Star Formation NewsletterNo. 307 31-40
高橋実道（工学院大学）

31
32
33

Polar alignment of a protoplanetary disc around an
eccentric
binaryII: Eﬀectof binary and disc parameters
Astronomy& Astrophysics
manuscript
no. vla1623_letter_d1

c ESO 2018

July 3, 2018

1 and Stephen
2
Dense
gas
kinematics
andanarrowfilament
in
the
Orion
A
OMC1
regionusing
NH
RebeccaG.
MartinH.
Lubow
3
1
Department of Physics and Astronomy, University of Nevada, Las Vegas, 4505 South Maryland Parkway, Las Vegas, NV 89154, USA

1

2 Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA

2

3

4

4

astro-ph.SR]
2
Jul
2018
8ph.SR]
18 Jun 201818 arXiv:1806.08388v1[astro-ph.EP] 21 Jun 2018

STINA M ONSCH , JAIME E. P INEDA , H AUYU BAOBAB L IU , C ATHERINE Z UCKER , H OPE H OW-H UAN C HEN , K ATE P
Accepted
XXX. Received
YYY; in originalform ZZZ
7 SED
8, 9
10 1623 2417
1, 11
Revisedofthetripleprotostellar
systemVLAS TELLA S. R. O
FFNER
, JAMESI F RANCESCO ,A DAM G INSBURG , BARBARA E RCOLANO ,H ÉCTOR G. A RC
Draft
versionJune 6, D
2018
14
8, 9
2 1, 2
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1 ,13,
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2 , S.-P.
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Typesetusing
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style
AASTeX61
N.
M.
MurilloD.
Harsono,M.
McClureLai
R ACHEL F RIESEN,
H ELEN K IRK , PAOLA C ASELLI , AND A LYSSA A. G OODMAN
E
ABSTRACTGA]
5 Jun 272018
[astro-ph.SR]
Jun 2018

18

In a recent paper Martin& Lubow showedof
thatthea circumbinary
disc aroundaneccen-Vicinity
Sub-arcsecond
Kinematic
Structure
Outflowinthe
34 1 1 Leiden Observatory, Leidentricbinary can undergo damped nodal oscillations that lead to the polar (perpendicUniversity,
P.O.ofBox
9513,relative
2300 RA,
Leiden,theorbit.
Netherlands
ular)alignment
the disc
to thebinaryThe München,
disc angular momentum
Universitäts-Sternwarte,
Ludwig-Maximilians-Universität
Scheinerstr.
1,
81679
München,GermanyoftheProtostarinL483
e-mail:nmurillo@strw.leidenuniv.nl
aligns to the eccentricity vector of the binary. We explore
the2018
robustness ofc ESO
Astronomy& Astrophysics manuscriptvector
no. prisinzano
2
Anton
for Astronomy,of Amsterdam,
Park 904,
1098
XH,
2 Max-Planck-Institut
mechanism University
for a low mass
disc (0.001Scienceof the binary
mass)
and
itsAmsterdam,
dependence The Netherlands
June 19,
2018Pannekoek Institute thisfürextraterrestrische
Physik,Giessenbachstrasse
1,85748
Garching, Germany
3onsystem parameters
byNational
means ofTsinghydrodynamic
disc simulations.
We
describehow
InstituteofAstronomy
andDepartmentofPhysics,
Hua
University,
101
Section
2
Kuang
Fu
Road,
Hsinchu
30013,EFFICIENTMETHODFOR
DETERMININGTHECHEMICALEVOLUTIONOFGRAVITATIONALLY
1
2
1,3,4
5,6,7
35 AN
the
evolution
depends
upon
the
disc
viscosity,
temperature,size,
binarymass
ratio,
Taiwan3 European
Yoko Oya Southern, Nami Sakai, Yoshimasa(ESO),
Watanabe, Ana López-Sepulcre2, 85748,
Observatory
Karl-Schwarzschild-Str.
Garching, Germany
4
orbitaleccentricity
andinclination.
We
compareresults
withpredictionsoflineartheAstronomy & Astrophysics
no.ofaa_2
COLLAPSING
Academia manuscript
Sinica Institute
Astronomy and Astrophysics,
P.O. Box 23-141,PRESTELLAR
Taipei 10617, Taiwan CORESc ESO 2018ory. We show6,7
that polar alignment of a low
6,7mass disc may occur over a wide range
1,8 ofJune 9, 2018
4 Harvard-Smithsonian
Cecilia Ceccarelli, Bertrand
Lefloch, andofSatoshi
Yamamotobinary–disc parameters.
We discuss
the application
our results
to Garden
the formationSt.,
of Cambridge, MA, USA
Centerfor
Astrophysics,
60
July
3,
2018
Low mass star formationandsubclustering
in
the
H
II
regions
planetary systems around eccentric binary stars.
5 Jeremiah
36 Astronomy
RCW 32,33Key
and27PaperNfrac_BIZZ2
oftheUniversity
Vela Molecular
Ridge
Horrocks
Institute,
Lancashire
PR1
2HE,
UK
words:
accretion,accretion
discs –ofbinaries:
general1Lancashire,– hydrodynamics – Preston,planets
1Central
1ESO
c& Astrophysics
manuscriptno.
2018
F. D. Priestley,
ABSTRACT S. Viti, and D. A. Williams
andsatellites:
formation
oya@taurus.phys.s.u-tokyo.ac.jp
June 5, 62018
A photometricdiagnostics
to identify ofM-typestars National Tsing Hua University, Hsinchu, Taiwan
InstituteofAstronomy
andDepartment
Physics,
Context. VLA 1623
2417 is1 a triple protostellar
systemdeeply embedded
in Ophiuchus
A. Sources
A and B have a separation of
1
1
1
1
2
1
00 L. Prisinzano , F. Damiani , M. G. Guarcello , G. Micela , S. Sciortino , E. Tognelli , and L. Venuti
7
1.1, making their study difficult beyond the submillimeter regime. Lack of circumstellar gas emission?
suggested that VLA 1623
37
DepartmentofAstronomy,
The
University
of
Texas
at
Austin,2515
Speedway,
Stop C1400, Austin, TX 78712-1205, USA
Kinematics
of
dense
gas
in
the
L1495
filament
B
has
a
very
cold
envelope
and
is
much
youngerthansourceA,
generally
consideredtheprototypicalClass0source.
1 INTRODUCTION
cular
orbit
binary undergoes uniform nodal precession with
Received;
accepted
INAF - Osservatorio
Astronomico di Palermo, Piazza del Parlamento 1, 90134, Palermo,
Italy
1
Aims.
Weloredana.prisinzano@inaf.it
explorethe consequencesof new ALMABand 9constantdataCollege
ontilt.
theThespectralenergydistribution
ofparVLA 1623
2417
and UK
8 National Research
Departmentof Physics
and Astronomy,
University
London,
Gower
Street,LondonWC1E
6BT,
angularmomentum
vectorof(SED)the test
e-mail:Councilof
Canada,Herzberg
InstituteofAstrophysics,
5071
West
SaanichRoad,
Victoria, BC, V9E 2E7, Canada
Binary and multiple
systems
observed to becom2 , P.star
1 , are1 A.
3 ticle4 , A.theHacar
5 , and L.
1
precesses
binary angularmomentum
vector.
theirinferred1,
A. 14
Punanova
J.
E.
Pon
,
M.
TafallaBizzocchi
Department
ofnature.
PhysicsCaselli‘E. Fermi’, University
ofPineda
Pisa, Largo ,Bruno
Pontecorvo
3, I-56127
Pisa,about
Italy
mon (Ghez
al. 1993; Duchêne & Kraus 2013). Turbulent
15R.et+each component in
Similarly,amisaligned
discaroundacircularbinarydisplaysMon.
Not.
Astron.
Soc.
000,
1–23
(2015)
Printed
20
June
2018
(MN
L
T
X
style
file
v2.2)
Methods.
Using
dust
continuum
observations
spanning
fromcentimetertonear-infrared
wavelengths,
the
SED
of
9 Department
E
N/
N
ratio
measurements
inprestellar
cores
with
N
H
:
new
2
molecular
cloudscanlead tochaotic
accretion
during the UniversityofPhysics
andAstronomy,ofVictoria,
3800
Finnerty
Rd.,
Victoria, BC, V8P 5C2, Canada
the form of same ABSTRACT
precession. The disc is able to hold itself
38
VLA
1623
2417
is
constructedandanalysed.
star formation process (McKee & Ostriker 2007; Bate et al.15
1?
togetherandprecess
as
a
solid
body
for
Max-Planck-Institut
fürextraterrestrische
Physik,Giessenbachstrasse
1,85748
Garching,
Germany
ABSTRACT
Results.
The
ALMA
Band and
9evidencedata
presented discs
here
show
that
the SED of VLA 1623 2417 B doessuﬃciently
not peak warmat 850µm as previouslyofN-antifractionation
10
and
thus
circumstellar
circumbinary
are
2003)
2
and
narrow
discs(e.g.,
Larwood&
Papaloizou1997).
DissiJansky
fellowofthe
National
Radio
Astronomy
Observatory,
1003
Lopezville
Rd,
Socorro,
NM
87801
USA
Ural Federal
University,
620002,19
Mirastreet,Yekaterinburg,
Russiaexpected,butinsteadpresents
the
same
shape
as
VLA
1623
2417
A
at
wavelengths
shorter
than
450
µm.
We
developanalytic
approximations
tothedensityevolutionofprestellar
cores,
basedontheresultsofhydrodynamlikely
toform
misaligned
withrespect
totheorbitalplane
Context. Most stars born in clusters and recent results suggest that star formation(SF) within
preferentiallyoccursin subclusters.
Studying
pation
the
disc
leads
to
alignmentwith the binary ore-mail: anna.punanova@urfu.ru
MNRAS
000,
1–12
(2015)
Preprint
6
June
2018
Compiled
using
MNRAS
LSpitzer
TEX styleobservations
file4v3.0
1
1
1
1,
2
1
3 ,andConclusions.
The
resultspresented
here
indicatethattheprevious
assumption
that
the
flux
in
Herschelisofthebinary(Monin
et
al.
2007;
Bate
et
al.
2010;
Bate
the
morphology
andSF
historyofyoung
clustersiscrucialtounderstanding
earlyclusterformation
processes.
11
E.
Redaelli,L.
Bizzocchi,
P.
Caselli
,
J.
Harju
,
A.
Chacón-Tanarro,
E.
Leonardo
and
L.
Dore
bital
plane
(Papaloizou&
Terquem
1995;
Lubow
&
Ogilvie
3
The
formationofprotostellar
binariesinprimordialical
simulations.
We
use
these
approximations
as
input
for
a
time-dependentgas-grainchemicalcode
to investigate
Excellence
Cluster
OriginandStructureoftheUniverse,
Boltzmannstr.2,
85748
Garching,
Germany
Aims.
We
aim
to identify
theembedded
populationofyoung
objects(YSOs)
down1151
tothelowmass starsinthe
M-typeregime,DepartmentofPhysics
andAstronomy,
The
University
ofstellar
Western
Ontario,
Richmond
Street,London,
ON,
N6A
3K7,
Canada2018).
The
torquefromthebinarysystemalterstheforsolely
dominated
by
VLA
1623
2417
A
is
not
valid,
andinstead,
VLA
1623
2417
B
most
likelycontributesasignificant
fraction
2000; Nixon
al.Vela2011;
NixonRidge.
2012;
et al. 2013;39
in the three
H regions
RCW
33, RCW
32 anddiscs
RCW 27
located in to
the northwesternregion ofetthe
Molecular
OurFacchiniaim
4mationprocessesforplanets
inthesecompared
Observatorio(IGN),
Alfonso
XII
3, of
28014
Madrid,Spain
ofeﬀects
theflux atoftheirNacional<properties,
450 µm.
These
results,
however,notthelack2013;
ofcircumstellar
andthepuzzling
natureWeof confirm that our method
Lodato& Facchini
Foucart& Lai
2013,2014). inthediﬀering
modesofcollapseon
core.
isAstronómico
to characterise
suchasmorphology
andextentthedoclusters
inexplain
the thethree
H molecularregions,
derivestellarabundancesages
andgasthe emission
12
minihalos
5
2000;
Mayer
et al. 2005;
discs
aroundsinglestarsof(Nelson
DepartmentofAstronomy,
University,
P.O.
Boxbinaries
208101,
New Garching
Haven,
Centrefor
Astrochemical
Max-Planck-Institut
extraterrestrische
Physik,Gießenbachstraße
1, D-85749
bei CT 06520-8101, USA
Leiden Observatory,
University
Leiden,Niels
Bohrweg
2, Yale2333fürCA
Leiden,Themain
Netherlands
connectionoftheSF history
withtheStudies,
environment.
VLA
1623
2417
B.
However,sequencearecommonly
2006; ThroughMartinet al.photometric2014; Fusurveys
et al. such2017).
Aftera gi-2MASS
Methods.
publicas Gaia,
VPHAS,
andexact
Spitzer/GLIMPSE,
we identify YSOs
with classi- of both the hydrodynamics and chemistry while
canBoss
providereasonableagreement
withannumerical
solutionMünchen(Germany)found disks
onobjects:
eccentric
orbits(e.g., 2417
Duquennoy& Mayor1991;
13
calplanettechniques
aimed
atadetecting
IR, H↵disc,
UV
excesses,signatureand theaccretion.
In addition,we
implementroleofexternal
FUV
irradiationinsurvival
astrophysical
ant
forms
in
misaligned
thetorqueasfrom
theof circumstellar
Keywords.
stars:
formation-andstars:
low-mass- ISM:
individual
VLA
1623
-of
methods:
observational- techniques: VA 22903, USA
National
Radio
Astronomy
Observatory,
520
Edgemont
Rd,
Charlottesville,
June 9, 2018The
e-mail:[eredaelli,bizzocchi,caselli,harju,achacon]@mpe.mpg.de
Raghavanetal.
2010).
The
eccentricity
distributionisamethodtodistinguishmain
sequence
(MS)
stars
and
giantsinthe
M-typeregime,bycomparingthereddeningderivedinseveralopsignificantly
lesscomputationallyallowing
athelarge
grid of models varying multiple input parameters
binarycan result
the planetnolonger remaining copla- expensive,interferometric
1? ofin
1,2
3
1
Department
Physics,
PO
Box
64,
00014
UniversityofHelsinki,
Finland
40 being
tical/IRcolor-color
diagrams,
assuming
suitabletheoreticalmodels.
Since
thisdiagnostic
issensitive
tostellargravity,procedurenearlyflat out to eSchleicher∼ 0.6 and declines
somewhat at higher
R.
Riaz
S.
Bovino†S.
Vanaverbeke‡
D.R.G.
§
ices
in
Elias
29
narallows
to
the
disc
(Picogna&
Marzari
2015;
Lubow
&
Martin14
usDunlap
tode
identify
also pre-main
sequencedo(PMS)
stars.
Institutefor
Astronomy&
Astrophysics,
50
St.
GeorgeSt.,
TorontoON
CanadaM5S
3H4
Istituto
Astrofísica
eUnderstandingCiências
Espaço,UniversidadedeLisboa,OAL,
Tapadadade
Ajuda,
PT1349-018
Lisboa(Portugal)
values.
Consequently,
thebinaryeccentricity
shouldbeconto 2016;
be
run.
We
present
resultsusing
thismethodtoillustratehowthechemistryisaﬀectednotonlyby
the collapse
DepartamentodeAstronomı́a,
Facultad
Ciencias
Fı́sicasy Matemáticas,
Universidad
Concepción,
Av.
EstebanIturras/ne-mail:
BarrioMartinetal.
2016).
thedisc
Results. Using the classical membership criteria, we finda evolution
large
populationof
YSOs
showingsignaturesofcircumstellar
disks
with
ABSTRACT
1
2

