Star Forma)on Newsle0er#279 26-30
麻生 有佑

SEARCHING FOR SPECTROSCOPIC BINARIES WITHIN
TRANSITION DISK OBJECTS1
Saul A. Kohn
Lowell Observatory, 1400 W. Mars Hill Road, Flagsta↵, AZ 86001, USA

arXiv:1602.07582v1 [astro-ph.SR] 24 Feb 2016

TDはPMS円盤進化の中で中間的な存在。Cieza+10がOph (140 pc)のTDをダスト成長(降着Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA,
有+負のIR slope
44%)、巨大惑星(降着有+正のIR
slope 13%)、光蒸発(降着無+高円盤光
19104, USA
度17%)、デブリTD (降着無+低円盤光度13%)に分類。
saulkohn@sas.upenn.edu
伴星が開ける例もあり、Ciza+10の空間範囲は8-20 AUなので、<8 AUを補う (VBでなくSB)。
Evgenya L. Shkolnik

School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287, USA M型。
Spitzer C2DからTDとわかっているOphの24個を中心とするサンプル。主にK,
Fig.
4.—
The
spectrumAZof SSTc2d
J163154.7-250324 on UT110614. The S
Magellan (Clay) 6.5 Lowellmで0.5”スリット、4900-9150Å,
R~47,000。2010年と2011年に観測。
Observatory, 1400 W. Mars
Hill
Road,
Flagsta↵,
86001, USA
system is evident in all absorption features, including the Li lines at 6708
shkolnik@asu.edu

SpTが近い標準星と相互相関をとってRadial Velocityを得る。不定性は~400 m/s。
J. Weinberger
無回転モデルを作って、Li I 6708Å, CaAlycia
I 6718Åから自転線幅を引く(Fourier
Method)。
Department of Terrestrial Magnetism, Carnegie Institution of Washington, 5241 Broad
Branch Road, NW, Washington, DC 20015,0.35USA
3つの違いは時刻。

UT100620
UT100622
UT110614

weinberger@dtm.ciw.edu
2回観測があるので、その平均で2回が説明できなけ
ればsingle-lined SBだが、なかった (χ2 Joleentest)。doubleK. Carlberg
peaked SBは1つだけ(SSTc2d
J163154.7-250324)。
NASA/GSFC
Code 667, Greenbelt, MD 20771, USA
0.30

Correlation

0.25

joleen.k.carlberg@nasa.gov

K7とK9型星、質量比0.95、a<0.6 AU, P<150 daysと推and定。
Joe Llama

0.20

0.15

0.10

0.05

0.00
400

300

200

100

0

100

200

Radial Velocity (kms 1)

Lowell Observatory, 1400 W. Mars Hill Road, Flagsta↵, AZ 86001, USA

300

400

SEARCHING FOR SPECTROSCOPIC BINARIES WITHINの続き
TRANSITION DISK OBJECTS1

arXiv:1602.07582v1 [astro-ph.SR] 24 Feb 2016

Saul A. Kohn
Lowell Observatory, 1400 W. Mars Hill Road, Flagsta↵, AZ 86001, USA

single-linedがなかったことも検
Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA,
19104, USA
証。フラックス比も考慮してランダムに擬似観測。
saulkohn@sas.upenn.edu
例えばSZ Chaでは伴星が0.4
Evgenya L. Shkolnik
Mo, P<30 or 70<P<75 daysでSchool of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287, USA
80%検出可能など。
Lowell Observatory, 1400 W. Mars Hill Road, Flagsta↵, AZ 86001, USA
P<100 daysはおよそ検出可能。
shkolnik@asu.edumul)plicityは0.04+0.12–0.03になっAlycia J. Weinberger
た。
Department of Terrestrial Magnetism, Carnegie Institution of Washington, 5241 Broad(Chameloeon 0.07, Taurus-Branch Road, NW, Washington, DC 20015, USA
Auriga 0.06, planet hos)ng wide
weinberger@dtm.ciw.edu
binary 0.054, low mass ﬁeld star
Joleen K. Carlberg
0.03 or 0.09)
他の円盤に比べてTDの NASA/GSFC Code 667, Greenbelt, MD 20771, USAmul)plicityが高いわけではない joleen.k.carlberg@nasa.gov
Fig. 6.— Calculated contours in (Msecondary , P )-space representing the probability of detecので、伴星は主な原因ではない。
anding a companion star spectroscopically, given the precision and timing of our RV measurments. Contour levels of probability of detection are shown in 10% bins from 40 100
Joe Llama
Shown next to the name of the target system is the mass of the primary in solar massaccordingthe PMSmodelsFlagsta↵,of Bara↵eal. (2015).
Lowell Observatory,
1400 W.toMars
Hill Road,
AZet86001,
USAWe imposed that the secondary ma2MASS, Spitzer, Herschel and APEX data (Furlan et al.
SURVEY FOR 100-1000 AU COMPANIONS AROUND YOUNG STELLAR OBJECTS IN THE ORION
submitted). AN HST
MOLECULAR CLOUDS: EVIDENCE FOR ENVIRONMENTALLY DEPENDENT MULTIPLICITY
1

2

3,4

5

M. Kounkel , S. T. Megeath , C. A. Poteet , W. J. Fischer , L. Hartmann
4.1. The Identificationof Companions
Draft version February 25, 2016

1

arXiv:1602.07635v1 [astro-ph.SR] 24 Feb 2016

To search for an excess density of sources, ABSTRACT
we utilize the mean surface
densityof survey
companions(LarsonWe present
a near-IR
for the visual
multiples in the Orion molecular clouds
region at sepamul)plicityは重いと多かったり、進化すると少なかったり、denseclusterで少なかったりする。
rations
between
100
and
1000
AU.
These
data
acquired at 1.6 µm with the NICMOS and WFC3
1995), which is related to the two point correlationwere
funccamerason the Hubble Space Telescope. Additional photometry was obtained for some of thesources
質量とCompanion
Frac)onの関係は固有か進化かわからない。widebinaryを見れば、tion (Bate et al. 1998).
In with
thisNICMOS
approach,theL′ -band
densityofat 2.05 µm
and in thewith NSFCAM2
on the IRTF. Towards 129 protostars
and 197
sequence annuli
stars with centereddisks observedon
with WFC3, we detect 21 and 28 candidate comobjects is determined
inpre-mainconcentricinterac)on前なのでわかる(interac)onがあるとすぐ散るから？)。àONC,d=420 pc
panions between the projected separations of 100—1000 AU, of which less than 5 and 8, respectively,
each Spitzer-identified
dusty
YSO
withinthe
NICMOS,are chance line of sight coincidences. The resulting companion fraction (CF ) after the correction for
WFC3 and NSFCAM2
The density
is+1.1then
the linefields.
of sight contamination
is 14.4% foraverprotostars and 12.5+1.2−1.3−0.8 % for the pre-main sequencestars.
These
valuesaresimilar
to
those
found
for
main
sequencestars,
suggesting that there is little
aged over
all the dusty
YSOs2.05
usingµm)とIRTF
the equation
Spitzer
YSOをHST(WFC3(NSFCAM3)で。点源カタログを作った。201個。
variation in the CF with evolution, although several observational biases may mask a decrease in the
CF from protostars to the main sequence stars. After segregating the sample into two populations
CFと進化段階、環境の関係を調べる。視線方向上の偶然の重なりは統計的に区別。
based on the surrounding surface density of YSOs, we find that the CF in the high stellar densityN!
Y SO
regions(ΣN
pcr−2 )−is ∆i/2.
approximately
50%
higher than that found in the low stellar density
Y SO > 45(j,pc< thisr≤
revidencecompi ). We interpreti + ∆i/2)−2
regions(Σ<45
asfor theY SO, elevated formation of companions
Σcomp (ri ) =
2
2
at
100
to
1000
AU
in
the
denserenvironmentsofOrion.
We
discuss
possible reasons for this elevated
NY SO j=1
π[(ri + ∆i/2) − (ri − ∆i/2) ]formation.
Subject headings: (stars:) binaries: visual — stars:
Tauri — in(1) formation — stars:protostars,Tfrared:stars —ISM:individual(Orion A) — ISM:individual(Orion
compB)

