Star Forma)on Newsle0er#285 11-15
麻生 有佑

Water around IRAS 15398–3359 observed with ALMAP. Bjerkeli1,2 , J. K. Jørgensen1 , E. A. Bergin3 , S. Frimann1 , D. Harsono4 , S. K. Jacobsen1 ,3
8
J. E. Lindberg5 , M. Persson4 , N. Sakai6 , E. F. van Dishoeck4,7 , R. Visser
P. Bjerkeli,, etS.
al.:Yamamoto
Water around IRAS 15398–3359 as observed with ALMAP. Bjerkeli, et al.: Water around IRAS 15398–3359 as observed with ALMA

Ø accre)on historyØster Voldgade 5–7, 1350 Copenhagen K., Denmarkß化学。冷却は100-1000年。
e-mail: per.bjerkeli@nbi.dk
2
Department of Earth and Space Sciences, Chalmers University of Technology, Onsala Space Observatory, 439 92 Onsala, Sweden
Ø FU 3Oriより若くてもバーストするか。
Department of Astronomy, University of Michigan, 1085 S. University Ave., Ann Arbor, MI 48109-1107, USA
4
Leiden Observatory, Leiden University, Niels Bohrweg 2, 2333 CA, Leiden, the Netherlands
Ø IRAS
15398-3359, Lupus I, Class0, 1.8 Lo,
5NASA Goddard Space Flight Center, Astrochemistry Laboratory, Mail Code 691, 8800 Greenbelt Road, Greenbelt, MD 20771,
USA
WCCC。H13CO+
3-2で今のLに対して大きい
6
The Institute of Physical and Chemical Research (RIKEN), 2-1, Hirosawa, Wako-shi, Saitama 351-0198, Japan
7
Max-Planck-Institut für Extraterrestische Physik, Giessenbachstrasse 2, 85478, Garching, Germany
穴。分子流,にもイベントあり。
8.06158v1 [astro-ph.SR] 22 Aug 2016

spectrum represents the average of the emission within 100 from1
Centre for Star and Planet Formation, Niels Bohr Institute & Natural
History
the central
position. Museum of Denmark, University of Copenhagen,Department of Physics, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan

Received 26 April 2016 / Accepted 1 August 2016

Ø ALMA Cycle 2, HDO (101-000) 465 GHz Eu=22
ABSTRACTK, H218O (414-321) 391 GHz Eu=390 K, θ~0.5”,
Context. Understanding how protostars accrete their mass is one of the fundamental problems of star formation. High dust column~5”をカバー。
densities and complex kinematical structures make direct observations challenging. Moreover, direct observations only provide aspectrum represents the average of the emission within 1 from+の穴の中snapshot. 13
Chemicaltracers provide analternative to characterise the infall histories of protostars.
the central
position.
Ø HDOはH
CO&interesting
CH3OH分子流。
Aims. We aim to map the distribution and kinematics
of gaseous water towards the low-mass embedded protostar IRAS 15398–3359.
P. Bjerkeli, et al.: Water around IRAS 15398–3359 as observed with ALMA00

Fig. 2. All spectra within 200 (100 for HDO (101 000 )) from thecentre of the map, averaged together. The vertical dashed line
represents the source velocity at LSR = 5.5 km s 1 .

Previous observations of H13 CO+ showed a depression in the abundance towards IRAS 15398–3359. This is a sign of destruction ofP. Bjerkeli,
et al.: Water around
IRAS 15398–3359
as observedinwith+
HCO+ by an enhanced presence of gaseous water in an extended
region,relatedto Ha13 CO
recenttheALMA
accretion. Direct
HDO ispossibly
detected in theregion whereis not burst
detected
+
(see
Fig.
3,
and
Jørgensen
et
al.
2013,
their
Fig.
1),
but
an
extenobservations of water vapour can determine the exact extent of the emission
andconfirmthehypothesis
that
HCO
is indeed a goodsion of the HDO emission towards the south-west of the H13 CO+
tracer of the water snow-line.
ring is visible as well. The extent of this emission is ⇠300 AU
and follow the cavity walls of the blue-shifted outflow outlined
Methods. IRAS 15398–3359 was observed using the Atacama Large
Array(ALMA)
at 0.500 resolution
by theMillimeter/submillimeter
CH3 OH emission. Furthermore, a red-shiftedcomponent
Fig. maps
3. HDO emission(black)comparedto the H13 CO+ centre
emissioFig.
1.
Continuumandintegrated
line
emission
towards
IRAS
15398–3359,
18
the3
outflow
lobe atthe 4 level. This (brown,
panel) and the CH
in two setups at 390 and 460 GHz. Maps of HDO (101 000 ) and His2 observed
O=(4
taken
simultaneously
withupper
observationsof
3 OH emission
0red-shifted
1 (green, low
14in 0921 ) 00were
–34
06.7
.
The
lines
are
integratedoveravelocity
range
of
=
0.75
km
s
(exceptfofeature is spatially coincident with the emission knot observed panel) presented in Jørgensen et al. (2013). Contours are fro
18N2 H+ (5–4) lines and continuum at 0.65 and 0.752000
the CS (8–7) andmm.
TheCOmaps
were
using
dust
radiative
18 1 . The transfer
in high-velocity(2–1) (Bjerkeli
et interpreted
al. 2016,
their
Fig.
3) and3 . insteps
oncontinuum
peaklevel
is indicatedwithindic
a starhas
beenused).
Contours
are
from
3
in
steps
of
1
For
H
O
and
CS,
the
2
is
also
2
the separation to the central source is ⇠500 AU. In Fig. 4 we plot
calculations of2the protostellar infalling envelope with an outflow cavity.
red
shadedonly
regionsmarkintegrated
the directions
the and
3.5 bluelevel contours
for emission
over di↵er-of the outflow cones (same geometry as in the mo
13+
ent
at higher
velocitywithto reported
90-percent
levelofEmission
the beamprofileis indicatedwitha circlein eachpanel.
Theatbeam
is shownth
Results. HDO is clearly detected and extended over the scales of the
Hvelocity
COintervals.
depression,
althoughitisrespect
displacedbyby⇠500
AU
theJørgensen
et al.in(2013)
345 GHz,
where theinbea
the systemic
velocity
are indicatedin this figureby
withdarker red
size wasfrom
similar.theThe largest
recoverable scales in the observ
The
continuummaps
are zoomed-ina factorofabsent
two.
direction of the outflow. H18
Oistentatively
detected
towards
thered-shifted
outflowlobe,
butotherwiseitismappedand blue than the lower velocity emission. Comparing di↵erent tions presented here range from 4 – 500 . We therefore cannot ex2velocityentirely
bins in this way
shows a possible
gradientorigin,in the mappedthat emission
the ambient envelope is resolved ou
region, which suggests that temperatures are low. Although we cannot
excludea shock
this clude
indicates
thatfromanotherregion.1.
In ALMA
general, emission
at higher velocities is detected at and some low-level extended emission is observed. The lowe
Tableobservations.
process is responsible for the water emission.
greater distances from the source than at lower velocities.
contours of the emission presented in Fig. 1 should therefore b
The H18321 ) line models,in contrast to we
HDOconclude
is not detected thatconsidered
as unreliablebecausespacing data.
2 O (414
Conclusions. Based on the temperature structure obtained from dusttowards
radiative
transfer
thefrequency
water
wasBandwidth
mostwe lack shortLine+
thewindow
protostar. There
are twooftentative
featuresin the out- Center
Spectral
Numberchannels/ resolution
The N
2 H (5–4) line at 465.825 GHz is detected towards thflow lobes,
but onlyat the 3 accretionlevel. The north-easternthese islikely released from the grains in an extended hour-glass configuration
duringa recent
burst. ofHDO
only
detectedinthecavity walls in the red-shifted outflow lobe and in a series oknots is located downstream of the feature detected in knots in the cavity wall and inner regions of the blue-shifted ou
HDO setting:region closest to the protostar, at distances of up to 500 AU. These emission
signatures
has recently
HDO(101 000 ). can only be explained if the luminosity+
flow lobe. GHz
No emission 234.375
is detectedMHz
towards theitsel
960 / 244.141 kHz
465.818
Nprotostar
2 H (5–4)
A clear velocity gradient is visible in this dataset, and higher v
been increased by orders of magnitudes. Additionally, the densities in01 the outflow conesmustbesufficiently
low.
960 / 244.141 kHz
464.928 GHz
234.375 MHz
HDO (101 0

H

O <3σ

回転

加速

3.5σ contours

3.2.
2 Continuum and other128lines/ 15625.000 kHz

locities are detected farther away from the central source tha

465.000 GHz

2000.000 MHz

Continuum

close to the outflow launching region (Fig. 4).
Key words. ISM: individual objects: IRAS 15398 – ISM: molecules– ISM:is detectedjets and– Stars:formation– isStars:
18continuumThewith aoutflows
peak flux of 36±1
mJy beam 1
CS (8–7)
detectedwinds,
towards IRAS 15398–3359, and th

Water around IRAS 15398–3359 observed with ALMAP. Bjerkeli1,2 , J. K. Jørgensen1 , E. A. Bergin3 , S. Frimann1 , D. Harsono4 , S. K. Jacobsen1 ,J. E. Lindberg5 , M. Persson4 , N. Sakai6 , E. F. van Dishoeck4,7 , R. Visser3 , S. Yamamoto8.06158v1 [astro-ph.SR] 22 Aug 2016

1の続き

P. Bjerkeli, et al.: Water around IRAS 15398–3359 as observed with ALMA

Centre for Star and Planet Formation, Niels Bohr Institute & Natural History Museum of Denmark, University of Copenhagen,Øster Voldgade 5–7, 1350 Copenhagen K., Denmark
e-mail: per.bjerkeli@nbi.dk
2
Department of Earth and Space Sciences, Chalmers University of Technology, Onsala Space Observatory, 439 92 Onsala, Sweden
18
11
–3
3
Departmentof Astronomy, University of Michigan, 1085 S. University Ave., Ann Arbor, MI 48109-1107, USA
2
4
Leiden Observatory, Leiden University, Niels Bohrweg 2, 2333 CA, Leiden, the Netherlands
5NASA Goddard Space Flight Center, Astrochemistry Laboratory, Mail Code 691, 8800 Greenbelt Road, Greenbelt, MD 20771,
USA
6
The Institute of Physical and Chemical Research (RIKEN), 2-1, Hirosawa, Wako-shi, Saitama 351-0198, Japan
7
Max-Planck-Institut für Extraterrestische Physik, Giessenbachstrasse 2, 85478, Garching, Germany
8
Department of Physics, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan

Ø 穴の中はバーストシナリオでOK。
Ø H O <3σ à RADEX ànT<10 cm K。
Ø 分子流部分はショックにしてはHDOの線幅(~1 km/s)が小さい。
+中心星付近しかHDOがないのはおかしい。
Ø 分子流部分もバーストシナリオだろう。
Ø RADMC, infall model (Mo0ram+’13), p=–1.4, Rout=1000 AU。
Received 26 April 2016 / Accepted 1 August 2016
Ø 球状à分子流で拡大àH13CO+の中心が星。HDOが遅い(~1 km/s)。à✕ABSTRACTØ 分子流があって密度が<105 cm–3ならOK。

Fig. 4. 3.5 levelin di↵erent
velocity intervals
from theaccrete
systemictheirvelocity
the lowest problems
velocities areContext.
Understanding
howo↵set
protostars
mass(seeis inset).
one ofFortheHDO,
fundamentalof star formation. High dust column
towards the central
regionandand complex
slightly displaced
into thestructures
blue-shiftedmake
outflow.
Highervelocities arechallenging.
furtheroutaroundin bothP.detected
Bjerkeli, etal.: Water
IRAS
15398–3359
as observed with
ALMA
densities
kinematicaldirectobservations
Moreover,directobservations
only
provide aoutflow lobes.snapshot.
The 465 GHz(for HDO)
and 403
GHz (forand N2 H+ )alternative
continuum istoplottedwith black
contours.
The extentof
of protostars.
Chemicaltracers
provideanCSinteresting
characterise
theinfallhistories
noise ratio attained for HDO) assume that this is an underestithe outflow is indicated in gray.

à分子輝線観測でhistory。
Aims. We aim to map the distribution and kinematics of gaseous water towards the low-mass embedded protostar IRAS 15398–3359.
mation by a factor of two, velocities are still on the lower end.

We therefore
concludethat this towards
is most likely
not themain cause
Previous observations of H13 CO+ showed a depression
in theabundance
IRAS
15398–3359.
This is a sign of destruction of
the anextendedemission.
HCO+ by an enhanced presence of gaseous waterof inextendedregion, possibly related to a recent burst in the accretion. Direct
observations of water vapour can determine the exact extent of the emission and confirm the hypothesis that HCO+ is indeed a good
4.2.3. Water sublimation in low-density outflow
tracer of the water snow-line.
anotherpossibility
is thatMillimeter/submillimeterwater was released from the grainsArray (ALMA) at 0.500 resolution
Methods. IRAS 15398–3359 was observed usingYetthe
AtacamaLarge
at the time when the protostar
18 underwent a luminosity burst, but
in two setups at 390 and 460 GHz. Maps of HDO(1the000 ) out
andto H
(414occurred
321 )waswere
taken
simultaneously with observations of
01 distance
that
where
changedsignifi2 Othis
the CS (8–7) andat compared
0.65 and
0.75is expected
mm. Thewere interpretedusing dust radiative transfer
cantlyto whatfor amaps
simple power-law
den5 N2 H+–3(5–4) lines and continuum
sity profile.
If densities
are lower in the inner parts of the outflow
calculations of the protostellar infalling envelope withan outflow
cavity.
cavity, then the 100 K radius13can be+ changed significantly com4 clearly–3detected and extended over
Results. HDO isthescalesof theonly
H anCO
depression,
althoughpared
to thecase whereenvelope
is present. To
test that, it is displaced by ⇠500 AU in the18
we adopted
a modelsimilar to the one
presented
in Bjerkeli
et al.
direction of the outflow. H2 O is tentatively detected
towards
the red-shifted
outflowlobe,
but otherwise
it is absent from the mapped
Model M3).
geometryof the model
presented
in that origin, this indicates that anotherregion, which suggests that temperatures are low.(2016,
AlthoughweThecannotentirely
excludea shock
paper resembles the structure of the emission and the observed
process is responsible for the water emission.
line profiles well, both the large-scale CO outflow and the smallC2 H emission,
tracing
the outflow
cavity walls(Jørgensen
Conclusions. Based on the temperature structure scaleobtainedfrom dust
radiative
transfermodels,we conclude that the water was mostet al. 2013).
The infalling envelope
profileaccretionin this caseburst. HDO is only detected in thelikely released from the grains in an extended hour-glass
configuration
duringdensity
a recent
is the same as before, but we also included an outflow that isregion closest to the protostar, at distances of up describedto 500 AU.
These signatures
onlytheir
beFig.
explained
if the luminosity has recently
by a wind-driven
shell (Lee etcan
al. 2000,
21).
The details
this system.
model
beoutflow
found inshow
Bjerkelietal. (2016).
been increased
by ordersmagnitudes.
Additionally,
the densities
incan
the
cones
beatsufficiently low.
Fig. 5. 100 K distancefrom the protostar
as aoffunctionof the angle
to the mid-planeof theThe
curvesthe must
distance

破線: HDO最遠

球エンベロープ+分子流 (10 cm )〃(10 cm )破線: HDO最遠on theavailable
data towards
IRAS 15398–3359
we canwhich the temperature drops below 100 K for three di↵erent scenarios. InBasedthe first
scenario(blue),
a pure envelope
density profile5
not estimate
density
the–added
gas
insidethemodel.
outflowcone,and – Stars:formation – Stars: winds,
ISM: (black),
individual
objects:–density
ISM:theISM:
jets
and outflows
is considered. Key
In the words.
second scenario
an outflow
coneIRAS
with a 15398
constant
atmolecules
10
cm of3 isto theThethird

1. Light curve of Z CMa inferred from AAVSO observations. The spectroscopic observations of the H
The 2008 outburst in theFig.
SystemCMainYoung
the figure. TheStellar
dashed zone corresponds
to theZ2008
outbust of the system.

III - Multi-epoch high-angular resolution
andspectraof thecomponents
Table images
1. Observing log.
Sr-2.2µm
corresponds
to the Strehl
ratio measured at 2.2µm.
in near-infrared
UT DateNameInstr.

Filter (Grism)

Camera3 , M. Benisty1,2 , G. Duchêne1,2,4 , J. Bouvier
1,2 , P. J. V.
M. Bonnefoy1,2 , G. Chauvin1,2 , C. Dougados1,2 , Á. Kóspál
2009-01-31
Z CMa
NACO
J, H, K s , L0
S13, L27
0
7 , and L. Podio
7
NACO
J, H, K s , L
S13, L27
Garcia5 , E. Whelan6 , S. AntoniucciHD54335

2009-02-06

Z CMa
SINFONI
J
0.025
Z CMa
SINFONIH
0.025
Univ. Grenoble Alpes, IPAG, F-38000 Grenoble, France
Z CMa
SINFONIK
0.025
2
CNRS, IPAG, F-38000 Grenoble, France
2009-01-28
HIP072241
SINFONIJ
0.25
e-mail: mickael.bonnefoy@obs.ujf-grenoble.fr
2009-02-22
HIP054970
SINFONIH
0.25
3
2009-02-07
HIP071218
SINFONI of Sciences,K
Konkoly Observatory, Research Centre for Astronomy and
Earth Sciences,
Hungarian Academy
PO Box 67,0.25
1525
Budapest, Hungary
2009-02-26
Z CMa
NACO
J, H, K s , L0
S13, L27
4
Astronomy Department, UC Berkeley, 501 Campbell Hall, Berkeley CA 94720-3411,
HD54335 USA
NACOJ, H, K s , L0
S13, L27
5
Universidade do Porto, Faculdade de Engenharia, Rua Dr. Roberto
Frias,
s/n,
P-4200-465
Porto,
Portugal
2009-03-11
Z CMa
NACO
J, H, K s , L0
S13, L27
6
Department of Experimental Physics, National University of Ireland Maynooth,Maynooth,
Co. Kildare,J,Ireland
HD54335
NACO
H, K s , L0
S13, L27
7
INAF - Osservatorio Astrofisico di Arcetri - L.go E. Fermi 2009-12-07
5, I-50125 Firenze,
Italy
Z CMa
NIRC2
Jcont , Hcont , Kcont
9.96mas/pix
HIP33998
NIRC2
Jcont , Hcont , Kcont
9.96mas/pix
1Exp. Time

Sr-2.2µm

90s
90s
240s
240s
240s
10s
12s
10s
90s
90s
90s
90s
8.6s
8.6s

(32%)
22%
n.a.
n.a.
n.a.
n.a.
n.a.
n.a.
(42%)
41%
(41%)
34%
45%

rXiv:1608.08035v1 [astro-ph.SR] 29 Aug 2016

Ø CMa OB1 associa)onのPMS binary Z CMa=FU Ori+Herbig Be (~0.11”), d=450-1100 pc,
EX Ori burst (‘87, ‘00, ‘04, ‘08, ‘11, ‘15, ‘16)。
Ø Oumlow (3.9 pc) ß HBeのwiggling jet。FUORにもtwin jet。HBeにdust cocoon。
Ø bipolar wind (Brγ)àmass lossà変光 vs. cocoonの減光変化(偏光観測)à変光。
Received April 12, 2016 ; acceptedKeck/NIRC2+OSIRIS,
June 22, 2016
Ø JHK, VLT/NACO+SINFONI,
R~4000。
M. Bonnefoy et al.: Multi-epoch images and spectra of the components of Z CMa in the near-infrared during the 2008 outburst

6

ABSTRACT

HBe

K (mag)OSIRISSINFONIP1640

NIRSPEC

FUOR

KH(mag)(mag)

Visual Magnitude

KH(mag)(mag)