A

A

II

II

1

2

13

eleonardo@oal.ul.pt

sidered in dynamical models of interactions between a stel-v1 [astro-ph.EP] 21 Jun 201831

Polar alignment of a protoplanetary disc around an
eccentric binary II: Eﬀect of binary and d7c41Tf[(ec)1(097.3e95r)]5(rs)(E)]TJETQq2.907 1653-4c14BTc4Q0BTc4215.689T7/c61TR

National Research Council of Canada, Herzberg Institute of Astrophysics, 5071 West Saanich Road, Victoria, BC, V9E 2E7, Canada
9 Department of Physics and Astronomy, University of Victoria, 3800 Finnerty Rd., Victoria, BC, V8P 5C2, Canada
10 Jansky fellow of the National Radio Astronomy Observatory, 1003 Lopezville Rd, Socorro, NM 87801 USA
Dense gas kinematics and a narrow filament in the Orion A OMC1 region using NH3
11 Excellence Cluster Origin and Structure of the Universe, Boltzmannstr.2, 85748 Garching, Germany
1
2
3
4
4
5, 6
12 Department
K RISTINAM ONSCH
,
J
AIME
E.
P
INEDA
,
H
AUYU
B
AOBAB
L
IU
,
C
ATHERINE
Z
UCKER
,
H
OPE
H
OW
-H
UAN
C
HEN
,
K
ATE
P
ATTLE
,
of Astronomy, Yale University, P.O. Box 208101, New Haven, CT 06520-8101, USA
7
8, 9
10
1, 11
12
S
TELLA
S.
R.
O
FFNER
,
J
AMES
D
I
F
RANCESCO,ADAMGINSBURG,
B
ARBARAE
RCOLANO
,
H
ÉCTOR
G.
A
RCE
,
13
1
2
3 USA 2
4
National Radio Astronomy Observatory,
52013,
Edgemont
Rd, Charlottesville,
VA 22903,148,94ONSCH 14 Dunlap
AIME
INEDA
AUYU
AOBAB
IU
ATHERINE
OPE
OWR
ACHEL F RIESEN
,
H
ELEN
K
IRK ,
P
AOLA
C
ASELLI,AND A LYSSA A.UCKERGOODMAN
Institute for Astronomy & Astrophysics, 50 St. George St., Toronto ON Canada M5S 3H4

32

Dense gas kinematics and a narrow filament in the Orion A OMC1 region using NH3

TINA M
, J
E. P
, H
B
L , C
Z
, H
H -H UAN C HEN ,
7
8, 9
10
1, 11
1 Universitäts-Sternwarte,
S TELLA S. R. O FFNER , JAMESD I F RANCESCO, A DAMG INSBURG, München,
BARBARAH ÉCTOR
Ludwig-Maximilians-Universität
München,Scheinerstr. 1, 81679
Germany E RCOLANO ,13,
14 für extraterrestrische Physik,
8, 9Giessenbachstrasse 1, 85748 Garching,
2 Germany4
2 Max-Planck-Institut
ABSTRACTR ACHEL F RIESEN
,
H
ELEN
K
IRK
,
P
AOLA
C
ASELLI
,
AND
A
LYSSA
A.
G
OODMAN
3

EuropeanSouthern
Observatory(ESO),
Karl-Schwarzschild-Str.
2, 85748
Garching,
We present combined observations of the
NH3 (J,
K) = (1,1) and (2,2) inversion
transitions toward
OMC1
in Germany
4 Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA, USA
Orion A obtained
by
the
Karl
G.
JanskyVery
Array (VLA) and the 100 m Robert C. Byrd Green Bank
1 Universitäts-Sternwarte,Large
Ludwig-Maximilians-Universität
München,Scheinerstr.
1,
81679
München,Germany
5 Jeremiah Horrocks
00
Institute,
UniversityofCentralLancashire,
Preston,Lancashire
PR1
2HE,
UK
Telescope (GBT). With an angular resolution of 6 (0.01 pc), these observations reveal with unprecedented
6 Institute of Astronomy and Department of Physics, National Tsing Hua University, Hsinchu, Taiwan
2detail the complex filamentary
structure extendingnorthof the active Orion BN/KL
regionin a field covering
Max-Planck-Institut
fürextraterrestrische
Physik,Giessenbachstrasse
1, 85748 Garching, Germany
7
Departmentof Astronomy,
The University
ofanTexas
at Austin,
2515
Speedway,
Stop
C1400,
Austin,
TX 78712-1205, USA⇠ 60 ⇥ 70 . We find a 0.012
pc
wide
filament
withinOMC1,
with
aspectratio
of⇠37:1,
thatwasmissedin
3 8European
National ResearchCouncilof Canada,
Herzberg
Instituteof Astrophysics,
5071 West Saanich
Road,theVictoria,
V9E 2E7,
CanadaSouthern
Observatory(ESO),
Karl-Schwarzschild-Str.
2,BC,
85748
Garching,
Germany
previous studies. Its orientation
is directlycomparedto therelativeorientationof the magnetic
field from
9 Department of Physics and Astronomy, University of Victoria, 3800 Finnerty Rd., Victoria, BC, V8P 5C2, Canada
4 Harvard-Smithsonian
James Clerk Maxwell Telescope
BISTROsurvey in Orion A. CenterWe find a forsmallAstrophysics,
deviation of ⇠ 1160
betweenthe St., Cambridge, MA, USA
Garden10 Jansky fellow of the National Radio
Astronomy Observatory, 1003 Lopezville Rd, Socorro, NM 87801 USA
mean orientation of the filament and 11
the magnetic field, suggesting that they are almost parallel to one another.
5 Jeremiah Horrocks
Excellence Cluster
Origin and
Structure of theof
Universe,
Boltzmannstr.2,
85748 Garching,
Germany
Institute,
University
CentralLancashire,
Preston,Lancashire PR1 2HE, UK
The filament’s column density is estimatedto be 2–3 orders of magnitude larger than the filaments studied with
12 Department of Astronomy, Yale University, P.O. Box 208101, New Haven, CT 06520-8101, USA
Herschel and is possibly
self-gravitating13given the low values of turbulence found. We further produce maps
6 InstituteofAstronomy
andDepartment
Tsing
Hua
National Radio
Astronomy
Observatory,of
520Physics,
Edgemont Rd,National
Charlottesville,
VA 22903,
USA University, Hsinchu, Taiwanof the gas kinematics by forward modelingthe hyperfine structure of the NH3 (J, K) = (1, 1) and (2, 2) lines.
14 Dunlap
Institute for Astronomy & -1
Astrophysics, 50 St. George St., Toronto ON Canada M5S 3H4
7
The resulting
distribution
velocity dispersionsat ⇠ 0.5 km, close atto thesubsonic2515
regimeSpeedway,of the gas.
Department
ofofAstronomy,
Thepeaks
University
ofsTexas
Austin,Stop C1400, Austin, TX 78712-1205, U
-1
This
value
is
about
0.2
km
s
smaller than previously measured in single-dish observations of the same region,
8 National Research Council
ABSTRACTofCanada,Herzberg
Institute
Astrophysics,
5071 West Saanich Road, Victoria, BC, V9E 2E7
suggesting that higher angular and spectral resolution observations will identifyof
evenlower velocity dispersions
We present
combined
observationsof the NH3 (J, K) = (1, 1) and (2, 2) inversion transitions toward OMC1 inthat might9 Department
reach the subsonicturbulence
regimeindense
gas
filaments.
of Physics and Astronomy, University of Victoria, 3800 Finnerty Rd., Victoria, BC, V8P 5C2, Canada
Orion A obtained by the Karl G. Jansky Very Large Array (VLA) and the 100 m Robert C. Byrd Green Bank
10 Jansky
00
fellowofthe
National
Radio
Astronomy
Observatory,
1003—Lopezville
Rd, Socorro, NM 87801 USA
Telescope(GBT).
Withanangularresolution
of
6
(0.01
pc), thesereveal with unprecedented
Keywords: astrochemistry – ISM: clouds — ISM: individual (OMC1) — ISM:
kinematics
andobservations
dynamics
detail—theISM:
complexfilamentary
structureextendingnorthformationof the active Orion BN/KL region in a field covering
11 Excellence
ISM: molecules
magnetic
fields—radiolines:
ISM—
stars:
Cluster
OriginandStructureoftheUniverse,
Boltzmannstr.2,
85748
Garching,
Germany00⇠ 6 ⇥ 7 . We find a 0.012 pc wide filament within OMC1, with an aspect ratio of ⇠37:1, that was missed in
12
previous
studies. Itsis directly
to theP.O.
relative
theisotopomagnetic
field
from
the
1. INTRODUCTION
in Yalethese comparedregions, severe
depletionof208101,
CO andofitsNew
Departmentof orientation
Astronomy,
University,
Boxorientation
Haven,
CT
06520-8101,
USA
logues occurs
freeze-out
grainsdeviation(Caselli etofal.⇠ 11 between the
Clerk molecules
Maxwell Telescope
BISTROsurveydue
in to
Orion
A. Weonto
finddust
a small
13 National
Ammonia (NH3 ) is one of theJamesmost
usefulavailRadio
Astronomy
Observatory,
520
Edgemont
Rd,
Charlottesville,
VA
22903,
USA
1999;
Bacmann
et
al.
2002;
Berginetal.
2002;
Tafallaetal.
of the filament
and the magnetic field, suggesting that they are almost parallel to one another.
able for studying the physicalmean
and orientation
chemical properties
of
14The
2002, 2004).
Undersuch conditions,
theGeorgeamountthanof St.,
nitrogenfilament’s
columndensity
is estimatedto be
2–3 ordersof magnitudelargerthe filaments
studiedwithDunlapInstituteforareAstronomy&
Astrophysics,
50 St.
TorontoON
CanadaM5S
3H4
cold and dense gas found in prestellar
cores,
where
stars
+
bearing
species,
such
as
NH
and
N
H
, found.
increases
2
Herscheland is possibly
self-gravitating
given the low values of3 turbulenceWe(e.g.,further produce maps
likely to form. At the typically
low temperatures(. 10–

