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 determine
withintheannuli,we
first
identifromN26%
for0.1—0.5Mstars,
to44%
for0.7—1.3M
comp⊙⊙or more stars (Reipurth et al. 2014), or from changes inand finally sources
to 60% for 8—16
M⊙ stars (Lada
fied a sample stars,of primary
by selecting
the2006;
Spitzerthe binding mass due to the ejection of gas in protostellar
Duchêne & Kraus 2013).
envelopes by outflows (Connelley et al. 2008b).
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 toform 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. Obser2011). The
number of companions
overwhichthe totalthe
numberages and extended
nebulous
sources incentralvations 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 ) 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

AN HST SURVEY FOR 100-1000 AU COMPANIONS AROUND YOUNG STELLAR OBJECTS IN THE ORION
MOLECULAR CLOUDS: EVIDENCE FOR ENVIRONMENTALLY DEPENDENT MULTIPLICITY
M. Kounkel1 , S. T. Megeath2 , C. A. Poteet3,4 , W. J. Fischer5 , L. Hartmann1

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

Draft version February 25, 2016

ABSTRACT
We present a near-IR survey for the visual multiples in the Orion molecular clouds region at separations between 100 and 1000 AU. These data were acquired at 1.6 µm with the NICMOS and WFC3
cameras on the Hubble Space Telescope. Additional photometry was obtained for some of the sources
at 2.05 µm with NICMOS and in the L′ -band with NSFCAM2 on the IRTF. Towards 129 protostars
and 197 pre-main sequence stars with disks observed with WFC3, we detect 21 and 28 candidate companions between the projected separations of 100—1000 AU, of which less than 5 and 8, respectively,
are chance line of sight coincidences. The resulting companion fraction (CF ) after the correction for+1.2
the line of sight contamination is 14.4+1.1−1.3 % for protostars and 12.5−0.8 % for the pre-main sequencestars. These values are similar to those found for main sequence stars, suggesting that there is little
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
based on the surrounding surface density of YSOs, we find that the CF in the high stellar density
regions (ΣY SO > 45 pc−2 ) is approximately 50% higher than that found in the low stellar density
regions (ΣY SO < 45 pc−2 ). We interpret this as evidence for the elevated formation of companionsat 100 to 1000 AU in the denser environments of Orion. We discuss possible reasons for this elevatedformation.
Subject headings: (stars:) binaries: visual — stars: formation — stars:protostars,T Tauri — infrared:stars —ISM:individual(Orion A) — ISM:individual(Orion B)
1. INTRODUCTION

Multiplicity is a common property of stars that influences both the future evolution of a star and its potential to host habitable worlds (e.g. De Marco 2009; Smith
2014; Wang et al. 2014). Roughly one third of all fieldstars are multiple systems instead of single stars, with thefraction of multiple systems increasing with stellar mass,from 26% for 0.1—0.5 M⊙ stars, to 44% for 0.7—1.3 M⊙stars, and finally to 60% for 8—16 M⊙ stars (Lada 2006;
Duchêne & Kraus 2013).
Spatially resolved images of pre-main sequencestars and protostars show that most stars probably
form in multiple systems (Reipurth & Zinnecker 1993;
Haisch et al. 2004; Connelley et al. 2008a; Kraus et al.
2011). The number of companions over the total numberof primaries and single stars (referred to as the companion fraction or CF ) is observed to be high for protostars.
The CF ranges from 0.91 for Class 0 protostars to 0.5
for the more evolved Class I protostars, as measured overa separation range of 50 to 5000 AU (Connelley et al.
2008b; Chen et al. 2013; Reipurth et al. 2014). After the
protostellar phase, pre-main sequence stars can still showa high incidence of multiplicity. For example, the CF

Molecular Cloud is 0.47 over a range of 18 to 1820 AU.
This is 1.9 times higher than that for solar-type field stars
in that separation range (Leinert et al. 1993). The implied decline in the observed companion fraction over thisseparation range with evolution may come from changes
in the orbital parameters and potential ejection of companions. These changes could result from the formationof the companions in non-hierarchical systems with threeor more stars (Reipurth et al. 2014), or from changes inthe binding mass due to the ejection of gas in protostellar
envelopes by outflows (Connelley et al. 2008b).
Since many stars form in young clusters, interactions
with other stars in these clusters are also thought toplay a significant role in determining both the fractionof multiple systems and the companion fraction. Observations of young stars in both low stellar density associations, such as that in the Taurus Molecular Cloud,and in the dense young clusters, suche5.9(r)-.1201-16.699957229(n)0.9 4(.9(4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

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

Draft version February 19,
10 2016

ABSTRACT
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 etal. (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
1. INTRODUCTION

Approximately a half of Sun-like stars belong to binaryor higher order multiple systems (Raghavan et al. 2010),
and this fraction increases for more massive primaries(e.g. Duquennoy & Mayor 1991; Kouwenhoven et al.
2007; Rizzuto et al. 2013).
Observations of several
nearby non-clustered star-forming regions and associations revealed that they contain a larger fraction of themultiple systems as compared with the significantly more
evolved field stars on the other hand, high-resolution
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

reexamine the environmental dependence on the evolution of the multiplicity. Constructing a better definedsample of the close binary systems that can be obtained
through multi-epoch spectroscopic monitoring is an important step in this process.
In addition, identifying spectroscopic binaries and removing them from the sample in the kinematic studies of star forming regions can help refine tests of cluster formation. There is debate over whether clusters
form in a slow process, taking place in clouds initially supported by supersonic turbulence (e.g. Tan et al.
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

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

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
andBo ReipurthInstitute for Astronomy, University of Hawaii at Manoa, 640 N. Aohoku Place, Hilo, HI
96720, USA
Received / Accepted
ABSTRACT
We have performed an optical spectroscopic and photometric search for youngstellar objects associated with the molecular cloud Lynds 1340, and examined thestructure of the cloud by constructing an extinction map, based on SDSS data.
The new extinction map suggests a shallow, strongly fragmented cloud, having
a mass of some 3700 M⊙ . Longslit spectroscopic observations of the brightest
stars over the area of L1340 revealed that the most massive star associated with
L1340 is a B4 type, ∼ 5 M⊙ star. The new spectroscopic and photometricdata of the intermediate mass members led to a revised distance of 825+110−80 pc,and revealed seven members of the young stellar population with M ! 2 M⊙ .
Our search for Hα emission line stars, conducted with the Wide Field Grism
Spectrograph 2 on the 2.2-meter telescope of the University of Hawaii and covering
a 30′ × 40′ area, resulted in the detection of 75 candidate low-mass pre-main
sequence stars, 58 of which are new. We constructed spectral energy distributionsof our target stars, based on SDSS , 2MASS , Spitzer , and WISE photometricdata, derived their spectral types, extinctions, and luminosities from BVRIJ
fluxes, estimated masses by means of pre-main sequence evolutionary models,

–の続き
36 –

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