circles
intensities
consistofmomenta and 3 lengths (positions) (see the text in more
and redshiftedcomponents,
signs denotemean
two detail).
components along the velocity direction; the component
at 7 kms 1 . described
V . 8 above
km s in1 theappears
the simplest
hypothesis
calcu- to be
au and ⇠ 2000 au for the shorter and longer pairs, reassociatedto emission
surroundingthelation below
for the SMM4B
outflow. SMM4A,
This shouldwhilebe
spectively.
1
reasonableapproximation
becausemore
redshiftedcomponent(8 kmitssbending. V suggests. 9 km s 1 )that the inclination angle di↵erence can strongly a↵ect
the projected momentum in this system.
The inclination angles can be estimated from Figure
8c on the assumption discussed above. With a given inclination angle ib (ir ) of a blueshifted (redshifted) lobe
(0  i  90 and 0 means the pole-on configuration),
an intrinsic momentum, p, is observed as a projected
momentum, pb = p cos ib (pr = p cos ir ), while an intrinsic length, l, is similarly observed as a projected length,lb = l sin ib (lr = l sin ir ). These are summarized aslb /lr = sin ib / sin ir and pb /pr = cos ib / cos ir . These
ratios are independent of the assumed excitation temperature and the conversion factor if those are the samein the blue and red lobes. With the derived mean momenta and the 3 lengths, the inclination angles are

線状の2つのペア

4.2. Continuum Visibility● SMM4Bアフトフローが曲がっている原因

Young stellar objects show remarkable structures depending on their evolutionary phases, growing disks
out of spherical or flattened envelopes. To reveal such
structures related to evolutionary phases in SMM4A
and SMM4B, the observed continuum visibilities are inspected in this subsection in detail, which unveil intriguing aspects of the continuum structures more clearly
than from the image inspection (Section 3.1). The visibility plots shows in Figure 9 are derived from the averaging over all scans for each pair of antennas.
Since the total flux density of the continuum emissionin SMM4A is & 3 times larger than that in SMM4B,
the visibility distribution is expected to be dominatedby flux from SMM4A. In fact, Figure 9 shows that thei) 0.1 pcスケールのアウトフローとの力学的相互作用ii) アフトフローと磁場（mGのオーダー）に起因する電流での、電磁相互作用iii) より小スケール構造（ゆがんだdisk?）←空間分解できていない

3Dでのそれらのずれは、~40

12● C18O

SMM4 in Serpens MainbcAso et al.
7

The extended component can also be seen in the image
domain(Figure1). 連続放射に対する吸収and a more
extended brighter component at velocities
SMM4A：> 7.35 km s 1 with a size of ⇠ 600 (2600 au), decreasing
at higher4.3.
velocities.
small velocity gradient from a
SMM4B：
放射として観測
C18 O A
abundanceablueshifted-southern part to a redshifted-northern partOn thecan
basis
of thecontinuum
structuresdSMM4B周辺：
落ち込み、回転するenvelope
be seenin thisPV diagram
though it isdescribed
not as proabove, we
cancalculatethecolumndensity(Figureof H6a,2
nounced as that in the other PV diagrams
molecules6c,alongeach line of sight with the following
and 6d).
1000 auequation: The main velocity gradient seen in the C18 O line is neither parallel nor perpendicular to the associated 12 CO⌧dust
outflow.
bending
outflow
alsoecomplicates
theIcont.
= (BTheB⌫ (T),(1)ge⌫ (T )bg ))(1ometry of this system and the uncertain orientationand inclination angles prevent us from measuring kinewhere Icont.
, B⌫ , T , Tbg = 2.73 K, and ⌧dust arematic quantities such as rotation and infall motion. We
Figure 4. Integrated intensity (moment 0; contours)theand observed continuum intensity, the Planck function,
thus only mention two interpretations of the velocity
mean velocity (moment 1; color) maps in the C18 O emisFigure 11. Map of C18 O abundance estimated from the
18the
the
dust/gas
temperature,
background・SMM4Bの連続波ピークでのCOの存在量：
gradient
in the C18 O
line.
One is a temperature,
rotating and insion of SMM4A and SMM4B. The integrated velocity range
observed C18 O and continuum emission. Coordinates are
and the falling
dust opticalrespectively.
The dust
envelope depth,
whose rotational
axis is parallelto theis from 6 to 9 km s 1 . Contour levels of the integratedo↵sets from the SMM4B position, where 100 corresponds to
典型的なISMよりも約50倍小さい
intensity maps are from 3 in steps of 5 , where 1 opacity
corassociatedoutflow.
6c overall andshowsthea velocity
law,
gas anddustFigure
temperature,gas1
1
429 au. Contours and synthesized beam (red ellipse) are theresponds to 6 mJy beam
km s . Plus signs and circle
gradient
along
outflow direction,axis (c)in Figto-dust mass
ratio
aretheassumed
to be (850µm)=
same as those in Figure 1. Pixels are masked if the continuum
are the same as in Figure 1. A blue-filled ellipse at thethe blueshifted components on the north・~1500 auスケールでの存在量：
20.035 cmure
g 4,1 from
(Andrews& Williams 2005),= 1,
bottom-left corner denotes the ALMA synthesized beam;
intensity is below the 3 level.
ern side to the redshifted components on the southern
0.00 64⇥0.00 52, P.A. = 83 . Yellow solid lines passing SMM4BT =20 Kside,
(Lee
et
al.
2014),
and100,
respectively.
Inより広いスケールでの観測値と矛盾しない
including compact components in the higher velocshow cuts for position-velocity (PV) diagrams (Figure 6).
addition, ities.
the meanmolecular
weight2.37 istoadopted
toThe gradientdirectionis similar
the one seen
C18 O abundance is thus at least 10 times smaller than
12 column density of gas to the number
change themassin theCO outflow; such a gradient can be observed
the ISM value in this temperature range.
if there ofis H
a 2disk-like
infalling envelope. On the othercolumn density
molecules.
We are unable to carry out the same analysis forhand,
6c alsothat thenorthernmost
part
Similarly,
theFigureobservedlineshowsintensity
beforecontinuum
SMM4A
as the C18 O line shows negative intensities
is redshifted and the southernmost part is blueshifted,
subtractionisprobably due to foreground absorption.
cannot be explained by the simple infalling mo● SMM4A、SMM4B、SMM11（Classwhich0）と進化フェーズを比較
tion. Figure 6d, a cut along the(⌧direction
perpendicgas +⌧dust )Iline ular
= (Bto⌫ (T) B⌫ (Tshows), (2)bg ))(1the eblueshifted components
5. DISCUSSION
the outflow
on the southern side and the redshifted components on
SMM4B（collimateしたアウトフロー、コンパクトな連続波源、SO輝線でトレースされる質量降着）：5.1. Possible Mechanisms of the Bending Outflow
where Iline⌧gas areobserved
line
intensityandtheandnorthernside.theSucha velocity
gradient
perpendicthe opticalthe molecular
applying
In Section 4.1, we found that the SMM4B 12 CO outulardepth
to theof
outflow
axis can beline.
due toBy
rotationof the(a) SMM4A（高い輝度温度、fan型アウトフロー、大きなdisk状構造）よりも若い進化段階と考えられる(b)aroundSMM4B.
IfO
this
is the case,the linear
Equation envelope(2) to theobserved
C18
emissionabove
theflow bends at an angle ⇠ 40 . Since similar bending
18
Figure 5.
C18 O line profiles of (a) SMM4A and3 (b)level atmorphology
of
the
C
O
passing
the center
each channel, we canemission
derive theopticaldepthofoutflows have been reported in previous observations of
SMM4B. Horizontal dashed lines and red curves denote 3
the PV diagram in Figure 6d appears more like rigidat ineach channel. We assume LTE and the same gas temprotostars (e.g., Ching et al. 2016; Tobin et al. 2016;
cuto↵s andthe best-fit Gaussian
profiles, respectively,
SMM11：
放射温度、放射光度、内部光度がSMM4AやSMM4Bよりも小さい
body rotation than di↵erential
rotation on the scale of
18
as
the
dust.
The
C
O
columndensityateach
Yen et al. 2017; Aso et al. 2017b), it is worth consideach panel. (a) The spectrum was made within the 300 perature⇥ 300
00
our angular resolution, ⇠ 0. 55 (240 au). The other inregion centered at SMM4A except
for the 100 ⇥ 100 region
C1818Oの存在量：数十倍ほどSMM4Bよりも小さい
channel isterpretation
derived fromtheoptical
depth
at
each
chanering possible mechanismsof this apparently common
SMM4Bよりも更に若いof the main velocity gradient seen in Figcentered at SMM4A, where the C O line has negative innel, and thecolumnderivedby summing
outflow bending. In the case of SMM4B, one of the simure total
4 is theglobaldensity
rotationis of
the surrounding
envetensities. The best-fit Gaussian profile is described by a peak1
lope, while
its rotation
axischannel.
is di↵erent
fromfractional
the outflow
densityat eachThe
plest possibilities is the orbital motion between SMM4A
temperature of 5.6 K, a mean連続放射：velocity of 7.46 km s球状エンベロープ（diskやコンパクト成分なし）,up
andthe column
18
18
axis
by
40
50
.
This
is
possible
becausetheoutflowa FWHM velocity width of 1.0 km s 1 . (b) The spectrum
abundance of C O relative to H2 , X(C O) is then deand SMM4B. It is, however, not likely, even if the two
was made within the 0.00 5 ⇥ 0.00 5 region centered at SMM4B.
is thelaunched
on
athe
scale
smallerthancircumstellar-disk
rived
from
ratio
of
two
columndensities.
protostars are gravitationally bound, because their pro1
The main component at V > 7.35 km s was used for the
scales, while the C18 O emission traces velocity gradients
Figure11shows
thespatialdistributionofthedejected separation corresponds to ⇠ 500 (2100 au). Such afitting. The best-fit Gaussian profile is described by a peak
on
the
much
largerenvelope
scale.
Such
misalignment
1
temperatureof 15.8 K, a mean velocity of 7.86 km s ,rived
and C18 O abundance. The abundance is . 10 8 atwide orbit only yields an orbital velocity of . 1 km s 1
SMM4Aが最も進化したフェーズにあり、SMM4B、SMM11と続くof an envelope-rotation axis and an outflow axis is prea FWHM velocity width of 0.91 km s 1 .
the SMM4B
position,
which is & 50 times
lower
than
with a central stellar mass of ⇠ 1 M , for example,
dictedin magneto-hydrodynamics(MHD)
simulations
7
inthecontext
ofmisalignment
betweenmagnetic
fieldsone in the interstellar medium (ISM) (e.g., 5 ⇥ 10 ,which is negligible compared to the outflow velocity of2 (1978)
NUMERICAL
SETUP
fined by Draine
at ultraviolet
wavelengths, with thattions and the production of synthetic observations. In SecThe gas is initially fully adefinedbyBlack(1994)
atlongerwavelengths;
the ISRF
tion 3 we present
theresultsofthesimulations
andthesyn18O observations of ﬁbrous ﬁlaments: the2.1 problems
Simulations
initially
fully molecular gas, an
18
5. Synthetic
Cofmapping
from
PPV
to
PPP
is normalised to the local ISRF, G0 = 1.7 in Habing (1968)
thetic C O observations. In Section 4, we discuss the sigperatures,show no significant
1
Theissimulations
this paper
have been perunits. The ISRF
attenuatedpresented
using the in
TreeColalgorithm
nificance of the results and compare to previous work andresults
ofGlover& Clark (201
S. D. Clarke,
A. P. Whitworth, R. L. Spowage, et al.presented in formed
the&moving-meshcode we
Arepo(Springel
Clark, using
GloverKlessen (2012),
directthe 2010).
observations. In Section 5, we summarise our conclusions.
who find that the initial chemcode
self-gravitatinghydrodynamics,
reader to thatThepaper
forusesmoredetails. The cosmic
ray ioniza-with timesignificantly alter the global ddependent
chemistryandthermodynamics.
The
17coupled
1tion rate is ⇣CR = 10
s , consistent with that measured
density is above ⇠ 100 cm 3 .
● フィラメント形成と分裂は複合プロセス： もつれ相互接続しているサブ構造と、複雑な運動で示される
boundary conditions are periodic for the hydrodynamics,
in
dense
gas
(Caselli
et
al.
1998;
Berginetal.
1999).
The resolution of the s
2 NUMERICAL SETUP
but not for self-gravity. Ten simulations are performed with
(3Vcell /4⇡)1/3 , where Vcell is t
The gas is initially fully atomic and at 40 K; runs withdi↵erent random seeds (labelled Sim01 to Sim10).
PPP空間での密度構造は、分裂と星形成を反映する
ment is used to ensure that the
2.1 Simulations
initially fully moleculargas, and runsdomain
at di↵erent
initialThe computationalis definedbytemCartesian coTruelove criterion (Truelove eperatures, show
no significant
This
ordinates(x, y, z), di↵erences.
with |x| < 3.0
pc,supports|y| < 3.0 the
pc and |z| <一方、分子線観測はPPV空間での特徴を明らかにするのみ
The simulations presented in this paper1 have been perwhere Jeans is the local Je
results of Glover& Clark(2012)density
and Clark(2015),symmetric
2.5 pc.
The initial
field&isGlover
cylindricallyformed using the moving-mesh code Arepo (Springel 2010).
the gas in the filament has d
who find thatabout
the initialchemicalof a cloud
does notthe z axis,
so we statealso introduce
a radius
variable w =The code uses self-gravitating hydrodynamics, with timeto ⇠ 10 18 g cm 3 , giving sp
・PPV空間からPPP空間へのマッピングは、視線方向での重なりで難しい
22
1/2
significantly alter
evolution once the gas(x +they ) global, anddynamic
putdependent coupled chemistry and thermodynamics. The⇠ 3 ⇥ 10 3 to ⇠ 3 ⇥ 10 4 pc. D
density is above ⇠ 100⇢cm 3 .
1
3boundary
conditions
areperiodicforthehydrodynamics,
ulations end with ⇠ 107 cells
15 M pc (w/pc) , w < 3.0 pc, |z| < 1.5 pc;
・PPV空間での特徴（i.e. velocity coherence）の同定基準
The resolution
is of order rcell =⇢(w, z)=of the simulation(1)
3
but not for self-gravity. Ten simulations are performed with
0.015 M pc ,elsewhere.
(3Vcell /4⇡)1/3 , where Vcell is the volume of a cell. Cell refinedi↵erent random seeds (labelled Sim01 to Sim10).
そのような特徴が、PPP空間において物理的に連続的で確かなものかどうかはわからないHere
the low-density
gas is simply
a fillerin the theouter regions
2.2 Synthetic observatio
ment is used toensurethat the resolution
alwayssatisfies
The computational domain is defined by Cartesian coof the(Truelove
computational
andrcellplays
significant
role
Truelove criterion
et al. domain,1997), i.e.
< no
/8,
Jeans
We generate maps of the C18 O
ordinates (x, y, z), with |x| < 3.0 pc, |y| < 3.0 pc and |z| <of thelength.
filament;
it constitutes⇠ 0.01% of
where Jeans inisthe
theevolution
local JeansThe
majority oftensity, Ivobs from the simulati● Simulation
2.5 pc. The initial density field is cylindrically symmetricthefilament
total mass.
The
initialindensity
field is⇠set10up21
and settled
the gas in thehasdensitytherangeradiative transfer code RADM
6
about the z axis, so we also introduce a radius variable w =18 with ⇠3 10 cells all having approximately the same mass.
to
⇠
10
g
cm
,
givingspatialresolution
in
the
range
2
2
1/2
C18 O(J = 1 0) line is chosen
初期密度場(x + y ) , and put
初期速度場
is given by the sim34
⇠ 3 ⇥ 10to ⇠ 3The⇥ 10initialpc.velocity
Due tofieldcell refinement
detection of fibres by Hacar e⇢⇢ulations end with ⇠ 107 cells
startedwith
106|z|). < 1.5 pc;
0.75 r̂(having
km s 1 +v< 3.0⇠pc,
To run RADMC-3D we
15 M pc 3 (w/pc) 1 , w < 3.0 pc, |z| < 1.5 pc;
turb , wv(w, z)=(2)⇢(w, z)=(1)
0 km s 1 ,elsewhere.
rithm to map the Voronoi me
0.015 M pc 3 ,elsewhere.