1

j番目のSpitzer YSOの周りi番目の環にあるカタログの点源がN

下図。

where the Spitzer identified YSOs at the center of theannuli (hereafter: primaries)
are numbered j = 1 to
1. INTRODUCTION
Molecular Cloud is 0.47 over a range of 18 to 1820 AU.
<1000
AUでは環に偶然たくさん入る。
thThis is 1.9 times higher than that for solar-type field stars
NY SO , ∆i is the
width
of
the
i
annulithat
extends
Multiplicity is a common property of stars that influin that separation
range (Leinert et al. 1993). The im左が原始星、右がPMS
ences
both
the
futureevolution
of
a
star
and
its
poten30 number of
80-1000
AUに原始星29個、PMS27個のbinary。
from ri − ∆i/2
to ri + ∆i/2, and Ncomp is theplieddeclineintheobserved
companion fraction over thistial to host habitable worlds (e.g. De Marco 2009; Smith
separation
range
with
evolution
may come from changes
NICMOS,
WFC3
and/orNSFCAM2
sourceswithinthe
2014; Wang et al. 2014). Roughly one third of all field
3重連星は1個ずつ。
in the orbital parameters and potential ejection of comth
thinstead of single39stars, with the
stars
are
multiplesystemsi annulus centeredon the j Spitzer YSO.
panions. These changes could result from the formation
fraction of multiple systems increasing with stellar mass,of the companions in non-hierarchical systems with three
To Class
determine
withintheannuli,we
first
identi0/I (NICMOS)
fromN
26%
for
0.1—0.5Mstars,
to44%
for0.7—1.3
M
comp⊙⊙Class 0/I (WFC3)or more stars (Reipurth et al. 2014), or from changes infakestarsを入れstars,
and finally sources
to 60% for 8—16
M⊙ stars (LadaIIfied aClass
sampleof primary
by selecting
the2006;
Spitzerthe binding mass due to the ejection of gas in protostellar
Unidentified
Duchêne & Kraus 2013).
envelopes by outflows (Connelley et al. 2008b).
て測った
identified YSOs
whichresolved
appearas ofpoint
sourcesin theSpatially
imagespre-mainsequence
Since many stars form in young clusters, interactions
stars excludes
and protostars
show that
most
stars
HST data. This
sourcesthataretooprobably
reddenedwithother stars in these clusters are also thought tocompleteness。
form in multiple systems (Reipurth & Zinnecker
1993;
play a significant role in determining both the fraction
to be detected
in et
the
F205W,
andKraus
L′ -band
Haischal. F160W,
2004; Connelley
et al. 2008a;
et al. imof multiple systems and the companion fraction. Obser75,
50,the2011). The
number 上から99,of companions
over
the total
numberages and extended
nebulous
sources inwhich
centralvations of young stars in both low stellar density assoof primaries and single stars (referred to as the companprotostar is notdetectedasapoint
source.
Tofindtheciations, such as that in the Taurus Molecular Cloud,ion fraction or CF ) 25%。
is observed to be high for protostars.
and in the dense young clusters, such as the Orion
The CF as
rangesfrom 0.91 forofClass
0 protostars
to 0.5 prinumber of sources
a function
radiifrom these
Nebula Cluster (ONC), have shown that stars in thefor the more evolved Class I protostars, as measured overmary sources,a we
use
the
point
sourcecatalog
extracted
low density associations have 0.2 companions per logseparation range of 50 to 5000 AU (Connelley et al.
arithmic interval of separation, while stars in the densefrom the NICMOS,
WFC3,
and
NSFCAM2
2008b; Chenet al. 2013;
Reipurthet al. 2014).data.
After theclusters have 0.08 companions per logarithmic interval
protostellar
phase,
pre-mainsequencestarsthecanFig.
stillshow
3.— The mean surface
densityetof companions,, as a etfunctionof projected
The bin size is 250 AU, except for the first
In Figure 3,
we
plot
the
Σ
(r
)
for
protostars(Leinert
al. 1993; ΣProsser
al. 1994;
Petrseparation.
et al. 1998;
compia high incidence of multiplicity. For example,
the contains
CF companions
bin, whichwith separations of 80–250 AU. The error bars were determined by dividing the sample randomly into fourcomp