Anto.+09

K (mag)telescope (van Dam et al. 2004). W
M. Bonnefoy et al.:Context.
Multi-epoch
imagesand spectraof the componentsof Z with
CMa aincurrent
the near-infrared2008
outburst
from 1.0 to 2.5 µm that clearly resolv
Z CMa
is a complex
pre-mainsequence binary
separation duringof 110the
mas,
known
to consist of an FU Orionis
the system with the facility AO-dedic
star (SE component) and an embedded Herbig Be star (NW component).
Although it represents a well-studied and characterized
108
10
a 1024 ⇥ 1024 detector for which w
Herbig2008theOutburst
system, the origin of photometric variabilities,
component properties, and the physical configuration of the system remain mostly
88
Fu Orimas pixel 1 scale and whose absolute
unknown.
0.13 ± 0.02 (Ghez et al. 2008). We u
Aims. Immediately when the late-2008 outburst of Z CMa was announced
to the community, we initiated a high angular resolution
6
6
10
Jcont , Hcont , and Kcont centered on 1.21
imaging campaign aimed at characterizing the outburst state of both components of the system in the near-infrared.
4
4
to avoid the saturation of the star. The
Methods. We used the VLT/NACO and the Keck/NIRC2 near-infrared
adaptive optics instrument to monitor the astrometric position
1
2 34
5
2
2
the near-infraredof thethe components
Z CMa components
outburst
phase
and
year
after. The VLT/SINFONI also
and reported in Table 1. Both compo
AMBER
M. Bonnefoy et al.:andMulti-epoch
images photometry
and spectra ofof Z CMaduringin thethenear-infrared
duringtheone2008
outburst
to determine the relative flux and posi
12
Keck/OSIRIS integral field spectroscrographs were in addition used to characterize for the first time the resolved spectral properties
10 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 20161010
10of the FU Orionis
and the Herbig Be component during and after theoutburst.
Date (years)
Herbig2008
Outburst
8
Results. We confirm that the NW star dominates the system flux88in the 1.1-3.8 µm range and is responsible for the photometric
8
Fu OriFig.near-infrared
2. Left: VLT/NACO
K s -band
image
Z CMa onJanuray 2.3.
Fig. 1. Light curve of Z CMa inferred fromoutburst.
AAVSO observations.
The spectroscopic
observationsof the HBe and FUOR(R⇠2000-4000)
are reported
We extract
the first
medium-resolution(1.1-2.4 µm)
spectraof theofindividualcomponents.
The VLT/SINFONIin the figure.
of the system.
6 The dashed zone corresponds to the 2008 outbust
6 Right: Keck/NIRC2
631, 2009.
image on December
7, 2009.
6
SE component has a spectrum typical of FU Orionis objects. The
NW
component spectrum K
iscontcharacteristicof embedded
outbursting
We used the SINFONI instrument (STable 1. Observing
log. Sr-2.2µm corresponds
to the Strehland
ratio EXmeasured
2.2µm.
4
protostars
Oratobjects.
It displays numerous emission lines 44whose intensity correlates with the system activity. In particular,
4
Field Observations, see Eisenhauer e
2 33The5outburst of the NW component
1 and
weFilterfinda correlation
betweenthe Sr-2.2µm
Brof theequivalentwidth
the systembluingthe 5continuum
BonnefoyMulti-epoch
imagesspectracomponents
ofand
Z CMa
in thenear-infrared
theof2008
1
UT Date 2
Name
Instr. et al.:(Grism)CameraExp. Time
Airmass
Comment
2 M.
2 brightness.
2
44during22004), located at the Cassegrain focus
M. Bonnefoy et al.: Multi-epoch
imagesandspectraofthecomponents
of
Z
CMa
in
the
near-infrared
duringthe
2008
outburst
2.2.
Keck/NIRC2
along
theS13,absolute
flux
and color-variationof the system during the outburst suggests that the outburst was caused by a complex
2009-01-31
Z CMa
NACO
J, H, K with
,L
L27
90s
(32%)
1.19
observe Z CMa during the outburst p
10
10
HD54335
NACO
J,
H,
K
,
L
S13,
L27
90s
22%
1.25
psf-ref
10
10interplay
betweena variationof theextinction
the line of sightof the NW component on one hand, and the emission of shocked
101010
2008inOutburst
2009-02-06
Z CMa Herbig
SINFONI
J
0.025
240s
n.a.
1.05
On 10
December17, 2009 (transient phase), imaging observations The instrument provides AO-assisted i
Herbig88
2008
Outburst
Z CMa
SINFONI regionsH
0.025the NW240sn.a. on the
1.09 other.
Fu
Ori
close
to
componentWe
confirm
therecently
reported
wigglingoftheSE
component
jetfrom[FeII]
8 obtained using the AO system on the 10 m Keck II It uses a modified version of the Mu
8 Z CMa8
88
were8also
Fu Ori SINFONI K
0.025
240s
n.a.
1.22
We find a10s
point-like
2009-01-28 6 HIP072241
SINFONI line
J emission. 0.25
n.a.structure
1.06 associatedtelluric with a peak emission at 2.098µm coincidental with the clump or arm seen in
2009-02-22
SINFONI
H
0.25
12s
n.a.
1.09
telluric
66 emission along a PA=214 . The origin of these two structures
6 6 HIP054970
66
polarizationdi↵erential
as additional di↵use
2009-02-07
HIP071218
SINFONI broadband
K
0.25
10s
n.a.imaging
1.22as welltelluric
4
2009-02-26 4 Z CMa
NACO
H, K , L
L27
90s
(42%)
1.06
is J,unclear
and S13,deserves
further
investigation.
44
44
0

s

0

J, H, K s , L0
J, H, K s , L0
J, H, K s , L0
4
Jcont , Hcont , Kcont
Jcont , Hcont , Kcont

1

H (mag)
JH
(mag)
(mag)

H (mag)
JH
(mag)
(mag)

NACO
NACO
NACO
NIRC2
NIRC2

0

s

S13, L27
41%
1.11
psf-ref
1 90s
2 34
5
2
S13, L27 1 1 90s
(41%)
1.02
2233
4 4 sequence, individual55
Key words. Techniques:
resolution,
Binaries: general,(Z CMa)22
2 2Stars: pre-main
S13, L27
90shigh angular34%
1.04
psf-ref
444
4
5.48•10
5.49•10
5.50•1045.51•104
2009-12-07
9.96mas/pix
8.6s 5.0•10
1.29
4.0•10
4.5•105.5•1010109.96mas/pix
8.6s
45%
1.51
psf-ref
10
1010
10
JMD
−
2400000(day)
JMD − 2400000 (day)
8
8
88
88
telescope (van Dam of
et al.FUOR
2004). We component
obtained direct images
1.
Introduction
were able totoprevious
reproduce
the UV-optical spectrum by aFig. 4. Resolved
Naco
and
Keck
JHK
photometry
relativetothe
HBe comparedmeasurements
66authors
from 1.0 to 2.5 µm that clearly resolved the two components of66
6 6model of an optically thick accretion disk surrounding an 1the system withthe facility Koresko
AO-dedicated NIR
cameraNIRC2, Haas et(unresolved
components)
fromtheliterature(VDA4,
et
al.
1991;
al.
1993,
and
ref.
therein).
The
epochswith
Z Canis Majoris (Z CMa)a detector
complexpre-maina 1024 ⇥ is1024
for which
we used the sequence
9.963 ± 0.005 binary
4
43 M star with an accretion rate of 10 3 M .yr 1 . The model
2009-03-11 2

HD54335
Z CMa
HD54335
4
Z CMa
HIP33998s

K (mag)
HJK(mag)
(mag)
(mag)

K (mag)
HJK(mag)(mag)

バーストはHBeが支配。

バースト中を拡大

(black) compared to our best -fit model for an outer radius of theline-emitting region of 3.5 au (red).

The 2008 outburst in the Young Stellar System Z CMa
the same regions as they show both distinct emission profiles
III - Multi-epoch high-angularresolution images and spectra of the components(Sect. 5.1.2), and di↵erent behaviors with time (Sect. 5.1.5). It
Fig. 12. Profile of strong and weakly blended lines for the HBe is therefore
in likely
near-infrared
that simple models assuming constant densityの続き

and FUOR components. The black solid lines correspond to the and temperature are not an adequate representation of the HIM. Bonnefoyal.: Multi-epoch
imagesspectraof 1,2the componentsof Z1,2
CMa in the near-infrared
during1,2
the 2008 outburst 1,2,4
1,2 , and3 , M. Benisty
SINFONI(outburst)etdata,while
the golden
lines
correspondto Dougados
M.
BonnefoyG.
Chauvin, C.
, Á. Kóspál, G. Duchêne
J. Bouvier1,2 , P. J. V.
emitting medium.
Modelsof spherically expanding
wind in ,LTE
5 , E. Whelan6 , S. Antoniucci7 , and L. Podio7
the OSIRIS spectra (post-outburst).
both high Pa /Br ratios and flat HI excitation diagrams
OUTBURSTQUIESCENCEGarciapredict
1.0-5(Lorenzetti
et al. 2009; Antoniucci et al. 2011). The observed
AMBER
AMBER
Pa
flux
and
mass-loss rates 10 6
1
Univ. Grenoble Alpes,
IPAG, F-38000 Grenoble,1FrancePa /Br ratio would require
SINFONISINFONI
7-8–3
2. Full radiativetransCNRS, IPAG, F-38000
Grenoble, FranceM yr0.8and an envelope thickness > 100R
OSIRISOSIRIS
fer modelinga disk or
outflowmodel
would
be required,e-mail: mickael.bonnefoy@obs.ujf-grenoble.fr
M. Bonnefoyin
et eitheral.: Multi-epoch
imagesand spectraof thecomponentsof Z CMa in the near-infrared during the 2008 outburst-4
3
but Astronomy
thisthe scopeof thispaper. Academy of Sciences, PO Box 67, 1525
Konkoly Observatory, Research Centre forand Earth
Sciences,
Hungarian
0.6is beyond

-2

AMBER
SINFONIOSIRISdM/dtと関係。
0.0 areas around Herbig stars. They found that the regions
emitting
冪指数–1.25
ABSTRACT
also a characteristic feature of other EX Or (see Fig. 11). Eisnerlog(-1 x Equivalent width)-3cm àdisk表面かoumlowの根元。

OUTBURSTQUIESCENCE
Budapest, Hungary
1.0
-5
AMBER
Astronomy Department, UC Berkeley, 501 Campbell Hall, Berkeley CA 94720-3411,
USA
0.4
5
5.1.4.
ModelingoftheCO
emissionlines
SINFONI Porto, Portugal
Universidade do Porto, Faculdade de Engenharia, Rua Dr. Roberto Frias, s/n, P-4200-465
0.8
6OSIRIS Co. Kildare, Ireland
Department of Experimental Physics, National University of Ireland Maynooth, Maynooth,
-4
The
CO
overtones
seen
inemissioninthe
HBe
component
are7
INAF - Osservatorio Astrofisico di Arcetri - L.go
0.2E. Fermi 5, I-50125 Firenze, Italy
0.64