Here the low-density gas is simply a filler in the outer regionsof the computational domain, and plays no significant role
18O観測
4 S. D.
et al.
inClarke
the evolutionof the filament; it constitutes⇠ 0.01% of● シミュレートされたフィラメントのC
the total mass. The initial density field is set up and settledwith ⇠ 106 cells all having approximately the same mass.
The initial velocity field is given by⇢
0.75 r̂ km s 1 +vturb , w < 3.0 pc, |z| < 1.5 pc;v(w, z)=(2)
0 km s 1 ,elsewhere.
Without the turbulent component, vturb , this gives a cylindrically symmetric inflow of 70 M Myr 1 pc 1 towards thez axis. The dense gas initially at w ⇠ 3 pc takes ⇠ 4 Myr
to reach the z axis. Since the simulations are only run for⇠ 0.45 Myr, the low-density filler gas outside w ⇠ 3 pc does
not have time to influence the dynamics near the z axis
1

The preliminary results from these simulations werepreviously presented in the thesis of Seamus Clarke(http://orca.cf.ac.uk/102784/)

2.2

drically symmetric inflow of 70 M Myr

pc

towards thewith a resolution of 0.01 pc, an+2.0 pc; this domain includes
flow, while omitting most of t
RADMC-3D is run assum
equilibrium and uses the large
tion (Sobolev 1957). To test
velocity gradient approximati
calculated and compared to th
scale, L, is defined as

We generate maps
the dense
C18 O(J1 0) monochromaticin- ⇠ 4 Myrz axis.ofThe
gas=initiallyat w ⇠ 3 pc takes
obs
tensity, Iv fromthe thesimulations,using
post-processing
to reachz axis. Sincethethesimulations
are only run for⇠ 0.45Myr,
the low-density
filler gas outsidew ⇠ 3 pc doesradiative transfer
code
RADMC-3D(Dullemond2012). The
18
not
have
time
to
influencethedynamics
near
C O(J = 1 0) line is chosen because it was used in the firstthe z axis
detection of fibres by Hacar et al. (2013).
To run RADMC-3D
we use the in-built Arepo algo1 The
preliminary results from these simulations wererithm to 視線方向において様々な速度成分を持ち、
mappreviously
the Voronoi
mesh
fixedthesis
Cartesiangrid,presentedontoin atheof Seamus
Clarkewith a resolutionof 0.01 pc, and covering 2.0 pc < x, y, z <(http://orca.cf.ac.uk/102784/)
複雑なスペクトルを示す+2.0 pc; this domain includes the filament and the accretion
実際の観測と似ている
flow, while omitting most of the low density ‘filler’ gas.
RADMC-3D is run assuming non-local thermodynamic
equilibrium and uses the large velocity gradient approximation (Sobolev 1957). To test the applicability of -1
the large
速度成分の多くはkms scale以下の線幅
velocity gradientapproximation the~0.4
Sobolev
lengthiscalculated and compared to the grid size.
The
Sobolev
length遷音速 limit ＠~10 K
scale, L, is defined as

Figure 2. On the left, the integrated intensity map of the C18 O emission, with black dots showing the location of the five spectra
displayed on the right. Four of the five spectra show multiple velocity components (as shown in Section 4.1 and Fig. 5).

0.04 pc, and finally adding noise. For each voxel, the noise

Without
the turbulent component, vturb , this gives a cylinSynthetic
observations
1
1

As with the first moment map, only velocity channels with

↑観測結果（sub-sonicor trans-sonic）と一致
L=,(3)| dv/dr |c 2002 RAS, MNRAS 000, 1–18

L=

|d

c

● Fibre：

今回のsimulationで多く見られる（長さ~3pcのフィラメント中に、平均で22のFibre）

PPV空間でvelocity coherent構造として定義 by Hacar et al. (2013)
Figure 7. A 3D plot showing the velocity centroids of the velocity components in PPV space, colour coded to show the individual groups
identified using the friends-of-friends algorithm. The structures are generally filamentary and resemble the fibres in Hacar et al. (2013)
それらFibreは、高密度でのCO
freezeoutが含まれていようがいまいが、強く影響を受けない
8 S. D. Clarke et al.

Figure 7. A 3D plot showing the velocity centroids of the velocity components in PPV space, colour coded to show the individual groups
identified using the friends-of-friends algorithm. The structures are generally filamentary and resemble the fibres in Hacar et al. (2013)

Figure 8. The lefthand frames display the same five spectra presented in Fig. 2, and the righthand frames display the density profiles along
the corresponding lines-of-sight. The coloured bars identify the ranges contributing to the di↵erent velocity components (vc ± 1.15 c ).

● フィラメント中の速度coherentなFibreの同定

c 2002 RAS, MNRAS 000, 1–18

Fibreは別々の構造であり、フィラメントにおいて building blockとなる
The problems of mapping from PPV to PPP
個々のFibreやFibreのグループを調べることで、フィラメントの内部構造が推測できる

しかしながら、

PPV空間からPPP空間へのマッピングは視線方向の重なりで難しい

Fibreの約50%が物理的に離れているガスからのコンタミあり
PPV空間での特徴が、PPP空間で繋がっている50%なのかを知ることは、
Figure 8. The lefthand frames display the same five spectra presented in Fig. 2, and the righthand frames display the density profiles along
the corresponding lines-of-sight. The coloured bars identify the ranges contributing to the di↵erent velocity components (vc ± 1.15 c ).

観測者は不可能c 2002 RAS, MNRAS 000, 1–18

Figure 9. A 3D plot showing the fibres identified in Fig. 7 mapped into PPP space, using the same colour code.

9● PPVで同定されるFibreは、PPPで同定されるsubフィラメントには関係しないが、

the three ‘spectra’ displayed on the right, showing multiple velocity components, separated by ⇠ 1 km s .
二次元に投影されたFibreとsubフィラメントの形は似ている
The problems of mapping from PPV to PPP 11

Figure 12. The lefthand frame displays the column density of the sub-filament from Fig. 11, and the black dots show the positions of1(2013). NH has also been used by Williams et al. (2018) to
多くの視線方向において、

how these features relate to fibres as defined by Hacar et al.
3

study the more massive filaments (aka spokes) in the huband-spoke system SDC13. However, they find no evidence
for fibres; each of the four filaments (spokes) shows only asingle velocity component.
It will be important to understand better how fragmenting filaments appear when observed with nitrogen bearing
molecules. These molecules trace di↵erent gas from C18 O,
and therefore mapping from PPV space to PPP space may
be more straightforward. Synthetic N2 H+ and NH3 observations are outside the scope of this paper, but will be thefocus of future work.

subフィラメントも重なっており、同定は難しい？

5
Figure 13. A map of the number of di↵erent sub-filaments alongeach line-of-sight. Over 30% of lines-of-sight intercept more than
one sub-filament.

