SF newsletter 337 #15-21
M. Momose (Ibaraki Univ.)
15, 16, 18 (複数スライドで紹介)
19 (一枚のスライドで内容を紹介)
その他(アブストラクトのみ)

15.

The mass-loss rates (from 7e-8 to 3e-6 Msun/yr) are larger than what was measured for Class II jets. Similarly to Class
II sources, the mass-loss rates are 1%-50% of the mass accretion rates suggesting that the correlation between ejection andaccretion in young stars holds from 1e4 yr up to a few Myr.

The Carina Nebula and Gum 31 molecular complex III: The distribution of the 1-3 GHz
radio continuum across the whole nebulaDavid Rebolledo, Anne J. Green, Michael G. Burton, Shari L. Breen, Guido Garay We report the most detailed
1 3 GHz radio continuum emission map of the nearest region of massive star formation, the Carina Nebula. As part of alarge program with the Australia Telescope Compact Array, we have covered ⇠ 12 deg2 , achieving an angular resolution of⇠ 16 arcsec, representing the largest and most complete map of the radio continuum to date. Our continuum map shows aspectacular and complex distribution of emission across the nebula, with multiple structures such as filaments, shells, and fronts
across a wide range of size scales. The ionization fronts have advanced far into the southern and northern region of the Galactic
Plane, as fronts are clearly detected at distances ⇠ 80 pc from the stellar clusters in the center. We estimated an ionization
photon luminosity QH = (7.8 ± 0.8) ⇥ 1050 s 1 which corresponds to ⇠ 85% of the total value obtained from stellar population
studies. Thus, approximately 15% of the ionizing flux has escaped from the nebula into the diﬀuse Galactic Interstellar Medium.
Comparison between radio continuum and the hydrogen atomic and molecular gas maps oﬀers a clear view of the bipolar outflow
driven by the energy released by the massive stellar clusters that also aﬀects the fraction of molecular gas across the nebula.
Comparison between 8µm and 70µm emission maps and the radio continuum reveals how the hot gas permeates through themolecular cloud, shapes the material into features such as pillars, small shells and arc-like structures, and ultimately, escapes.

• Carina Nebulaの1-3GHz連続波をATCAを使ってかつてない広さ(12deg2)と完全さで16asecでマップ• 目を見張るイメージ取得• 様々なスケールでのフィラメント・シェル・Fronts• 電離フロントは銀画面から遠く離れたところ，星団中心から80pcにまで到達
6• 電離光子のLuminosity QH= (7.8±0.8) × 1050s-1，星団からの電離光子の85%• H原子との比較：アウトフロー構造の確認．そのほか，8umや70umとの比較も

F IG . 1.— Mosaic pattern of our ATCA observations overlaid in a map of
the 0.835 GHz continuum emission in the CNC-Gum 31 complex obtainedwith the Molonglo Observatory Synthesis Telescope (Green et al. 2014). In
total, 532 pointings were observed, divided into 4 independent mosaics of
133 pointings each (illustrated with a different color). Each mosaic was observed using 11 array configurations to maximize u − v coverage. Thus, ourobserving campaign completed 44 sessions with the ATCA. Each array configuration observation was individually calibrated before combination for final imaging.

Figure 1 shows a map of the 0.835 GHz continuum emis-

中心部分
の拡大図

HIとの
比較

COとの
比較

8um & 70umとの比較

8um: green
1-3GHz: red

70um: Cyan
1-3GHz: red14Some small-scale structures
Rebolledo et al.

Bipolar outﬂows in 1-3GHz and Sp. Index

Effect of Feedback in the Carina Nebula
ATCA 1-3 GHz radio continuum

15

ALMA+APEX 3 mm radio continuum

Car I
Cores

F IG . 13.— Left: 1 −3 GHz radio continuum emission map of the object with an identified bipolar outflow/jet structure. The image was created using multi-terms
and wide frequency imaging with the CASA task tclean. The color bar is in Jy/beam. We identified a clear central source, with a bipolar emission structure,similar to FR II extragalactic sources. Right: Spectral index map of the region. The values are > −0.5 in the lobes, which are consistent with non-thermal emission
in those regions.

gas remaining due to the continuous erosion from the nearbystars. Probably, the cometary clouds we detected in the radio
continuum map correspond to the last stage, where almost no
gas remains, and isolated structures resembling small pillars
or cometary clouds are the only survivors of previous multiple
episodes of star formation.

Compact
Sourcecording to this classification, the source identified in Figure
13 seems to show an emission morphology similar to a FR II
object.
Figure 13 also shows a spectral index map of the source.
Our data allows us to estimate the spectral index values in the
Frontslobes only, as the emission in the jets are relatively weaker.
The range of the values are > −0.5 in the lobes, with some
4.2.2. Bipolar jet/outflow structure
regions showing values close to −1 in the lobe extending to
the north-east. These are values consistent with non-thermal
Slightly below the cometary structures, we identified aemission, typical of FR II objects. Follow up observations tosource with structure similar to a bipolar jet or outflow. Figthis interesting object will clarify its nature, and will provide
ure 13 offers a high spatial resolution image of the 1 − 3 GHz
Jy/beamfurther details
on itsandphysicalat
properties.
radio continuum emission towards
this object. In thisHII regions
incase,1-3GHz(left)
3mm (right)
Jy/beamthe imaging was performed using the multi-term and multi4.2.3. Detailed view of Car I
frequency (MT-MFS) algorithm available with the CASA task
F IG . 14.— Left: ATCA 1 − 3 GHz radio continuum image towards the H II region Car I. This image was generated with robust parameter equal to −0.5 to
Trumpler 14 and the bright H II region Car I have been maximize
tclean. MT-MFS allows us to maximize the uv coverage by
the spatial resolution. The beam size is 5.!! 6 × 4.!! 1. White arrows show the approximate direction of the radiation from massive stars in the Trumpler
the target of numerous studies at multiple wavelengths. The 14 cluster. The white dashed arcs show the regions where we identified ionization fronts in ALMA 3 mm continuum data (Rebolledo et al. 2020). Right: ALMA
using the full 1 − 3 GHz wide spectral coverage available fromAPEX combined continuum image at 3 mm from Rebolledo et al. (2020). Black contours shows the 1 − 3 GHz radio continuum emission, with levels of 4
extreme-ultraviolet photons released by Trumpler 14 ionize +mJy/beam
our ATCA observations. MT-MFS provides the spectral shape×k starting at 4 mJy/beam, with k = 1, 2, 3, 4, 5, 6, 7, 8, and 9. The black dashed box shows the region covered by ALMA observations. The black
dashedarcs
shows the ionization front in left panel. Red arrows shows the position of the resolved cores identified in our ALMA 3 mm continuum data.
the ambient neutral media, and play an important role in theof the source by modeling the spectrum of each flux compo-