Equivalent width [Angstroms]

黒体Ø T~500-1000 K, n=10log(-1 x Equivalent width)rXiv:1608.08035v1 [astro-ph.SR] 29 Aug 2016

Equivalent width [Angstroms]

HI Bracke0 excita)on

Received April 12, 2016 ; accepted June 22,et2016
al. (2014) have used interferometry to resolve the CO line-3

0.4

of the disks emitting in the CO bandhead lines are located beEX Lupi
tween-0.2
0.05 and 2 au from the central star. We therefore modeled-1case B再結合
Context. Z CMa is a complex pre-main sequence binary with a current separation of 110 mas, known to consist of an FU Orionis
the CO lines of the HBe spectrum acquired in outburst follow-2

0.2

0.0
star (SE component) and an embedded Herbig Be star (NW component). Although it represents a well-studied
and characterized
ing thea -0.4similarapproach
as Kóspáletphysicalal. (2011b)
for EX Lupi.
system, the origin of photometric variabilities,
component
properties,
and theconfigurationof theThesystem remain mostly
CO disk -1
emission model and related fitting procedure are-0.2 de0
unknown.
scribedinAppendix
A.9.0We conclude
that theCOgas
4700 4800 Aims.
4900 Immediately
5000 5100
5200
5300 outburst
8.0
8.5 announced
9.5
10.0
10.5
11.0in ZaCMa
whenthelate-2008
of
Z
CMa
was
to
the
community,
weinitiatedhigh angular resolution
Fig. 13. H band HI BrackettMJD
excitation
diagram for the HBe of- 2 450000 [Days]
Visualmagnitude[mag]has
an excitation
temperatureof about
4300 ±in100
K, and-0.4 theimaging
campaign
aimedatcharacterizing
theoutburst
state
of
both
componentsofthesystemthenear-infrared.
ZCMa (circles). All line fluxes are normalized to the HI Brackett
0 density
columnis between
2⇥1018instrument
cm 2 and to2⇥1019 cm,
Methods. We used the VLT/NACO and theCO
Keck/NIRC2
near-infrared
adaptive
opticsmonitorthe 2astrometricposition
11 line. Open circles show the
lines
that
are
probably
contami4700 4800 4900 5000 5100 5200 5300
8.0
8.5
9.0
9.5
10.5
11.0
and
the
near-infrared
photometry
of
the
Z
CMa
components
duringtheoutburst
phase
and
one
year
after.
The
VLT/SINFONI
and 10.0
depending
on
the
disk
size.
Combinations
of
the
outer
radius
of
MJD
2
450
000
[Days]
Visualmagnitude
[mag]
Fig.
15. Blue
Declineof the Br
widthdetectedwith time (left)
and with the system V-band magnitude (right).
nated.
triangles
showequivalent
theline ratios
EX Lupi
Keck/OSIRIS
integral fieldinspectroscrographs
werein
additionusedtocharacterize
for
the
first
time
the
resolved
spectralproperties
the emitting disk region Rout and of the CO column density NCO(Kóspál et al. 2011b). The ofgreen
curvesareandpredictions
fromthe FU
Orionisthe Herbig Be
component
duringand after
the showoutburst.
give
similarfit. Wein Fig.
14timethe (left)best-fittingfor V-band magnitude (right).
4Fig.can15. Declineof the Br
equivalent
width
with
and withmodel
the systemcase B recombination from Hummer& Storey
forNW
T=10
Results. We
confirm(1987)
that thestar dominates
2.0
Rout =3.5theau.system flux in the 1.1-3.8 µm range and is responsible for the photometric8
3
7
K and n=10 cm (lower curve)
and
T=500
K and
n=10
outburst.
Wefor
extract
the first
medium-resolution(R⇠2000-4000)
near-infrared (1.1-2.4µm) spectra Aof=15
the individual components. The
AV=15
Herbig
Herbig
1 5
VWetherefore
concludethat theCO emission
canbe repro12
2.0
Fu
Ori raFuspectrum
Oricomponent
has a spectrum
typicalof FU Orionis
objects. The
NW component
is characteristicof embedded outbursting
cm 3 (upper curve).
dottedlines show
expected
line
AV=15The redSE
A =15exduced
to
first
order
by
the
emission
from
a
disk
model.
The
Herbig
5
A =15
1
2
1.5
10
protostars
and EX
objects.
It displays
lines
whose
intensity
correlates
withthesystemactivity. In particular,Herbig
tios from blackbody emission
at T=1000
K Or(lowercurve)and numerous emission
12
Fu
Ori
Fu Ori4
A =15
AV=10 temperature
citationisalmost2000
Khotterthan
theonederived
4
A
=10
we
find
a
correlation
betweentheBrequivalent
width
and
the
systembrightness.
ThebluingofthecontinuumoftheNW
component
3
2
1.5
10
V
T=10 K (upper curve).
4
A =10
for EX
Lup
by Kóspál(2011b)with thedisk
modelA =10
3 during etalong with the absolute fluxand color-variationof thesystemtheal.
outburst
suggests
thatsame
the outburst
was caused by a complex
AV=10
10
1 - Oct. 6, 1990
1.0
Aline
=10 of sight of the NW component
ing
procedure.
interplay
betweenavariationoftheextinction
in
the
on
one
hand,
and
the
emissionofshockedA=5
10V
2 - Jan. 31, 2009
1 - Oct. 6, 1990
1.0
4
AV=5
A =5
2 - Jan.
31, 20098reported wiggling
3 - regions
Feb. 26, 20094
close to the NW component on the other. We confirm
therecentlyof theSE component jet from [FeII]
A =581
3 - Feb. 26, 2009
reddening correction.
For4 -thePa11, line,
March
2009 we integrated the emis1
52
4 - March
11, 2009 at 2.098µm
line
emission.
We
findapoint-likestructureassociated
with
a
peak
emissioncoincidental
with the clump or arm seen in 2 5
A=1
AV=5 3
1V- Dec. 07,
2009
A =11
4
A =5 3
5
Dec.
07,
2009
A
=0
4
sion in0.5the same velocity 5range
asobserved
in
Br
,
that
is
beAV=1V
1 A =08
A =1variability
1
broadband polarization di↵erential
as 0.5wellSpectro-photometricas additional di↵use emission
along 8a APA=214. The origin of these two structures
2 imaging5.1.5.
A =0
V=0 2 45 4
52 km s 1 . This very high ratio is marginally2
tween -300 and +300
3
isunclearanddeserves
further
investigation.
3
1
Oct.
6,
1990
1 - Oct. 6, 1990
1
Oct.
6,
1990
1
Oct.
6,
1990
6
5
A =1
6
5
A =1
1
J (mag)[J-H]

V

H (mag)

V

V

V

V

V

Ø 減光の影響もあり、HBe jetのwiggling
やknotから降着/放出も関係。
VV

H (mag)VV

J (mag)[J-H]

Ø 赤化ベクトルの向きは減光変化。
Ø HBeの垂直は黒体の温度変化か。

V

V
V

Vwith case-B recombination and would exclude
1 spectroscopic
2 -2009
Jan. 31, 2009
5 2 - Jan. 31, 2009
3 1op4We
reportin Fig. 1 the dates of theobservations
4compatible
A 31,=0 2009
2 0.0- Jan.
31,
5321 - 4Jan.
4
3 - Feb. 26, 2009
3 - Feb. 26, 2009
0.0 AV=0
3 - Feb.Binaries:
26, 2009 general,
3 - Feb. 426,
2009
Key
words.
Techniques:highangularresolution,
Stars:
pre-mainsequence,
individual(Z
CMa)
Herbig
March
11,
2009
4
- March 11, 2009
5
of
the
HBe
on
the
light
curve
of
the
system.
6tically thick blackbody emission.
The limit for opticallythick2 4 - March 11, 2009
32
32
Herbig
4 - March
11,
5
Fu Ori5 - 2009
Dec. 07, 2009
5 - Dec. 07, 200963
3
2
5 -0.5- The
Dec. 07,2009
5 - Dec.
07, 2009
blackbody emission is Pa /Br Fu
 Ori
4 (Antoniucci et al. 2011).
low-resolution
spectrum (R⇠250)of thesystem
gath4
0
1
2
3
1
3
4
0
1
2
3
4
5
-0.5 it is not clear that the Pa and Br lines originate from44
However,
ered -1during
ourburst
by Antoniucci
et al.0 (2009)
also2 displays
H-K (mag)
-1
0
1
2
3
4
0
1
2
3
4[H-K]
0
1
2
3 J-H (mag)451.
Introduction
authors were able toH-Kreproduce
the UV-optical spectrum by a
[H-K]
J-H (mag)
(mag)
model
of NIRan opticallyaccretion
disk
an 1-state (1; October 1990
Fig. 16. Evolution of the FUOR
and HBe
colors and thickphotometrywhen Z
CMasurrounding
was in a quiescent
Z Canis Majoris (Z CMa) is a complex pre-main
sequence
binary(2-3-4;
1
10
observations),in outburst
NaCoofobservations
February 26, and March 11,
3 encircled
M star disks;with corresponding
an accretionto rate
10 3 M on.yrJanuary. The31,modelV
V

BANYAN. VIII. NEW LOW-MASS STARS AND BROWN DWARFS WITH CANDIDATE CIRCUMSTELLARDISKS.
A NNE B OUCHER1 , DAVID L AFRENIÈRE 1, J ONATHAN G AGNÉ 2,3 , L ISON M ALO4 , JACQUELINE K. FAHERTY2,5,6, R ENÉ D OYON1 , AND
C HRISTINE H. C HEN7
1 Institut de Recherche sur les Exoplanètes (iREx), Université de Montréal, Département de Physique, C.P. 6128 Succ. Centre-ville, Montréal,