arXiv:1602.07635v1 [astro-ph.SR] 24 Feb 2016hewherenearthenumberofhighthatAltected outside
a limiting object.
radius wherecompleteness(Figure
12).
Theofcorrection
is incalculatedcompis NN5
measuredenoughtoobjects
theprimary
itby surroundingmatednumberof linesight
contaminants.
a particular
When thecomputingNN5,
ityregionsareequal.
For
each
of
these
we
is
≥
99%
for
that
value
of
∆m
.
We
determinethemining∆m
betweeneach
object
in
the
2000
to
160
160
s anweaccurate
assessment
ofasthedensityFOR
100-1000
AROUNDYOUNGOBJECTSthat
IN THEORION
ely,
can thinkofAN
theHST
CFSURVEY
thesurface
integralof AU
theCOMPANIONS
we do notincludeanySTELLARof the sources
wereidentibarsannulus
forthe linesight
contamination.
In comratioas
withthecompanions
equation:DEPENDENT
AU
and
the
targetedprimaryin the fied
MOLECULAR
CLOUDS:EVIDENCEFOR
ENVIRONMENTALLY
MULTIPLICITY
inants.
Wethencalculatethenumberofurfacedensityof ofcompanions
minus
thestaraveragelikelysince noneof them have been
e
set
r
=
100
AU
which
implies
there
1
2
3,4
5
1
of
the
annulus,andthenadopting
thecriteria
that
inner
の続き
M.
Kounkel,S.
T.
Megeath,C.
A.
Poteet,W.
J.
Fischer,
L.
Hartmannsoffromlinetheof equationsight contaminants, over an integraresolved in the Spitzer N
sample.
We 2thenuse" the NN5
!
cont
2
#
ver
subtractionofthecontamination.
The
minating
objects
in
the
line
of
sight
can
only
be
deDraft version February
25,
2016
1 high and1000− ri regions bycompYSOs into
nge of 100 to 1000 AU (Figure3). "Multiplicity
to divideΩthelow density
!
=
,
(4)
of(MF)
the lineofsightcontamination
ensuresoutsidealimiting
radiuswherethecompleteness22Ω
is alsofrequently
used compin the, literature;whetherorcontnotから偶然の重なりを予想して<1000
theirnearest neighbordensity,
as given
Ω
Ncont
5000
−
2000
ABSTRACT2000-5000
AUのN
AU
(2)
N
=
N
−
N
i=1
comp
cand arecont 160
ations
in
the
CF
not
due. tohigher sys-the by 3/(πr2 cont
99%
for
that
value
of stars∆m
Weaamultiple
determine
iven
by
the
fractionof), theexceeds
the thresholdsurfacedensity (seeWehostingpresent
near-IR survey
for the visual multiples
inOrion molecular
clouds region
at sepaΩcont
N
N
5
hance
coincidences
withonly
otherYSOs
in andrewiththeequation:rations
between100
1000
AU.から引く。
These
data wereacquired
1.6 µmwiththeith
NICMOS
WFC3のN
d counts
each system
once.
Since
the
CF
Megeathal.toat2016
forthedefinition
nearestwhere
ri iset
set
r99%
for
the
objectandinof
thethe2000-5000
cand
camerasonthe
HubbleSpace
Telescope.
Additional
photometrywasobtained
for
some
of
the
sourceserdensity.
We
find
that
for
the
range
of
N
is
the
numberofcandidatecompanions
withAU
annulus,down
toaminimum
value
of
100
AU.
The
edcandfrom the surfaceNdensityofpoint
sourcesfromneighbor
densityadoptedinthispaper).
!atprimaries"riは2000-5000
2.05 µm
and in the L′ -band withNSFCAM2 on the IRTF. Towards 129 protostars
contAUのi番目の25-99%半径。
N5values,theprotostars
and
young
stars
2 withbetween
2NICMOS#edseparations
from
their
100
1 the Orion− ri sequenceΩcompidentified
numberofwithcontaminates
is 21
reducedby HSTa factorof 0.46e havecompanions,
it is stars
the with disks
Inobserved
Figure13,WFC3,
we plottheCFs 28
ofcandidate
thesampleforand1000
197 pre-main
we detectandcomundin anddense
regionshavea higher
ofthe
CF
= use
, in
(4)
00
AU,
Ncont
is
the
numberof sourcesthepanions
betweenprojected
separationsof100—1000AU,of surface
whichless density
than
5 andfor8, respectively,
2
2
forprotostars
andafactorof
0.42
pre-mainsequence原始星でN=18-18.6、PMSは23.6-24.7。
statistictoin
our
analysis.
The
CF
is
then
the
high
and
low
regionsforthresholdΩcont 2000
Nand
5000
−line
2000
comp
cont 5000
arechanceof sight
resulting companion fraction (CF ) after the correction for
densityregions.
NoteAU).
that
the
CF
s forcoincidences. The
between−2
i=1stars.
This
analysis wasusing
the (65∆mpc
densities
corresponding
to%repeated
N
Nthe
5=
25000
AU
),
160 vs
+1.1
+1.2
!
"
+1.5
the
line
of
sight
contamination
is
14.4
%
for
protostars
and
12.5
for
pre-mainsequence原始星はCF=11.4+1.5–1.3%,
PMSは10.2%。
s,
pre-mainsequencestars
withdisks,
and
−1.3
−0.8
ssume
that
N
gives
the
numberofcontami−2−2
cont Ncontth ΩcompN–1.6
radius
curve
for
a
25%
level
of
completenessbyadoptcomp
30000
AUmain(45sequencepc ) stars,
and suggesting
35000 AU
pcis little); these valstars.
These invaluesaresimilarfound forthat(33
thereri CF
isYSOsset
the density
iandobject2000-5000=toinr99%
,the
(6)
−high
sty
theforregions
arestars,
eitherforegroundbackgroundstars
orto thosevariation
in
the
CF
with
evolution,althoughseveralobservationalbiasesmaymaskadecrease
in
the
ing
r
for
the
inner
radius(Figure12).
Thisつまり進化段階の違いはない。
25%
ues
bracket
the
NN5
where
the
numberofobjectsin high
N
N
Ω
prim
prim
cont of 100 as
nnulus,down
toa lineminimum
value
AU.
Thesequence stars. After segregating the sample into two populations reduces
th eachotherwithintheuncertainties,
Orion
YSOs
in
the
of CF
sight,
we toscalebyfromwhichprotostars
the mainthenumberofcontaminants
byafactorof
0.6
for
andoflowdensityareinequal.
eachof theseprowe
er
of
isof
reducedfactor
0.46 density
basedcompanion
onby
the a
surrounding
surfaceYSOs,
we find regionsthat the CF
the high For
stellardensitytheprotostars,
disks,
and
dusty
YSOs
in−2ofconosof contaminates
the
solid
angles
of
the
and
Nof
is
the
numberprimaries.
The
calculaprim
tostars
and
0.56
for
pre-mainsequencestars.
By
reducinclude
error
bars
for
the
line
of
sight
contamination.
Inregions
(Σ
>
45
pc
)
is
approximately
50%
higher
than
that
found
in
the
low
stellardensity
Y SO
otostars
and toa factorof 0.42pre-mainsequencetion
regions
estimatethenumberof45 contamity regions.
−2 Aptheuncertainties
for theCF foris(Σdescribedin
理由は5つ。主系列では質量に依るが、ONCでは測れていない。原始星エンベロープがCF
ingtheestimated
number
of
line
of
sight
contaminants,
regions<pc).
Weinterpret
this
asevidencefortheelevatedformationofcompanions
Y SO the ∆mthis figure, we set rinner = 100 AU which implies there
Thisanalysis
analysis
wasberepeated
using
160
objectsin the companion
If we
ignore
thevs
orous
can
done
with
the
WFC3
atregion.
100
to 1000
AUin the denser
environmentsof Orion.of
Wecompanions
discuss possibletothis elevatedB.
the number
increases frommaybean over
subtraction reasonsof protostars
theforcontamination.
Thesﬀerent
curve
for
a 25%
level
offormation.
completenessby adoptを下げている。1.60µm源なので後期原始星に偏っている。100-1000
AUという制限。進化f incompleteness,
the
ratio
of
solid
anglesbecomesvalues
of
. 5In
Table
6,
we
show
inner
CF
s are
given
in rTable
for
an
r
=
100
AU.
15.9
to
18
for
r
and
18.6
for
r
,
and
the
numberinner
25% line
99%
subtractionof theof sight contamination
Subject
headings:(stars:)binaries:
visual— stars: formation— stars:protostars,T
Tauri — in- ensures
for theinner
radius (Figure
12).
This
reduces+1.0
a5%ofextending
from
100
to
1000
AU—ISM:individual(Orionf primaries
andcompanionsin10.3thelowandFumberof theallofannulus
the
dusty
YSOs
is
%
for
the
of
companions
to
pre
main
sequencestars