16.

Chemical analysis of early-type stars with planets

C. Saﬀe, P. Miquelarena, J. Alacoria, M. Flores, M. Jaque Arancibia, D. Calvo, G. Martín Girardi, M. Grosso,
A. Collado Aims. To explore the chemical pattern of early-type stars with planets, searching for a possible signature of planet
formation. In particular, we study a likely relation between the lambda Bootis chemical pattern and the presence of giant
planets. Methods. We performed a detailed abundance determination in a sample of early-type stars with and without planets
via spectral synthesis. Results. We compared the chemical pattern of the stars in our sample (13 stars with planets and 24 stars
without detected planets) with those of lambda Bootis and other chemically peculiar stars. We have found four lambda Bootis
stars in our sample, two of which present planets and circumstellar disks (HR 8799 and HD 169142) and one without planets
detected (HD 110058). We have also identified the first lambda Bootis star orbited by a brown dwarf (zeta Del). This interestingpair lambda Bootis star + brown dwarf could help to test stellar formation scenarios. We found no unique chemical pattern for
the group of early-type stars bearing giant planets. However, our results support, in principle, a suggested scenario in which
giant planets orbiting pre-main-sequence stars possibly block the dust of the disk and result in a lambda Bootis-like pattern.
On the other hand, we do not find a lambda Bootis pattern in diﬀerent hot-Jupiter planet host stars, which do not support theidea of possible accretion from the winds of hot-Jupiters, recently proposed in the literature. Then, other mechanisms should
account for the presence of the lambda Bootis pattern between main-sequence stars. Finally, we suggest that the formation ofplanets around lambda Bootis stars such as HR 8799 and HD 169142 is also possible through the core accretion process andnot only gravitational instability [abridged]• λ Bootis(うしかい座)star：金属量が太陽に比べ1/10低い特異な化学組成を持つA型星
ALMA observations of the early stages of substellar formation in the Lupus 1 and 3
molecular
clouds• ~2%of B-F MS,
but ~33% of Herbig Ae/Be stars，起源は謎．

A. Santamaría-Miranda, I. de Gregorio-Monsalvo, A. L. Plunkett, N. Huélamo, C. López, Á. Ribas, M. R.
Schreiber, K. Mužić, A. Palau, L. B. G. Knee, A. Bayo, F. Comerón, Boo
A. HalesThe dominant mechanism leading• 惑星がある星13個とない星24個で大気化学組成を詳細に探査，λ型星との関連調査
to the formation of brown dwarfs (BDs) remains uncertain. The most direct keys to formation, which are obtained fromyounger
objects (pre-BD
cores and proto-BDs), are limited by the very low number
statistics
available. We aim to identify and• 4つ(+λBoo)がλ
Boo型，うち2つが惑星・星周円盤付き（HR8799,
HD169142）
characterize a set of pre- and proto-BDs as well as Class II BDs in the Lupus 1 and 3 molecular clouds to test their formation• 他のうち1つはBD付随
mechanism. We performed(zeta
ALMADel)，他の1つは惑星なし(HDband 6 (1.3 mm) continuum observations110058)
of a selection of 64 cores previously identified from
AzTEC/ASTE data (1.1 mm), along with previously known Class II BDs in the Lupus 1 and 3 molecular clouds. Surveyed• 惑星があるとダストの流入が妨げられた結果かも．．．はっきりしたことは言えないがarchival data in the optical were used to complement these observations. We expect these ALMA observations prove eﬃcientin detecting the youngest sources in these regions, since they probe the frequency domain at which these sources emit most of• Hot theirJupiterからのウインドが中心星に降着したと言う説とは合致しない（特段の差が見られない）
radiation. We detected 19 sources from 15 ALMA fields. Considering all the pointings in our observing setup, the ALMAHARPSHARPS-NHIRES
SOPHIEELODIE
REOSC

115000115000
67000
75000
42000
13000

Detector
4k x 4k
4k x 4k
2k x 4k
4k x 2k
1k x 1k
1k x 1k

size
15 µm
15 µm
15 µm
15 µm
24 µm
24 µm

La Silla 3.6m
TNG 3.6m
Keck 10m
OHP 1.93m
OHP 1.93m
CASLEO 2.1m

Wave. Range
3800 - 6800
3800 - 6800
3750 - 9000
3900 - 6800
3850 - 6800
3800 - 6000

今回のサンプルと観測諸元

Table 1. General characteristics of the spectrographs used in this work.
Instrument

R

CCD
Pixel
Telescope
Detectorsize
4k x 4k
15 µm
La Silla 3.6m
4k x 4k
15 µm
TNG 3.6m
2k x 4k
15 µm
Keck 10m
4k x 2k
µm
OHP
1.93m
A&A
proofs:15
manuscript
no. saffe
1k x 1k
24 µm
OHP 1.93m
1k x 1k
24 µm
CASLEO 2.1m