OMC 1 :活発な星形成領域 Orion BN/KL を含む
NH3の観測、VLA+GBT 6”~0.01pc の分解能
D ENSE GAS KINEMATICS AND A NARROW FILAMENT IN OMC1

3

細いフィラメント〜0.012pc
これまでの~0.1pc は動径分布の平均化のせい？
（Panopoulou+2017）
NH3はダストより高密度領域を見ているので注意

NSCH ET AL . (2018)

misred
h &
using
) by
pine.
from

bethe
e of
st-fitcorance
the
each
mble
2 is
lues
ngth
) pc,
1 for

t F2
file,
meter
et al.

12 Figure 7.

M ONSCH. (2018) filaMean integrated intensity profile
of ET
theALaveraged
ment profile of F2 as function of radial distance, calculated between
8.1 – 8.4 km s-1 (solid, black line) after the background emission
has been subtracted. The yellow shade corresponds to the standard
deviation of the cuts at each radial distance. The solid, gray line
shows the beam response with a FWHM of 600 . The dotted, blueline corresponds to a Gaussian fit with a deconvolved FWHM of
0.012 pc, and the red, dashed line to a Plummer fit with p = 5.1 and
Rflat = 0.013 pc. The vertical, dotted lines show the fitting ranges for
the Gaussian (blue) and Plummer (red) profile, respectively. The
best fit parameters for both profiles are listed in Table 2.

Table 2. Best fit parameters for the radial intensity profile of F2.
Type

Gaussian
Plummer

Amplitude

WidthaJy km(10-2 beam)s

(10-2 pc)

1.8 ± 0.5
1.9 ± 0.6

0.7 ± 0.2
1.3 ± 0.5

Exponent

FWHMdeconv(10-2 pc)···
5.1 ± 1.0

1.2 ± 0.3
2.0 ± 0.8

a Width corresponds to the standard deviation ( ) in the Gaussian
profile and to the flattening radius (Rflat ) in the Plummer proThedeconvolved
FWHM
then calculated
using
relation
Figurefile.
8. Top:Zoom-ininto
box in theisintegrated
intensity map
shownthein Figure
5 with overlaid B-field half-vectors from Pattle et al.
pthe white
2 from(2017);
Ward-Thompson= et al.
(2017). 2Lower
left: Position
anglesof F2 (PAetblack(2015),
curve) and the nearest B-field vector to F2 (PAB , blue)
F2 , al.
FWHM
FWHM- HPBW
Könyves

柱密度~1022.5-23 cm-2
Cygnus やTaurusより2-3桁大
self-gravitating
磁場の向きとの比較
角度のずれ~11度
概ね磁場とそろっている（重いのに！）
フィラメント形成過程が複数？

RevisedSEDofthe
tripleprotostellar
system
VLA
1623
2417
RevisedSEDofthetripleprotostellar
system
VLA
1623
2417
33
July 3, 2018

807.00640v1 [astro-ph.SR] 2 Jul 2018

1 , D. Harsono1 , M. McClure2 , S.-P. Lai3, 4 , and M. R. Hogerheijde1, 2
N. M. Murillo
N. M. Murillo1 , D. Harsono1 , M. McClure2 , S.-P. Lai3, 4 , and M. R. Hogerheijde1, 2

ABSTRACT

1

1
Leiden Observatory,
University,
Box 9513,
2300
RA,
Leiden,the Netherlands
LeidenLeiden
Observatory,
Leiden P.O.
University,
P.O. Box
9513,
2300
RA, Leiden,
the Netherlands
Context.
VLA
1623nmurillo@strw.leidenuniv.nl
2417 is a triple protostellar system deeply embedded in Ophiuchus A. Sources A and B have a separation ofe-mail:e-mail:nmurillo@strw.leidenuniv.nl
21.100 , making
their Pannekoek
study difficult
beyondthe submillimeter
regime.
Lack ofSciencecircumstellargasemissionsuggestedthat
VLA 1623
2
Anton
Institutefor Astronomy,
Universityof Amsterdam,
Park
904,
1098
XH,Amsterdam,
Amsterdam,
The
Netherlands
Anton Pannekoek
Institutefor
Astronomy,
UniversityofAmsterdam,
Science
Park
904,
1098
XH,
The
Netherlands
3 cold envelope and is much younger than source A, generally considered the prototypical Class 0 source.
B has a very
Institute of
Astronomy
and Department
ofNational
Physics, National
TsingUniversity,
Hua University,
101
Section2 KuangFu
Fu Road,Road, Hsinchu
30013,
3
InstituteofAstronomy
andDepartmentofPhysics,
Tsing
Hua
101
Section2
Kuang
Hsinchu
30013,
Aims. We explore
theconsequences
of
new
ALMA
Band
9
data
on
the
spectralenergydistribution
(SED)
of
VLA
1623
2417
and
TaiwanTaiwan4
Academia
theirinferrednature. Sinica Institute of Astronomy and Astrophysics, P.O. Box 23-141, Taipei 10617, Taiwan
4
Academia
SinicaInstituteof Astronomy
and Astrophysics,
Box 23-141,
Taipei 10617,
Taiwan the SED of each component in
Methods.
Using
dust continuum
observations
spanning fromP.O.
centimeterto near-infrared
wavelengths,

3, 2018
VLA 1623July2417
is constructed and analysed.
July 3,Results.
2018 The ALMA Band 9 data presented here show that the SED of VLA 1623 2417 B does not peak at 850µm as previously
expected, but instead presents the same shape as VLA 1623 2417ABSTRACT
A at wavelengths shorter than 450 µm.
Conclusions. The results presented here indicate that the previous assumption that the flux in Herschel and Spitzer observations is
ABSTRACT
Context.
VLA
1623
2417
is
a
tripleprotostellar
systemdeeplyembeddedin Ophiuchus
A.
Sources
A and Bahave
a separationofsolely dominated
by
VLA
1623
2417
A
is
not
valid,
andinstead,
VLA
1623
2417
B
most
likelycontributes
significant
fraction00
1.1
beyondthe submillimeter
regime.
Lackofof circumstellar
circumstellar gas
that VLA
1623ofof the flux at , making< 450theirµm.study
Thesedifficult
results,
however,do not explain
the lack
gasemission
emissionsuggested
and puzzling
natureContext. VLA 1623
2417
is aenvelope
triple protostellar
system thandeeplyembeddedin Ophiuchus
A.prototypical
Sources A
and0 B
have a separation of
B
has
a
very
cold
and
is
much
youngersourceA,
generally
considered
the
Class
source.
00 VLA 1623 2417 B.

0v1 [astro-ph.SR] 2 Jul 2018

astro-ph.SR] 2 Jul 2018

Taiwan4
Academia Sinica Institute of Astronomy and Astrophysics, P.O. Box 23-141, Taipei 10617, Taiwan