QC H3C 3J7, Canada. boucher@astro.umontreal.ca

v:1608.08259v1 [astro-ph.SR] 29 Aug 2016

2 Department of Terrestrial Magnetism, Carnegie Institution for Science, 5241 Broad Branch Road NW, Washington, DC 20015, USAØ デブリ円盤や遷移円盤は3 NASA Sagan Fellow
4
substellarで少ない。 Canada-France-Hawaii Telescope, 65-1238 Mamalahoa Hwy, Kamuela, HI 96743, USA PT or WT
5 Department of Astrophysics, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10034
6 NASA Hubble Fellow andØ 惑星がいそう。星形成の7 Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA
lower limit。
Draft version August 31, 2016
TD的ABSTRACTØ Young Moving
Groupが対象。
We present
the results of a search for new circumstellar disks around low-mass stars and brown dwarfs with
spectral types >K5 that are confirmed or candidate members of nearby young moving groups. Our search input
Ø 10-250 Myr,
1600
sampleK5V-M5V,
was drawn fromthe BANYAN surveys of Malo et al. and Gagné et al. Two-Micron All-Sky Survey
andWide-field
Infrared
SurveyExplorer data were used to detect near- to mid-infrared excesses that would
天体, 2MASS,
WISE。
reveal the presence of circumstellar disks. A total of 13 targets
convincing excesses were identified:↙︎Wwith3とW4が2温度必要↗︎Ø WISEのW3,
four W4のexcessや目
are new and nine were already known in the literature. The new candidates are 2MASS J05010082–
4337102 (M4.5), J08561384–1342242 (M8 γ), J12474428–3816464 (M9 γ) and J02265658–5327032 (L0 δ),
視で13個円盤同定。
and are candidate members of the TW Hya (∼ 10 ± 3 Myr), Columba (∼ 42+6
−4 Myr) and Tucana-Horologium
(∼
45
±
4
Myr)
associations,withmasses
of
120
and
13–18
M
.
The
M8–L0
objects in Columba and TucanaJupØ そのうち4つは初、うち2つをHorologium are potentially among the first substellar disk systems aged ∼ 40 Myr. Estimates of the new
candidates’ mean disk temperatures and fractional luminosities are in the ranges ∼ 135−520 K and 0.021−0.15,
可視ESPaDOnS@CFHTと近赤
respectively. New optical spectroscopy of J0501–4337 reveals strong Hα emission, possibly indicating ongoing
FIRE@Magellan
Baadeで観
accretion, provides
a detection of lithium absorption
and a radial velocity measurement that is consistent
PT的TD orwithPTamembershiptoColumba.
We
also
presentanear-infrared
spectrumofJ0226–5327
thatreveals
Paschenβ測。
emission and shows signs of low surface gravity, consistent with accretion from a disk and a young age.
Subject headings: Circumstellar matter, Brown dwarfs, Stars: Low-mass, Protoplanetary disks, Infrared: Stars

Ø 4つともT Tauri的ではない。

1. INTRODUCTION

The presence of debris disks is a signpost of a past planetary formation (Zuckerman & Song 2004; Moór et al. 2011;
Raymond et al. 2011), whereas the presence of protoplanetaryor transition disks can be a sign of ongoing planetary formation (Espaillat et al. 2010; Kraus & Ireland 2011). Searchingfor circumstellar disks is thus an interesting way to identify
new exoplanets and study their formation. Disks are usuallymore amorphous (indicating a lesser amount of grain growth
and thermal processing). Since debris disks are colder (∼ 10–
100 K), their weaker excesses are mostly observable in the
mid-infrared (MIR) and beyond (> 20 µm; Rhee et al. 2007;
Schneider et al. 2012a; Liu et al. 2014). Transition disks (TD)are intermediate cases: they feature an inner region devoid ofwarm dust, and an outer region that still contains a significant
amount of dust. Transition disks display an excess startingttps://webcast.stsci.edu/webcast/detail.xhtml;jsessionid=201F62F7409A2DA45E9387E3E524CC72?talkid=2482&pa

BANYAN. VIII. NEW LOW-MASS STARS AND BROWN DWARFS WITH CANDIDATE CIRCUMSTELLAR−1
his analysis has yielded Hα10% = 210.7+7.6
and a DISKS.
Settl models (Baraffe et al. 2003; Allard et al. 2012).
の続きTh−2.2 km s

v:1608.08259v1 [astro-ph.SR] 29 Aug 2016

2,5,6by minimizing
respondingAaccretion
rate1 , of:best-fitting
model wasselectedχ2 over sev
NNE B OUCHERDAVID L AFRENIÈRE 1, J ONATHAN G AGNÉ 2,3 , L ISON
M ALO4 , JACQUELINE
K. FAHERTY, R ENÉ D OYON1 , AND
7
C HRISTINE H.
C HEN
eral
high-S/Norders, and was then Doppler-shifted (1 free pa
1 Institut de Recherche+0.07−1 (iREx), Université de Montréal, Département de Physique, C.P. 6128 Succ. Centre-ville, Montréal,
sur les Exoplanètes
rameter), convolved with a Gaussian instrumental line sprea
log10 Ṁac = −10.80−0.05 M⊙ yr QC. H3C 3J7, Canada.
(6)boucher@astro.umontreal.ca
2 Department of Terrestrial Magnetism, Carnegie Institution for Science, 5241 Broad Branch Road NW, Washington, DC 20015, USA
0501–––
RVはCOL
Myで、
function(42(1 Myr)を示唆。Li吸収から<50
free parameter for the Gaussian width)and mul
3 NASA Sagan Fellow−10501のHαtiplied with (45a linearslope (2 free parameters) to account fo
Natta et al. (2004) use a threshold4 Canada-France-Hawaii
of Hα10% ≥ Li
200
km s
EWはβPMGよりTHAMyr)を示唆。
Telescope, 65-1238 Mamalahoa Hwy, Kamuela,
HI 96743, USA
instrumental
effects.
TheNew
Interactive
Data Language (IDL
determine whether a 5substellar
low-mass
objectis acDepartment ofor
Astrophysics,
AmericanMuseumof Natural History,
Central Park Westat 79th Street,
York, NY 10034
6 NASAPa0226–––
βはガス降着を示唆。RVからTHA(45 My)。
Fellow andof the amoeba Nelder-Meaddownhill sim
ing; 99.3% of the Monte Carlo steps
described above re- Hubbleimplementation
7 Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA
plex algorithm (Nelder & Mead 1965) was used to minimiz
cted this criterion. In the present case, it cannot be Draft
ruled
version August 31, 2016
2
with certainty that the Hα emission is due totheχ/Ldifference
between the forwardØchromo4つともf=L>10–3なので<100Myr。 model and the data i
disk
IR
*
ABSTRACTeric activity rather than accretion.
fifteen 0.02 µm-wide windows regularly distributed betweeØ0856と1247はfWe
present
theresultsofasearchfornewcircumstellar
disks aroundlow-mass
disk>0.01なのでガスもありそう。
A radial velocity measurement was obtained from the FIRE
1.5100–1.5535µm instars
theandH brownband,dwarfs
wherewiththere is a large S/Nspectral types >K5 that are confirmed or candidate members of nearby young moving groups. Our search input
ctrum of J0226–5327,
using a forward modelingmethodanda good radial velocity information content. This metho
Ø surveys
0856はT
disk
sample was drawn from the BANYAN
of Malo
etが高いので穴はなさそう。1温度で合う0501
al. and Gagné et al. Two-Micron All-Sky Survey
ed on the zero-velocity,
solar Infrared
metallicity
CIFIST2011
and Wide-field
SurveyExplorer dataBTwere used to detect near- to mid-infrared excesses that wouldと0226は穴開きか。
reveal the presence of circumstellar disks. A total of 13 targets with convincing excesses were identified:
0501のリチウム吸収0501以外はM
MJでBDとしても小さい。
four are new and nine were alreadyØ
known
in the literature. disk
The=13-17
new candidates
are 2MASS J05010082–
4337102 (M4.5), J08561384–1342242 (M8 γ), J12474428–3816464 (M9 γ) and J02265658–5327032 (L0 δ),ØHya
これまでの<5
Myrに対して10-50
Myr。
and are candidate members of the TW(∼ 10 ± 3 Myr), Columba(∼942+6−4 Myr) and Tucana-Horologium(∼ 45 ± 4 Myr) associations, with masses of 120 and 13–18 MJup . The M8–L0 objects in Columba and Tucana-02265658–5327032: Horologium
Including the are
new potentiallyraamong the first substellar disk systems aged ∼ 40 Myr. Estimates of the newmeasurement to previous observables in thecandidates’
mean
disk
temperaturesand fractional luminosities are in the ranges ∼ 135−520 K and 0.021−0.15,
tool yields a probability of 99.96% that J0226–
respectively.
New optical spectroscopy of J0501–4337 reveals strong Hα emission, possibly indicating ongoingmember of the Tucana-Horologium
association
accretion,a detection of lithium absorption and a radial velocity measurement that is consistent witha most probable statisticaldistance ofprovides
43.4+2.8−2.4 pc
HA membership). Only aa trigonometricmembershipdistanceto Columba. We also present a near-infrared spectrum of J0226–5327 that reveals Paschen βt is needed to confirm thistarget asanda bonafide signs of low surface gravity, consistent with accretion from a disk and a young age.
emissionshows
HA. This very late-type object (L0 δ) is also one
Subject
w-surface gravity (δ) objects
fromheadings:
the BASS sur-Circumstellar matter, Brown dwarfs, Stars: Low-mass, Protoplanetary disks, Infrared: Starset al. 2016).
nce of Paβ emission is a sign of ongoing accremore amorphous (indicating a lesser amount of grain growthmeans that there is still gas in the disk, 1.
andINTRODUCTION
further
this Fbrowndwarf
isyoung.
This
targethasaW
4
and thermal processing). Since debris disks are colder (∼ 10–
IG . 3.— Top panel: Hα emission line of J05010082–4337102. Bottom
The line
presenceof datadebrisdisks is a signpost of a past planabsorption
forJ05010082–4337102.
Both butare consistent
ag inpanel:
thelithium
WISE
aperture
photometryset,
100 K), their weaker excesses are mostly observable in thewith a young age.
See Section
6.1 for more details.
formation(Zuckerman & Song 2004; Moór et al. 2011;
ofile-fit
one. etary
mid-infrared (MIR) and beyond (> 20 µm; Rhee et al. 2007;
n to the above
considerations,the presenceof the presence of protoplanetary
Raymondet al. 2011),
whereasThere are some discrepancies in the kinematics of this star
Schneider et al. 2012a; Liu et al. 2014). Transition disks (TD)ed emissionthesefour objects
providesorTWA,
transition
disks
canmembershipbe fura signof ongoing planetary formafrom that ofin
explaining
its modest
probare intermediate cases: they feature an inner region devoid ofe forability.
their This
youth:
Zuckerman&
Song(2004)
brown
dwarf could
be a memberof a& Ireland 2011). Searchingtion(Espaillat
et also
al.
2010;
Kraus
for J02265658–5327032.
young association
not stars
yet included
the >spatialkinemat- F IG . 4.— K I absorption lines and Pa β emissionwarm
al. (2006)
argue thatwith infdisk
10−3andare
dust, anddisk
an outer region that still contains a significant
The
Pa β emissionway
line is consistent
with the presence of a circumstellarforcircumstellar
disks
is
thus
an
interestingtoidentify
ics
modelsfrom
BANYAN
II,
such
as
the
Lower
Centaurus
100 Myr.
and a young age. See Section 6.1 for more details. amount of dust. Transition disks display an excess starting