HARPS
115000HARPS-N
115000
HIRES
67000
SOPHIE
75000
ELODIE
42000
REOSC
Table 2. Sample of stars studied
in this work.13000
Star name13

SpectralType

Exoplanet host stars
β Pic
A6V
Fomalhaut
A4V
KELT-9B9.5 – A0
HD 95086
A8III
HD 169142
F1VekA3mA3 HAeBeHR 8799
F0+VkA5mA5
KELT-17
A2
KELT-20
A0
MASCARA-1
A8
WASP-33
kA5hA8mF4
HAT-P-49
A8
WASP-167
F1V
WASP-189
A4/5IV/V
Stars with a brown dwarf (BD) companion
β Cir
A3Va
59 DraA7 HAeBeζ Del
A3Va
Stars with no-companion detected
HD 133803
F2IVm-2
HR 4502 A
A0V
BU Psc
A9V/IVHD 29391
F0 IV
HD 105850
A1V
HD 110058
A0V
HD 115820
A7/8V
HD 120326
F0V
HD 129926
F0VSr+G1V
eff
HD 146624
A1 Va
HD 153053
A5IV/VHD 156751
A7II/III
HD 159492
A5IV/VHD 188228
A0Va
HD 23281
A5III/IV
HD 50445
A3V
HD 56537
A4IV
HD 88955
A2Va
V435 Car
A5V
λ Boötis
A0Va lBoo
Vega
A0Va

Approx.
Wave. Range
3800 - 6800
3800 - 6800
3750 - 9000
3900 - 6800
3850 - 6800
3800 - 6000

Companion
Detection
MethodCompanion
Mass [MJup ]Companion
Type

IR
ExcessSpectraS/N@5000 ÅCompanion &IR Excess Refs.

Imaging
Imaging
Transit
Imaging
Imaging
Imaging
TransitTransitTransitTransitTransitTransitTransit

9.9, 8.9
<1
2.88
2.6
< 1, < 10
8.3, 8.3, 9.2
1.31
3.5
3.7
< 4.1
1.73
<8
1.99

PlanetPlanetPlanetPlanetPlanetPlanetPlanetPlanetPlanetPlanetPlanetPlanetPlanet

Yes
Yes
No
Yes
Yes
Yes
No
No
...
...
...
...
...

HARPS
REOSC
HARPS-NHARPS
HARPS
ELODIEREOSC
HARPS-N
HARPS-NHIRES
SOPHIE
HARPS
HARPS

1500
490
550
310
210
370
210
450
560
250
135
205
1105

R1, R14, R20, R21
R2, R20, R21
R3, R23
R4, R14, R24, R25
R5, R26
R6, R14, R27, R28
R7
R8
R9
R10
R15
R16
R17

250
350
290

R11, R22
R12
R18

300
130
110
410
650
450
250
200
600
620
600
410
720
840
470
680
620
590
200
525
1230

R14
R14
R14
R14
R14
R14, R29
R14
R14
R14
R14
R14, R22
R14
R14, R22
R14, R21
R14
R14
R14, R20
R14, R20
R14
R20, R21
R19, R20, R21

Fig. 2. Effective temperature Teff derived in this work versus literature
Yes
data. Average dispersion bars areImaging
showed in58.7the upperBDleft corner
ofHARPS
the
RV
25
BD
...
ELODIE
panel.
...
50
BD
...
ELODIE

3

...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...

...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...

...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...

...
...
...
...
...
Yes
...
...
...
...
Yes
...
Yes
Yes
...
...
Yes
Yes
Yes
Yes
Yes

3. Stellar parameters and abundance analysis
3.1. Effective temperature and gravity

HARPS
HARPS
HARPS
HARPS
HARPS
HARPS
HARPS
HARPS
HARPS
HARPS
HARPS
HARPS
HARPS
HARPS
HARPS
HARPS
HARPS
HARPS
HARPS
ELODIESOPHIE

temperature T and superficial gravity log g were
21Effective
first estimated by using the Strömgren uvbyβ mean photomeFig. 1. Effective temperature versus luminosity for stars with planets,
without planets and with a BD companion (filled circles, empty circles and crosses). Evolutionary tracks for stars of different masses are
showed in blue/magenta for main-sequence/evolved stars. The numbers
are expressed in solar masses.

try of Hauck & Mermilliod (1998) for most stars in our sample or by taking previously published results. We used the program TempLogG (Kaiser 2006) together with the calibrationof Napiwotzki et al. (1993) and derredenned colors according
to Domingo& 1.Figueras
in orderderive forthe stars
fun-with planets,
Fig.
Effective (1999),
temperature
versus toluminosity
damental parameters. Then, these values were refined (whenFig. 2. Effective t
data. Average disppanel.

3. Stellar par

3.1. Effective te

Effective tempe
first estimated b
try of Hauck &ple or by taking

今回求められた星の基本パラメータ
Saffe et al.: Early-type stars with planets

ntal parameters derived for the stars in this work.

Star
β Pic
Fomalhaut
KELT-9HD 95086
HD 169142
HR 8799
KELT-17
KELT-20
MASCARA-1
WASP-33
HD 133803
β Cir
59 Dra
HR 4502 A
BU PscHD 29391
HD 105850
HD 110058
HD 115820
HD 120326
HD 129926
HD 146624
HD 153053
HD 156751
HD 159492
HD 188228
HD 23281
HD 50445
HD 56537
HD 88955
V435 Car
HAT-P-49
λ Boötis
Vega
WASP-167
WASP-189
ζ Del