14

S. D. Clarke et al.

actually be classified as sub-filaments. N2 H+ should be abetter tracer of sub-filaments, since N2 H+ emission is lessinfluenced by shocks than C18 O, and the volume-filling factor of N2 H+ -bright gas is much lower than C18 O-bright gas,leading to less line-of-sight confusion.
Ammonia (NH3 ) is also a dense gas tracer, and isthought to trace similar gas to N2 H+ (Johnstone et al. 2010;
Hacar, Tafalla & Alves 2017). NH3 has been used to detect
elongated features in the TMC-1 cloud in Taurus, using the
NbClust algorithm (Fehér et al. 2016), but it is unclear

CONCLUSIONSFilament formation and fragmentation is a complex process, characterised by tangled, interconnected sub-structuresand complicated kinematics, on both large and small scales.
While it is the real density structures in PPP space that
ultimately reflect the process of fragmentation and starformation, molecular-line observations only reveal featuresin PPV space. Unfortunately, the mapping from PPV space
to PPP space is compromised by confusion along the lineof-sight, and the identification criteria for features in PPV
space (i.e. velocity coherence) do not guarantee that suchfeatures are physically continuous and distinct in PPP space.
Synthetic C18 O observations of simulated filaments
show complex spectra, with multiple velocity components on
many lines-of-sight, similar to real observations of filaments

c 2002 RAS, MNRAS 000, 1–18

Figure 10. A 3D plot showing the sub-filaments found using DisPerSE. In the top panel, the di↵erent sub-filaments are colour coded.
In the bottom panel the colour shows the line-of-sight velocity from the simulation at that position.
c 2002 RAS, MNRAS 000, 1–18

Figure 14. J moments of the sub-filaments (lefthand plot) and fibres (righthand plot) from Sim02, confirming that at all levels they areelongated. The square represents the trunk of the dendrogram, circles the branches, and triangles the leaves.

Jプロット（Jaﬀa et al. 2018）を用いると、Fibreは平均的にはsubフィラメントよりも、やや狭く、時折より曲がっている6. Water and interstellar complex organics associated with the HH 212 protostellar disc
C. Codella, E. Bianchi, B. Tabone, et al.

Orion BのHH 212 (Class 0)に対して、HDOとCH3CHOで観測(Cycle 1 & Cycle 4 ALMA Band 7)
Codella et al.: Water and iCOMs around HH 212 mm● 14のCH3CHO輝線と1つのHDO輝線を検出
Codella et al.: Water and iCOMs around HH 212 mm
Codella et al.: Water and iCOMs around HH 212 mm

1. Left panel: HH 212 protostellar system as observed by ALMA-Band 7 during Cycle 1. Blue and red contours plot the blueFig. 1. Left Fig.
panel:
HH 212 protostellar thesystemas observed by ALMA-Band 7 during Cycle 1. Blue and red contours plot the blueand red-shifted SiO(8–7) jet and 34
C34 S(7–6) asymmetric cavity (magenta and green contours) overlaid on the continuum at 0.9
and red-shifted
SiO(8–7)
jet andthe CareS(7–6)
asymmetric(magenta
andMM1
green
contours)
overlaid
0.9 and HDO line profiles in T b scale (with a spectral resolution of 1 km s 1 ) observed during ALMA Cycle 1 and 4
mm (white
contours).
Positions
given withrespect to cavity
the coordinatesof theprotostar,reportedin Sect.on2.theThecontinuum
filled2. CH3atCHO
Fig.
mm (white ellipse
contours).
are beam
given(HPBW)
with respect
to the coordinatesthe). MM1
protostar,reportedinimages
Sect.
The filledshows Positions
the synthesisedfor the continuum:
0.00 36 ⇥ 0.00 28of(–62
The beamfor the SiO
and C3 4S
is2. panels)(rightoperations. Species, transitions, and upper level excitations (Eu in K) are reported (see Table 1). The vertical dashed
00
00
1
00
00
3
0. 43
⇥ 0.
33 (–64 ). First
contours
and steps
continuum are0.arebeam). The) andbeam
60 , respectively.
SiO,Ctheellipse showsthesynthesised
beam(HPBW)
forforthethecontinuum:
365⇥ (1.5
0. 28mJy(–62
for the SiOForand
imagesline4S
standsfor isthe systemic velocity vsys = +1.7 km s 1 (e.g. Lee et al. 2014). Red curves are Gaussian fits, the results of which1
contours
and contours
steps are 5 andandsteps
25 , forrespectively:
the blue map
has been
obtained
integrating
down
km s 1 (1 =For SiO, the0.00 43 ⇥ 0.00 33first(–64). First
the continuum
are are5 1(1.5
mJybybeam) 1and601to –21
, respectively.
1
1
34
are
reportedinTable 1. In some of the panels, vertical red segments indicate an additional CH3 CHO line close to that centred at
29 mJy beam km s ), and the red map collects emission up to +12 km s (1 = 23 mJy beam km s ). The C S map has
first contours
andsteps byareintegrating
5 and the25 velocities, respectively:
thes blues 1CH(1 DOH= labels (see also the magenta profile in the upper left panel, residual of the (18 –17 )A and (18 –17 )A1
1 been obtained by integrating down to –21
vsys.134Thebeen
obtainedfrom -1 km
to +1map
km shaswith respect
to the systemic velocity
v = +1.7
km
skm
2
5,14
5,13
5,13
5,12
1
1
1
1 sys
1
1
1 s
29 mJy beams ), andthecontour
red mapto +12= 23 mJyCentral
beam panels:
km Zoom-ins ). The
CareS formapemission
has(Lee etkm
al. 2014):
the first
and collects
steps are 5emission(10 mJy up
beam
km skm) and 3(1, respectively.
offit)thelines of deuterated methanol, published by Bianchi et al. (2017). Some unidentified lines (U labels) are also
been obtainedby region
integrating
the byvelocities
from7 Cycle-1 km1: sCH1 3to+1 km
s 11,16
withrespect
to the4,15systemicv sysreported.
= +1.7 km s 1
centralas observed
ALMA Band
CHO(18)E andCH3 CHO(18–174,14 )A velocity
emission integrated
1,17 –171
1
1
over ±5the
km first
s 1 with
respectand
to vsteps
The first
contours
are33 , (18mJy beam Central
km s 1 ).panels:
The HPBWs
sys (black(Lee et al. 2014):
contour
arecontours).
5 (10 mJy
beam
kmands steps) andrespectively.
Zoom-in of theare 0.00 41 ⇥ 0.00 33 (–64 ) for CH3 CHO(181,17 –171,16 )E, and 0.00 44 ⇥ 0.00 33 (–63 ) for CH3 CHO(184,15 –174,14 )A. The black triangle
central region
as theobservedby ALMABand
7 Cycle1: CH3 CHO(18)E
andCHequatorial)A emission
integrated
1,17 –17
1,16
3 CHO(18
4,15 –17
4,14
shows
MM1
coordinates,
andthetiltedcross
indicatesthedirections
of
the
jet
and
of
the
plane.
Right
panels:FurtherTable
1. CH3 CHO and HDO emission lines detected towards HH 212 mm during Cycle 1 and Cycle 4 observations.
11over ±5 kmzoom-ins 1 with
respect
tov(blackcontours).
The
first
contours
and
steps
are
3
(18
mJy
beam
km
s
The HPBWs
sys as observed by ALMA Band 7 Cycle 4, showing the HDO(33,1 –42,2 ), CH3 CHO(180,18 –170,17).)E,of the central region,00
00
1
are 0.00 41 ⇥ and0.00 33)
forCH
CHO(18
–17
)E,
and
0.
44
⇥
0.
33
(–63
)
for
CH
CHO(18
–17
)A.
The
black
triangle aCH(–64
CHO(18–17)A.
The
emissionwas
integrated
over
10
km
s
aroundv(upperpanels;black
contours).
The
first
3
1,17
1,16
3
4,15
4,14
3
0,18
0,17
sys
Transition⌫0 a
Eu a S i j µ2 a rms b
T peak b
Vpeak b
FWHM b
Iint b1
contours
and steps areand
3 (14
beam
km
s 1 ). The HPBW
is 0.00 15 ⇥ of
0.00 12-88 ).
first-momentshows the MM1
coordinates,
themJytiltedcross
indicates
the directions
the(PA
jet=andofThethecorresponding
equatorial plane.
Rightmaps
panels: Further
(GHz)
(K)
(D2 )
(K)
(K)
(km s 1 )(km s 1 )(K km s 1 )1
1
1
the lower panels.
Contours
are from
0 km s4, to+4 km s thein stepsof 0.5km s .
zoom-in of are
thereported
centralin colour
region,scale
as inobservedby ALMABand
7 Cycleshowing
HDO(33,1 –42,2 ), CH3 CHO(180,18 –170,17 )E,
Cycle 1and CH3 CHO(180,18 –170,17 )A. The emission was integrated over 10 km s 1 around v sys (upper panels; black contours).
The18first
CH3 CHO347.2883
215
210
0.2
1.3 (0.2)+1.7 (–)c
5.0 (–)c
6.8 (0.4)
5,14 –175,13 A
00
4. steps
PhysicalN(Hestimate.
H2 column
dencontours andare 3properties(14 mJy beam 1 km s 1 ). The HPBW isderive
0.00 15 an⇥ 0.
122 )(PA= -88However,). The assuming
corresponding
first-momentmaps
CH3 CHO 18
347.2949
215
210
0.1
1.1 (0.2)+1.7 (-)c
5.0 (–)c
5.8 (0.2)
5,13 –175,12 A
24
2
1
1
1
-2 221is a typicalvalue
CH3 CHO 183,16 –173,15 A 15
347.5192179
0.2
1.4 (0.2) +0.9 (0.3)
6.6 (0.7)
10.1 (0.9)
are reported
0 kmarounds to10+4cm
km ,swhichin stepsof 0.5kmfors hot. corinos
3in colour scale in the lower panels. Contours are from sities

放射領域は垂直方向に~0.ʼʼ18 (73au)広がっている

全てのプロファイルのピーク：系速度の付近で、幅5-7 kms-1● CH Given
CHO輝線のLTE解析:
温度78 14 K、柱密度7.6
10 cm179
we CHO3.2
18 –17 E 347.5633
the lack of the collisional rate coefficients available in in Perseus and in B335 (Taquet et al. 2015, Imai et al. 2016),CH
literature, the excitation temperature and column density of

3

3,16

221

3,15

1.4 (0.2)+1.5 (0.1)

5.1 (0.2)

7.7 (0.2)