0226のPa β

Crux (LCC)new
association(Gagné et al.
2016,
submitted).
exoplanets
and
study
theirLCC
formation. Disks are usuallymembers have similar UVW kinematics to those of TWA,

特に0501と0226はガスありとして極めて長生き。

Connecting low- and high-mass star formation: theintermediate-mass protostar IRAS 05373+2349 VLA 2

Connecting low- and high-mass star formatio

G. M. Brown,1? K. G. Johnston,1 M. G. Hoare1 and S. L. Lumsden1

Table 1. Summary of Continuum Observations.
1 School of Physics and Astronomy,
University of Leeds, West Yorkshire, Leeds LS2 9JT, UK
Wavelength

Array

Date ofNo. ofTime on-Synthesised

P.A

arXiv:1608.08677v1 [astro-ph.GA] 30 Aug 2016

observation
antennas source (hr) beam size (”) ( )1 September
2016
Ø 中質量星(2-8Mo)は橋渡し。
6 cm
VLA-C
12 Mar 2008 27 (24)
1.5
4.55 ⇥ 4.02
27
Ø energe)c collimated oumlows,
3.6 cmVLA-C
10 Mar 2008 26 (23)2.0
2.97 ⇥ 2.86
-13
ABSTRACT
1.3 cmVLA-C
10 Mar 2008 26 (21)
1.3
1.23 ⇥ 1.04
48
there havebeen few studies of the 15
protostellar
evolution ofintermediate中間的なinside out envelopes.Until recently,
2.7 mmCARMA-D 24 Apr 2007
5.7
4.92 ⇥ 4.28
78

Map rms(mJy beam 1 )
0.026
0.016
0.047
2.6

mass (IM) stars, which may bridge the low-and high-mass
regimes.lowThisandpaper
aims star formation 5
Connecting
high-mass
to investigate whether the properties of an IM protostar within the IRAS 05373+2349
embedded cluster are similar to that of low- and/or high-mass protostars. We carriedsmoothingand line length corrections w
out Very
Large andArray
as well as
for ResearchHanningin Millimeter
AstronTable
2. Assumed
determined
fluxCombined
and phase Arraycalibrator
12
plied
to
the
data
in
miriad,properties.
omy continuum and CO(J=1–0) observations, which uncover seven radio continuumwhich gave spectral resof 1.27
0.32protostar
km s 1 foristhe two narrow windo
sources (VLA 1–7). The spectral index of VLA 2, associatedwith andthe IM
12
ering
the
CO
(J=1–0)consistent with an ionised stellar wind or jet. The source VLA 3 is coincident with line
pre-emission. The data we
SourceFluxdensity(Jy)
Cal
exportedfromtheiroriginal
viously observed H2 emission line objects aligned in the north-south direction (P.A. -20format into casa where
6 cm
1.3an
cmionised
2.7 mmtype
ductionwere carried out. The source 05
to -12 ), which
may3.6becm
eitherjet emanatingfrom
VLA 2andor imaging(shock-)ionised
was used
to calibrate
and gain of thcavity walls in the large-scale outflow from VLA 2. The position
angle
between both
VLAamplitude
20137+331
5.52 misaligned
A outflow wevation;assumed flux
is listed in Table 2.
and
3 is slightly
withthe large-scale
map theat ⇠5-arcsec
resolu1331+305
5.22 ), which
2.58 in the -case of A
The imagesThecreatedfrom the millimetre continu
tion
in 12 CO (P.A.
⇠30
a jet suggests precession.
emission
120530+135
6.70
A+G
COestimate(J=1–0) its
linemass
emissionfromthe mm coreassociatedwith
VLA
2 is also
detected; weto be are presented in Sect
0559+238
0.41
0.37
G
TheFurthermore,
two continuumthe
spectral
12–23
M , dependingon the0.35
contribution
fromionised gas.
large-windows were cleaned t
0539+145G
producesingleimage with a central frequscale outflow has properties intermediate between outflowstofrom
low- aandhigh-mass
Briggs weighting with a robust
young stars.
Therefore,
concludethegainIM caliprotostar113.279
withinGHz,
IRASusing05373+2349
Absolute
flux calibrators
arewedenotedby ‘A’that
and the
eter
of
0.5.
The
synthesisedisphenomenologically
as
well
as
quantitatively
intermediate
betweenthelowandbeam size and noise, alo
brators are denoted by ‘G’ in the ‘cal type’ column.
the number of antennas and time spent on-sourcehigh-mass domains.

Ø IRAS 05373+2349 (d=1.2 kpc)の初mm干渉計観測。
Ø VLA, CARMA (2.7 mm, 12CO 1-0)
Ø Δv=0.32 km/s, θ=5”x4”。

6 cm

3.6 cmØ VLA 2に注目。VLAはfree-free。
+: 2.7 mm
x: MHO (水素分子)Ø VLA 3を初検出。
Ø MHOはVLA 2からのジェット起源★: Class I ↓observation, can be found in Table 1.
words: COstars:
formationstars: protostars – ISM: jetsFor
and– radio
2.2KeyCARMA(J=1–0)
and–2.7-mm(PA=–20~–12°)。
theoutflows
CO (J=1–0)
line image, the two narrocontinuum:stars – techniques: interferometriccontinuum
tral windows were combined at 115.271 GHz using
Ø 2.7 mm, 27 Kàコア~12-23 Mo
weighting and a channel width of 1.3 km s ; uv–d
Combined Array for Research in Millimeter Astronomy
12

12

1

smaller than 3 k were excluded. The beam size
(CARMA2 ) observations at = 2.7 mm were taken on 24
12
CO (J=1–0) image was 4.92 ⇥ 4.28 arcsec P.A. 78
April 2007. The antenna array during the observation connoiseinranged
from ⇠0.07
beam 1 in an empty chan
1 INTRODUCTION
photons
becomes
easilyobservable
cm continuum
andJythesisted of fifteen antennas, six 10 m and nine 6 m in diameter1
to ⇠0.5 Jyphasebeamis notin theinner channels.
mass andabove
a pre-main
sequence
observprimarybeams sizes orof 64 arcsec
115whicharcsec,reAs much research has focusedwith
on either
distinguishingable(Beltrán&deWit2016).
spectively.
A mosaic
was created from nine pointing centres
unifying the formation of high-massstars and
their low-mass
high-mass bystars, whose descent onto the mainin (IM)a squarepattern.
were separated
counterparts, intermediate-massstars gridare ofinterestTheas pointingsUnlike
sequence
occurswhile
still deeply
embedded and actively
30
arcsec.
3 RESULTS
they provide a bridge between the two mass regimes. IM prowithin
their parent cores, IM stars have a longer
The CARMA
correlator
up with two
sidebands,
tostars – the precursors of Herbig Ae/Bestars – aredefinedwas setaccreting
6, 3.areand1.3-cm continuum
pre-mainsequence
timescale, so3.1
that VLA
their discs
revealed
placedeither
sidefinalof thechosen local
oscillator
frequency
as young stellar objects (YSOs)
that willreachmasses
for
part
of
their
formation,
similartotheirlow-masscounof113.280
GHz,
with
the
upper
bands
situatedtomeasureof 2–8 M and have luminosities between ⇠50–2000 L (BelIn this section, we present
the VLA images at eac
12
terparts.
Thisisaresultoftheiraccretion
timescales
beCO(J=1–0)line
emission.
Both
the
upper
and
lower
sidetrán 2015). The lower limit of 2 M originates from the fact
length and calculate spectral indices.

Connecting low- and high-mass star formation: theintermediate-mass protostar IRAS 05373+2349 VLA 2の続き

1 formation
1
low- 1andstar
7
G. M. Brown,1? K.8Connecting
G. G.
Johnston,M.
G.
and S. L. Lumsden
M. Brown
ethigh-massal. Hoare

1 School of Physics and Astronomy, University of Leeds, West Yorkshire, Leeds LS2 9JT, UK

arXiv:1608.08677v1 [astro-ph.GA] 30 Aug 201612CO at VLA 2

1 September 2016

onnecting low- and high-mass star formation

Table 4. Derived properties of the blue- and red-shifted lobes ofthe outflow centred on VLA
12 2 traced by 12 CO (J=1–0) emission.

グレー: CO mom1

kinetic energy, mean velocity, length, dyn

mass transfer rate, mechanical force andØ MHOを覆う大スケー
nosity for the blue and red lobes of the ou
ルoumlow。
The velocity range shows the range ofParameter
Outflow☆:Class
IIred lobe
that were integrated over to produce the oABSTRACT
blue lobeØevolution
MHOはcavityの中を行
Until recently, there have been few studies of the protostellarof intermediateThe inner,
low velocity channels were exc
massVelocity(IM) stars,
which
regimes.
This paper
aims flux; channels with irange (kms ) may bridge-25.9 tothe-1.2low-and
5.3 high-mass
to 20.9
absorption
or missing
to investigate
the properties
withinく歳差運動したジェット
thesionIRAS(< 3 05373+2349) in the high-velocity wings weMass, M (Mwhether)
0.53of an IM protostar
0.26
embeddedclusterarekm
similarthat(4.82)
of low- and/or
high-mass protostars.
We carried
Momentum,P (Ms ) to4.06
1.57 (1.87)
The outflow
mass, M, was deriv
Very Large
as Combined
Array
for Researchによるショック(ß大質
in Millimeter AstronE (M Array
km s as) well 20.70(29.24)5.80 (8.19)
7 out Energy,
following Scoville et al. (1986):
omyEnergy,
continuumwhich
E (10 anderg) CO(J=1–0)
4.14observations,(5.85)
1.16(1.64)uncover seven radio continuum
量的)、またはwall。
v(km s1–7).
)
7.61(9.04)
sources(VLA
The spectral
indexof VLA5.92
2, (7.03)
associated with
the IM protostar is

Table 4. Derived properties of the blue- and red-shifted lobes ofthe outflow centred on VLA 2 traced by 12 CO (J=1–0) emission.