Teff [K]log g [dex] vmicro [km s−1 ] v sin i [km s−1 ]8084 ± 130 4.22 ± 0.13
3.31 ± 0.83
113.0 ± 1.38745 ± 195 4.17 ± 0.10
2.95 ± 0.74
82.0 ± 3.2
9329 ± 118 4.00 ± 0.14
2.27 ± 0.57
113.5
Saffe
et ±
al.:4.6
Early-type stars with planets
7593 ± 122 4.02 ± 0.14
3.09 ± 0.77
30.0 ± 1.47296 1.
± General
365 4.20± 0.25 of 2.75
± 0.6955.0in±this
0.8work.
Table
characteristics
the spectrographs
used7301 ± 190 4.12 ± 0.23
2.76 ± 0.69
50.5 ± 1.0
Instrument
R ± 0.14
CCD
Pixel
7471
± 210 4.20
2.50 ± Telescope
0.63
43.0Approx.
± 0.6
size
Wave.
Range
8652 ± 160 4.11 ± Detector
0.20
3.03 ± 0.76
111.0
± 3.1
HARPS
1150004k x 4k
15 µm
La Silla 3.6m
3800 - 6800
7687
±
238
4.09
±
0.14
3.17
±
0.79
99.0
± -3.9HARPS-N
1150004k x 4k
15 µm
TNG 3.6m
3800
6800
7373
± 164 67000
4.14 ± 0.20
0.7110m
82.5± -2.0HIRES
2k x 4k
152.86µm ± Keck
3750
9000
SOPHIE
4k x 2k
152.29µm ± OHP
3900
6800
6998
± 193 75000
4.08 ± 0.23
0.571.93m 89.5
± -1.3
ELODIE42000
1k x 1k
24 µm
OHP 1.93m
3850 - 6800
8552
±
297
3.94
±
0.18
3.12
±
0.78
61.0
± 0.8
REOSC
13000
1k x 1k
24 µm
CASLEO 2.1m
3800 - 6000
7053 ± 194 4.18 ± 0.21
2.38 ± 0.60
53.0 ± 1.1
9569 ± 253 4.00 ± 0.16
1.96 ± 0.49
18.5 ± 0.77185 ± 160 4.22 ± 0.14
2.59 ± 0.65
53.0 ± 2.67259 ± 167 4.12 ± 0.20
2.70 ± 0.68
70.0 ± 1.79052 ± 167 4.08 ± 0.08
2.61 ± 0.65
125.0 ± 1.57839 ± 202 4.00 ± 0.14
3.26 ± 0.81
153.5 ± 2.97610 ± 135 4.30 ± 0.15
3.11 ± 0.78
92.2 ± 1.86925 ± 143 4.37 ± 0.11
2.17 ± 0.54
66.5 ± 1.57101 ± 167 4.18 ± 0.20
2.46 ± 0.62
113.0 ± 2.1
9489 ± 184 4.13 ± 0.07
2.06 ± 0.52
34.0 ± 0.57916 ± 129 4.03 ± 0.14
3.29 ± 0.82
103.0 ± 1.67432 ± 175 3.92 ± 0.21
2.93 ± 0.73
100.0 ± 4.38076 ± 128 4.24 ± 0.13
3.31 ± 0.83
52.3 ± 1.2
10262 ± 172 4.29 ± 0.06
1.17 ± 0.29
83.0 ± 3.57761 ± 135 4.18 ± 0.15
3.22 ± 0.80
77.7 ± 2.4
Fig. 2. Effective temperature Teff derived in this work versus literature
7922 ± 117 4.03 ± 0.14
3.29 ± 0.82
96.0 ± 1.9
data. Average dispersion bars are showed in the upper left corner of the8231 ± 122 3.70 ± 0.12
3.29 ± 0.82
146.0 ± 4.3
panel.
8733 ± 154 3.76 ± 0.10
2.96 ± 0.74
99.0 ± 3.07510 ± 165 4.21 ± 0.14
3.01 ± 0.75
106.4 ± 1.96730 ± 234 4.02 ± 0.14
1.82 ± 0.46
14.8 ± 0.2
3. Stellar parameters and abundance analysis
8512 ± 144 3.95 ± 0.06
3.15 ± 0.79
115.0 ± 3.1
9505 ± 188 3.95 ± 0.19
2.04 ± 0.51
20.5 ± 0.7
3.1. Effective temperature and gravity
6770 ± 210 4.05 ± 0.14
1.90 ± 0.47
52.0 ± 2.0
Effective temperature Teff and superficial gravity log g were7946 ± 136 3.85 ± 0.12
3.30 ± 0.82
95.2 ± 3.38236 ± 124 3.60 ± 0.12
3.29 ± 0.82
108.0 ± 3.6
first estimated by using the Strömgren uvbyβ mean photome-

有効温度Fig. 1. Effective temperature versus luminosity for stars with planets,

try of Hauck & Mermilliod (1998) for most stars in our sam-v sin iA&A proofs: manuscri

be s
aver
dex
in p
serv
diffe
dex
gati
sma
533
Ti ii

3.7.

Fig. 3. Projected rotational velocity v sin i derived in this work versus
literature data. Average dispersion bars are showed in the upper left
corner of the panel.

ing the abundances. Finally, the total error was estimated as thequadratic sum of e1 , e2 , e3 and e4 . These values are presented
in the Table A.1 of the Appendix, in order to determine theircontribution to the total error.

We
ues
thes
Ersp
Col
201
201
Lun
And
201
with
low

KEL
0.56
Giv
sibl
gian

• 黒が観測，青が合成したスペクトル，赤が差

Abundance analysis& spectra fit• 赤が今回同定されたλBoo型．λBooは青

Saffe et al.: Early-type stars with planets

Saffe et al.: Early-type stars with planets

A&A proofs: manuscript no. saffe

1.0

1.0

1.0

0.8

0.8

0.8

0.6

0.6

0.6

0.4

0.4

0.4

0.2

0.2

0.2

0.0

4500

4520

4540 4560
Wavelength

4580

4600 4500

4520

4540 4560
Wavelength

4580

4600

0.0

4500

4520

4540 4560
Wavelength

4580

4600 4500

4520

4540 4560
Wavelength

4580

4600

4500

4520

4540 4560
Wavelength

4580

4600 4500

4520

4540 4560
Wavelength

4580

4600

. Observed, synthetic and difference spectra (black, blue dotted and red lines) for the stars in our sample, sorted by v sin i.
Fig.
Fig. 5. Observed, synthetic and difference spectra (black, blue dotted and red lines) for the stars in our sample, sorted by v sini. 6. Observed, synthetic and difference spectra (black, blue dotted and red lines) for the stars in our sample, sorted by v sin i.

h for other possible chemically peculiar stars in our sample.
ly, we discuss the possible implications of our results within
ontext of the planet formation models.