increases
fromの違いと環境の違いを分けていない。
frared:starsA) —ISM:individual(Orion
B) not
−1.0
that
the
variations
in
the
CF
are
due
to a higher
byofa.thefactorof 0.6extendfor procompanions
overtheofareaegions as acontaminants
functionrinner
Theannulus
resulting+1.0
20.1 to of
23.6
and 24.7
for r25% withand other
r99% , YSOs
respectively.
edsample,10.8pre-main
the
HSTstars.
sample,andnumberchancecoincidencesin res and0.56
forsequence
By reduc−0.9 %m
2000
to 5000AU
forforthecontaminants:This
anincrease
of
1.35σ
for
the
protostars
and
1.5σ
for
1.
INTRODUCTION
Molecular
Cloud
is
0.47
over
a
range
of
18
to
1820
AU.
gions
of
higherdensity.
We
find
that
for
the
range
of
e for
estimated
number
of
line
of
sight
contaminants,
the WFC3
sample.
Thus,
the
CF
does
!
"
This
is
1.9
times
higher
than
that
for
solar-type
field
stars
the
pre-mainsequencestars.
The
numberofcandidate
2Multiplicity
2 isdiﬀerent
a commonpropertyof stars that
influthresholdNN5
theprotostars
and
young
stars
−2
umber
ofCF
companions
increasesfromngeΩsignificantly
betweenthesamples.
2 values,
1000
−to
100
in andthat
separation
range(Leinert et al. for1993).
The
im(Σ >
45
pc)protostarscomp)として、高密度と低密度を分ける。
companions
the
level
contamination
thediﬀerent
ences
both
the4番目に近い距離からΣ=3/(πrfutureevolution of a (3)star and its
poten==
0.047.
+1.5
NN5
with
disks
found
in
dense
regionshaveahigherof, 2habitable(7)
R=
plied decline in the observed companion fraction over thisCF
oHST
18
for
r
and
for
r99%
and
218.6
sample,CFshost
11.4, −1.3
%thefornumberproworlds(e.g.
DeMarco 2009;
Smith of r
Ωcont
−to−2
2000
choices
are
given
the
WFC3
CF25%
(Σ 5000<the45tial
pc
)are
inner
separation
range
with forevolution
maythatcomesample
fromthe low
densityregions.
Note
the changes
CFins Tafor
2014;
Wang et原始星ではRの中央値1.74、PMSは1.28。つまり高密度ほど多い。
al.
2014).increases
Roughly one
third ofthan
all field
mpanions
to premain
sequencestars
fromand 10.2+1.5
%
for
the
pre-mainsequencestars.
intheorbitalparameters
andpotential
ejectionofcom-andble
4.
Again,
thedeterminationoftheuncertainties
is
−1.6
stars
are
multiplesystems
insteadofsinglestars,
withthe
the
protostars,
pre-mainsequencestars
withdisks,
ofcontaminantsinthe2000-5000
AU
ano
23.6
and
24.7
for
r
and
r
,
respectively.
dmber
using
a
Bayesianparameter
estimationinpanions.
Thesechangescould
resultfromtheformation
25%
99%
h the CF for pre-mainstars isincreasingslightlywith stellar
described
inAppendix
fractionsequenceof multiple systems
mass,
combined
dusty
YSOs A.
inin non-hierarchicalthe high densityof the companions
systems regionswith three are
nd
the
of7.
companions
are
given
an
increase
1.35σfor26%
theandandinnumber
Table
Since
ra-1.5σfromforprotostars
0.1—0.5Mthe
to44%forfor 0.7—1.3 M⊙
高密度と大クラスターが重ならず、interac)onならむしろ高密度でCFは下がるので違う。
⊙ stars,he
CFpresented
scorrected
areofconsistent
withinthe uncertainties.
or
more
stars
(Reipurthetal.
2014),
orfromchangesin asconsistent
with
each
other
withintheuncertainties,
es 3fornot
for
each
ofchoicesthethreesamples.
contamstars,
andfinallyto 60%The
forM⊙ stars (Lada 2006;
4.4.
The
Companion
Fractionre-mainsequencestars.
The
numberof8—16candidateoes
appearstrongly
dependentonthe
diﬀerent
of
r
are
given
for
the
the
binding
mass
due
to
the
ejectionofgasinprotostellar
inner
Duchêne& Kraus 2013).
are the CFenvelopess of thebyprotostars,
disks,etand
dusty YSOs in−2
集まっている星が重い可能性ßKS検定で棄却。
theandtotal
numberofcontaminants
fordiﬀerent
all ofanionsthelevelcontamination
for
the
+1.7
5isvalue,
we
use
the
45
pc
density
threshoutflows (Connelleyal. a2008b).
The
incidenceof multiplicity
among
population of
Spatially
resolved
imagesof pre-main
sequence
sample
in
Table
5.
CF
increases
from
12.3
%
−1.4
the
low
densityregions.
maries.
The
numberofcontaminants
is smalldue
Since many stars form in young clusters, interactions
sspatialof rinner
are
given
the
WFC3
sampleTadistribution
offor
YSOs
in ourshow
samplestars
andprotostars
that inmoststars stars
probably+1.6+1.1星が集まる場所はガス密度も大きく、連星ができやすいのでは？
can bequantified
companion
fraction,CF ,withother analysis
starsbyinthe
theseclusters
are withalso thoughtto%extinction
and
% for
the
protostars,
A1993;
more
rigorouscanbe donethe orWFC3
hightowards
YSOs:
0.04
companforminmultiplesystems& Zinnecker
−1.5
−1.3
Again,
thedeterminationofFigure
theuncertainties
is whichthresholdis14.4
presented
inthe
the14.(ReipurthAsusingisdefined
by
the
ratio
of
the
numberofcompanions
playasignificant
role
indeterminingboththefraction
Haischet al. 1000
2004;
Connelley
et al.pre2008a; Kraus
et usingal.
data
diﬀerent
valuesandof rthe. In Table
6, we show
primary
100100andAU.
thedvaluer99%, respectively(Table6).
For,Giventheinner
in Appendix
A.
erbed
of
rbetween
to roftheof number
multiple systems
companion
fraction. Obserinner from
99%
to
the
total
of
singlestars
andsystems,
2011).
TheAU
numbercompanions
over the total
number
+1.5
the numbervationsof primaries
andincompanions
the lowumber
of companions,however,
asformanyas %26%of young stars
both low stellarindensity
asso-andquencestars,
thefromCFincreases
from
10.2
to
of R decreases
1.96
toand
1.74
protoof primaries
singlestars(referred
to as the compan−1.6
ciations,
such
as
that
in
the
TaurusMolecular
Cloud,
4.4.
The
Companion
Fractionhighdensityregionsasafunctionofr.
Theresultingompanionsmaycontaminants.
Thus,
the
+1.2
ion
or
CF ) isandobserved
to beprihigh for protostars.
Byoung+ 2Tclusters,+ 3Qinner
1.28
pre-mainsstars,
fromandfor12.5% beforsequencerfractionand
rfrom
respectively
and in CF
the densesuch
the Orion (5)25%
99% ,0.91−0.8
The
CF ranges
for Class0 protostars
to 0.5=, thatasstars
ratios,ncertainty
inthenumberofcompanionsisdueofformultiplicity
among
a population
ofmeasured overorincidence
themergedsamples.
Each
of
these
three
Nebula Cluster (ONC),
have
shown
in the
S
+
B
+
T
+
Q
forpre-main
the moreevolvedClass
I stars
protostars,
as
6).
The
CF
s
the
sequenceandcontamination
subtraction.
In
AppendixA,
welowdensityassociations
have
0.2
companions
perlogcanbe quantified
companion
fraction,CF,istentlyshow
an by
elevated
CFrange
in of
the
a the
separation
50 dense
to 5000(Connelley
et al.
−2 stars in the densearsbothincreaseandremainconsistent,
andorAUthearithmicintervalofseparation,
while
CF
(Σ
>
45
pc
)
how
we
measuretheuncertainty
inthecontamiwhereSisthenumberofsinglestar
systems,B
thenum2008b;
Chen
et
al.
2013;
Reipurthetal.
2014).
After
the
,is
althoughtheCFis highest
for evodefinedbythechange
ratio ofinthe
numberof companions,=
clustersRhave
0.08 companions per
logarithmic
interval (7)ofasignificant
diﬀerence
betweenthetwoprotostellar
phase,
pre-mainsequence
stars
can
still
show
−2
subtraction
using
the Poisson
statisticsof the line
ber of binary
systems,T (Σtheof) ternary<number
45etpc(Leinert
et al.CF
1993;
Prosseral. 1994;
Petr et al.systems,
1998;
numberof single
anda high stars
incidenceof systems,
multiplicity. For example, the CF
ytotalstagespersists.