10-9

335 KでのHDO輝線のLVG解析: 個数密度nH2は108 cm-3以上

4 emission
lines,
and following
maps of Fig. 1,available
corrected theGiven the lackof thecollisional
ratethecoefficientsinobserved
intensities
for a source size
the totaldensity
emitting reliterature, theexcitation
temperatureand (ofcolumnofgion) of 0.00 18. We derived an excitation temperature of 78±14
CH3 CHO were
derived using the rotational diagram approach
K and column density of 7.6±3.2 ⇥ 1015 cm 2 . The temper(Fig. 3), assuming
local
thermodynamic
equilibrium(LTE)
conature agrees
reasonably
well with the
Cycle 0 results
reported
ditions and by
optically
thin
usedconsistent
Cycle 1withandtheCycle
Codella etal. emission.
(2016), and We
it is also
temperatures
165±85 K andderivedfrom methanol
4 emission lines,
andoffollowing
the 171±52
maps ofKFig.
1, corrected
theobservationsfor(coveringa similar
range)emitting
by Lee etreal.
observed intensities
a source
size excitation(of the total(2017b)andBianchietal.
(2017).
On
the
other
hand,
the
columngion) of 0.00 18.
Weis derived
excitation
temperatureofdensityhigher by ana factor
4 than what
was reported
by 78±14
Codella15
2
K and column
densityThisof discrepancy,
7.6±3.2 ⇥however,
10 cm
The temperet al. (2016).
can be. explained
given
size of 0.00 3 assumed
in Codella
et al. (2016).
The reported
lower colature agreesthereasonably
well with
the Cycle
0 results
umn
densityderived
using
the
Cycle
0
datasetisanaverageoverby Codella et al. (2016), and it is also consistent with the temlarger assumed emission area. The Cycle 4 data analysed in thisperatures ofapaper
165±85K
and
171±52K
derivedfrommethanolallow us to measure the size of the emitting region, hence
observationsto (covering
a similar
range)by Leeet andal.
obtain a reliablemeasureexcitationof the CH3 CHO
columndensity(2017b) andanBianchial. (2017).
the otherAshand,theincolumn
improvedetestimateof theOnabundance.
stressed
Codellaetal.
(2016),
thecontinuum
emission,
being
optically
thick
(see
density is higher by a factor 4 than what was reported by Codella
e.g.This
Lee discrepancy,
et al. 2017a, andhowever,referencescan
therein),cannot be usedtoet al. (2016).
be explained
given
the size of 0.00 3 assumed in Codella et al. (2016). The lower col-0.1

can infer XCH3 CHO ' 8 ⇥ 10 9 . This is in good agreement withCH CHO 184,15 –174,14 A 347.6504
195
216
0.4
1.5 (0.2) +1.4 (0.4)
5.5 (0.8)
8.7 (1.3)
the CH3 CHO abundance found in a region within a few 10 au 3CH347.7563
194
213
0.2
1.5 (0.2)+1.7 (–)c
6.3 (0.5)
10.2 (0.7)
derivetheanB335N(Hprotostar
However,
assuming
H
columnden3 CHO 18
4,15 –174,14 E
92 ) estimate.
2al.
around
using
ALMA
(2
⇥
10
;
Imai
et
CHO
184,14 –174,13 E 347.8310
195
213
0.1
1.3 (0.1) +1.7 (0.2)
5.3 (0.4)
7.1 (0.5)
sities around 1024 cm 2 , which is a typical value CH
for 3hotcorinos
2016).
CH
184,14213
0.1
1.4 (0.1) +0.5 (0.1)
5.9 (0.3)
8.8 (0.3)
in Perseus
in B335
al. 2015,
ImaiLarge
etal.3 CHO
2016),
we–174,13 A 347.8390 195
The HDOandemissionwas (Taquet
analysed etusing
a non-LTE
9CH
350.1334
179
221
can infer
XCH3 CHO
8 ⇥ 10. This is etinal.good
with
Velocity
Gradient(LVG)'model(see Ceccarelli2003),agreementas- 3 CHO 18
3,15 –173,14 A
0.1
3.1 (0.1)+1.7 (–)c
5.0 (-)c
16.3 (2.3)
CHa3 CHO
183,15221
sumingcoefficients found
for the insystemHDO-H
2 comthe CHcollisionala region
withinfew 10au–173,14 E 350.1344 179
3 CHO abundance
9
puted
by Faure
et al. (2012).
A Boltzmann
distribution
thearoundthe B335
protostarusing ALMA
(2 ⇥for
10CH; CHO
Imai 18
et1,17
al.–171,16 E 350.3628 164
226
0.2
1.9 (0.2) +1.3 (0.2)
5.2 (0.3)
10.6 (0.6)
ortho-to-para H2 ratio, in agreement with the Faure et al. (2012) 3CH CHO 181,17 –171,16 A 350.4458
163
226
0.5
2.4 (0.4)+1.7 (–)c
5.0 (–)c
12.5 (1.2)
2016).
computations,
was found, showing that para-H2 and ortho-H2 3
Cycle 4collisionalcoefficientsare di↵erent
at temperatures
45
The HDOemission
was only
analysedusing a ⌧non-LTE
Large
HDO 33,1 –42,2
335.3955
335
0.4
0.5 16.2 (1.3) +2.1 (0.1)
6.6 (0.2)
101.6 (1.9)
K.
Di↵erentGradientto Codella(LVG)
et al. (2016),
can now
use the meaVelocity
modelwe(seeCeccarelli
et al.CHO
2003),
as180,18 –170,17 E 335.3181
155
227
0.6
8.5 (1.3) +3.0 (0.2)
5.3 (0.2)
47.8 (2.6)
sured size of 0.00 18. Figure 3 shows the LVG predictions in CH
the 3
sumingcollisionalcoefficients
systemcom8for the3
9 HDO-H
3
2
T kin –N(HDO) plane for densities of 10 cm (blue), 10 cm
CH3 CHO 180,18 –170,17 A 335.3587
155
227
1.1
9.6 (1.3) +2.9 (0.2)
5.6 (0.5)
57.3 (4.5)
puted by andFaure(2012).
A Boltzmann
for
the
a
(magenta),
1010etcmal.3 (red;representing
the LTE distribution
regime).
Frequencies
and spectroscopic parameters have been extracted from the Jet Propulsion Laboratory molecular database (Pickett et al. 1998) for5
When
we assumeHN(HDO)/N(H
XH2 O =⇥ all
10 the;et transitions.
ortho-to-parathe3 Faure
al. (2012) Upper level energies refer to the ground state of each symmetry. b Gaussian fit. Spectral resolution of 1 km s 1 . c Assumed.
2 O)  0.1, with
2 ratio, in agreement
see
Taquet et al. 2015)
a source
size ofthat
0.00 18,para-H
then Fig.
3
computations,
was andfound,
showing
2 and ortho-H2
shows that only densities of at least 108 cm 3 are possible, leadcollisionalcoefficients⌧ 45
17 are2 di↵erent only7 at temperatures3
ing to N(HDO)  3 ⇥ 10 cm . Densities of 10 cm would
2
K. Di↵erent
et al.
(2016),
canthatnow
use the meaimply
N(HDO) to 3Codella⇥ 1016 cm, whichare wevalues
were
00
CH
CHO
(grey
8
3
suredoutsizeof LVG
0. 18.
Figurein3Fig.
showsthea density
LVG predictionsin the region in Fig. 3) are consistent with the solu- 5. Kinematics
ruledby thesolutions
3. Withof 10
3 HDO. In conclusion, our dataset allow us totions foundwithcm, the opacityplaneof the for
HDO
line is 0.3,
lower3 values
T kin3 –N(HDO)
densities
ofwhile108 cm(blue),
109 cmareexpected forandhigherdensities.
temperaturesderivedfromfurther
17with HDO＋(magenta),
1010
cm 3 The(red;
representing
theLTE constrain
regime). the physical properties associated(Fig.
3), assuming
local thermodynamic(LTE) conNを10
cm equilibriumと仮定すると、CH
H2
3CHOの存在量 XCH3CHOは ~8ditions and optically thin emission. We used Cycle 1 and Cycle

CHproperties
using the rotational
3 CHO were derived24
4. Physical-2 diagram approach

柱密度NHDO < 31017 cm-2● 赤道面に沿って、系速度に対して約 2 km s-1の速度勾配がある in CH3CHO, HDO
Blue shift：
Red shift：

北西方向

南東方向

より内部の原始星領域の別の分子トレーサーを使った以前の結果とよく一致
study of kinematics
is instructive:
1 (lower panels)e.g.,
C . O, SO,The
HCO, CH3OH,NHFig.
2CHO
10 cm

CHO:
When we assume N(HDO)/N(H2 O)  0.1, XHand=CH
3 3⇥
10 5T; kin = 78±14 K and nH2
2O
00

3

8

3

reports the distribution of the first moment of the HDO andCodella et al.: Water and iCOMs around H● 赤道面に沿ったCH3CHOとHCOのPV図
Codella et al.: Water and iCOMs around HH 212 mm
原始星から離れるにつれて速度↑

化学的に豊富なwarm gasのedge-onリングからの放射の可能性が高い

半径：~0ʼʼ.15 (60 au)で、以下の結果とよく一致(i) 別のiCOMs（NH2CHOとか）で測られた以前の結果(ii) 連続光で観測された光学的に厚いdiskの半径(iii) HCO＋の落下運動から推測される遠心力バリアの場所
今回の観測は、化学的に豊富なガスを見ている
そこで、落ち込むenvelopeが回転円盤に当たり、低速度のショックを作っている？

Fig. 7. Position-velocity cut of HDO(33,1 –42,2 ) (colour scale,magenta contours) along (left panels) and perpendicular (rightpanels) to the equatorial plane (PA = 112 , see Fig. 1) overlaid with the CH3 CHO(180,18 –170,17 )-E (upper panels) andCH3 CHO(180,18 –170,17 )-A (lower panels), drawn as white contours. The first contours and steps correspond to 3 (3.1 K kms 1 ). Dashed lines mark the position of the HH 212 mm protostar and the cloud VLSR (+1.7 km s 1 ; Lee et al. 2014). The error
bars are drawn in the bottom right corners.

Fig.（低速度ショックによる化学の研究には、正確なモデリングが必要）
7. Position-velocity cut of HDO(33,1 –42,2 ) (colour scale,magenta contours) along (left panels) and perpendicular (rightpanels) to the equatorial plane (PA = 112 , see Fig. 1) overlaid with the CH3 CHO(180,18 –170,17 )-E (upper panels) andCH3 CHO(180,18 –170,17 )-A (lower panels), drawn as white contours. The first contours and steps correspond to 3 (3.1 K km
● 円盤面の上下40-50
au以下で、低速度の放射（系速度から
1 km s-1）がCH3CHOとHDOで見られるs 1 ). Dashed lines markthe position of the HH 212 mm protostar and the cloud VLSR (+1.7 km s 1 ; Lee et al. 2014). The error
より進化した原始星L1527で最近発見された（Sakai
et al. 2017）ような、遠心力バリアの垂直構造を示唆
bars are drawn in the bottom right corners.

Fig. 8. Cartoon (not to scale) illustrating the scenario expectedin the inner 60 au region around the protostar for low-velocity
emission ( 1 km s 1 with respect to vsys ) in case of outflowing(left) or infalling (right) chemically enriched gas (see text).

観測による空間分布
光学的に厚い円盤面の上下の、.