λ Boötis stars in our sample

standard deviation of the different stars, as derived
distancebyofHeiterζ Del. There is also evidence of IR excess around ζ(2002). The figure shows two panels for eachDelstar,likely
correspondrelated to the presence of dust (Nielsen et al. 2019;
ing to elements with atomic number z<32 andEsposito
z>32. Inetgeneral,al. 2020). To our knowledge, ζ Del is the first λthese stars present near-solar values of C andBoötis
O, together
with by a brown dwarf, which could be used asstar orbited
subsolar values of the other metals. An individual
description
a laboratory
to test stellar formation scenarios. Interestingly, ourfor each star can be read in the Appendix B.sample
HD 169142
was
includesother two stars orbited by brown dwarfs (59 Dra

statusand theof a circumstellar disk (King & Patten(2015) proposed that the λ Boötis observedin ∼33%of presence
preHowever,this peculiar classification was then ruled out
main-sequence Herbig AeBe stars (Folsom1992).
et al. 2012),
origibydifferent
authors,nates when Jupiter-like planets (with mass between 0.1 and 10 using an optical spectral (Holweger et al.
1997) and disk.
also fromM Jup ) block the accretion of dust from the primordial
Our the ratio of UV lines (Cheng et al. 2016).
In thisbeen
work,
we do not identify the star β Pictoris with a λ Boötis
sample includes the star HD 169142, which haveclassified
pattern.
other
as a young pre-main-sequence object and also
as a λ The
Boötisstaryoung star (HD 95086) presents mostly so-

4.2. λ Boötis stars and hot-Jupiter planets

Hot-Jupiter planets present short orbital periods (< 1large planetary masses (> 0.1 M Jup ), that is, they are gorbiting very close to their stars (e.g. Wang et al. 20
cently, Jura (2015) proposed that λ Boötis stars could

今回見つけたλ Boo型のabundance pattern
HR8799は惑星あり
HD169142 はリングギャップを含む円盤が付随
ζ Delは912au付近にBD付随
HD110058は特段の兆候なし
一部の研究者は，HR8799のようにmetal
Poorな星周りの惑星形成はGIによると主張しているが，単にダスト降着を妨げた結果なのかもしれない．

One more but less clear star (HD156751) & λ Boo自身
A&A proofs: manuscript no. saffe- どちらも，これまで惑星の兆候は得られていない

Fig. 9. Abundances of the stars HD 156751 and λ Boötis (black), compared to the average pattern of λ Boötis stars (blue). We show two panels
for each star, corresponding to elements with z<32 and z>32.

(HAe)や- 若い方がλ Boo型の割合が多いと知られていたが，HD169142-We have found four λ Boötis stars in our sample, two of
which present planets (HR 8799 and HD 169142), one withoutplanets (HD 110058), and the first λ Boötis star orbited by abrown dwarf (ζ Del). This last interesting pair composed by a λHR8799(42±5Myr)が該当したが，β PicやHD96086 (<50Myr)は違った

Saffe et al.: Early-type stars with planets

その他

Table A.1. Continued. Abundances derived in this work. For each specie, we present average±total error and the uncertainties e1, ..., e4.
Specie

[N/H]

Ci
Oi
Mg i
Mg ii
Si ii
Ca i
Sc ii
Ti ii
Cr ii
Fe i
Fe ii
Sr ii
Ba ii

-0.06 ± 0.07
0.08 ± 0.13
-0.50 ± 0.23
-0.38 ± 0.15
-0.30 ± 0.18
-1.10 ± 0.34
-0.77 ± 0.22
-0.48 ± 0.15
-0.53 ± 0.07
-0.68 ± 0.12
-0.59 ± 0.13
-1.13 ± 0.31
-0.53 ± 0.18

e1

e2
ζ Del
0.06
0.04
0.13
0.03
0.06
0.07
0.09
0.04
0.14
0.07
0.11
0.23
0.11
0.09
0.03
0.05
0.04
0.03
0.02
0.10
0.03
0.04
0.16
0.13
0.14
0.11

e3

e4

0.01
0.02
0.04
0.01
0.07
0.02
0.02
0.03
0.02
0.02
0.03
0.03
0.01

0.01
0.01
0.21
0.11
0.07
0.22
0.16
0.14
0.05
0.07
0.12
0.23
0.01

• Hot Jupiter とλ Boo現象が関係していると言う説があったが，今回得られたサンプル（７個）ではそのような兆候は見られない

Saffe et al.: Early-type stars with planetspre-BD or deeply embedded protostellar candidates. We detected a promising candidate for a Class 0/I proto-BD source andinferred the disk dust mass of a bona fide Class II BD. The pre-BD cores might be the byproduct of an ongoing process oflarge-scale collapse. The Class II BD disks follow the correlation between disk mass and the mass of the central object that isobserved at the low-mass stellar regime. We conclude that it is highly probable that the sources in the sample are formed as ascaled-down version of low-mass star formation, although disk fragmentation may be responsible for a considerable fraction of
BDs.

18.