SPECTROSCOPIC BINARIES IN THE ORION NEBULA CLUSTER AND NGC 2264
Marina Kounkel1 , Lee Hartmann1 , John J. Tobin2 , Mario Mateo1 , John I. Bailey, III.1 , Meghin Spencer1
Draft version February 19, 2016arXiv:1602.05630v1 [astro-ph.SR] 17 Feb 2016

ABSTRACT
Sun-likeの半分は連星、クラスターでないと進化するとmul)plicityが高い、若いクラスターは
We examine the spectroscopic binary population for two massive nearby regions of clustered starformation, the Orion Nebula
Cluster and NGC 2264, supplementing the data presented by Tobin et
低い、Orionで高密度ほどwide
binaryが多い、など。
al. (2009, 2015) with more recent observations and more extensive analysis. The inferred multiplicity
fraction up to 10 AU based on these observations is 5.3 ± 1.2% for NGC 2264 and 5.8 ±
1.1% for the
クラスター形成は超音速乱流で支えられるslowと自由落下のrapid
modeがある。
ONC; they are consistent with the distribution of binaries in the field in the relevant parameter range.
Eight of the multiple systems in the sample have enough epochs to make an initial fit for the orbital
Tobin+09,15でONCのSBが調べられが、星がガスに対してblueに偏っていたので再解析。
parameters. Two of these sources are double-lined spectroscopic binaries; for them we determine themass ratio. Our reanalysis of the distribution of stellar radial velocities towards these clusters presents
a significantly better agreement between stellar and gas kinematics than was previously thought.
Subject headings: stars: formation, objects: ONC, objects: NGC 2264

Magellan Clay Telescope, R~20,000, Mg I Hα Li I, Hectochelle (R~35,000)を追加。
対象はONCとNGC 2264、RVの精度はそれぞれ0.8,
1.2 km/s。
1. INTRODUCTION
reexamine the environmental dependence on the evolution of the multiplicity. Constructing a better defined
Approximately
a half of Sun-like stars belong to binary NGC
Tobin+ではreduced
χ2>16で、ONCで79/1154,
2264で51/903がRV
sampleof the close binary systems thatvaliableとして見つ
can be obtainedor higher order multiple systems (Raghavan et al. 2010),
through multi-epoch spectroscopic monitoring is an imandthisfractionincreasesformoremassiveprimaries
かった。 (e.g. Duquennoy & Mayor 1991; Kouwenhoven et al. portant step in this process.
In addition, identifying spectroscopic binaries and re2007; Rizzuto et al. 2013).
Observationsof 2264で6.7%、Heliocentric速度をLSRにすると5.8%
several
最終的なmul)plicityはONCで8.0%,
NGC
movingthem from the sample in the kinematic studnearby non-clustered star-forming regions and associaiesofstar
forming regions can help refine tests of clustions revealed that they contain a larger fraction of theと5.3%←擬似観測と一致。
ter formation. There is debate over whether clusters
multiple systems as compared with the significantly moreform in a slow process, taking place in clouds inievolved field stars on the other
hand, high-resolution
double-linedはONCで5、HGC
2264で10個。
tially supported by supersonic turbulence (e.g. Tan et al.
imaging suggests that some young clusters are deficient in binaries (Duchêne & Kraus 2013, and references
therein). Since most stars are thought to form in denseclusters (Adams 2010), studies of binary frequencies asa function of young cluster structure and dynamics canshed light on the processes behind the present day stellar
multiplicity.
The Orion Nebula Cloud (ONC) and NGC 2264 are
two of the closest regions of clustered star formation(d ∼400 pc and ∼ 900 pc, ages 1—2 Myr and 1.5—
3 Myr respectively, Menten et al. 2007; Sandstrom et al.
2007; Sung et al. 1997; Baxter et al. 2009; Hillenbrand1997). While the binarity of nearby stars is relatively
well understood, it becomes increasingly more diﬃcult tocharacterize the full membership of multiple stars in theyoung star forming regions due to their larger distances.
Nonetheless, extensive studies of optical binaries in the
ONC have led to interesting findings. Most of the studies
concentrated on wider binaries that can be detected withphotometric surveys, with smallest separations between
two companions of ∼60 AU, set by the diﬀraction limit

2006; Hennebelle 2012), or whether clusters form rapidly
on the scale of a free-fall due to a gravitational collapse (e.g. Hartmann & Burkert 2007; Elmegreen 2007;
Kuznetsova et al. 2015). Simulations have shown that in
the case of the former, any subclustering in the initial environment would not change significantly in the cluster
evolution; for the latter any substructure would rapidly
dissipate in only a few Myr (e.g. Scally & Clarke 2002).
By examining cluster dynamics of the massive and clustered star forming regions it is possible to set important
constraints on models that would more eﬀectively distinguish between these two theories.
Tobin et al. (2009, hereafter T09) attempted to identify spectroscopic binaries that typically have significantly shorter separations through the multi-epoch spectroscopic monitoring of 1613 objects towards the ONC bysearching for variability in the radial velocities (RV) thatcan be attributed to a presence of a companion. NGC
2264 has not yet been a subject to a systematic binary
surveys, though Tobin et al. (2015, hereafter T15) did
report on the multi-epoch spectra towards 695 objects