流れ出し、広がって、回転する2つのリングの証拠？

Fig. 8. Cartoon (not to scale) illustrating the scenario expectedin the inner 60 au region around the protostar for low-velocity
emission ( 1 km s 1 with respect to vsys ) in case of outflowing(left) or infalling (right) chemically enriched gas (see text).
.

更なるALMA観測が必要

1

3

Sternwarte, University of Hamburg, Gojenbergsweg 112, 21029, Hamburg, Germany; 6 School of Physics, Astronomy& Mathematics, University of Hertfordshire, College Lane, Hatfield, Hertfordshire, AL10 9AB, UK; 7 Department ofDiﬀuseX-ray emission in the Cygnus OB2 association
Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK; 8 I. Physik. Institut,
1
2
4
2
3
J.F. University
Albacete of
ColomboJ.J. Drake, E. Germany;
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Kashyap, M.G.College
Guarcello
Cologne,, D-50937
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9 at angular resolutions of ∼ 0.
C18 O J3 ,=J.S.
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1 lines55 (240 au). The 1.3 mm continuum emission shows that SMM4 is
SciortinoE-mailcontact:
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spatially resolved intoArray
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.
4
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into two
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au emission,in SMM4B.
CO
point-likesources detected
in21029,
our survey,
background-corrected
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the Theadaptive
6
Sternwarte,
UniversityofGermany;
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K,with little
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and SMM4B 112,
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emissiontracesfan-shaped
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with SMM4A
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emission.
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Soft [0.5: 1.2]
7 respectively.
& Mathematics,
University
of Hertfordshire,CollegeLane, associatedHatfield,
Hertfordshire,
AL10
UK;
Department
ofThestructures.
Theirseparation
isoutflow∼ 2100au.
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visibilities
reveals
a disk-likestructure
with
◦
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[1.2
:
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and
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in
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Hard
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stacked
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have
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.
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inclination
andbending
angles8spectral analysis
Physics and Astronomy, University College London,
Gower
Street, London
WC1E 6BT,
UK;−1 I. Physik. Institut,
12
diﬀ
34
◦
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a sharpatr ∼240
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SMM4A,
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18
emissiontracesfan-shapedandcollimatedoutflows
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temperaturecomponents
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E-mailcontact:
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energyemission
likelyarisesfrom
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thermalized
wind-windcollisions
in
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medium.
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resultssuggestthat
SMM4A
evolvedSMM4B.
Our
studiesin
Serpens
Main shockedin the 3D space are estimated at ib ∼ 36 , ir ∼ 70 , and α ∼ 40 , respectively. The SO emission traces
We demonstratepresent
a oflarge-scale
studyof
diﬀuseX-ray
emissioninthenearbymassivestellarassociation
CygnusOB2
aspart
regionstheassociation,
while
the
soft
band
emissionprobablyarisesfrom
lessenergetic
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continuum
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at millimeter
wavelengths
us to diﬀerentiate
evolutionary
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and the vicinityof SMM4B.
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O emission
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anddiﬀuseemission
appears
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rotating
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C in
O our
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point-likesources
detectedsurvey,background-corrected
X-ray
the
adaptivethe medium band emission. The diﬀuse X-ray emission is generally spatially coincident with low-extinction
AcceptedbyThe
AstrophysicalJournalinterstellar
medium.
Thesediﬀuse
resultssuggestthatDiﬀuse
SMM4A
is morethan
SMM4B.
studiesin Serpens Mainsmoothinglarge-scale
emission.
emission
was evolved
detectedin themassive
sub-bandsSoft
regionsreveals
that weattributetothe X-rayubiquitous
influenceof powerfulstellarwinds fromstarsOurand[0.5
their: 1.2]
interaction
demonstratethat
continuumandline
observationsatmillimeter
wavelengths
allow
us
to
diﬀerentiate
evolutionary
andhttps://arxiv.org/pdf/1806.10743
Mediumand marginally inDiﬀuse
the Hard[2.5emission: 7.0] keVband. From X-ray
analysis of stacked
with the[1.2local: 2.5],
Interstellar-Medium.
X-ray
is volume-filling,ratherspectral
than edge-brightened,
oppositely
diﬀ
34
−1
spectrawecomputea total[0.5–7.0
diﬀuseX-ray
luminosityof Lx evidence≈4.2×10erg s haloes, characterized
withevolved
plasmamassive
phasesprotostars
withinthekeV]Class
0 phase.
to of
other
star-forming
regions.
We
revealthefirstobservationalof X-rayaround sometemperaturestars. components at kT≈0.11, 0.40 and 1.18 keV, respectively. The Hi absorption column density corresponding
Accepted
byofTheAstrophysicalJournal22
Eﬀect
stochastic
grain
heatingchemistry
to thesetemperatures
has a distribution
consistent on
withcold
NH = dense
0.43, 0.80clouds
and 1.39×10
cm−2 . The extended medium
Accepted
by
ApJS
1
2,3
band
energy emission
likelyarises Changfrom O-type
stellar winds
by wind-wind collisions in the most populated
https://arxiv.org/pdf/1806.10743
Long-Fei
Chen1,2, Qiang, Hong-Wei
Xithermalized
http://arxiv.org/pdf/1806.01231
regionsoftheassociation,
while
the
soft
band
emissionprobablyarisesfromless energetic termination shocks against
1
2
Xinjiang Astronomical
Observatory,
ChineseSciences,
150 Science
1-Street,
Urumqithe surrounding
Interstellar-Medium.
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Soft diﬀuseofemission
appears
more widelydispersed
and830011,
intenseChina;
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AcademyTheof Sciences,
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100049,China; spatially
Nationalcoincident
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the ofmediumband emission.
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with Observatories,
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The
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0Protostars
inSerpens
SMM4
Academyof
Sciences,
Beijing
100101,
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regions that we attribute to the ubiquitous influence of powerful stellar winds from massive stars and theirMain
interaction
1,2
1
2,3
1
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2
3
1,4
Long-Fei
Chen,HiranoQiangNaomi, Hong-Wei
withE-mailthe local
Interstellar-Medium.
DiﬀuseX-ray
emissionis volume-filling,rather thanedge-brightened,
oppositely
YusukeAso,chenlongf, YuriAikawa, Xi
Masahiro
N. Machida, Shigehisa
Takakuwa, Hsi-Weicontact:
atChang
xao.ac.cn
5
6 first observational evidence of X-ray haloes around some evolved massivetootherstar-forming
regions.
We
revealthe
Yen
andJonathanP.
Williams
1
2
Xinjiang
Astronomical
Observatory,of Sciences,
150 Science
1-Street,clouds.
Urumqi
830011,
The temperaturesof dustgrains play Chinese
importantAcademy
roles in thechemical evolutionof molecular
UnlikelargeChina;
stars.
1
2
3
Academia
Sinica Instituteof of
Astronomy
andAstrophysics/P.O.
Box 23-141,
Taipei106, Taiwan;
Departmentof Chinese
grains,thetemperaturefluctuationsof smallgrainsinducedbyChina;
photonsmaybesignificant.
Therefore,
if the grain
Universityof Chinese
AcademySciences,
Beijing
100049,National
Astronomical
Observatories,
Acceptedby
ApJS
Astronomy,
Graduate
Schoolof
Science,
The
UniversityofTokyo,
7-3-1
Hongo,
Bunkyo-ku,
Tokyo
113-0033,
Japan;
size distribution
is included
astrochemical
Academyof Sciences,
Beijing in
100101,China models, the temperatures of small dust grains may not be assumed 4to3
DepartmentWeof simulate
Earth and
Planetary
Sciences,
Facultyof Sciences
University,
Fukuoka
Japan;
http://arxiv.org/pdf/1806.01231
be constant.
a fullgas-grain
reaction
networkwith a Kyushu
set of dust
grain radii
using812-8581,
the classicalMRN
E-mailcontact:
chenlongf
atxao.ac.cn
DepartmentofPhysics
andAstronomy,
Graduate
Schoolof
ScienceandEngineering,Kagoshima
University,
grain size distribution and include the temperature fluctuations of small dust grains. Monte Carlo method1-21-35
is used5
Kagoshima,890-0065,
Japan;Southern
Observatory,Karl-Schwarzschild-Str.
2,
toKorimoto,simulate thereal-time
dust
grain’stemperaturefluctuations
is causedby the ofexternal
low energy
photonsTheof dustKagoshima
grainsplay
importantrolesEuropean
in Protostars
thewhichchemicalmolecular
clouds.
Unlikelarge
6NatureThetemperatures
Distinct
Evolutionary
of
two
Class
0
inevolution
Serpens
Main
SMM4
D-85748
Garching,
Germany;
Institutefor
Astronomy,
UniversityofHawaiiat
Manoa,
Honolulu,
Hawaii,USA
andtheinternal
cosmicray
inducedsecondaryphotons.
The
increaseof
dust
grainsradii
asice
mantles
accumulate
grains, the temperaturefluctuationsof smallmay be significant.
Therefore, if the grain
1
1
2 grains induced by photons
3
1,4
YusukeAsocontact:, Hirano
Naomi, Yuri, Masahiro
N. thatMachidaShigehisa
Takakuwa, Hsi-Weiongrain
surfacesis alsoincludedin Aikawa
our models.
We foundsurface, CO
inmodelswithnotgrain
E-mailyaso
at asiaa.sinica.edu.tw
2 abundances
size
distribution
isincludedinastrochemical
models,thetemperatures
of
small
dust
grainsmay
be size
assumed to5
6
Yendistribution
and Jonathan
P. Williams
andtemperaturefluctuations
are
more
than
one
order
of
magnitudelarger
than
those
with
singlegrain
We have observed
the submillimeter
continuum
condensation
Main grainusing theAtacamaMilbe
We simulatea full gas-grain
reaction
networkSMM4
with ina Serpens
set of dust
radii
using Largethe classicalMRN
1 constant.
size. Small
amountsof terrestrial
complexorganic moleculesBox(COMs)
canalso 106,
be formed
on2 smallgrains due
Academia
SinicaInstituteof Astronomy
and Astrophysics/P.O.
23-141,
TaipeiTaiwan;Departmentof to thegrain
size distribution
andofinclude
thetemperaturefluctuations
ofcosmic
small
dust
grains.
MontephotonsCarlomethod is used
Astronomy,
Graduate
Science,
Thelow
Universityof Tokyo,7-3-1 Hongo,
Bunkyo-ku,
Tokyo
113-0033,
Japan;overheattemperature
spikesSchool
inducedby externalenergy photons.
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inducedsecondary
3 simulate the real-time dust grain’s temperature fluctuations which is caused by the external low4 energy photons
toDepartment
of so
Earth
Planetary
Sciences,of Sciences
KyushuFukuoka
Japan; of surface
10 formed
small grainsthat andsurface
CO sublime
andFacultyless radicals
areonUniversity,
grains surfaces,thus812-8581,
the production
andtheinternal
cosmicray
inducedsecondaryphotons.
The
increaseof
dust
grainsradii
asice
mantles
accumulate
DepartmentofPhysics
andAstronomy,
Graduate
Schoolof
ScienceandEngineering,Kagoshima
University,
1-21-35
CO2 and COMs decreases by about one order of magnitude. The overheating of small grains can beoﬀset
by grain
5
Korimoto,
Kagoshima,
Kagoshima890-0065,
Japan;
EuropeanSouthern
Observatory,Karl-Schwarzschild-Str.
2,
on grainis alsoincludedin ourCO
models.
We foundthat
surface
CO2 abundances in models with grain size
growthsurfaces
so that theformationof surface
becomesmore
eﬃcient.
2 and COMs
D-85748 Garching,
Germany; 6 Institutefor Astronomy,
Universityof HawaiiatManoa,
Honolulu,
Hawaii,
distribution
andtemperaturefluctuations
are
more
than
one
order
of
magnitudelargerthanUSA
those with single grain
Accepted by MNRAS