Characterizing the line emission from molecular clouds. Stratified random sampling of
the Perseus cloud

M. Tafalla, A. Usero, A. Hacar Context. The traditional approach to characterize the structure of molecular clouds is to
map their line emission. Aims. We aim to test and apply a stratified random sampling technique that can characterize theline emission from molecular clouds more eﬃciently than mapping. M ethods. We sampled the molecular emission from the
Perseus cloud using the H2 column density as a proxy. We divided the cloud into ten logarithmically spaced column density
bins, and we randomly selected ten positions from each bin. The resulting 100 cloud positions were observed with the IRAM
30m telescope, covering the 3mm-wavelength band and parts of the 2 and 1mm bands. Results. We focus our analysis on 11
molecular species detected toward most column density bins. In all cases, the line intensity is tightly correlated with the H2column density. For the CO isotopologs, the trend is relatively flat, while for high-dipole moment species such as HCN, CS, andHCO+ the trend is approximately linear. We reproduce this behavior with a cloud model in which the gas density increases
with column density, and where most species have abundance profiles characterized by an outer photodissociation edge andan inner freeze-out drop. The intensity behavior of the high-dipole moment species arises from a combination of excitationeﬀects and molecular freeze out, with some modulation from optical depth. This quasi-linear dependence with the H2 column
density makes the gas at low column densities dominate the cloud-integrated emission. It also makes the emission from mosthigh-dipole moment species proportional to the cloud mass inside the photodissociation edge. Conclusions. Stratified random
sampling is an eﬃcient technique for characterizing the emission from whole molecular clouds. It shows that despite the complex
appearance of Perseus, its molecular emission follows a relatively simple pattern.

7ペルセウス座分子雲をターゲットに以下を実施
方法

結果と考察

• 分子雲構造を探る際，マップするのではな• Line intensityはH2柱密度と正の相関

く，階層的ランダムサンプリングで特徴づけられないかを試験• H2柱密度の10binそれぞれに10標本点(計100点)，λ=3mmバンド全体と2mm & 1mm
バンド一部をIRAM 30mでカバー• 11molecular species + isotopologues解析‣ COはわりとflat‣ μが大きいspeciesほどlinearに近づく(HCN, CS, HCO+, HNC)

• 以下の組み合わせで簡単に振る舞いを理解‣ 励起効果‣ ほぼ全てのbinで検出‣ Edge (光解離) - Center (凍結)で線形補間‣ 様々なdipole moment μ (← critical density)‣ Optical depthによる変調をちょっぴり

標本点の位置(左)と柱密度M. Tafalla et al.: Characterizing the line emission from molecular clouds.

Fig. 1. Sampling of the Perseus cloud. Top: H2 column density map of the Perseus molecular cloud from Zari et al. (2016) with squares indicating
the location of the 100 positions selected to characterize the line emission from the cloud using stratified random sampling. The number ineach square indicates the column density bin to which the position belongs, and ranges from 1 (lowest column density) to 10 (highest). Bottom:
Expanded view of the three regions that concentrate most of the high column density positions, and that correspond to the well-known star-forming
regions NGC 1333, B1, and L1448. Contours are in units of N(H2 ), start at 1.25 ⇥ 1021 cm 2 , and increase by factors of 2.5. The 10 pc scale bar
assumes a distance of 300 pc.

vals was taken as 0.2 dex, equivalent to a factor of 1.6 in column

mentioned above, this approach is impractical when sampling

A&A proofs: manuscript

Fig. 2. H2 column density as a function of sample number for the 100
positions randomly chosen to represent the Perseus molecular cloud(magenta circles). The dashed horizontal lines mark the boundaries of
the ten column-density bins in which the cloud was divided, and thevertical lines enclose the ten points chosen to sample each bin. The blue
circles indicate the geometrical mean of the H2 column densities inside each bin, and their error bars indicate their dispersion. All values
derived from Zari et al. (2016) data.

scop
Sept
3mm
2012
and
serv
ter (
rece
200
F
minu
the p
serv
ditio
ried
EMI
HCO
obta
end
reso
I
chan
dow
1100 -

COMPLETEとの比較：CO isotopologues
M. Tafalla et al.: Characterizing the line emission from molecular clouds.

青がCOMPLETE
赤が本研究

Fig. 3. Comparison between sampling observations and COMPLETE full maps for 12 CO(1–0) and 13 CO(1–0). Top panels: Scatter plots of theintegrated intensity as a function of N(H2 ). The blue dots represent the results from the COMPLETE maps presented by Ridge et al. (2006) andeach of them contains more than 2 ⇥ 105 spectra. The red symbols represent the 100 measurements obtained using stratified random sampling. The
dotted lines mark the 3 detection level of the COMPLETE maps. Middle panels: Ratio between the mean intensity derived using the sampling
data and the COMPLETE maps for each of the ten N(H2 ) bins in which the cloud was divided. For 13 CO(1–0), the measurement in lowest N(H2 )bin is not reliable since the sampling data show that the intensity often lies below the COMPLETE detection limit. Bottom panels: Ratio between
the rms derived using the sampling data and the COMPLETE maps. As with the mean values, the 13 CO(1–0) measurement for the lowest N(H2 )bin lies below the detection limit, so the rms estimate is not reliable. We note how both the mean and rms ratios for the two CO isotopologs
lie in the vicinity of 1, indicating that the sampling method allows estimating the main emission parameters with an accuracy of about 50-20%
depending on the parameter.

結果(1)：COA&A proofs: manuscript no. 38727ms

Fig. 4. Integrated line intensity as a function of H2 column density for the J=1–0 transition of the four main CO isotopologs. For reference, eachpanel shows a linear relation that fits the average intensity of the highest column density bin (dashed line). Depending on the transition, the lower
limit of the intensity scale (0.05 K km s 1 ) approximately corresponds to one to three times the noise level in the integrated intensity.

which we have divided the cloud. Given the large dispersion of
the data, we operated in logarithmic units and later converted theresults to a linear scale. The results of this calculation are shownin the middle and bottom panels of Fig. 3 in the form of ratios

4.2. Data overview

The number of molecular lines detected in each position depends
strongly on its column density. Toward positions with the highest column densities (bin number 10, with N(H2 ) 1023 cm 2 ),

結果(2)：large μ species
M. Tafalla et al.: Characterizing the line emission from molecular clouds.