1

1

2

outflow

2

12

44
1

out f low

consistent
an ionised stellarwindor jet. 43000
The source
Length,withL (au)
35000(41000)(51000)VLA 3 is coincident with pre- 5 (T + 0.926)⌧(M ) = (P.A.
2.29 ⇥-20
10
viouslyobservedHemissionline
objectsalignedinthe north-south M
direction
42
tdyn (10 yr)
2.15 (2.15)
3.41 (3.41)
e 5.53/T ⌧ e ⌧to -12), whichmay
ionised
5 M yr1 ) be either anṀ (102.48(2.48)jet emanating
0.78 (0.78)from VLA 2 or (shock-)ionised
4 Min km1 yr 1 )cavitywalls
thes large-scale
outflowfrom VLA
2.(0.55)
The position angle between VLA 2
F (101.88 (2.24)
0.46
Parameter
Outflow
4 M kmmisaligned
2 s 2 yr 1 )and Ė3 (10is slightly
withlarge-scale
we mapat ⇠5-arcsec
9.61the(13.56)
1.70outflow(2.40)
where⌧ is high-mass
the resoluopticalstar
depth,
which we seConnecting
lowandformation
9
blue lobe
red lobe
Figure 4. 12 CO (J=1–0) spectral profile measured at the position
tion Lin(L12 CO(P.A. ⇠30 ), which0.16
in thecase of 0.03
a jet(0.04)
suggests precession.
The emission)(0.22)
ingthesourcetobeoptically
thin, and t
h
m
s
0
00
of VLA 2: 05 40 24.22 +23 50 54. 79 (J2000).
from the mm core associated with VLA 2 is also detected; we estimate
mass to4beterm of its
Equation
was set to unity. The d
Velocity range (km s 1 )-25.9 to -1.2
5.3 to 20.9
12–23The
Mproperties, dependingonthecontribution
fromionisedgas.
Furthermore,
the1.2largegiven within parentheses have been corrected atassumedtobekpc.
S is the integrated
Mass, M (M )
0.53
0.26
Figure5.
Centredon VLA 2 (marked
by a between
white plus)
the
scale
outflow
hasintermediate
outflows
low- and high-mass v
an inclinationi = properties
57.3 , otherwise
no correction
was applied(i = from1
locitychannel,
v,
that
was
found by summin
12
Momentum, P (M km s )4.06 (4.82)
1.57 (1.87) contours
CO (J=1–0)
emissionover - within IRAS 05373+2349
youngstars. Therefore,
welineconcludethatintegrated
the IM protostar
0 ). show
Energy, E (M km2 s 2 )20.70 (29.24)
5.80 (8.19) 25.9 - 1.2 km s 1 (blue) and 5.3 - 20.9 km s 1 (red) and 2.7-mm
withinaregiondefinedbythe 1 = 0.5 Jy
is phenomenologically as well as quantitatively intermediate between the low- andEnergy,E (1044continuumerg)
4.14 (5.85)
1.16 (1.64)
3.2.1
2.7-mm(themaximalnoise
level
withinthe spec
continuum
emission(black). The contours are over-plotted onhigh-mass
domains.
vout f low (km s 1 )7.61 (9.04)
5.92 (7.03)
themillimetre
continuum
emission
was emission
calculatedbetween
using 12 CO
citation
temperatureoftheoutflowgas, wa
first
momentmapofthe(J=1–0)Continuum
emission at 2.7 mm
was only detected
towards
1stars:Length, L (au)35000 (41000)
43000 (51000) 25.9Key
words:
formation–2 Sstars:
protostars– ISM:
jets toandoutflows
– the
radio
d
to
20.9
km
s
velocity
channelswithpixelsmasked
be⌫
be
equal
to
full
Planckfunctiond
VLA 2. Fig.
3 shows the continuum emission from the reMdust = interferometric(3)stars – contours
techniques:tdyn (104 yr)
2.15 (2.15)
3.41 (3.41) lowcontinuum:
1
Jy.
Blue-shifted
are
-3,
3,
4,
5,
7,
10,
12,
14
⇥
B
(T
)

temperature,
given
as:
⌫
D
⌫
gion around
VLA1 2 at 111.1 GHz (⇠ 2.7 mm) with MHOs
5

Ø oumlow質量0.8 Moは
low mass (<0.01 Mo)とhigh mass (>5 Mo)の中間。

+ HII region
o: YSO
x: low mass jetØ コア質量、oumlow質
量、oumlowの性質がṀ (10 M yr )2.48 (2.48)
0.78 (0.78) 3.0 Jy beam km s , red-shifted contours are -3, 3, 4, 5, 7, 10,
where d = 1.2 kpc and T = 27 K are the distance and dust
745
A,
B
and
C
(K11)
indicatedascrosses.
ThemorpholF (10 M km s yr )1.88 (2.24)
0.46 (0.55) 15, 20 ⇥ 2.0 Jy beam km s
the blackare asflux
intemperature (Molinari et andal. 2000).
S is contours
the integratedogyof theM emissionshowscore withan(2.40)exten中間的である。 3.92 ⇥ 10 [Ė (10km s yr) a compact
9.61 (13.56)
1.70
Fig.
3.
The
synthesised
beam
is
shown
in
the
bottomleft
cordensity measured
in the1 contour at = 2.7 mm. B (T )
sion
from
the south–east
direcVLA2
L (L) the south of the source
0.16 in(0.22)
0.03 (0.04)= 0.048 and[⌫ (GHz)]the value
scale ofbarthein Planck
the bottom
middle.
aretheshown
photons
easilyobservablein Tcm(K)continuum
the ln 1 +is thefunctionat becomes
T MHOs. Finally
dust
tion. The integrated and peak1fluxINTRODUCTION
densities, measured in aner andF (Jyas crosses.
A Class[see Fig.
1 (cd)]
and which
abyClass
II object sequence phase is not observabovea pre-main
opacity, = I0.1807
cm
g and
,mass
was
found
extrapolating
1 contour, were 53.7 ± 2.6 mJy
and
30.1± 1.6 mJy,
respecAs
muchresearchhas
focusedoneitherdistinguishing
or
黒点線:
jet
The properties given within parentheses have been corrected atreported by Gutermuth et al. (2009)
shown1994)
as de
a to
black
and
(Beltrán
&
Wit
model
opacity(Ossenkopfable&areHenning
2.72016).
mm,
tively. The peak position, measured
atthe
theformationbrightestofpixel,
where ✓ is the beamsize and F is the peunifying
stars respectively.
andtheir data
low-mass
an inclination i = 57.3 , otherwise
no correction
was appliedhigh-mass(i =white star,
Unlikestars, whose thedescent
ontoatthe
mainassuming
gasinterest
densityasof 1⇥10 g cm
andhigh-massthin ice mantles,
was(J2000).
outflow
frequency⌫. For the derived
intermediate-mass (IM)stars area of
0 ). 05 40 24.18 +23 50 55. 01counterparts,
赤破線:
singlestar
sequence
occurswhile
stilldeeplyembeddedandactively
where
,
the
dust
opacityindex
withfrequency,
wasfittedA 2D-Gaussian was alsothey
fittedtothesource.
Howprovide
a bridge between the two mass regimes. IM proin Table 4 the largest peak flux from eit
T
=23.7
K
from
ﬂux
accretingwithintheir toparentcores, IM stars have a longer
to be stars-1.82.–Aaregas-to-dustof 100 was
assumedinfer
B that only the inner
ever, we foundcompactcore couldofproFigure 7. Close up of VLA 2 and VLA 3 with 6-cm emistostars– the precursors
Herbig Ae/Be
defined ratio
4

1

4

h

2

m

s

1

2

1

1

1

1

0

00

1D

⌫

⌫

⌫

2

D

1

5

3

D

8

B

⌫

⌫

12
lobe was used to define the bright
The total
COcore(J=1–0)emission
appears
to showa emission
bipolarso thatshifted
the millimetre continuum emission was calculated using
sequence
timescale,discs aremass.
In the casepre-mainof all of the
2.7 mmduce a satisfactory fit; we derived
an integrated
flux(YSOs)
den- thatthe
sion showntheirby greyscale
andrevealed
black contours at -3, 3, 4, 5 ⇥ 26
as young
stellarobjectswillreach onfinal
massesforthat
outflow,which we found to be 6
2
outflow
centredVLA
2,appearing
in
the
same
orienta1
for
part
of
their
formation,
similartheirlow-massµJy
beam to. The
redcontours counshow 3.6 cm emission at 3, 4, 5,
d2–8
Sdensity
originating
from
the
dust,
the
total
core
mass
is
23
M
.
This
sity of 53.7 ± 5.9 mJy, a peak offluxof have29.9 ±
3.3
mJy⌫ M andluminosities
between ⇠50–2000 L (Bel1
Mdust =
(3)tion
1
5.3
km
s
from
the
lobe.
W
7
⇥
16
µJy
beam
.
The
black
x’s
the positionsof MHOaspreviously
seen
by
Zhang
et
al.
(2005).
There
is
also
terparts.
be- red-shiftedin close fromagreementwith thevalue ofThis⇠26 isMa result
found ofbytheir accretion timescales indicate
and a deconvolved source sizeB
by lower
2.9 ± 0.6
(T D4.1) ⌫± 0.4The
⌫of
trán
2015).
limitarcof 2 M isoriginates
the fact

745 A, B and C detected by Khanzadyan et al. (2011). The beams

AN#UPPER#LIMIT#TO#THE#MASS#OF#A#CLOSE#COMPANION#CANDIDATE#TO#σ#ORI#E##
1,2
By#José#A.#Caballero ,#Hervé#Bouy2#&#Jorge#Lillo:Box3,2##
1Landessternwarte#Königstuhl#(ZAH),#Heidelberg,#Germany#
2Centro#de#Astrobiología#(CSIC:INTA),#Madrid,#Spain#
3European#Southern#Observatory,#Santiago#de#Chile,#Chile###