Aims.
We explore
thebeyondconsequencesof new ALMA Band
9 dataon theenergy distribution(SED)
of VLA 1623
1.1 , making theirstudy
difficultthe submillimeter
regime.
Lackof spectral
circumstellar
gas emission
suggestedthat 2417
VLAand1623
inferrednature.
B has Keya verycoldtheir
envelopeandis muchyoungerthansourceA, generally
consideredthe 2417
prototypicalClass
0 source. - techniques:words.
stars:
formation- stars:
low-mass- ISM:
individual
objects:
VLA 1623- methods:
observational
Methods.
Using dust continuum
spanning
to near-infrared
wavelengths,
the SEDof each1623
component
Aims. interferometric
We explore
the consequencesof new observations
ALMA Band
9 datafrom
on centimeter
the spectralenergy distribution(SED)
of VLA
2417inand
VLA 1623 2417 is constructed and analysed.
their inferred nature.
Results. The ALMA Band 9 data presented here show that the SED of VLA 1623 2417 B does not peak at 850µm as previously
Methods. Usingexpected,
dust continuum
spanningfromwavelengths,
but insteadobservations
presents the same
shape asVLAcentimeter
1623 2417to
A near-infraredat wavelengths shorter
than 450theµm.SED of each component in
+
+
+
VLA
1623 2417Conclusions.
is constructed
and analysed.
The resultspresented here indicate that the previous
assumption
that(C
the18flux
HerschelandSpitzerobservationsis
1. Introduction
not detect
warmO, cin C
H
)
or
cold
(DCO
,
N
D
,
N
H
)
3 2
2
2
solely dominatedby VLA
1623 2417
is notthat
valid,theandSED
instead,
VLA
1623
2417
B mostlikelycontributesaBsignificant
fraction
Results. The ALMABand 9 data
presented
hereAshowof VLA
1623associated2417
B doesnotpeak
at 850µm
as previously
gasemission
with
VLA
1623
(Murillo
et al. 2013,
VLA 1623(hereafter
VLA
1623)
is as
aresults,
deeplyembeddedof theflux at the< 450µm.shape
These
do notthelack ofcircumstellargasemissionand puzzlingof obserexpected,
but 2417
insteadpresentssame
VLAhowever,
1623
2417
A explain
at2016,
wavelengths
shorterthan 450µm. (SMA,
2018).
Submillimeter
Array
Ho et al.nature
2004)
VLA
1623
2417 B. Ahere
protostellar systemin
Ophiuchus(L1688),andfirstConclusions.
The
resultspresented
indicatethattheobserved
previous assumptionthat theSO
fluxpeaking
in Herscheland sources
Spitzer observations
isvations detected
betweenA and B (Murillo
by Andréet al.Key(1990).
observations
place
L1688
solelydominatedbywords.
VLARecent1623
2417
A is- stars:
not valid,
and
VLA
1623
2417
B
most
likelycontributes
significant
stars: formation
low-mass- instead,
ISM:andindividual
objects:
VLA
1623
2417
- methods:
observational- techniques:& Lai2013).
Even
moreinterestingis thea detection
offraction
a variable
VLA
a<distance
137.3results,± 1.2 however,pc (Ortiz-León
al. theofthe 1623
flux at at interferometric
450 µm.ofThese
do not etexplainof circumstellar
gas emission
puzzlingof deH2 Olackmaser
centered on VLA
1623 Band(Furuya
et al.nature2003),
2017).1623
VLA24171623B.is generally considered to be the prototypicalVLA
tected between 8 to 13 km s 1 . Suggestions have been made that
Class 0 source (André et al. 1993). Observations at centimeter
VLAnot1623
B warmcould
bebackgroundobject,such
as
18- amethods:+- techniques:+a galaxy.
+Keywords.
stars:
formationstars:
low-mass
ISM:
individual
objects:
VLA
1623
2417
observational
1.
Introduction
detect
(C
O,
c
C
H
)
or
cold
(DCO
,
N
D
,
N
H
)
wavelengths with the Very Large Array (VLA) revealed several
3 2
2
2
The gasvelocity
shiftassociatedof the Hwith
O maserwouldB suggest
aetredshiftofinterferometricemission
VLA
1623(Murillo
al.
2013,
2
continuumVLA
peaks(Bontemps& Andre1997),
were inter5
1623
2417 (hereafterVLA
1623)which
is a deeply
embedded
3–4⇥10. Thus,Submillimeter
if the maserArrayis associated2016,2018).
(SMA, Howith
et al.VLA
2004)1623
obser-B,preted as protostellar
the central systemobject inofOphiuchus
VLA 1623
and
the
jet
knots
A,
A (L1688), and first observed
vations
detectedSO
peaking
betweensourcesA
andB(Murillothen
thissourceislocatedwithinourgalaxy.
VLA
1623
W, sepB and C. However, observations of the outflow suggested more

三重連星VLA1623-2417のうちの二つ(A, B)はseparation ~1.1”
sub mmのSEDの観測困難 ALMA Band 9 で観測34

Sub-arcsecond
Structureof theOutflow in the Vicinity
Sub-arcsecond
Kinematic Kinematic
Structure of the
Outflow in theVicinityof– thein L483
2 – Protostarof theProtostar in L483
1
2
1,3,4
5,6,7
Yoko
Oya
,
Nami
Sakai
,
Yoshimasa
Watanabe,AnaLópez-Sepulcre,
ABSTRACT
Cecilia Ceccarelli6,7 , Bertrand Lefloch6,7 , and Satoshi Yamamoto1,8:1806.10298v1 [astro-ph.SR] 27 Jun 2018arXiv:1806.10298v1 [astro-ph.SR] 27 Jun 2018

Yoko Oya1 , Nami Sakai2 , Yoshimasa Watanabe1,3,4 , Ana López-Sepulcre5,6,7 ,Cecilia Ceccarelli6,7 , Bertrand Lefloch6,7 , and Satoshi Yamamoto1,8
oya@taurus.phys.s.u-tokyo.ac.jp

The bipolar outflow associated with the Class 0 low-mass protostellar source
Received;oya@taurus.phys.s.u-tokyo.ac.jp
accepted(IRAS 18148–0440) in L483 has been studied in the CCH and CS line emission

CCHとCSでClass 0 outﬂowの構造
at 245 and 262 GHz, respectively.
Sub-arcsecond
resolution
observationsof
these
outﬂow cavity を model ﬁt
Received; acceptedlines have been conducted with ALMA. Structures and kinematics of the outflow
速度、opening
angle,を
cavity wall are investigated in the CS line, and are analyzed by using a parabolicmodel of an outflow. We constrain the inclination angle of the outflow to be 他天体と比較
1
from 75 to 90 , i.e.
the outflow
is Theblowingalmostperpendicular
to the lineof113Departmentof Physics,
Universityof Tokyo,7-3-1, Hongo, Bunkyo-ku,
Tokyo0033, Japansight. Comparing the outflow parameters derived from the model analysis with2

cavity の回転運動も見えた？

RIKEN Cluster for Pioneering Research, 2-1, Hirosawa, Wako-shi, Saitama 351-0198,

those of other Japan
sources, we confirm that the opening angle of the outflow and3
Divisionof Physics,of PureAppliedSciences,timescale
University of
the gas velocity on
its cavity
wall Faculty
correlate
withandthe
dynamical
ofTsukuba,
the1
Department of Physics, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113Tsukuba, Ibaraki 305-8571, Japan
outflows. Moreover, a hint of a rotating motion of the outflow cavity wall is found.
40033, Center
Japanfor the History of the Universe, Faculty of Pure and Applied Sciences,
Tomonaga
Although the rotation
is marginal,
the 305-8571,
specificJapan
angular momentum of the
Universitymotionof2 RIKEN
Tsukuba,
Tsukuba,
IbarakiCluster for Pioneering Research, 2-1, Hirosawa, Wako-shi, Saitama 351-0198,
Radioastronomie
Millimétrique(IRAM), 38406, toSaintgas on the outflow5 Institut
cavityde wallis evaluatedto be comparable
orMartin
twiced’Héres,that France
of
Japan
6
Université Grenoble Alpes, IPAG, F-38000 Grenoble, France
the infalling-rotatingenvelopeof L483.
3
7
Division
Physics,
Faculty of Pure and Applied Sciences, University of Tsukuba,
CNRS, IPAG,
F-38000ofGrenoble,
France8Class 0 原始星のCCH, CS, SOの観測
CCH, CSでアウトフロー、SOは円盤に対応
アウトフローはほぼ横から見ている(i=80 )– 31 –

アウトフローの parabolic model でのﬁtPerpendicular to the disk/envelope direction (P.A. 105º)

Velocity (km s-1)

8

0.10
6

0.05
4

Northwest

SW-5”SoutheastNE
0”

Angular Oﬀset

5”

0.00

– 33 –

Outﬂow

0.15

Resolution

Jy beam-1

Outﬂow

軸に垂直なPV(CS)中心星からのoﬀset
2”-10”

アウトフローの回転を考慮すると楕円に歪む
j=1~2 jenv
が観測と良く合うj > jenvなら円盤の比角運動量が減少
centrifugal barrier?

F. D. Priestley, S. Viti, and D. A. Williams

35

rXiv:1806.01699v1 [astro-ph.GA] 5 Jun 2018

N EFFICIENT METHOD FOR DETERMINING THE CHEMICAL EVOLUTION OF GRAVITATIONALLY
AN EFFICIENTMETHOD CORESFOR DETERMINING THE CHEMICAL EVOLUTION OF GRAVITATIONALLYCOLLAPSING PRESTELLARCOLLAPSING PRESTELLAR CORES

1 Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK

F. D. Priestley,1 S. Viti,1 and D. A. Williams1

ABSTRACT
1
1
1
F.
D.
Priestley,
S.
Viti,
and
D.
A.
Williams
We develop analytic approximations to the density evolution of prestellar cores, based on the results of hydrodynam-

artment of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK

699v1 [astro-ph.GA] 5 Jun 2018

ical simulations. We use these approximations as input for a time-dependent gas-grain chemical code to investigate
the eﬀects of diﬀering modes of ABSTRACT
collapse on the molecular abundances in the core. We confirm that our method
1 Department
can provide reasonableagreement
withand
anofAstronomy,
exact
numerical
solutionof boththe hydrodynamics
and chemistrywhileof Physics
University
London,Gower Street, London
WC1E 6BT,UKe develop analytic approximations
to the density
evolution
prestellar cores,
based onCollege
the resultsof hydrodynambeing
less computationallyallowinga largegrid ofmodelsvarying multiple input parameterssimulations.
Wesignificantly
use these approximations
as input for expensive,a time-dependentgas-grainchemicalcode
to investigate
be run.modes
We ofpresent
this abundances
method toinillustrate
the chemistry
isaﬀected
not
only
by
the
collapse
eﬀects oftodiﬀeringcollapseresultson theusing
molecular
the core. how
We confirm
that
ourmethod
ABSTRACT
provide reasonableagreement
with
an by
exact
numerical
solution of
the hydrodynamics
andchemicalchemistry parameters.
whilemodel adopted,
but
also
the
large number
ofbothunknown
physical andModels which are
We develop
analytic
tovaryingthedensityevolutionof prestellar
cores,
based onthe results of hydrodynamg significantly
less gravitationallycomputationallyexpensive,
allowing
asimilarlarge gridof models
multiple
inputdensities
parameters
initially
unstablepredictapproximations
abundances
despitediﬀering
and collapse
timescales,while
e run. We present results ical
usingsimulations.
this method to illustratehow
the chemistry
is aﬀected not
only by forthe collapse
We
use
these
approximations
asinput
time-dependentgas-grainchemical code to investigate
ambipolar diﬀusion produces more extended inner depleted regions which are nota seenin observationsof prestellar
el adopted, but also by the large number of unknown physical and chemical parameters. Models which aretheobservationseﬀectsof arediﬀering
modes
of collapseonmolecular
abundancesin unknown
the core.values
We ofconfirm that our methodcores. Molecularcapabledespiteof discriminating
betweenmodesof collapse
despite theally gravitationallyunstablepredict
similarabundances
diﬀering
densities
andthecollapsetimescales,whilevariousproduces
input parameters.
alsodepleted
investigate
theevolutionofseenthediﬀusiontimescalefor atherangeof collapse
can provide
reasonableagreement
with
exact
numerical
solutionof bothhydrodynamics
and chemistry whilepolar diﬀusion
more
extendedWe
innerregions
which
are
notan
inambipolar
observationsof prestellar. Molecularobservations
are capableof discriminating
betweenmodesfindingof collapse
despitetheallowing
unknown
valuesoftogrid
modes,
metallicities
andcosmicray less
ionization
rates,
thatit remains
comparable
or larger
than thecollapsebeing
significantly
computationallyexpensive,a largeof modelsvarying
multiple input parameters
us inputtimescaleparameters.during
We alsotheinvestigate
the evolution
ofmodels
the ambipolar
diﬀusion but
timescalefor a rangeof collapse
initialstagesforallweconsider,becomessmalleratlater
evolutionary
stages.
This not only by the collapse
to
be
run.
We
present
resultsusing
thismethodtoillustratehowthechemistryisaﬀectedes, metallicities
andthatcosmicray ionization
rates, findingthat it remains
comparable
to or gas,largerbut
than
the collapse
confirms
ambipolar
diﬀusionisanimportantprocessfordiﬀusebecomesless significant
as coresparameters.
collapse
model
adopted,
but
also
by
the
large
numberofunknown
physicalandchemicalModels which are
scale during the initial stages for all models we consider, but becomes smaller at later evolutionary stages. Thisto higher densities.
rms that ambipolar diﬀusion is an important process for diﬀuse gas, but becomes less significant as cores collapse

initially gravitationally unstable predict similar abundances despite diﬀering densities and collapse timescales, while
gher densities.
ambipolar diﬀusion produces more extended inner depleted regions which are not seen in observations of prestellar
Keywords: astrochemistry – stars: formation – ISM: molecules
cores.
Molecular
Keywords: astrochemistry– stars:formationobservations– ISM: moleculesare capable of discriminating between modes of collapse despite the unknown values ofvarious input parameters. We also investigate the evolution of the ambipolar diﬀusion timescale for a range of collapse
modes, metallicities and cosmic ray ionization rates, finding that it remains comparable to or larger than the collapse
timescale during the initial stages for all models we consider, but becomes smaller at later evolutionary stages. Thisconfirms that ambipolar diﬀusion is an important process for diﬀuse gas, but becomes less significant as cores collapse
to higher densities.