3 2

2

4

1 mass protostar.
a Sun-like
Department of Earth and Planetary Science, University of California, Berkeley, CA, USA; 2 Department of As335investigateK) have been
imagedinchemical
the inner∼ 70 auofregion.
thermalanalysisof the CH3 CHO emission
Aims: We
the physicalandproperties
the gas The
associatedwaterequilibrium
interstellar
complex
3 local withtrophysics, Israel
Instituteof Technology,
Haifa,
Israel;Department
ofand
Earth
15
−2and Planetary Science, Weizmannleads
temperature
of on
78±14
and
a the
columndensity ofof7.6±3.2
× 10 cm , which,when NH2 of 1024 cm−2 isorganic
molecules
arounda protostar
solar K
systemThe Instituterole toof aofmultiple
giant
impacts
inscales.
formation
the Earth-MoonsystemScience,Rehovot,
Israel−9
Methods:
The HH 212
protostellar
system, in Orion
B, has been mapped thanks to ALMA-Band 7 Cycle 1 and Cycle
assumed,leads
to an abundance
1
2 of XCH3 CHO ≃ 8 × 10 3 . The large velocity gradient analysis of the HDO emission
I. Citron, HagaiB.(HDO)
Perets, andOded Aharonson
8−3angular resolution down to
4 Robert
observationsofdueterated
water
and
acetaldehyde
with
3 CHO)
E-mailcontact:
ricitronatberkeley.edu
also places severe constraints on the volume (CHdensity,nHemission
cman. The line profiles are 5–7 km s−1 wide, and2 ≥ 10′′
1 15 (60 au).
2∼0.
−1
Department
Earthand bothPlanetary
Science,
Universityof California,
Berkeley,CA,ofUSA;
Departmentof AsCH3 Earth-Moon
CHOof andHDO
a ± 2tokms formedvelocity
gradient
over gianta size∼ 70 au(blue-shifted
emission
towardsThe
systemis14showsuggestedhavethrougha singlecollision,
in163
which
the Moonaccretedfrom3
Results:
Manyemission
lines
due
to
CH
CHO
and
1
HDO
transitionsathighexcitation(E
betweenK and3utrophysics,
IsraelInstituteofTechnology,
Haifa,
Israel;Department
of
Earth
and
Planetary
Science,
Weizmannthenorth-west
andred-shifted
emission
towards
thesouth-east)
along
the
disc
equatorial
plane,
inagreement
withimpact-generated
debrisdisk.
However,
giant impacts
are analysis
rare, andduringits evolution
335K) thehaveofbeen
imagedin the inner∼ 70
au region.
The suchlocal thermal
equilibriumof theCH3 CHOemission the Earth experienced
Institute
Science,Rehovot,
Israel
15
−2
24
−2
what
was
found
so
far
using
other
molecular
tracers.
leads tomany
a temperatureof 78±14
K and aproducing
column densityof 7.6±3.2
× 10, which, when
NH2 of 10
cmmultiple-impact
ismore smaller
impacts,
smallersatellites
thatcmpotentiallycoevolved.
In thehypothesis
E-mailConclusions:contact:
ricitronatkinematics
berkeley.edu
The
of
CH
CHO
are
consistenttheofacentrifugal
barrier,thatassumed,leads to anabundanceof XCH3 CHO≃ 83×
10−9and. TheHDO
large velocity
gradient withanalysisofoccurrence
the HDO emissionof lunar formation, the current Moon was produced
from the mergers of several smaller
satellites (moonlets), each
8
−3
−1
also
placessevereconstraints
onthevolumedensity,
n
≥
10
cm
.
The
line
profiles
are
5–7
km
s
wide,
and
H
is,
the
infallingenvelope-rotating
disc
ring,
which
is
chemicallyenriched
throughlow-velocity
accretion
shocks.
The
2 through a single giant collision, in which the Moon accreted fromThe Earth-Moonsystemis disks
suggestedto−1haveby
formedformedfromdebrisproducedsuccessive
largea size
impacts.
InautheMyrs between
impacts,a pre-existing moonlet
CH
CHO
and
HDO
both
show
a
±
2
km
s
velocity
gradient
over
of
∼
70
(blue-shifted
emission
towards
113
emissionradiusdebris
is ∼ disk.
60 untilau,
ina good
agreement
withforms
what
beforeanotherinterstellar
complexthe impact-generated
However,such
giantimpact
impacts
arerare,wasandfoundduringits evolution
the
Earth
experienced
tidally
evolvesoutwardsubsequentnewmoonlet,at for
which
point
both
moonlets
will organic
tidally
the north-west
andred-shifted
emission
towards
the south-east)
along theadisc
equatorial
plane,
in agreementwithmany molecule
more smaller
impacts,
producingsmallersatellites
thatpotentiallycoevolved.
Inthemultiple-impact
hypothesis
such
as
NH
CHO.
We
supportaverticalstructureforthecentrifugal
barrier,suggestingtheoccurrenceof2
evolvemergeror molecularsystem disruption.
In this work, we examine the likelihood that pre-existing moonlets survive
what wasfounduntil
so fara using
othertracers.
two outflowing,
expanding,andandrotating
rings
abovewithandbelow(of about
40-45 au)theopticallyequatorial
disc
Conclusions:
The kinematics
of CH3 CHO
HDO theareconsistenttheoccurrenceof systems
a centrifugal
thattwo thick
subsequent
impactevents,andexploredynamics
of Earth-moonlet
thatbarrier,containmoonlets
generatedplane.apart.
It
is tempting
todiscspeculatethat
these rings
couldcanprobe
thebasis of accretiona wind launchedfrom thisregion.
is, the infallingenvelope-rotating
ring,
which
is chemicallythroughlow-velocity
shocks.
11enriched
Myrs
We demonstratethat
pre-existing
moonlets
tidally
migrateoutward,remainThestableduringsubsequentemissionAccepted
radius is ∼
60
au,
in
good
agreement
with
what
was
found
beforeforanotherinterstellar
complexorganic
by later
A&Amerge with newly created moonlets (or re-collide with the Earth). Formation of the Moon from theimpacts, andmolecule such as NH2 CHO. We support a vertical structure for the centrifugal barrier, suggesting the occurrence ofmergersof severaland
moonlets
thereforebe a(ofnaturalbyproduct
the Earth’s
growth discthrough multiple impacts.
http://arxiv.org/pdf/1806.07967
two outflowing,
expanding,rotating couldrings aboveand below
about 40-45au) the of
optically
thick equatorialMoregenerally,
we examine
the likelihood
consequencesEarthhavingprior
plane. It
is tempting
to speculatethat theserings couldandprobe
the basis of a ofwindlaunchedfromthis moons,region. and find that the stability ofmoonlets
Accepted
by A&Aagainst disruption by subsequent impacts implies that several large impacts could post-date Moon formation.

The many-faceted
light curves of young disk-bearing stars in Upper Sco and ρ Oph
Acceptedby ApJ
7http://arxiv.org/pdf/1806.07967
observed by K2 Campaign 27

http://arxiv.org/pdf/1806.00506
Ann Marie Cody1 and Lynne A. Hillenbrand2
The many-faceted light curves of young disk-bearing stars in Upper Sco and ρ Oph1
observed
by K2
Campaign
2
NASA
Ames
ResearchCenter,
USA; 2 California Institute of Technology, USA
18

Synthetic
C O observationsof fibrous filaments: the problems of mapping from PPV
Cody
and Lynne
A. Hillenbrand
5Ann Marie
E-mailcontact:
annmarie.codyatnasa.gov
to PPP
1

1

2

NASA Ames Research Center, USA; 2 California Institute of Technology, USA

The
MissionhasP.photometricallymonitored
thousandsof stars at high precisionand1cadence
in a 2seriesof ∼801
2
2
1
S.
D.K2
Clarke, A.
Whitworth2 , R.
L. Spowage, A. Duarte-Cabral, S. T. Suri
, S. E. Jaﬀa
, S. Walchand P. C. Clark
The K2stellar
Missionobjects
has photometricallythousandsstars at highprecisiona series of regions.
∼80(YSOs) inmonitored
the ∼1–3
Myr ρ ofOphiuchus
and
5–10 and
Myrcadence
Upperin Scorpius
From this set, we
1
2I.
Physikalisches
Institut,
Universityof
Cologne,Zülpicher
Str.
77,
D-50937
Cologne,Germany;
Schoolof Physics
day campaigns
focusedonsectionsoftheeclipticplane.
Duringits
secondcampaign,
K2
targeted
over
1000
young
have carefully vetted photometry from WISE and Spitzer to identify those YSOs with infrared excess
indicativeofstellar andobjects(YSOs) in Cardiﬀ
the ∼1–3University,
Myr ρ Ophiuchus
and
5–103AA,Myr Upper
Scorpius regions. From this set, weAstronomy,
Cardiﬀ,
CF24
UK
primordial circumstellar disks. We present here the resulting comprehensive sample of 288 young disk-bearing stars
have carefully vetted photometry from WISE and Spitzer to identify those YSOs with infrared excess indicative of
from
Bcontact:
through
M spectral
types
andresulting
analysisof their associatedlight curves.
Using
E-mailclarkeph1.uni-koeln.deprimordial
circumstellar
disks.
Weatpresent
here thecomprehensive
sample of K2
288 youngdisk-bearingstarsstatistics of periodicity
andsymmetry,
wetypescategorize
curves
intoK2eightdiﬀerent
variability
classes,
notably
from BMolecular-line
through
M spectral
and analysis
oflight
theirinassociatedlightcurves.have
Usingstatisticstheof periodicity
observationsof eachfilaments
star-forming
regionsrevealed
existenceof including
elongated “dippers”
coherent(fading
events),“bursters”(brightening
events),stochastic,andquasi-periodic
types.
Nearlyall(96%)
of disk-bearing
and symmetry,wecategorize
each light
curves into eightdiﬀerent
variability
classes,
notably including“dippers”
features within the filaments; these features are termed fibres. Here we caution that, since fibres are traced
in PPV(fading YSOs
events),are“bursters”(brightening
events),stochastic,andquasi-periodic
types.
Nearly all(96%) of of
disk-bearing
identified
asvariableat
30-minutecadencewiththesub-1%
precision
K2.
Combining
ourvariability
space,
thereasis variable
no guaranteethat cadence
they represent
coherent
featuresspace. ourWevariability
illustrate this contention using
YSOs areidentified
at 30-minutewith thesub-1%
precisionof in
K2.PPP
Combiningclassifications
with(circum)stellar
properties,
wefind thatthebursters,
stochastic
sources,and the largest
amplitude
18
simulations
ofthegrowthofafilament
fromaturbulentmedium.
Synthetic
CO
observationsof the simulatedclassifications with (circum)stellar properties, we find that the bursters, stochastic sources, and the largest amplitudequasi-periodic
stars
largerofinfraredcolors,and hencestronger
circumstellar
disks. Theycoherent
also tendfeaturesto haveinlarger
filaments
the haveexistence
fibresvery
similarto theobservedones,
thequasi-periodic
starsreveal
have larger
infrared colors,
and hencestronger
circumstellar
disks. They
alsoi.e.
tend elongatedto have larger
Hαequivalent
widths,indicativeofhigheraccretion
rates.
The
dippers,
on
the
other
hand,
cluster
towardHα equivalent
widths,of higher
accretion
The dippers,on the(i.e.
other3D
hand,clusterfields)
toward also
moderate
resulting
PPVindicative
data-cubes.
Analysis
ofrates.
the PPP
data-cubes
densityreveals elongated moderate
coherent
infraredcolorsandlow resolved
Hα.
Using
diskweobservations,wefurtherfind thatthe latter
favorthehigh
inclinations,infraredfeatures,
colors andlow Hα.
disk resolved
observations,furtherfind isthat
thelatter correspondence
favorhigh inclinations,which
we Using
term
sub-filaments.
Unfortunately
there
very
poor
betweenfibresand theapart froma few
notableexceptions
withclose to face-on
disks.toTheseobservations
supportthe idea that support
YSO timethe idea that YSO time
apart
from
a
few
notableexceptions
with
close
face-ondisks.
These
observations
sub-filaments in the simulations. Both fibres and sub-filaments derive from inhomogeneities in the turbulent accretion
domain domain
properties are dependentonseveral factors
includingaccretion
rate andaccretionview angle.rate and view angle.
dependent
severalfactors
includingflow ontoproperties
the mainare
filament.
As aonconsequence,
fibresare often aﬀectedby line-of-sight confusion. Similarly, subE-mail contact:
annmarie.cody
at nasa.gov
day campaigns
focusedon sections of the ecliptic plane. During its second campaign, K2 targeted over 1000 young
2