Fig. 5. Integrated line intensity as a function of H2 column density for the survey species detected in at least five column density bins. Top:
Traditional dense gas tracers (blue symbols). Bottom: Additional tracers of dense gas (green symbols). For reference, each panel shows a linear
relation that fits the average intensity of the highest column density bin (dashed line). For HCN(1–0), CN(1–0), N2 H+ (1–0), and C2 H(1–0), theintensity includes the contribution from all detected hyperfine components. For CH3 OH(2–1), the intensity includes the contribution from the A+
and E components. Depending on the transition, the lower limit of the intensity scale (0.05 K km s 1 ) approximately corresponds to one to threetimes the noise level in the integrated intensity.

to N(H2 ) < 1022 cm 2 ). It likely results from the photodissociation of the CO molecules in the outer cloud by the UV photons

but they often present strong sensitivity to additional processes
such as shocks, UV radiation, or CO freeze out: CH3 OH, CN,M. Tafalla et al.: Characterizing the line emission from molecular clouds.

柱密度 vs.
ライン積分強度

COは基本的に外側で稼ぐ
Large μは比較的全体で稼ぐものが多い
Fig. 7. Normalized ratio between integrated intensity and H2 column density as a function of H2 column density. The data points represent binaveraged values and the error bars represent the rms dispersion. The horizontal gray band encloses the region were deviations from unity are withina factor of 2.
Table 1. Linear square fits to the log-Int vs. log-N(H2 ) plots.

モデルの構築とCOとの比較
M. Tafalla et al.: Characterizing the line emission from molecular clouds.

• COのJ=2-1と1-0の比からT=11Kで一様‣ 外側のUV photonの加熱はCO解離に使

M. Tafalla et al.: Characterizing the line emission from molecular clouds.

われ大して効かない• 密度：柱密度の関数で与える．HCNや
0.75
CSの複数遷移間の比からN(H)
2Fig. 10. Comparison between observations and model results for the family of CO isotopologs. The red symbols represent the observed intensities

Fig. 10. Comparison between observations and model results for the family of CO isotopologs. The red symbols represent the observed intensitiesof the J=1–0 line, previously presented in Fig. 4, and the dashed blue lines represent the model results. The sharp drop at low column densities iscaused by the photodissociation edge in the abundance profile.

of the J=1–0 line, previously presented in Fig. 4, and the dashed blue lines represent the model results. The sharp drop at low column densities iscaused by the photodissociation edge in the abundance profile.
abundance profile. We aimed to describe these profiles using a for an outer abundance increase in the small hydrocarbons driven

0.15
速度分散：C18O(2-1)からN(H)
2•abundance profile. We aimed to describe these profiles using aparameterization that is both simple and consistent with our current knowledge of the chemical processes occurring in a molecular cloud like Perseus. After some exploring, we found that reasonable fits can be obtained by using a parameterization containing three terms:

parameterization that is both simple and consistent with our current knowledge of the chemical processes occurring in a molecular cloud like Perseus. After some exploring, we found that reafor an outer abundance sonable
increase
inbethesmallhydrocarbons
fits canobtainedby using
a parameterizationdriven
containing three terms: +by gas-phase reactions involving C .
= X0 ⇥ fout (N(H2parameterization)) ⇥ fin (N(H2 )),The final factor inX(N(Hour2 ))abundanceis f(1)in ,which describes possible
variationsin the cloud interior (i.e., ata constant scaling factor, and fout and fin are
where X0 represents
outthat representchangeswithhigh N(H2 ) values). Fortwo
allnormalized
speciesfactors
exceptN2 H+ ,abundance
the data
requireto X0 in the outer and inner parts of the cloud (i.e., at low
a systematic abundancerespectdecreasewith
N(H2 ), likely caused byand high H2 column
densities).
Appendix
C provides
a detailed
discussionof the meaning
freeze out. This is consistent
withprevious
findings
towardstar-2of the di↵erent factors and the analytic expressions used in theless dense cores in di↵erent(Caselli
et ideasal. 1999;
model. In environments
this section, we summarize
the mainthat arerequiredetto al.
understandthe modelpresented
below. we
Bergin et al. 2002; Tafalla2002),
and results
for thisreason,The fout factor represents any abundance change that takes
inlayers
parameterized fin with an
expression
usedbycloud,
Tafallaeta al.
(2002)
placein the outerof 2
thelikely as
resultof their
exposure
to theexpression
external UV radiation
field.only
It is dominatedby
to describe such systems.
This
has
as
free
pathe contribution of molecular photodissociation in a thin outer
rameter the volume densityof freeze
out,layer of acharacteristic
few magnitudes of extinction,a processthat which
has beenmodeled in great detail by2
previous chemical work (e.g., Tiehas been adjusted for eachmolecular
species.
As with the pholens & Hollenbach 1985; van Dishoeck & Black 1988; Le Bour3
lot et al. 1993;
Sternberg& Dalgarno(1-21995; ⇥
Vissercm2009;)todissociation edge, a narrowrange
of choices
10et5 al.