分子雲コアの時間発展の解析モデル gas-dust chemical code に使用
dynamics, chemistry がシミュレーションを再現
unknown physical, chemical parameter の依存性が大きい
ambipolar diﬀusion timescale の見積り 重力崩壊前のdiﬀuse gas で重要
Keywords: astrochemistry – stars: formation – ISM: molecules

Low mass star formation and subclustering in the H II regions
Low
mass
star
formationandsubclusteringintheH
II regions
RCW
32,
33
and
27
of
the
Vela
Molecular
Ridge
36
RCW 32, 33 and 27 of the Vela Molecular Ridge

A photometricdiagnostics
to identifystars
A photometricdiagnostics
to identifyM-type
M-type stars

1 , ,M.
1 , G. Micela
1 , S. ,Sciortino
2 , L.
Prisinzano
F. Damiani, M. G. Guarcello, G. Micela
S. Sciortino1 ,, E.
, andVenutiL. Prisinzano1 , F. L.
Damiani
G. GuarcelloE.Tognelli
Tognelli
and
L. Venuti1
1

1

1

1

1

2

1

1

1

INAF - Osservatorio Astronomico di Palermo, Piazza del Parlamento 1, 90134, Palermo, Italye-mail: loredana.prisinzano@inaf.it
INAF - Osservatorio2Astronomico
di Palermo, Piazza del Parlamento 1, 90134, Palermo, Italy
Department of Physics ‘E. Fermi’, University of Pisa, Largo Bruno Pontecorvo 3, I-56127 Pisa, Italy

arXiv:1806.06625v1 [astro-ph.SR] 18 Jun 2018e-mail: loredana.prisinzano@inaf.it
2
Department of Physics ‘E. Fermi’, University of Pisa, Largo Bruno Pontecorvo 3, I-56127 Pisa, Italy
ABSTRACT

Context. Most stars born in clusters and recent results suggest that star formation (SF) preferentially occurs in subclusters. Studying
the morphology and SF history of young clustersABSTRACT
is crucial to understanding early cluster formation processes.
Aims. We aim to identify the embedded population of young stellar objects (YSOs) down to the low mass stars in the M-type regime,in the three H II regions RCW 33, RCW 32 and RCW 27 located in the northwestern region of the Vela Molecular Ridge. Our aim
Context. Most stars bornclusterstheirandproperties,
recent results
suggest that(SF)
preferentiallyoccursin subclusters.
is toincharacterise
such as morphology
and star
extentformationof the clusters
in thethree H II regions,derive stellar
ages and the Studying
the morphology and SFconnection
history of
ofthe
young
clusters
is environment.
crucial to understanding early cluster formation processes.
SF history
with the
Methods.
Through public
photometricof
surveyssuch
as Gaia,objects
VPHAS,(YSOs)
2MASS andSpitzer/GLIMPSE,
we identify
withM-typeclassi- regime,
Aims. We aim to identify
the embedded
population
young
stellardown
to the low mass
starsYSOs
in thecal techniques aimed at detecting IR, H↵ and UV excesses, as signature of circumstellar disks and accretion. In addition, we implementin the three H II regions
RCWto33,
RCWmain
32 andRCW
27stars
locatedin intheof thethereddening
Vela Molecular
Ridge.
a method
distinguishsequence(MS)
and giants
thenorthwestern
M-type regime, byregion
comparing
derived in several
op- Our aim
is to characterise their tical/IR
properties,
suchdiagrams,
as morphology
and extent
ofmodels.
the clusters
the three
H II regions,stellarages and thecolor-color
assuming suitable
theoretical
Since thisindiagnostic
is sensitive
to stellar derive
gravity, theprocedure
allows uswith
to identify
also pre-main sequence (PMS) stars.
connection of the SF history
the environment.
Results. Using the classical membership criteria, we find a large population of YSOs showing signatures of circumstellar disks with
Methods. Through public
photometricsurveysas Gaia,
VPHAS,2MASS
and Spitzer/GLIMPSE,
we ofidentify
YSOsstars
with classior without
accretion. In
addition,suchwith thenew techniqueof M-typestar selection,
we find a rich population
young M-type
cal techniques aimed atwith
detectingH↵ andUV excesses,
ofpopulation.
circumstellar
andofaccretion.
In addition,
we implementa spatial IR,
distribution
strongly
correlated toas
thesignature
more massive
We finddisks
evidence
three young clusters,with different
for whichwe estimate
the individual
by using
TGAS Gaia
data of the brighter
subsample. derived
In addition,a method to distinguishmorphology,
main sequence(MS)stars andgiants indistances
the M-type
regime,by comparing
the reddening
inwe
several opidentify field stars falling in the same region, by securely classifying them as giants and foreground MS stars.
tical/IR color-color diagrams,
assuming
suitabletheoreticalmodels.
Since
diagnostic
is sensitive
stellargravity,
the33,procedure
Conclusions.
We identify
the embedded
population
of YSOs,down thisto about
0.1 M , associatedwith thetothree
H II regions
RCW
allows us to identify alsopre-mainsequencestars.Vela T2, Cr 197 and Vela T1, respectively. All the three clusters are located at a similar
RCW
32 and RCW
27 and the(PMS)
three clusters
distancemembershipbut show very different
morphologies.
resultssuggest a decreasingrate in Velasignatures
T2 and triggered
SF in Cr 197 anddisks with
Results. Using the classicalcriteria,
we find aOur
large
population
of YSOsSFshowingof circumstellar
Vela T1.

or without accretion. In addition, with the new technique of M-type star selection, we find a rich population of young M-type stars
Keystrongly
words. techniques:
photometric– stars:formationpopulation.
– pre-main sequence– stars:
low mass,
ISM: HII regions
Galaxy: with
open different
with a spatial distribution
correlated
to the more
massive
We findevidenceof threeyoung
clusters,
and associations: individual: RCW 33, RCW 32, RCW 27, Vela T1, Vela T2, Cr 291, stars: formation
morphology, for whichclusters
we estimate
the individual distances by using TGAS Gaia data of the brighter subsample. In addition, we
identify field stars falling in the same region, by securely classifying them as giants and foreground MS stars.
Conclusions. We1.identify
the embedded population of YSOs, down to about The
0.1 northwestern
M , associatedwith
theVMR,
threefalling
H II regions
RCW
Introduction
regionof thein cloud D
has 33,
RCW 32 and RCW 27 and the three clusters Vela T2, Cr 197 and Vela T1,been
respectively.
at acensimilar
the subject Allof antheH↵ threesurveyclusters
covering are
a 5. 5located⇥ 5. 5 field,hm0
Molecular
Ridge (VMR) Our
is a large
molecular
tered on SF
RA rate(1950)=8
43. 2,(1950)=-40
by inPettersson
distance but showTheveryVeladifferent
morphologies.
resultssuggestclouda decreasing
in VelaT2Decandtriggered57SF
Cr 197 andcomplex, revealed by four strong emission peaks observed in & Reipurth (1994). The presence of three H II regions, RCW 27,
Vela T1.
12

the 1!0 transition of CO (Murphy & May, 1991), indicating 32 and 33, where signatures of recent low-mass SF have beenthat activephotometric
SF is taking place(Pettersson,2008).–Itpre-mainis located infound byis oneISM:of the H
peculiarities
this field.open
Key words. techniques:– stars:formation
sequence– thesestars:authors,
low mass,
II regionsofGalaxy:
the constellations of Puppis and Vela and it is part of a complex In fact, they identified 278 H↵-emission objects (with a comclusters and associations:individual: RCW 33, RCW 32, RCW 27, Vela T1, Vela T2, Cr 291, stars: formation
region including the very large H II Gum Nebula, the Vela super- pleteness limit V=19) associated with dark clouds and the threenova remnant and also a remarkable annular system of cometary H II regions. In particular, they found two major concentrations,
globules (Pettersson, 2008).
called Vela T1 and Vela T2 T Tauri associations, towards the
H II regions RCW 27 and RCW 33, respectively. They took also
Murphy & May (1991) identified four main clouds within The
1. Introduction
northwestern region of the VMR, falling in cloud D has
the VMR, named A, B, C and D, with the clouds A, C and D slit spectra of 24 of the emission-line stars and found that the
been thesubjectan H↵appearance
survey covering
5. 5stars.
⇥ 5. 5 field, cenmajority
have aofspectral
similar to T a
Tauri
located at 0.7±0.2 kpc and the B cloud located a 2 kpc. Several
h m attempted to assign a possible
et al. (1999a)agePettersson
The Vela Molecular Ridge(VMR)
is a also
large
tered on Yamaguchi
RA (1950)=8
43. 2, Dec (1950)=-40 570 bysmall H II
regions have
beenmolecular
found in thiscloud
region. Liseausuggesting
the sparse
T1Hassociation,in RCW 27,
al. (1992)
and Lorenzettial. (1993)
have foundin33 class
I sequence,complex, revealed byetfour
strongemissionet peaks
observed& Reipurth(1994).
ThethatpresenceofVelathree
II regions,

3

Department of Physics and Astronomy, The University of Western Ontario, 1151 Richmond Street, London, ON, N6A 3K7, Canada
4? ?
Observatorio Astronómico Nacional (IGN), Alfonso XII 3, 28014 Madrid, Spain
5
Leiden Observatory, University of Leiden, Niels Bohrweg 2, 2333 CA Leiden, The Netherlandsof dense
gasgasin theL1495
filament
Kinematics
of dense
in theL1495
filament
37 Kinematics

1, 2 , P.1,Caselli
1 , J. E.
1 , A. 1Pon3 , M. 3Tafalla4 , A. 4Hacar5 , and5 L. Bizzocchi1
2
1
A. Punanova
PinedaA. Punanova , P. Caselli , J. E. Pineda , A. Pon , M. Tafalla , A. Hacar , and L. Bizzocchi1