SPECTROSCOPIC BINARIES IN THE ORION NEBULA CLUSTER AND NGC 2264
Marina Kounkel1 , Lee Hartmann1 , John J. Tobin2 , Mario Mateo1 , John I. Bailey, III.1 , Meghin Spencer1の続き

Draft version February 19,
10 2016

arXiv:1602.05630v1 [astro-ph.SR] 17 Feb 2016

ABSTRACTsingle-linedも含めて複数観測あるのでフィットしWe examine the spectroscopic binary population for two massive nearby regions of clustered starformation, the Orion Nebula Cluster and NGC 2264, supplementing the data presented by Tobin etて軌道要素を決めた。
al. (2009, 2015) with more recent observations and more extensive analysis. The inferred multiplicity
fraction up to 10 AU based on these observations is 5.3 ± 1.2% for NGC 2264 and 5.8 ± 1.1% for the
ONC; they are consistent with the distribution of binaries in the field in the relevant parameter range.
Eight of the multiple systems in the sample have enough epochs to make an initial fit for the orbitalparameters. Two of these sources are double-lined spectroscopic binaries; for them we determine themass ratio. Our reanalysis of the distribution of stellar radial velocities towards these clusters presents
a significantly better agreement between stellar and gas kinematics than was previously thought.
Subject headings: stars: formation, objects: ONC, objects: NGC 2264 21

Tobin+は月光や低S/Nの影響があった。
今回13COと星にずれはなかった。

TABLE 5
Orbital parameters for double-lined binaries

Fig. 1.— Number of observations made for all the objects in the sample, shown in black. Red shows only sources with χ2 > 16. The
bottom panel shows the ratio of the number of sources with χ2 > 16 per number of all sources with a given number of epochs observed.
Left: ONC. Right: NGC 2264.

reexamine the environmental dependence on the evoluParameter Constructing
RV 1768
tion of the multiplicity.
a better defined RV 1659
Approximately a half of Sun-like stars belong to binary
sample of the close binary systems
that canbe obtained
Adjusted
Quantities
or higher order multiple systems (Raghavan et al. 2010),
P (d)4.7878± 0.0002
15.3182 ± 0.0007
through multi-epoch
spectroscopic
monitoringis an imand this fraction increases for more massive primaries
Tpin
(HJD)
2454289.50 ± 0.06
2454294.07 ± 0.05
portant
step
this
process.
(e.g. Duquennoy & Mayor 1991; Kouwenhoven et al.
e
0.55 ± 0.05
0.00 ± 0.02
In addition,
identifying spectroscopic
binariesω (deg)139.68 ±3.16 and re- 0.00 ± 0.60
2007; Rizzuto et al. 2013).
Observations of several
moving themfrom the sample inthe ±kinematic
stud- 22.83 ± 0.46
γ (km/s)
16.05
0.54
nearby non-clustered star-forming regions and associaK1 (km/s)regions can help
59.34refine± tests
6.34 of clus- 41.56 ± 1.07
ies
of
star
formingtions revealed that they contain a larger fraction of theK2 (km/s)± 6.32 clusters 52.20 ± 1.05
formation.
is debate 60.83
over whether
Fig. 13.— In black - distributionmultipleof of velocitiesof starsin Figureat four
declination cuts.
summeddistributionThereofsystems
as plottedcompared
with12thesignificantly
moreIn blue -ter
Derived Quantities
13
he CO at those declinations, scaled to the peak of the histogram.
form
in
a
slow
process,
takingplace
in clouds ini- 0.73 ± 0.04
3evolved field stars on the other hand, high-resolution
M1 sin i (M⊙ )0.254 ± 0.066
tiallysupportedbysupersonicturbulence(e.g.
Tan et al. 0.58 ± 0.03
3
M2 sin i (M⊙ )0.248 ± 0.065
imaging suggests that some young clusters are defi2006; Hennebelle
or whether0.98
clusters
q = M22012),/M1± form0.15 rapidly 0.80 ± 0.03
cient in binaries (Duchêne & Kraus 2013, and references
6 km)
a1 sin± 0.37on the scaleof i a(10free-fall
due to3.26
a gravitational
col- 8.75 ± 0.23
therein). Since most stars are thought to form in dense
6 km)
a
sin
i
(10
3.35 Elmegreen± 0.3711.00 ± 0.22
2
lapse
(e.g.
Hartmann&
Burkert2007;
2007;
clusters (Adams 2010), studies of binary frequencies as
6 km)
aet
sinal.
i (106.61have± shown
0.52 that in 19.75 ± 0.32
Kuznetsova2015).
Simulations
a function of young cluster structure and dynamics canOther Quantities
the case of theformer, any subclusteringin the initial enshed light on the processes behind the present day stellar
χ2
8.38
13.43
vironmentwould
notchangesignificantlyin the clusterN(primary)
10
9obs
multiplicity.
evolution; forthelatter any substructure
would rapidlyNobs(secondary)
8
8
The Orion Nebula Cloud (ONC) and NGC 2264 are(days)
2308.7dissipate inTime
onlyspana few
Myr (e.g. Scally& Clarke 2002). 2308.6
two of the closest regions of clustered star formation
rms1 (km/s)
1.62
1.22
By examining
cluster dynamics of the1.42
massive and clus(d ∼400 pc and ∼ 900 pc, ages 1—2 Myr and 1.5—
rms2 (km/s)
2.10
tered
star
forming
regionsit
ispossibletosetimportant
Tave (K)4021
4203
3 Myr respectively, Menten et al. 2007; Sandstrom et al.
constraints on models that would more eﬀectively distin2007; Sung et al. 1997; Baxter et al. 2009; Hillenbrandbution of of velocities of stars plotted in Figure 14 at two declination cuts. R.A range between 100.05
and between these two theories.
13 CO1997). outside
Whileof thebinarityof In
nearbystars is distribution
relatively of theguishminimize contamination from sources
the maincluster.
blue - summed
Tobin
et al. (2009, hereafter T09) attempted to ideno the peak of the histogram. well understood, it becomes increasingly more diﬃcult totify
spectroscopic
binaries that typically have significharacterize the full membership of multiple stars in thecantlyshorter
separations
through the multi-epoch specyoung star forming regions due to their larger distances.
troscopic
monitoringof1613
objects towards the ONC by
Nonetheless, extensive studies of optical binaries in the
searchingforvariability
intheradial velocities (RV) that
ONC have led to interesting findings. Most of the studies
can be attributed to a presence of a companion. NGC
concentrated on wider binaries that can be detected with
2264 has not yet been a subject to a systematic binary
photometric surveys, with smallest separations between
surveys, though Tobin et al. (2015, hereafter T15) did
two companions of ∼60 AU, set by the diﬀraction limit
report on the multi-epoch spectra towards 695 objects
1. INTRODUCTION