Accepted by Astronomical Journal

Accepted are
by Astronomical
filaments
often aﬀected Journal
by large velocity gradients, and even velocity discontinuities. These results suggest thathttps://arxiv.org/pdf/1802.06409
extreme care should be taken when using velocity coherent features to constrain the underlying substructure within a

https://arxiv.org/pdf/1802.06409
filament.

1

8

University of Hawaii at Manoa, Institute for Astronomy, 640 North Aohoku Place, Hilo, HI 96720, USA; 2 Staﬀ Astronomer at the Infrared Telescope Facility, which is operated by the University of Hawaii under contract NNH14CK55B
A Near-IR
Spectroscopic
Surveyof FU Orionis Objects
with the National
Aeronautics and Space
Administration
1,2
MichaelConnelley
and Bo Reipurth1
E-mailS.
contact:
msc at ifa.hawaii.edu

We have conducted
homogenous
spectroscopic
survey of640
33 objects
varying
degreesof similarity
to USA; 2 Staﬀ AsUniversityof Hawaiia at
Manoa, near-IR
Institutefor Astronomy,
North with
AohokuPlace,
Hilo,
HI 96720,
FU
Orionis. Common
featuresthat are characteristic
the threeclassical
FUors FUtotal
Ori, atomic
V1057 Cyg,
ice formation
followed spectroscopic
by non-distructive
photodesorption
from theofdust
grains.
The two-sided
mass
tronomerat theInfrared
Telescope
Facility,
whichis operated
bythatthe
University
ofthe
Hawaiiundercontract
NNH14CK55B−6 absorption,
−1
and
V1515
Cyg
are:
strongCOabsorption,
weak
metal
strongwater
bands,
low
gravity,strongblue
shiftedflux
estimated
from
the
[OI]
jet
sums
to
1.65
×10
M
yr
,
a
value
is
very
close
to
mass
flux
previously⊙
ice formation followed by non-distructive photodesorption
from the dust grains. The two-sided total atomic mass
with He
theI absorption,
National
andAdministration(if
emissioncriteria,
33
objects
for theAeronautics
SiOfew
andany)the
H2 Space
outflow.
WeBasedconclude
theof classify
the coolingfromCO, OHand [OI]
is−6on these−1 bulk weflux estimatedestimatedfromandthejet[OI]jetsums
tolines.
1.65
×10
Mthat
, a value
thattheis very
closeastoeither
the bona
mass
flux previously
⊙ yr
fide
FUors with(eruptionobserved),
FUor-like
objects(eruptionnotobserved),
or peculiar
objectswith
someFUor-like
associatedgas
excitedinoutflow
shocks,withtheblue-shifted(SE)
outflow
showing
evidenceofashock-induced
E-mailcontact:
msc
at
ifa.hawaii.edu
estimatedtheandSiO
the HatlasWe
conclude
the objects,
bulk
the
from
2 outflow.
characteristics,
present
aOH
spectralof 14linesbona-fide
FUors,
10thatFUor-likeand9 cooling
peculiar objects.
All OH and [OI] is
UV fieldfor
responsible
forjettheandemission.
Wateraroundthe protostar
reveala veryoflow
ortho-to-pararatio CO,that
associatedwithwegas
excitedin formation
outflow
shocks,withblue-shifted(SE)
outflow
showing
evidenceofobjects
thatclassify
as FUors
or FUor-likeverythesimilarnear-IRWe
useFinally
this
spectralsimilarity
to a shock-induced
can beconductedinterpreted
inoffrom ahave
primordialgas
reservoir
theenvelope.
comparisonsof theWe
havea terms
homogenous
near-IR
spectroscopic
surveyinspectra.
of33
objectswithvarying
degreesof similarity todeterminetheextinctiontoeachsource,andcorrelatetheextinction
to
the
depth
of
the
3
µm
ice
band.
All
bona
fide
[OI]
jet
mass-flux
to
the
mass
fluxesderived
for
SiO
and
H
renders
HH
211
the
first
embeddedsystem
where
an
UV
field
responsible
for
the
OH
emission.
Water
lines
aroundtheprotostar
revealavery
lowortho-to-pararatio that
FU Orionis. Common spectroscopic features that are 2characteristic of the three classical FUors FU Ori, V1057
Cyg,
FUors
still
today
maintainthespectrumofaFUor,
despitetheeruption
occurring
up
to
80
years
ago.
Most
FUors
atomicjet is demonstrably
shown
to possess fromenougha momentum
to gasdrivereservoir
the observed
molecular
jets andlarge scalecanbeinterpreted
in
terms
of
formation
primordial
intheenvelope.
Finally
comparisonsoftheand V1515
Cyg are:strongCOabsorption,
weak
metal
absorption,strong waterbands,
lowthegravity,andFUor-like
objects
occupya uniquespace ona plotof Na+Ca
vs. CO equivalent
widths,whereaspeculiarstrong blue shifted
outflows.
[OI]I objects
jetmass-flux
to themass
fluxesderivedfor SiOandrenders
HH 211wethe
first theembeddedsystemwhere bonaanHeabsorption,
few mostly(if any)
emission
Based
onH2athesecriteria,classify
objects
as eithertend to andbe foundelsewhere.
Sincelines.
most FUors
show
reflection
nebula,wealso present
an33atlasofAcceptedby
Astronomy&
Astrophysics
atomicjet isdemonstrably
shown
to possessenough(eruption
momentumdrive
observed
molecular
jets and
large
scale
K-bandimagesof eachtarget.
We foundthat theobjects
near-IR
spectraof FUors
andyoungthebrown
dwarfscanbe extremely
fide
FUors
(eruptionobserved),
FUor-likenotto
observed),orpeculiar
objectswith
someFUor-like
https://arxiv.org/pdf/1806.00311
outflows.
similar, a distinguishingfeaturebeing the Paschen
in theFUors,
spectra of
AlthoughV1647 Ori,
6a,characteristics,
and present
a spectral
atlas ofβ absorption
14 bona-fide
10FUors.
FUor-like
objects,andAR
9 peculiar
objects. All
and V346 Normae had been previously classified as candidate FUors, we classify them as peculiar objects with some
objectsthat
weclassifyFUorsor now
FUor-likehave very
similarnear-IR
this spectral similarity to
Acceptedby properties
Astronomy&theirAstrophysics
FUor-likesinceasspectradiﬀer significantly
frombona fide
FUors. spectra.
We confirmWe
two usenew FUor-like
SpiralArms
inDisks:
Planets
orGravitational
Instability?
determineeach source,
and correlatethenear-IR
extinction
to the depth of the 3 µm ice band. All bona fide10
objects thethat extinction
were initiallyto
identified
as candidates
based on theirmorphology.
https://arxiv.org/pdf/1806.00311
1
2
3,2
Ruobing
Dongmaintain, Joan R. theNajitaand SeanFUorsstill today
spectrumof aBrittain
FUor, despite the eruption occurring up to 80 years ago. Most FUors
Acceptedby Astron.
J.
1
Steward Observatory,
Universityof Arizona,933on
N aCherry
Tucson, vs.
AZ 85721,
USA; 2 National
Opticaland FUor-likeobjects occupy
a uniquespaceplot Ave,of Na+Ca
CO equivalent
widths,whereas the peculiar
http://arxiv.org/pdf/1806.08880
3
Astronomical
Observatory,
950
North
CherryAvenue,Tucson,AZ
85719,
USA;
DepartmentofPhysics&
Astronomy,
Spiraltend
Arms
Disks:
Planets
or Gravitational
objects
to beinfoundmostlyelsewhere.
Since most FUors Instability?
show a reflection nebula, we also present an atlas of
118 Kinard Laboratory, Clemson University, Clemson, SC 29634, USA
K-bandimagesof1 ,eachtarget.
We foundthat
the Brittainnear-IR spectraof FUors and young brown dwarfs can be extremely
2
3,2
Ruobing
Dong
Joan
R.
NajitaSean
Herschel
spectral-line
mappingandof the
HH211 protostellar system
E-mailcontact:
rbdongat
gmail.com
9similar,a distinguishingfeature being
the Paschen β 1absorption in the spectra of FUors. Although
V1647 Ori, AR 6a,12
1
2
Odysseas
Dionatos
,seen
Tom
Ray
and
ManuelGüdelSteward
Observatory,
UniversityofArizona,933
N
CherryAve,
Tucson,AZ
85721,
USA;
OpticalSpiralarm
structuresinscatteredlightobservations
ofprotoplanetary
disks
can
potentiallyserve
assignposts
and V346
Normae had been previously classified as candidate FUors, we classify
them as peculiar National
objects with
some
3
1
of
planetarycompanions.
They
can
also
lend
uniqueinsights
intodisk
masses,which
arecriticalinsettingthemass
Astronomical
Observatory,
950
North
CherryAvenue,Tucson,AZ
85719,
USA;
DepartmentofPhysics&
Astronomy,
Institute for
Astronomy (IfA),
Universityof Vienna,Türkenschanzstrasse
17, A-1180
Vienna;FUor-like
properties
since theirspectranow
diﬀer significantly
from bonafide FUors.
We
confirm2
budgetforLaboratory,
planetformationbut
arediﬃcult
determine
AStudies,
surprisingly
high fractionof disks
that2,
havebeentwo new FUor-like
Astronomy& Astrophysics
Section,Dublin to
Institutefor directly.
Advanced
31 Fitzwilliam
Place,
DublinIreland118
KinardClemson
University,
Clemson,SC
29634,
USA
objects
that were
initiallylight
identified
asarmscandidates
based
onastheirnear-IR
morphology.
well-studiedin scattered
have spiralof some kind
(8/29),
do a highfraction(6/11) of well-studied Herbig
E-mail contact: odysseas.dionatos at univie.ac.atintermediate
mass
stars at(i.e.,
Herbig stars > 1.5M⊙ ). Here we explore the origin of spiral arms in Herbig systems by
E-mailcontact:
rbdonggmail.com
Accepted by Astron. J.
1