June 9, 2018
1

1
Max-Planck-Institut
für extraterrestrische
Physik,Giessenbachstrasse
1, 85748
Garching,
Germany
ABSTRACT
Max-Planck-Institut
fürextraterrestrische
Physik,Giessenbachstrasse
1,85748
Garching,
Germany2
Ural2 Federal
University,
620002,19 MiraYekaterinburg,
RussiaRussia
Ural Federal
University,
620002,
19street,
Mira street,
Yekaterinburg,e-mail:e-mail:anna.punanova@urfu.ru
Context. 3Nitrogenbearing
species, such as NH3 , N2 H+ , and their deuterated isotopologues, show enhanced abundances in COanna.punanova@urfu.ru
3
Departmentof Physics
andAstronomy,
The
Universityof starWestern
Ontario,
1151 The
Richmond
Street,London,ON,contains
N6A
3K7,
CanadaDepartmentofPhysics
andAstronomy,
The
UniversityofWestern
Ontario,1151
Richmond
Street,London,ON,
N6A
3K7, Canada
depleted gas,
and
thus
are
perfect
tracers
of
dense
and
cold
gas
in
forming
regions.
Taurusmolecular
cloud
the
long
4
Observatorio
Astronómico
Nacional(IGN),
AlfonsoXII
3, XII
28014
Madrid,Spain Spain
4
Observatorio
Astronómico
Nacional(IGN),
Alfonso3,
28014
Madrid,L1495 filament
providinganexcellent
opportunity
to
study
the
processofstarformationin filamentary environments.
5
LeidenObservatory,
UniversityofLeiden,Niels
Bohrweg
2,2333
CA
Leiden,The
Netherlands
5+++
LeidenObservatory,
UniversityofLeiden,Niels
Bohrweg
2,2333
CA
Leiden,TheNNetherlands
Aims. We study the kinematics of the dense gas of starless and protostellar cores traced by the
2 D (2–1), N2 H (1–0), DCO (2–1),+
and H13 COtransitions along the L1495 filament and the kinematic links between the cores and the surrounding molecularJune(1–0)
9,June2018
9, 201803354v1 [astro-ph.GA] 8 Jun 20183354v1 [astro-ph.GA] 8 Jun 2018

star less, protostellar coreのkinematics
cloud.
Methods. We measure velocity dispersions, local and total velocity gradients and estimate the specific angular momenta of 13 dense
分子雲コアと周囲の関係
ABSTRACT
cores in the four transitions using the on-the-fly observations with
the ABSTRACT
IRAM 30 m antenna. To study a possible connection to thefilament gas, we use the fit results of the C O(1–0) survey performed by Hacar et al. (2013).
Context.
Nitrogenbearing
species,such asNHas, NH
N H, ,Nand
theirisotopologues,
show enhanced
abundancesin CO-in COContext.
Nitrogenbearing
species,such
H, and deuterated
theirdeuterated
isotopologues,
show enhanced
abundances
速度分散、速度勾配を見る
Results. The velocity
dispersionsofallstudiedcores
aremostlysubsonic
in
all
four
transitions,withsimilarandalmostconstant
depleted
gas,
and
thus
are
perfect
tracers
of
dense
and
cold
gas
in
star
forming
regions.
The
Taurusmolecular
cloud
contains
thelongdepletedgas, andareperfect
tracersof dense
cold
gas in star
formingThe
molecular
cloud
contains
dispersionL1495
acrossthe cores
in NthusD(2–1)
andopportunity
N H (1–0).
A and
small
fraction
ofstarthe
DCOregions.
(2–1)
and Taurus
H CO(1–0) lines
show
tran- the long
filament
providinganexcellent
to
study
the
processofformationinfilamentary
environments.
L1495
filament
anexcellent
opportunity
to study theprocessof star formationin filamentary
environments.
2D+, N2H+ DCO+ H13CO+
sonic dispersion
andexhibitaproviding
generalof
increaseingas
velocity
dispersion
withlinecores
intensity.
All
cores
have
velocity
gradients(0.6–
Aims.Aims.
We
study
the
kinematics
the
dense
of
starlessandprotostellar
tracedbytheND(2–1),
NH(1–0),
DCO(2–1),
N
We study
the kinematicsof the densegasof starlessand protostellar
cores traced
byvelocity
the N Dpatterns(2–1), NinHthe(1–0),
DCO (2–1),
6.1 km s andpcH ),CO
typicaloftransitions
dense
cores
in thelow-massstar
forming
regions.
All cores
show
similardi↵erent
(1–0)
along
L1495
filamentandthekinematic
links
between
the
cores
and
the
surrounding
molecular
and inH isolated
CO (1–0)transitions
along
the L1495
filament
and cores
the kinematic
linkscores
between
the
cores
and
the surrounding
moleculartransitions,simplestarless
cores,
andcomplexinprotostellar
andstarless
close
to
young
stellarobjects
where
cloud.cloud.
the gas motions
canWe
be measurea↵ected velocity
by outflows.
The large-scale
velocity
fieldgradients
traced byandC estimateO(1–0) does
not show
any perturbationdue
to の順で内から外Methods.
dispersions,
local
and
total
velocitythespecific
angularmomentaof
13
dense
Methods. We measure velocity dispersions, local and total velocity gradients and estimate the specific angular momenta of 13 dense
protostellar
feedback
and transitions
does not mimic
the on-the-fly
local variations
seen inwith
the theotherfour 30
tracers.
Specific
momentumJ/M varies
cores coresin theinfour
using usingtheobservations
IRAM
m antenna.
To angularstudy
possibleconnection
to the to thethe four transitions
the on-the-fly
observations
withthe IRAM
30 m antenna.
To astudy
a possible
connection
in a rangefilament(0.6–21.0)⇥10cm
sfit thewhichsimilartothesurvey
results
previously
densecores. J/M measured in N D (2–1) 外に行くほど乱流大gas, weusewetheuseresults
ofistheC theO(1–0)
performed
byobtained
Hacar
et foral. (2013).
filamentgas,
fit resultsof
C O(1–0)
surveyperformed
by Hacaret al. (2013).
Results.lower
The velocity
dispersions
ofinallDCO
studiedcores
subsonic
in all fourwith similar
and almost
constant
is systematically
J/MmeasuredandareH mostlyCO(1–0).
Results. thanThe velocity
dispersionsofall(2–1)
studiedcores
are mostly
subsonic
in alltransitions,four transitions,with similar
and almost
constant
dispersion
across
the
cores
in
N
D
(2–1)
and
N
H
(1–0).
A
small
fraction
of
the
DCO
(2–1)
and
H
CO
(1–0)
lines
show
tranConclusions. All
cores showproperties
the 10N D (2–1)
mostconcentrated
dispersion
acrosssimilar
the cores
in N D along(2–1) andN Hpc-long(1–0). filament.
A small fractionof theshows
DCO the(2–1)
andcentrally
H CO (1–0)
lines show 内側で速度勾配小transonic
dispersion
andexhibitageneralincreaseinvelocity
dispersion
with
line
intensity.
All
cores
have
velocity
gradients(0.6–
structure, followed
N H (1–0)
DCO(2–1), increase
which show
similardispersion
spatial extent,
and intensity.
H CO (1–0).
The have
non-thermalsonicbydispersion
and andexhibita generalin velocity
with line
All cores
velocity contrigradients (0.6–
6.1
km
s
pc
),
typical
of
dense
cores
in
low-massstar
forming
regions.
All
cores
show
similarvelocity
patterns
inthebution to the velocity
increasesfrom cores
higherin tolower density
tracers.
The changeof magnitude
anddirectionof thedi↵erent
6.1 km sdispersionpc ), typicalof dense
low-massstar forming
regions.
All cores
show similar
velocity
patterns
in total
the di↵erent
transitions,simpleinisolatedstarless
cores,
andcomplexinprotostellar
cores
and
starless
cores
close
to
young
stellarobjects
where
velocity gradientsdependingon thetracer usedindicatesthatcomplex
internal inmotionschangeat di↵erent
depthstheyoung
cloud.stellar
N D objects
and where角運動量輸送？
transitions,simplein isolatedstarless
cores, andprotostellar
cores
and starlesscoreswithinclose tothe smaller
gas motions
can bethana↵ectedbyoutflows.
Thetracers
large-scale
tracedby C O(1–0) does
not show
any perturbation
dueattoN H showlower
DCOvelocity
andvelocity
HfieldCO, implyingof specificangularmomentumthe gasgradientsmotions canbethea↵ectedbydensity
outflows.
The large-scale
field
traced bya ClossO(1–0)
does notshow any
perturbation
due toprotostellar
feedback
and
does
not
mimic
the
local
variations
seen
in
the
other
four
tracers.
Specific
angularmomentum
J/Mvariessmall scales. Atprotostellar
the level offeedback
cloud-core
the core’s
externalenvelope
DCO
H CO
is spinningup, consistentand transition,
does not mimic
the local
variations
seentraced
in the byotherfour andtracers.
Specific
angular momentum
J/M varies
in a range (0.6–21.0)⇥10 cm s which is similar to the results previously obtained for dense cores. J/M measured in N D (2–1) コアの境界で回転速度大with conservation
angularmomentum cm
duringcontraction.
tracespreviously
the more extended
cloudmaterial
kinematics
in aofrange(0.6–21.0)⇥10s corewhich
is similar toCtheOresults
obtained fordense
cores. whose
J/M measuredin NisD (2–1)
is systematically lower than J/M measured in DCO (2–1) and H CO (1–0).
systematically
J/MThemeasuredin DCO(2–1)angularand H momentum
CO (1–0). towards the centres of the cores shows the
not a↵ectedbyisthepresence of lower
densethancores.
decreasein specificConclusions. All cores show similar properties along the 10 pc-long filament. N D (2–1) shows the most centrally concentrated
All corestoshow
similarscale
properties
along the10
pc-long
N D (2–1) shows
the most
centrally
concentrated収縮とコンシステント
importanceof Conclusions.
localfollowedmagnetic
theandsmall
dynamics
thesimilarcores.
Thefilament.
randomof angles
the contritotal
structure,by fields
N H (1–0)
DCO (2–1),
which ofshow
spatialextent,distributionsand H CO (1–0).
The between
non-thermal
2

18

3

+

2

1

113

2

2

+

3

+

2

+

13

+

2

+
13

+

+

2

+

+

2

+

2

+

+

+

18

20

2

1

18

+

+

2

1

2

1
1

+

2

+

+2

18

13

+

2

+

2

+

2

+

+

+

13

13

+

+

13

+

+

1

+

13

+

20

2

2
1
20
2

+

18

+

18

13

+

1

+

+

18

+

13

+
13

+

2

+

2

+

2

+

2

+

13

+

2

+

+

structure,
followedby N2 H (1–0)
and DCOthat(2–1),
whichshow
similarspatialextent,and H13
CO+in(1–0).
The density
non-thermal
contrivelocity gradient
and
large
scale
magneticfieldsuggeststhemagnetic
fieldsmay
becomeimportant
only
thedirection
highbution to the velocity dispersion increases from higher to lower density tracers. The change of magnitude andof thegas
totalbution to the velocity dispersion increases from higher to lower density tracers. The change of magnitude and direction+of the total
within dense
cores.
velocity
gradients depending on the tracer used indicates that internal motions change at di↵erent depths within the cloud. N2 D and++change at di↵erent depths within the cloud. N2 D+ and+ velocity gradients depending on the tracer used indicates that+ internal13motions+
N2 HStars:formation
show smaller gradients
than the lower
density
tracers
DCO
and H COabundances, implying a–loss
ofmolecules
specific angularmomentumat
Key words.
– ISM:
kinematics
dynamics– ISM:
clouds
ISM:–
ISM:
individual
N2 H+ show smaller
gradients
than andthe lower
density
tracers
DCO–+ ISM:
and H13 CO+ , implying
a
loss
of
specific
angularmomentumat13+small scales. At the level of cloud-core transition, the core’s external envelope traced by DCO+ and H
COisspinning
up,
consistentobjects: L1495small– Radiolines:
scales.
At ISMthe level of cloud-core transition, the core’s external
envelope traced by DCO+ and H13 CO+ is spinning up, consistent18
with conservation of angular momentum during core contraction. C O traces
the more extended cloud material whose kinematics is
18with conservation of angular momentum during core contraction. C O traces the more extended cloud material whose kinematics is
not a↵ected by the presence of dense cores. The decrease in specific angular momentum towards the centres of the cores shows the2 with N H : new
N/ N ratio measurements
inprestellar
cores
2
15
?
38
Received****; acceptedevidence
*****
15
?
ofevidence
N-antifractionationof N-antifractionation
1 , P. Caselli1 , J. Harju1, 2 , A. Chacón-Tanarro1 , E. Leonardo3 , and L. Dore4
E. Redaelli1 , L. Bizzocchi
E. Redaelli1 , L. Bizzocchi1 , P. Caselli1 , J. Harju1, 2 , A. Chacón-Tanarro1 , E. Leonardo3 , and L. Dore4