ONC、黒が星、青が13CO、赤緯ごと。

NGC 2264

NCG 2264のCone Nebulaの星はガスよりblueで、decouple、理由は不明。
また、母体とは別に2 km/sに星のclumpがあり、ガスが散逸した古いclusterの可能性。
subclusterが拡散していないならが、星団形成モードの研究に使える。

arXiv:1602.08120v2 [astro-ph.SR] 29 Feb 2016

THE INTERMEDIATE-MASS STAR FORMING REGIONLYNDS 1340.
AN OPTICAL VIEW
Mária Kun, Attila Moór, Elza Szegedi-Elek
Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, Hungarian
Academy of Sciences, H-1121 Budapest, Konkoly Thege út 15–17, Hungary

Lynds 1340はl=130.1°, b=11.5°にあり、D=600 pcと言われていた。A-B starsで光る反射星
and雲があり、中質量星形成領域。中質量星のfeed backを調べたい。
Bo Reipurth
13COで1100 Mo、典型的なGMCより2桁軽い。C18Oでclump
A,B,C。NH3 dense coreの質
Institute for Astronomy, University of Hawaii at Manoa, 640 N. Aohoku Place, Hilo, HI
量とTkはTaurusとOrionの中間。
96720, USA

Received / Accepted– 35 –
Calar Altoの2.2 m,
Fred Lawrence Whippleの1.5 mなど。ハワイ大2.2 mでgrism分光。
Spitzer, AllWISE, SDSSも。SDSSから減光マップ。YSOはSEDのslopeから。
ABSTRACT
We have performed an optical spectroscopic and photometric search for young
過去の研究では反射星雲で距離を決めたが、今回は高分散分光なので2つの明るいB5,
stellar objects associated with the molecular cloud Lynds 1340, and examined theB4 starsに注目。unreddenedcolor
pcに更新。
structure of the cloudby indicesから750<D<940
constructing an extinction map, basedon SDSS data.

log (L / LO• )The new extinction map suggests a shallow, strongly fragmented
cloud, having
3
5.0
a mass of some 3700 M⊙ . Longslit spectroscopic observations of the brightest
F5よりearlyを11個(→青)。7個のHαstars over the area of L1340 starsが2-2.5
revealed that the most massive2 star 4.0
associated
with
3.0
2.5
L1340 is a B4 type, ∼ 5 M⊙ star. The
new spectroscopic and photometric
Moで温度と光度が上がり始めており、B-A
starsに
2.0
1data of the intermediate mass members led to a revised distance of 825+110
1.5−80 pc,なる。1-3 Myrに分布。ZAMSより下はedge-onだろう。
and revealed seven members of the young stellar population
with
M
!
2
M
⊙.
1.2
0
1.0
Our search for Hα emission line stars, conducted with the Wide Field Grism
0.5
0.8
1
-1 Hawaii and covering
Spectrograph 2 on the 2.2-meter telescope of the University of3
0.6
D = 825 pc
5Sp.type < F5
a 30′ × 40′ area, resulted in the detection of 75 candidate low-mass
pre-main
0.4
10-2
Sp. type > F5
Hα stars,
photometry
sequence stars, 58 of which are new. We constructed spectral energy
distributions
0.2-3 WISE photometricof our target stars, based on SDSS , 2MASS , Spitzer , and
4.2 from
4.1 4.0
3.9 3.8 3.7 3.6 3.5 3.4
data, derived their spectral types, extinctions, and luminosities
BVRIJ
log Teff
fluxes, estimated masses by means of pre-main sequence evolutionary models,arXiv:1602.08120v2 [astro-ph.SR] 29 Feb 2016

Fig. 11. Stars of diﬀerent SED shapes are distinguished. Filled circle
THE
INTERMEDIATE-MASSSTAR
FORMINGClass I Hα star, and open
circlesmark the Flat SED sources.
Squaresshow REGION
1340.
. Upward triangles are for II A type SEDs, andLYNDS
downward
triangles mark
–の続き
36 –
AN
OPTICAL
VIEW. Class III sources are plotted with diamonds. Similarly to several other
Kun, Attila2008;
Moór, Elza
Szegedi-Elek
ps (e.g Natta et al. 2006; Herczeg &Mária
Hillenbrand
Barentsen
et al.
Observatory,
Centre forand Earth Sciences, 10
Hungarian
be seen in the widelyKonkoly
scattered
points.Research
The linear
fit Astronomy
to the data,-6

HαからLaccを出し、円盤が5R
Academy of Sciences,
H-1121 Budapest, Konkoly Thege út 15–17, Hungary*までとしてdM/dtを計算。
他の領域に矛盾しない。

10-7

Macc (MO• yr−1)

log Ṁ = (1.49 ± 0.36) log M − (7.87 ± 0.09),

andBo Reipurth

10-8olid line. Its slope is consistent with the values between 1.0 and 3.0,
10
– 37 –
Institute for Astronomy, University of Hawaii at Manoa, 640 N. Aohoku Place, Hilo, HI–2ar-forming
regions
(e.g
Natta
et
al.
2006;
Herczeg&
Hillenbrand2008;
3つのclumpでN(H2)<2.5e21 cm でC18O検出閾値より小さいの
96720, USA
1011). で、kno0y
The medianforma)on←中質量星のwindが維持。減光マップにṀacc of the sample– 16 – is 7.6 × 10−9 M⊙ yr−1 , a typical value– 37 – 0.5
0.3
1.0
1.5 2.0 2.5
Received / Accepted
M /M
aking
into
account
the10%
uncertaintyof
EW(Hα)
andtheerrorslistedinもbubble。
t the accretion rates are accurate within ≈ 0.3 −−0.5
order of magnitude.
ABSTRACTd to the data over the 0.3 ≤ M∗ /M⊙ ≤ 3.0 region,
Fig. 11.— Accretion
rates, derived from the Hα luminosites as a func
rical質量分布はSalpeter
relationship results in IMF。
slightly higher accretion luminosities,
but does
We have performed an optical spectroscopic
searchfor young
The andfilledphotometriccircle Fig.
is the
only
Class
13.—
Extinction
mapI ofsource,
the centralopen∼ 18 ×circles
11 arcminindicate
area of the theclum
e of theṀacc ∗vs.
log N(M>Mm)star= plot.
(−1.38 ± 0.09) log m + (1.44 ± 0.025)
the 850 µm contours (orange) overplotted. Blue asterisks indicate the stars
-9

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00 squares.the73 00 II A sourc
stellar objects associated with the moleculartype
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and73byexamined
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are1340,
markedUpward triangles show
the reflection nebula DG 9, and red plusses show the IRAS point sources.
72 and58 SDSS72 58 young star
the cloud by constructing an extinction
data. show the Class III
are for II Tmap,
typebased
SEDs,ondiamonds
Flat, Class
IIが減光が多いところに。
magnitudes,
available
forstructure
the Hαof emission
stars, may oﬀer
an independent
new extinction
map suggests
a2 36shallow,
strongly
fragmented
cloud,
havingdata
is also2 28
drawn.
2 31
2 30
2 29
2 28
with that of Salpeter’sThe(1955)
initial massfunction.
30
2 32 3030
2 24 30
RA(J2000)
tion rates. Since most ofa our
stars
are
faint
in
the
U
-band,
andtheir
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clump Bの減光マップ。
73 20´73 20´stars
over the areaof L1340
revealed
the most
massivestar associatedned
non-simultaneous
photometric
data,
can
bethatregardedas prelimiace from
distributionof the candidate
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overplottedon the with
橙は850
Fig. The
13.—new
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map ofandthe73photometriccentral∼ 18 × 11 µm。
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L1340
is a B4 type, ∼ 5 M⊙ 73star.
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Fig.
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the 850ledµmtocontours
Blue asterisks indicate the stars
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a revised(orange)
distanceoverplotted.
of 825−80 pc,
B
盤の上層、GMCたちより上空。
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and
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<
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72 40´5
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ies following
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arXiv:1602.08053v1 [astro-ph.SR] 25 Feb 2016