10Midand their
far-infraredobservationsof theenvironment
embeddedrates.
protostars
reveala plethora
high excitation
studying
occurrence
rates, disk
properties,
and aroundstellar accretion
We findthat
two-armofspirals
are more

9

Spiralarm structures
seen inlines.
scatteredlightobservationsof areprotoplanetary
disks
can
serve as signposts
molecular
atomicemission
A intermediate
numberof diﬀerent
mechanisms
fordirectly
the originof theselinesplanet
havepotentiallybeen
proposed,commoninand
disks
surrounding
Herbigmass stars
than
imagedgiant
companions
to
http://arxiv.org/pdf/1806.08880
including
protostellar
jetsareandradiation
the embedded
protostarinteractingwithimmediateof planetarycompanions.
can
also
lend
uniqueinsights
disk
masses,whichsuggests
areitscriticalin setting the mass
mature A shocks
and B inducedstars. IfbyThey
two-arm
spirals
producedbyby
such
giantintoplanets,
thisdiscrepancy
that giant
surroundings.
planets
muchformation
fainter than but
predicted
by hot start
In addition,
the A
high
stellar accretion
rates
of Herbig
budgetfor areplanetare diﬃcult
to models.
determine
directly.
surprisinglyhighfraction
ofstars,
disks that have beenInthis paperover
we employextended
spectral-line
maps thatsuggest
spatially
resolveregionsare
where
diverseexcitation
processes
ifsustainedareasonablefractionof
theirlifetimes,
that
disk
massesmuchlargerthaninferredfromwell-studied inscattered light havespiral arms
somekind (8/29),
as do a high fraction(6/11) of well-studied Herbig
Herschel
spectral-line
mapping
of of
the
HH211
protostellar
systemappearto dominate.
Studying themorphology
andexcitationof themostimportantmolecular
and atomic
coolants,
their submillimeter
continuum
emission.Asa result,
gravitational
instability
is a possible
explanation
for multi-arm
intermediate
mass
stars
(i.e.,
Herbig
stars
>
1.5M
).
Here
we
exploretheoriginofspiralarms
in Herbig systems by
⊙
1
2
1
we
aim
to
constrainthephysicalconditions
aroundtheembedded
protostellar
system
HH
211-mm.
spirals. Future
observations
canRaylend insights
the issues
raised here.
Odysseas
Dionatos, Tom
and into
ManuelGüdelstudying
their occurrence
rates,
properties,
and emission
stellar accretion
We(CO,
findH2that
Spectro-imaging
observations
with disk
Herschel/PACS
providefrom major rates.
molecular
O andtwo-armOH) and spirals are more
Accepted by ApJ
1atomicincoolants(e.g.
[OI]).(IfA),
Emissionline maps
revealthe morphology
the observed
emissionsand allow
associations
Institutefor
Astronomy
Universityof Vienna,Türkenschanzstrasse
17, A-1180
Vienna;commondisks
surrounding
Herbigintermediate
mass
starsof thanare directly
imagedgiant
planet companions tohttps://arxiv.org/pdf/1806.05183
2
betweenthediﬀerent
species.
Comparisons
are
also
made
with
mid-infraredline-maps
fromSpitzerandsub-mmAstronomy& Astrophysics
Section,spirals
Dublinforby
Advanced
Studies,
31 thisFitzwilliam
Place,
Dublinthat
2, Ireland
matureA and
B stars. If two-arm
areInstituteproducedsuch giant
planets,
discrepancy
suggests
giant
interferometers. The excitation conditions of the detected molecular species along with the ortho-to-para ratio of
planetsaremuchodysseas.dionatos
fainterthan predictedby hot startmodels. In addition, the high stellar accretion rates of Herbig stars,
E-mailcontact:
at diagrams.
univie.ac.atwater
are assessed
through Boltzmann
Further investigations focus on constraining the CO/H2 ratio in
Radialvelocity
surveyofspatially
resolved
young,
low-massbinariesoverreasonable
ofastheir
lifetimes,suggestthat
diskmassesmuchlargerthan inferred from
11if sustained
shocks andthe amassflux of thefraction
atomic jet
tracedby [OI]. We
find thatmolecularlines areareexitedmainlyat the9Mid- and far-infrared observations of the environment around embedded protostars reveal a plethora of high excitation
molecularspectral-line
and atomic emission
lines. A numberof diﬀerent
mechanisms
for the originof these lines have been proposed,
Herschel
mappingof the
HH211
protostellar
systemincluding shocks inducedbyprotostellar
jets
andradiationbytheembedded
protostarinteracting with its immediate
Odysseas
Dionatos1 , Tom Ray2 and Manuel Güdel1
surroundings.
1
In thisforpaper
we employextended
spectral-line
mapsTürkenschanzstrassethat spatially resolve regions
whereVienna;
diverse excitation processes
Institute
Astronomy(IfA),
Universityof Vienna,
17, A-1180
2
appeartodominate.
Studyingthemorphology
andexcitation
of
the
most
importantmolecular
and atomic
Astronomy & Astrophysics Section, Dublin Institute for Advanced Studies, 31 Fitzwilliam Place,
Dublincoolants,
2, Ireland
we aim to constrain the physical conditions around the embedded protostellar system HH 211-mm.
E-mailcontact: odysseas.dionatos
at univie.ac.at
Spectro-imaging
observations with
Herschel/PACS provide emission from major molecular (CO, H2 O and OH) andcoolants (e.g.
[OI]). Emission
maps revealaroundthe morphology
of protostars
the observedreveal
emissionsand allow
associations
Mid- atomic
and far-infraredobservationsof theline
environment
embeddeda plethoraof high
excitation
betweenthediﬀerent
species.
Comparisons
are
also
made
with
mid-infraredline-maps
fromSpitzerandsub-mmmolecular and atomic emission lines. A number of diﬀerent mechanisms for the origin of these lines have been proposed,interferometers.
The byexcitation
conditionsof thedetected
speciesprotostar
along withthe ortho-to-pararatio ofincludingshocks induced
protostellar
jets andradiation
bymolecular
the embedded
interactingwith its immediate
water
are
assessedthroughBoltzmann
diagrams.
Further
investigations
focus
onconstraining
the
CO/H
ratio
in
2
surroundings.
shocks
and
the
mass
flux
of
the
atomicjetastraced
by
[OI].
We
find
that
molecular
linesareexitedmainlyattheIn this paper we employ extended spectral-line maps that spatially resolve regions where diverse excitation processes
terminal bowshocks of the outflow and around the position of the protostar. All lines show maxima at the SE bowshock
appear to dominate. Studying the morphology and excitation of the most important molecular and atomic coolants,
with the exception of water emission that peaks around the central source. Excitation analysis in all positions shows
we aim to constrain the physical conditions around the embedded protostellar system HH 211-mm.
that CO and H2 O are mainly thermally excited at Tex ∼ 350 K and 90 K respectively, with the CO showing a second
Spectro-imaging
emission analysis
from major
molecular
H2 OOH)
temperature observations
component at with
750 KHerschel/PACS
towards the SE provide
peak. Excitation
breaksdown in (CO,the caseof andOH attheandatomiccoolants(e.g.
[OI]).
Emissionline
maps
revealthemorphologyoftheobserved
emissionsandallow
associations
blue-shifted bowshock, indicating that the molecule is non-thermally excited. Comparisons between the CO and H2
betweenthe densities
diﬀerentsuggest
species.
areinalso
madesub-mmcolumnthatComparisons
the X[CO] value
shockscan with
be upmid-infrared
to an order ofline-maps
magnitude fromlower Spitzer
than theandcanonical−4The excitation conditions of the detected molecular species along with the ortho-to-para ratio ofinterferometers.
value of 10 . The water ortho-to-para ratio around the protostar is only 0.65, indicating low-temperature water
watericeare
assessedfollowed
throughbyBoltzmann
diagrams.
Further investigations
constraining
the CO/H
ratio information
non-distructive
photodesorption
from the dust focus
grains.onThetwo-sided total
atomic2 mass
−6
−1
shocksthe mass
flux
thejetatomicjet1.65
as tracedfind thatthat ismoleculararemass
exitedat thefluxandestimatedfromtheof[OI]sums to×10 byM⊙[OI].
yr ,Wea valuevery closelines
to thefluxmainly
previously
14
terminal
bowshocksoftheoutflow
andaroundthepositionoftheprotostar.
All
lines
show
maximaattheSEbowshock
estimated for the SiO jet and the H2 outflow. We conclude that the bulk of the cooling from CO, OH and [OI] iswithassociatedthe exception
emissionthatpeakswitharoundthe central (SE)source.
Excitation
positions showswith ofgaswater
excitedin outflow
shocks,the blue-shifted
outflow
showinganalysis
evidenceinofalla shock-induced
for the thermally
OH emission.
Wateraroundprotostar
reveal a verywith
low theortho-to-pararatioa thatthat UV
COfield
and responsible
H2 O are mainly
excitedat lines
Tex ∼350 Ktheand90 K respectively,
CO showing
secondcan be interpreted
in terms
a primordial
gas reservoir
in thebreaks
envelope.
Finally
comparisonsof atthethetemperaturecomponent
at 750ofKformation
towards fromthe SE
peak. Excitation
analysisdownin thecase of OH[OI]
jetmass-flux
to
the
mass
fluxesderived
for
SiO
and
H
renders
HH
211
the
first
embeddedsystem
where
an H2
2
blue-shifted bowshock, indicating that the molecule is non-thermally excited. Comparisons between the CO andatomicjetisdemonstrably
showntopossessenoughmomentum
to
drive
the
observed
molecular
jets
and
large
scale
column densities suggest that the X[CO] value in shocks can be up to an order of magnitude lower than the canonicalvalueoutflows.
of 10−4 . The water ortho-to-para ratio around the protostar is only 0.65, indicating low-temperature water

Accepted by Astronomy & Astrophysics
https://arxiv.org/pdf/1806.00311

14

10 Spiral Arms in Disks: Planets or Gravitational Instability?
Ruobing Dong1 , Joan R. Najita2 and Sean Brittain3,2
1

Steward Observatory, University of Arizona, 933 N Cherry Ave, Tucson, AZ 85721, USA; 2 National Optical
Astronomical Observatory, 950 North Cherry Avenue, Tucson, AZ 85719, USA; 3 Department of Physics & Astronomy,
118 Kinard Laboratory, Clemson University, Clemson, SC 29634, USA
E-mail contact: rbdong at gmail.com
Spiral arm structures seen in scattered light observations of protoplanetary disks can potentially serve as signpostsof planetary companions. They can also lend unique insights into disk masses, which are critical in setting the mass
budget for planet formation but are diﬃcult to determine directly. A surprisingly high fraction of disks that have been