ABSTRACT1

15
1
Centre forThe
AstrochemicalStudies,
Max-Planck-Institut
Physik,Gießenbachstraße
D-85749
Garching
beiContext.
N fractionation
has been observed
toextraterrestrischeshow large variations
among astrophysicalsources,dependingboth on bei
the type
Centrefor AstrochemicalStudies,fürMax-Planck-Institut
fürextraterrestrische
Physik,1,Gießenbachstraße
1, D-85749
Garching(Germany)
München (Germany)ofMünchentarget andon the molecular
tracer used. These variations cannot be reproduced by the current chemical models.
e-mail: [eredaelli,bizzocchi,caselli,harju,achacon]@mpe.mpg.de
14e-mail:
15 [eredaelli,bizzocchi,caselli,harju,achacon]@mpe.mpg.de
+
Aims.
Until
now,
the
N/
N
ratio
in
N
H
has ofbeen
accurately
measuredin Finland
only one prestellar source, L1544, where strong levels of2
2
2
Department of Physics, PO
Box 64,1500014
University
Helsinki,
FinlandDepartmentof Physics,
PO Box14
64,00014
UniversityofHelsinki,
15
in
N,
are
found
(
N/
N ⇡ Universidade1000).
In
this
paper
wePT1349-018
extendtheAjuda,
sampleto threee-mail:more(Portugal)bona fide
prestellar
3 fractionation, with depletion
3
Istituto dee Ciências dode
Espaço,deLisboa,OAL,
Tapadada
PT1349-018
Lisboae-mail:Istituto de Astrofísica e Ciências
doAstrofísica
Espaço, Universidade
Lisboa,OAL,
Tapadada
Ajuda,
Lisboa(Portugal)cores,in order to understandif the antifractionation in N2 H+ is a common feature of this kind of sources.
eleonardo@oal.ul.pt
eleonardo@oal.ul.pt
4+
15Chimica+ “G. Ciamician”,
15+ Università di Bologna, via F. Selmi 2, I-40126 Bologna (Italy). e-mail: luca.dore@unibo.it
4
DipartimentodiMethods.
Wedi observed
NCiamician”,
H
,
N
NH
and
NNH
inviaL183,
L429
and L694-2
with theIRAM
30m telescope. We modeled the
Dipartimento
Chimica“G.
UniversitàdiBologna,
F. Selmi
2, I-40126
Bologna (Italy).
e-mail:luca.dore@unibo.it
2
emission with a non-local
radiative
transfercode in order to obtain accurate estimates of the molecular column densities, including
Received****;
accepted*****
Received
accepted*****
the one ****;
for theoptically
thick N2 H+ . We used the most recent collisional rate coefficients available, and with these we also re-analysed
the L1544 spectra previously published.
ABSTRACTABSTRACT
Results. The obtained isotopic ratios are in the range
630 770 and significantly di↵er with the value, predicted by the most re15 close to the protosolar value. Our prestellar core sample shows high level of depletion of 15 N incent chemical
models,of⇡440,
Context.
The
N fractionation has been observed to show large variations among astrophysical sources, depending both on the typeContext. The 15 N fractionation
has
been
observed
to showlarge
amongcannot
astrophysicalsources,dependingboth on models.
the typeof target foundand on themolecular
tracerused. variations
These
variations
be reproducedby thecurrentchemicaldiazenylium,aspreviouslyinL1544.
A
revisionoftheN
chemical
networks
isneededinorder
toexplainthese results.
of target and on the molecular tracer used. These variations cannot be reproduced by the current chemical models.

806.01088v1 [astro-ph.GA] 4 Jun 2018arXiv:1806.01088v1
4 Jun 201
6.01088v1 [astro-ph.GA][astro-ph.GA]
4 Jun 2018

eleonardo@oal.ul.pt
144 Dipartimento15+ e-mail: luca.dore@unibo.it
diChimica“G.
Ciamician”,
UniversitàdiBologna,
via
F.
Selmi
2,
I-40126
Bologna(Italy).
N/ N ratio14measurements
in prestellar cores with N H : new +
15

14
15
+
Aims.
Until
now,
the
N/
N
ratio
in
N
H
has been accurately measured in only one prestellar source, L1544, where strong levels of
2
15
+

14
15
14
15
Aims.
Until
now,
the
N ratioin Nwith
has beeninaccurately
measuredinNonly
one prestellar
source,L1544,
wherestronglevelsofbona fide prestellar
2 Hmolecules
fractionation,
depletion
N,
are
found
(
N/
⇡
1000).
In
this
paper
we
extendthesample
to
three
more
Key words. ISM:N/clouds
–
ISM:
–
ISM:
abundances–Radio
lines:
ISM–
Stars:
formation
15+extend the sample to three more bona fide prestellar
fractionation, with depletionin inN,aretofound(14 N/15ifNthe⇡ 1000).
In this paper
cores,
orderunderstandantifractionationin Nwe2 H is a common feature of this kind of sources.
++ N215
15+
cores, in order to understandif the We
antifractionationcommonof thiskindsources.
Methods.
observed N2 Hin, N HNHis+ aand
NNHfeaturein L183,
L429
andofL694-2
with the IRAM 30m telescope. We modeled the
+
15
+
15
+
Methods. We observed N
NHa non-local
and NNH
in L183,
L429
L694-2
with theIRAM
30m telescope.
We modeled
emissionradiative
transfer
codeandin orderto obtain
accurate
estimatesof the molecularcolumnthe
densities, including
2 H , Nwith+
emission with a non-local
transfer
code
in N
order
obtainaccurate
estimatesof therate
molecular
columndensities,
includingtheradiative
one for the
optically
thickWeused themost recent
collisionalcoefficientsavailable,
and withthese we also re-analysed
2 H .to+the L1544
previously
published.
the one for the optically thickN2 H spectra. We used
the most
recent collisional rate coefficients available, and with these we also re-analysed
the L1544 spectra previously
published.
Results.
The obtained isotopic ratios are in the range 630 770 and significantly di↵er with the value, predicted by the most recent chemical
models,of range⇡ 440,630
close 770
to theandprotosolar
value.di↵er
Our prestellar
sampleshowsbyhighdepletion of 15 N in
Results. The obtained isotopic
ratios arein thesignificantlywith the corevalue,
predicted
thelevelmostofre1. Introduction
as previously
found invalue.
L1544.Our
A revisionof thechemicalshows
networks
neededorder to explain
cent chemical models, ofdiazenylium,⇡ 440, close
to the protosolar
prestellar
coreN sample
highislevel
of indepletionof 15 N thesein results.

Prestellar core の 14N/15N比を調べる
630-770、モデル計算だと~440
as previously
in L1544.
A nitrogen,revision
ofmoleculesthechemical
networks
is neededinorderthese results.
In thediazenylium,
last two decades
thefoundchemistrytheN fifth
mostabundantelement
into the
Universe,
has raised interest in the context
ISM:ofclouds– ISM:– ISM:
abundances– Radiolines:
ISM–explainStars:
formationof understanding
theclouds
formationof interstellar
materials –and
oflines:
our ISMown– Solar
System. In particular, the isotopic ratio N/ N seems
Key words. ISM:
– ISM: molecules– ISM: abundances
Radio
Stars: formation
HN2＋で15Nがdepletion
to represent
an important diagnostic tool to follow the evolutionary process from the primitive Solar Nebula (where measurements
indicate N/ N ⇡ 440 450, Marty et al. 2011; Fouchet et al. 2004) up to present. The materials of the Solar System, frommeteorites
to the Earth’s
atmosphere,
are enriched
in N, with the exception of Jupiter atmosphere. Measurements of N in the
N chemical
networkの改善が必要
1. Introduction
14

Key words.

14

15

15

15

2

terrestrial atmosphere led to the result of 14 N/15 N ⇡ 272 (Nier 1950), and carbonaceous chondrites show isotopic ratios as low as
1.
In thesuggesting
last two decades
of ofnitrogen,the fifth
most abundantelement
in the reservoirs
Universe, haswere
raisedpresentinterest in
the context et al.
50Introduction(Bonal et al. 2010),
thattheat chemistry
the origin
the Solar
Systemmultiple
nitrogen(Hily-Blantof understanding the formation of interstellar materials and of our own Solar System. In particular, the isotopic ratio 14 N/15 N seems2017).
In
the last two decadestothechemistryof nitrogen,the fifthtool
mostin theprocess
Universe,
interest
the context
represent
an importantdiagnostic
to abundantfollow theelement
evolutionary
fromhasthe raised
primitive
Solar14in
Nebula(where measurements
15
15 has beenof understanding
the isotopic
formationofN/interstellar
and ofet
our
Solar
System.
particular,
the isotopic
N/ ofNthe
seems
The nitrogenratio
measuredalso
in di↵erent
coldenvironmentsof Thethe ratio
interstellar
medium(ISM),and theindicate 14
N ⇡ 440materials
450, Martyal. own
2011;
Fouchetetal.In2004)
up to present.
materials
Solar System,
from

39

The formation of protostellar binaries in primordial
minihalos
1?
1,2
3
1
R.
Riaz
S.
Bovino†S.
Vanaverbeke‡
D.R.G.
Schleicher§
1

Departamento de Astronomı́a, Facultad Ciencias Fı́sicas y Matemáticas, Universidad de Concepción, Av. Esteban Iturra s/n Barrio
Universitario, Casilla 160-C, Concepción, Chile2

40
in original form ZZZABSTRACT

icesin Elias
29 FUV irradiation in the survival of astrophysical
The roleof external
ices in Elias 29
1,2?
1,3
W.
R.
M.
Rocha,S.
Pilling,1

1,2?
1,3Universidade do Vale do Paraı́ba, Av. Shishima Hifumi 2911, CEP 12244-000, São José dos Campos, SP, Brazil
InstitutodePesquisae Desenvolvimento(IP&D),W.
R.
M.
Rocha,S.
Pilling,
21SUPA, School of Physics & Astronomy, University of St. Andrews, North Haugh, St. Andrews KY16 9SS, UK
Instituto de Pesquisa e Desenvolvimento (IP&D), Universidade do Vale do Paraı́ba, Av. Shishima Hifumi 2911, CEP 12244-000, São José dos Campos, SP, Brazil
2
3 Departamento
SUPA, School of dePhysics& Astronomy,of St.deAndrews,
North Haugh,
Andrews
UK São José dos Campos, CEP 12228-900 SP, Brazil
Fı́sica,
Instituto University
Tecnológico
Aeronáutica,
ITA - St.
DCTA,
VilaKY16
das9SS,
Acácias,