The#famous,#very#young,#helium#rich,#magneticallyEactive,#radio#and#XE
Ø Heリッチ、磁場ac)ve、電波X線源、短周期変光という特徴的な星σ
Ori E。
ray# emitter,# shortEperiod# rotationally# variable,# spectroscopically#Ø 3 Myrのσ Orionis
clusterで一番重い7-8
B2 Vp型。
peculiar#star# σ# Ori# E# may# have#Mo,
a# close#
lateEtype# stellar# companion,#Ø 1.19日変光ßアバンダンスの不均質ß磁軸と回転軸のずれ、星周磁気圏にプラズマ雲。
which# could# explain# flaring# activity# observed# in# some# σ# Ori# E# XEray#light# curves.# In# 2009,# Bouy# et# al.# announced# the# detection# of# a# faint#Ø early typeでは見られないX線フレアを起こす。ß有力な説はK-M型の伴星。
companion#candidate#in#the#Ks#band#at#0.330#arcsec#(130#AU)#to#the#B2#
Ø Bouy+’09がNIR
AOで0.33”=130 AUに伴星候補。プラズマ雲は<0.04 AU。
Vp#primary.#Here,#we#carry#out#z’Eband#lucky#imaging#with#AstraLux#at#
Ø しかし、分解能ギリギリな上に確かめられていない。
the#2.2#m#Calar#Alto#telescope#in#an#attempt#to#constrain#the#properties#
of#the#companion#candidate#to#σ#Ori#E.#We#impose#a#maximum#mass#of#
2.0+0.2E0.1# Msol# and# an# earliest# spectral# type# of# K2±1,# which# leaves# the#AstraLux Norte@
2.2 m of Calar Altodoor#open#to#a#new,#inexpensive,#nearEinfrared,#adaptiveEoptics#study.###
Observatory, Spain。
#

lucky imaging (短いフレームをずらしてIntroduction#
足す)。SDSS z’ band。0.023”/pixel。
#

The#heliumErich#peculiarity#of#the#spectrum#of#the#B2#Vp#star#σ#Ori#E#(48#Ori#E,#V1030#Ori,#HD#37479,#Mayrit#42062)#was#first#noticed#in#1956#by#Berger1,#
and#two#years#later#made#widely#public#by#Greenstein#&#Wallerstein2.#Six#decades#
later,# dedicated# works# on# σ# Ori# E# have# received# over# 1000# citations# from#
6”x6”
approximately#50#dedicated#works#(e.g.,#The#magnetic#field#of#σ#Ori#E3,#The#rigidly##
rotating# magnetosphere# of# σ# Ori# E4,# Shell# and# photosphere# of# σ# Ori# E## –# New#
6,#
observations#and#improved#model5,#A#new#phenomenon#in#the#spectrum#of#σ#Ori#E#
FIG.#1#etc.).#Actually,#for#decades#the#star#attracted#more#attention#than#the#rest#of#stars#in#
Left:# part# of# a# SofI/3.6# m# New# Technology# Telescope# JEband# naturalEseeing# image#the# 3# MyrEold# σ# Orionis# cluster,# which# is# now# a# cornerstone# for# studies# of#centred#on#σ#Ori#Aa,Ab,B;#approximate#size#is#150#x#150#arcsec2.#The#brightest#stars#of#the#circumstellar#discs,#coronal#emission,#accretion,#and,#especially,#the#mass#function#
TrapeziumElike#system#are#labelled.#Right:#AstraLux#Norte/2.2#m#Calar#Alto#z’Eband#lucky#
7E9.# With# an# early# B# spectral# type# and# a# 2.#In#both#images,#north#is#up#and#
down# to# the# substellar# limit# and# beyondimage#roughly#centred#on#σ#Ori#E;#size#is#6.0#×#6.0#arcsec
east#is#left.#Note#the#very#small#size#AstraLux#field#of#view#with#respect#to#the#SofI#one.##mass# of# 7E8# Msol,# σ# Ori# E# is# one# of# the# most# massive# stars# in# the# homonymous#
TrapeziumElike# system# σ# Ori,# which# also# gives# the# name# to# the# cluster# and#

#

AN#UPPER#LIMIT#TO#THE#MASS#OF#A#CLOSE#COMPANION#CANDIDATE#TO#σ#ORI#E##
1,2
By#José#A.#Caballero ,#Hervé#Bouy2#&#Jorge#Lillo:Box3,2##
1Landessternwarte#Königstuhl#(ZAH),#Heidelberg,#Germany#
2Centro#de#Astrobiología#(CSIC:INTA),#Madrid,#Spain#
3European#Southern#Observatory,#Santiago#de#Chile,#Chile##の続き#

The#famous,#very#young,#helium#rich,#magneticallyEactive,#radio#and#XE
検出限界曲線とØ σrotationally#
Ori Eが7 mag,Δz’<3magà伴星は10 magより暗ray# emitter,# shortEperiod#
variable,#
spectroscopically#
伴星予想範囲。
い。 a# close# lateEtype# stellar# companion,#
peculiar# star# σ# Ori# E# may# have#
which# could# explain# flaring#
activity#in# some#
σ# Ori#E# XEray#Ø Siess
etobserved#
al. models(3 Myr,
Z=Zo=0.02)からM*<2Mo,
light# curves.# In# 2009,# Bouy# et# al.# announced# the# detection# of# a# faint#Teﬀ<4960 K, Sp>K2。
Table#I#companion#candidate#in#the#Ks#band#at#0.330#arcsec#(130#AU)#to#the#B2#
Apparent#and#absolute#magnitudes#in#the#red#optical#and#near:infrared#of#σ#Ori#E#
Vp#primary.#Here,#we#carry#out#z’Eband#lucky#imaging#with#AstraLux#at#
and#its#close#companion#candidate###the#2.2#m#Calar#Alto#telescope#in#an#attempt#to#constrain#the#properties#
Ø 予想されたK-Mに矛盾はしない。
#
σ#Ori#E#
Companion#candidate#of#the#companion#candidate#to#σ#Ori#E.#We#impose#a#maximum#mass#of#
Band#
Apparent#
Absolute#
Apparent#
Absolute#
Ø Gaiaでも無理。NACO,SPHERE,
GPI, MagAOなら30
magnitude#
magnitude#
2.0+0.2E0.1# Msol# and# an# earliest# spectral# type# of#magnitude#
K2±1,# which#leaves# the#magnitude#[mag]#[mag]#[mag]#[mag]##
分の観測でわかるだろう。
door#open#to#a#new,#inexpensive,#nearEinfrared,#adaptiveEoptics#study.##
#
+0.08
R#
6.84±0.01#
−1.09
#
…#
…#
−0.15
# FIG.#2#
Limit#of#our#AstraLux#Norte#z’Eband#image:#magnitude#difference#Δz’#as#a#function#I#
7.08±0.01#−0.85+0.08−0.15#…#…#
of#angular#separation#ρ#to#σ#Ori#E#(2.5%#best#frames).#The#vertical#dotted#lines#indicate#the#z’#
7.04±0.04#−0.89+0.10−0.16#>10.0±0.3#>2.1±0.3#
expected#location#of#the#candidate#companion#to#σ#Ori#E,#at#ρ#=#0.33±0.03#arcsec.####J#6.974±0.026#
−0.96
…#
…#
−0.15#
Introduction#
Table#I#H#
6.954±0.031#−0.98+0.09−0.15#…#…##
Apparent#and#absolute#magnitudes#in#the#red#optical#and#near:infrared#of#σ#Ori#E##
The#heliumErich#peculiarity#of#the#spectrum#of#the#B2#Vp#star#σ#Ori#E#(48#and#its#close#companion#candidate###1#
Ori#E,#V1030#Ori,#HD#37479,#Mayrit#42062)#was#first#noticed#in#1956#by#Berger
Table#II# ,##σ#Ori#E#
Companion#candidate#2
Upper#limits#to#the#presence#of#resolved#companions#to#σ#Ori#E#
and#two#years#later#made#widely#public#by#Greenstein#&#Wallerstein.#Six#decades#
Band#
Apparent#
Absolute#
Apparent#
Absolute##
later,#
dedicated#works#
on#
σ#
Ori#
E#
have#
received#
over#
1000#
citations#from#magnitude#
magnitude#
magnitude#
magnitude#
ρ##
s##
z’#
Mmax##
Earliest##
3
approximately#50#dedicated#works#(e.g.,#The#magnetic#field#of#σ#Ori#E,#The#rigidly#[mag]#[mag]#[mag]#[mag]#[arcsec]#[AU]##[mag]#[M
sp.#type#sol]#rotating#
magnetosphere#of# σ# Ori#of# σ# Ori#10.0±0.3#
E# –# New# 2.0+0.2E0.1#
R#
6.84±0.01#−1.09+0.08−0.15#…#…# E4,# Shell# and#
0.33#photosphere#
130#
K2±1#
5,#A#new#phenomenon#in#the#spectrum#of#σ#Ori#E6,#I#
7.08±0.01#−0.85+0.08−0.15#…#…#
observations#and#improved#model
1.00#
385#
10.9±0.3#
0.65±0.15#
K4±1#
z’#
7.04±0.04#−0.89+0.10−0.16#>10.0±0.3#>2.1±0.3#etc.).#Actually,#for#decades#the#star#attracted#more#attention#than#the#rest#of#stars#in#
2.00#
770#
12.6±0.3#
0.69±0.09#
K7±1#
+0.08
J#
6.974±0.026#−0.963#…#…# which# is# now#
−0.15#
3.00# a# cornerstone#1160#
14.3±0.3# of# 0.25±0.04#
M3±1#
the#
MyrEold#σ#Orionis#cluster,#for#studies#H#
6.954±0.031#−0.98+0.09−0.15#…#…##
circumstellar#discs,#coronal#emission,#accretion,#and,#especially,#the#mass#function##
7E9
down# to# the# substellar# limit# and# beyond # .# With# an# early# B# spectral# type# and# a##
Acknowledgements#
mass# of#
7E8# Msol,# σ# Ori# E# is# one# of# the# most# massive# stars# in# the# homonymous#
Table#II##
Upper#limits#to#the#presence#of#resolved#companions#to#σ#Ori#E#
TrapeziumElike# system# σ# Ori,# which# also# gives# the# name# to# the# cluster# and##+0.08