THE YOUNG STELLAR POPULATION OF LYNDS 1340. AN
INFRARED VIEW
M. Kun1 , G. Wolf-Chase2,3 , A. Moór1 , D. Apai4 , Z. Balog5 , J. O’Linger-Luscusk6 , G.
Moriarty-Schieven7

kun@konkoly.hu
B型星を中心とする、Isolatedとclusteredの中間の分子雲はわかっていない。
大体の星は<100個のcluster起源という説も。
ABSTRACT
L1340 (3700 Mo)は一例で、A, B, C3つのclumpを持つ。銀画面から160 pc。
We present results of an infrared study of the molecular cloud Lynds 1340, – 28 –forming three groups of low and intermediate-mass stars. Our goals are to identify
Spitzer IRAC, MIPS,and1 characterise
deg2, AllWISEとスペインのOmega-CassでNRO
7 clusterを高空間分
the young stellar population of the cloud, study the relationships
解能。
between the properties of the cloud and the emergent stellar groups, and integrate
L1340 into the picture of the star-forming activity of our Galactic environment.
– 56selected–
WISEdataWe
candidate young stellar objects from the Spitzer and WISE
SED slopeから155 bases
ClassusingII, 45ClassI,
25
Flat。Tから8bol and classified them based on thevarious published color criteria,
Class 0。Class IIのTslope
IIに近いClassI 170 Class II, 27 Flat SED,of thespectral energy distribution.
We identified
bolはT
eﬀに依る。Classand 45 Class 0/I sources. High angular resolution near-infrared observations
はedge-on。
of the RNO 7 cluster, embedded in L1340, revealed eight new young stars of
YSOの数密度とclumpに相関。
near-infrared excess. The surface density distribution of young stellar objects
shows three groups, associated with the –threemajor molecular clumps of L1340,
42 –each consisting of ! 100 members, including both pre-main sequence stars andembedded protostars. New Herbig–Haro objects were identified in the Spitzer
images. Our results demonstrate that L1340 is a prolific star-forming region of
our Galactic environment in which several specific properties of the intermediatemass mode of star formation can be studied in detail.

赤が原始星。
青がPMS。

Fig. 3.— WISE 4.6 µm (blue), 12 µm (green), and 22 µm (red) composite image of L1340.
Konkoly Observatory, Research Centre for Astronomy and Earth Sciences,
Hungarian Academy of SciThe size of the image is 1 square degree, and is centered on RA(J2000) = 37.◦ 625, Dec(J2000)◦
ences, H-1121 Budapest, Konkoly Thege út 15–17, Hungary= +72. 933. Small groups of 22-µm sources point to the three star-forming clumps of L1340.

1

2

The extended 12 µm emission (the Swan nebula) is excited by the B and A type stars
associatedwith L1340IL
B. Theannotated
Astronomy Department, Adler Planetarium, 1300 South Lake Shore Drive,
Chicago,60605
USAobjects are the most striking signposts of low-massstar formation: IRAS 02224+7227 is a FUor-like star (Kun et al. 2014), IRAS 02249+7230

3

is a protostellar
sourceAvenue,
exciting HHChicago,
489, RNO 7, RNO 8, and RNO 9 are nebulous, partiallyDepartment of Astronomy and Astrophysics, University of Chicago, 5640
South Ellis
embedded stellar groups, and V1180 Cas is an eruptive star (Kun et al. 2011).
IL 60637 USA

4

THE YOUNG STELLAR POPULATION OF LYNDS 1340. AN
INFRARED VIEW

arXiv:1602.08053v1 [astro-ph.SR] 25 Feb 2016

1

2,3

1

4

5

の続き

6

M. Kun , G. Wolf-Chase , A. Moór , D. Apai , Z. Balog , J. O’Linger-Luscusk , G.
Moriarty-Schieven7

kun@konkoly.hu
clumb BではA-B starsがdust clump ﬁlamentに一致。ジーンズ長。
A starsのfeed back。西が若い。
ABSTRACTSFEはclump Aで17%、Bで3%。

– 59 –

We present results of an infrared study of the molecular cloud Lynds 1340,
forming three groups of low and intermediate-mass stars. Our goals are to identify
他の中質量星形成領域と比べてclump
Bの星は離れている。
and characterise the young stellar population of the cloud, study the relationships
clump Bの中ではYSOは小さいclumpででき、光度の大きい星がいbetween the properties of the cloud and the emergent stellar groups, and integrate
L1340 into the picture of the star-forming
activity of our Galactic environment.
る大きいclumpは分裂している。
– 59 –We selected candidate young stellar objects from the Spitzer and WISE databases using various published color criteria, and classified them based on the
いくつかの中質量星形成領域は銀緯>10°にあり、GMCをともなわ
slope of the spectral energy distribution. We identified 170 Class II, 27 Flat SED,
45 Class 0/I sources. High angular resolution near-infrared observations
ない。expanding andsupershellもないので他のプロセスが必要。
of the RNO 7 cluster, embedded in L1340, revealed eight new young stars ofnear-infrared excess. The surface density distribution of young stellar objects
shows three groups, associated with the three major molecular clumps of L1340,– 59 –
each consisting of ! 100 members, including both pre-main sequence stars andembedded protostars. New Herbig–Haro objects were identified in the Spitzer
images. Our results demonstrate that L1340 is a prolific star-forming region of
our Galactic environment in which several specific properties of the intermediatemass mode of star formation can be studied in detail.
1

Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, Hungarian Academy of SciFig. 33.— A multi-wavelength view of the central, 17.16′ × 9.3′ area of tences, H-1121 Budapest, Konkoly Thege út 15–17, Hungary

青が24 µm, 緑が70
青がA-B stars
緑が8 µmでA starsに
cores (Paper II, green circles) and the contours of 850-µm emission (purpµm,
赤が800 µm
Department of Astronomy and Astrophysics, University of Chicago, at
5640
30, South
60, andEllis
120 Avenue,
Jy beam Chicago,), overplotted on the extinction map. C
紫が850
µmUSA
付随したbow shock ciated with tenth-of-parsec scale density enhancements, and a bubble-li
IL 60637

L1340 B. The upper panel shows the positions of the B–A type stars (

2

3

4

infrared sources(reddots), Flat SED (orange squares), Class
Astronomy Department, Adler Planetarium, 1300 South Lake Shore Class
Drive,0/IChicago,
IL 60605
USA−1

by submm emission around an A-type star can be seen. The middle pa