06.01769v1 [astro-ph.SR]
Xiv:1806.01769v1[astro-ph.SR]55Jun
Jun 2018
2018

The survival of astrophysical ices in the star-forming regions depends on the suitability oftemperature, density
andReceived
radiation
conditions.
In this paper, the role of Interstellar Radiation
Accepted
XXX.
YYY;
in
original
form
ZZZ
Accepted XXX. Received YYY; in original form ZZZField (ISRF) on ices in Elias 29 is addressed. This object is the most luminous protostar in⇢ Oph E molecular cloud, and is surrounded by many Young Stellar Objects distant only a
ABSTRACTABSTRACT
few arcminutes. In addition, other two
brightness
BV starsandHDregions
147889)enhancetheof the suitability of
The survivalof astrophysicalices in (S1theicesstar-forming
depends
on the suitability
The survivalof astrophysicalin the star-forming
regions
depends on
densityand radiation
conditions.
In thispaper,
the roleCarloof Interstellar
Radiation
external irradiation in Elias 29. Thistemperature,
study
was
carried
out
by
using
the
Monte
radiative
thispaper,
the roleof Interstellar
Radiation
Fieldtemperature,(ISRF) on icesdensity
in Elias and
29 isradiation
addressed.conditions.
This object isInthemostluminous
protostarin(ISRF) cloud,on ices
inis Elias29
isby
addressed.
This
object
iswe
the
most
luminous
protostar in
Einternal
molecularandsurrounded
many Young
Stellar
Objects
distant
onlyatransfer code RADMC-3D assuming⇢ Oph
anField
andexternal
irradiation.
As
result,found⇢ Oph E molecular
cloud,
is surroundedby andmany
distant only a
few arcminutes.
In addition, othertwoandbrightness
BV stars (S1
HDYoung147889)Stellar
enhanceObjects
thethat HD 147889 dominates the ISRF,
insteadoftheclosestprotostars,
andcontributes
toenexternalin Elias
This study
wastwocarriedout by usingMontefewirradiation
arcminutes.
In 29.
addition,otherbrightness
BVthe
stars
(S1Carlo
and radiative
HD 147889) enhance thetransfer
code
internal
and external
irradiation.
wehance the external irradiation in 44 times
theRADMC-3D
standard
Furthermore,
remarkablee↵ectsexternal
irradiationassuming
invalue.
Elias an
29.
This study
was carriedout Asbyresult,
using
thefoundMonte Carlo radiativethat HD 147889 dominates the ISRF, instead of the closest protostars, and contributes to entransfer
code
RADMC-3D
assuming
an internaltheand external
irradiation.
As result, we foundare observed in FIR spectrum, as wellin near-IR
image.
Additionally,snowlineposihanceas
the external
irradiationin 44 times
the standard value. Furthermore,
remarkablee↵ectsthat HDin147889
dominates
the
ISRF,
insteadofAdditionally,
the closestthe
protostars,
and contributes to enare
observed
FIR
spectrum,
as
well
as
in
near-IR
image.
snowline
positions of volatile compounds, such astions
CO,
O
,
N
and
CH
are
redefinedtoatoroidal-shaped
2
2
4
hance
the
external
irradiation
in
44
times
the
standard
value.
of volatile compounds, suchto aFurthermore,toroidal-shapedremarkable e↵ects
4 are redefined
7 as CO, O2 , N
2 2 and1 CH
7 In such
1 scenario, themorphology in the envelope, with low
FUV
ergs
cm
morphology
influxthe envelope,withlow FUV
cm 2 simage.
). In such
scenario, thethe snowline posiare
observedin(10FIR spectrum,
as flux
wells(10as ).
inergsnear-IR
Additionally,
formation
ofofcomplex
as resultof hydrogenationof volatile
species
tionsofvolatilemolecules
compounds,
such
as CO, O2 , orN2oxygenation
andvolatile
CH4 areredefined
to a toroidal-shaped
formation of complex molecules as resulthydrogenationoroxygenationofspeciesare expected
to be severely
morphology
in the a↵ected.
envelope, with low FUV flux (10 7 ergs cm 2 s 1 ). In such scenario, theare expected to be severely a↵ected.Key formationof complex—molecules
as resultof 29)hydrogenationor oxygenation
words: astrochemistrystars: individual(Elias— stars: pre-main
sequence — of volatile species
3 Departamento de Fı́sica, Instituto Tecnológico de Aeronáutica, ITA - DCTA, Vila das Acácias, São José dos Campos, CEP 12228-900 SP, Brazil

radiative
are transfer
expected to be severely a↵ected.

Key words: astrochemistry — stars: individual (Elias 29) — stars: pre-main sequence —Key words: astrochemistry — stars: individual (Elias 29) — stars: pre-main sequence —radiative transfer
radiative transfer

Elias 29：2つのB型星からあぶられる
輻射輸送計算 近傍の原始星よりB型星の寄与大1 INTRODUCTION

they found that outer envelopes in Cr A are heated up to 60 K by
a closer Herbig Be star. This same region was probed later on by
The gravitational collapse of molecular clouds is followed by hierLindberg et al. (2014), employing ALMA observations. As concluarchical fragmentation that breaks up a large molecular cloud into
sion, they state that evaporation of CO ice due to high temperaturesmaller cores to form low-mass stars (Larson 1978; Klessen et al.
1 INTRODUCTION
foundouterOrganic
envelopes
in Cr(COMs)
A are inheated up to 60 K by
prevents thethey
formationof thatComplex
Molecules
1998). In such a scenario of star-forming region, it is expected that
CrA cloud.in
theyfound heatedthat byouterenvelopes
Cr AHerbig
are heatedup to60region
K bywas probed later on bya closerBe star. This
same
all
Young
Stellar
Objects(YSOs)
areexternallyneighThe gravitational collapse of molecular clouds is followed by hierLindberg
et al.
(2014),
employing
ALMA
observations. As concluborhood protostars, once they increase
the FUVInterstellar
Radiaacloser
Herbig
Be
star.
This
same
regionwasprobedlater
onbyarchical fragmentation that breaks up a large molecular cloud into
sion, they regions
state that
evaporation
ice duetion Fieldby(ISRF)
by a few orders of magnitude. The standard ISRF
molecular clouds is followed
hierPhotodissociation(PDRs)
can also of
be CO
predicted
by to high temperaturesmaller
low-massstarsfield(LarsonKlessenet al.
Lindberg
etal.1978;(2014),
employing
ALMA
As emission
conclumight becores
definedtoasformfunctionof UV
Draine(Draine& Bertoldi
measuring thestrengththeofobservations.
ISRF
using fine-structurelines
prevents
formationof Complex
Organic
Molecules (COMs) in

snowline がtoroidal-shaped

複雑な分子の形成に影響を与える

& Pilling

ISRF and astrophysical ices
Direction to S1
Direction to S1-24°34'00.0"on t 9 tooitec 47i8o8n 89
ri
D D 1ct 8
Hire 47

Radius:3 arcminRa

dius: 3 arcmin

WL 11

Dec (J2000)

36'00.0"

38'00.0"[GY 92] 197

D D1
HElias 29
WL 16

WL 20

WL 17
WL 19

[GY 92] 245
40'00.0"

42'00.0"
30.00s20.00s10.00sRA (J2000)

27m00.00s

16h26m50.00s

age centered in Elias 29 with FOV of 10 ⇥ 10 arcmin. The colors represent the flux in Jy. The contours are the dust emission in 850 µm
BARU/JCMT in Jy/pixel. The dashed circle limits a region with radius of 3 arcmin. The arrows indicate
to S1 and HD 147889.
Figurethe4.direction
Tree-dimensional
spatial distribution of selected protostars in ⇢ Oph cloud. (a) Stars symbols are objects inside the dashed circle in Figure

数値計算で用いる近傍のYSOとB
star
29 is highlight in green label. The
connections among the objects shows that Elias 29 is embedded by UV
radiationの位置
field. (b) Same of Panel (a), b
Elias 29 の周辺環境(WISEEliasimage)
showing S1 and HD147889 B-type stars that dominate the radiation field in ⇢ Oph cloud. The connections are only to guide the eyes.

haracteristics of the objects presented in Figure 3.

Object

WL 11
WL 16
WL 17
WL 19
WL 20
Y92] 197
Y92] 245
D147889
S1

Elias 29 rho-Oph Eで最も明るい原始星、近傍に多数のYSO,
from Lommen et al.B型星も二つある(2008) to characterize a static envelope as(Boogert et al. 2002), ⇢ is the local dust density relative to ISM,
assumed to be 10 from Boogert et al., and d is the distance of eachin Pontoppidan et al. (2005).
object along the line of sight in parsec.
It is worth to note that disk dimension in Elias 29 presen
外部輻射によるスノーラインの変化を調べる
Using this methodology, it was found that external irradiferent values in literature. Boogert et al. (2002) has fixed thation interacting with Elias 29 is 44. In percentage terms,
size in 500 AU, whereas Miotello et al. (2014) propose a siz
外部輻射を考慮してenvelope
HD147889 roughly の温度構造を調べる
contributes with 93% with the external UV
tween 15 - 200 AU by considering an optically thick or thin

R.A. (J2000)(h m s)DEC (J2000)(d m s)Distancea(pc)

Relative distance j
(pc)

Lbol
(L )

LUV l
(L )

AiV m
(mag)

16 27 12.131
16 27 02.340
16 27 06.776
16 27 11.776
16 27 15.730
16 27 05.246
16 27 18.380
16 25 24.317
16 26 34.167-24 34 49.14-24 37 27.20-24 38 15.20-24 38 32.02-24 38 43.70-24 36 29.79-24 39 14.68-24 27 56.57-24 23 28.26

128b
125c
137d
123e
110 f
100g
105h
120i
120i

6.5 ⇥ 10 3
1.1 ⇥ 10 2
1.4 ⇥ 10 2
1.2 ⇥ 10 2
8.3 ⇥ 10 3
1.4 ⇥ 10 2
6.0 ⇥ 10 3
7.0 ⇥ 10 2
5.1 ⇥ 10 20.04e
250.00c
0.60e
58.00e
1.80e
0.15e
0.12e
4500.00k
1100.00k

0.01
10.30
0.07
3.05
0.17
0.02
0.02
116.00
35.70

26.4
26.4
26.4
28.4
27.8
25.9
25.6
18.2
20.0

5

rel
d

i

IS RF

field, whereas S1, WL 16 and others contribute with 5%, 1.5% andistance from Earth; b (Khanzadyan et al. 2004); c (Zhang et al. 2017); d (Ortiz-León et al. 2017);
0.5%, respectively.

respectively. As claimed by authors, the first case is unrealist
cause the dust properties cannot be addressed. In the second

10Rocha & Pilling

ISRF and astrophysical ices11

外部輻射の影響でエンベロープ温度が~30Kまで上昇
B型星HD147889 がFUVの93%の寄与
K-band が観測とあう。

Figure 9. Comparison among observation and model of Elias 29 as seen in K-band (2.16 m). Panel (a) shows Elias 29 as observed with ISAAC/VLT inpolarimetric mode (adapted from Huélamo et al. (2005)). Panels (b) and (c) show Elias 29 simulated with RADMC-3D assuming a scenario without and withexternal irradiation, respectively. No polarization is calculated in the models.

外部輻射を考慮するとsnow line がトロイダル状に。
CO ice の存在領域が減少
複雑な分子の形成が阻害される。
この温度構造を用いた化学反応計算は今後の課題。