• 化学組成は以下の式でパラメータ化
X(N(H2 )) = X0 ⇥ fout (N(H2 )) ⇥ fin (N(H2 )),(1)

where X0 represents a constant scaling factor, and fout and fin are
two normalized factors that represent abundance changes withrespect to X0 in the outer and inner parts of the cloud (i.e., at low
and high H2 column densities).

by gas-phase reactions involving C+ .
The final factor in our abundance parameterization is fin ,which describes possible variations in the cloud interior (i.e., athigh N(H2 ) values). For all species except N2 H+ , the data requirea systematic abundance decrease with N(H2 ), likely caused byfreeze out. This is consistent with previous findings toward starless dense cores in di↵erent environments (Caselli et al. 1999;
Bergin et al. 2002; Tafalla et al. 2002), and for this reason, weparameterized fin with an expression used by Tafalla et al. (2002)
to describe such systems. This expression has as only free parameter the volume density characteristic of freeze out, which
has been adjusted for each molecular species. As with the photodissociation edge, a narrow range of choices (1-2 ⇥ 105 cm 3 )is enough to fit all the observations.
For N2 H+ , the observations require an abundance enhancement toward the cloud interior, in agreement with the theoretical expectation that this species increases its abundance when
CO freezes out (Bergin & Langer 1997; Aikawa et al. 2001). To
parameterize this e↵ect, we used a simple expression related tothat used for freeze out, and which is further described in Appendix C.
As an additional constraint to the model, we required thatthe relative abundances of the isotopologs follow the ratios determined for the local ISM by Wilson & Rood (1994). We thus

f : UV解離の影響をPDRモデルで評価,
ただし，C HやCNはenhancef : N H以外はdense regionで減少(凍結),N Hは増加（CO凍結との関係で）

モデルとCO以外の分子種の比較

M. Tafalla et al.: Characterizing the line emission from mo

A&A proofs: manuscript no. 38727ms

Fig. 11. Comparison between observations and model results for HCN (top) and CS (bottom). Each row presents the intensity of the di↵erent
transitions observed for the species (main and rare isotopologs) as a function of H2 column density (blue symbols) together with the predictions
from the model (dashed red lines). The CS(3–2) dataset has fewer points due to the limited observations carried out in the 2mm-wavelength band.
Several H13 CN(1–0) points can be seen above the plot lower limit at very low column densities. A visual inspection of their spectra suggests thatthey represent noise or baseline residuals and not true molecular emission.

sion behaviors identified in the cloud. Modeling results for the
rest of the species and a table summarizing the abundance pa-

crease with respect to 12 CO near the cloud edge due to isotopic
fractionation, and the C18 O and C17 O abundances are expected

Fig. 12. Comparison between observations and model results for two
species that require special abundance profiles: N2 H+ (top) and C2 H
(bottom). In both panels, the green symbols represent the observed intensity, previously shown in Fig. 5. In the N2 H+ panel, the dashed redline represents a constant abundance model that fits the intensity at highcolumn densities. The blue dashed line represents the best-fit model,
and includes an internal abundance enhancement. In the C2 H panel, thedashed red line represents a model with no external enhancement, while
the blue line represents the externally enhanced best-fit model.

transition of both the main and rare isotopologs together withthe 3–2 intensity, but it is close to the lower boundary of thewith CN, require
the figure compar
two abundance m
constant-abundanchigh N(H2 ). As cmates the intensit
an abundance dro
blue line) correspand has a significsities, as expected
the latter species i
1997; Aikawa etthe emission boththerefore in better
noted, however, th(N(H2 ) ⇡ 1022 cm
abundance drop, agested by the modsion in this transiti
needed to fully cha
gas tracer throughThe bottom pa
C2 H(1–0) line. Ag
els with the survey
dard abundance m
inner freeze-out cthe inner cloud, b
low column densi
abundance profile
todissociation edg
C2 H abundance fr
for a full descripti
produces better thethe cloud in additi
with a smaller out
emission, as show
We summariz
Perseus data sugg
any species is mos
agents: (i) the UV
collisions at highcept N2 H+ , C2 H, aagents, in the sensdiation and they fr

19.

electrochemical properties of ice. A negative constant current was found wh
Behavior of Hydroxyl Radicals on Water Ice at Low Temperaturestemperatures below 50 K was exposed to both UV photons and electrons. It was de
Masashi Tsuge, Naoki Watanabe Because chemical reactions
on/in cosmic ice dust grains covered by amorphous solid
í
that
the
negativecurrentisinitiatedbytheformationofOH
ions onthe ASW swater (ASW) play important roles in generating a variety of molecules, many experimental and theoretical studies havefocusedare transported
to the bulk conventional
via the proton-holetransfer mechanism,
which won the chemical processes occurring on the ASW surface. Inthey
laboratory
experiments,
spectroscopic
and massspectrometric detection of stable products is generally employed100
to years
deduceand mechanisms.
despiteago reaction
as a mirrorchannels
image of protontransfer knownHowever,as the Grotthuss
mecha
their importance, the details of chemical reactions involving reactive
have notbeen clarified
becauseof furresultsspecies
indicate(i.e.,that freeOHí radicals)
ions are readilytransported
to the bulk
ice andthe absence of experimental methods for in situ detection of radicals.
Becausecan bewhere
easilythermal
producedin interstellar
reactions,even atOH
lowradicals
temperatures
diffusionis negligible.
conditions by not only the photolysis and/or ion bombardments of H2O but also the reaction of H and O atoms, they are
in-mantle chemical processes that have been considered inactive at low temp
thought to be one of the most abundant radicals on ice dust. In this context, the development of a close monitoring method ofworth reevaluating.
OH radicals on the ASW surface may help to elucidate the chemical
reactions occurring on the ASW surface.

（このアブストラクトは3つの段落のうち一段落目しかない）
Distinguishing between diﬀerent mechanisms of FU-Orionis-type luminosity outbursts

EduardI.
Vorobyov,VardanG.
Elbakyan,
Hauyu
BaobabLiu,
Michihiro
Takami
Aims.
Accretion
andluminosity• 低温下でのHydroxyl radicalsのアモルファス氷(ASW)表面での振る舞bursts triggered by three distinct mechanisms: the magnetorotational instability in the inner disk regions, clump infall ingravitationally fragmented disks and close encounters with an intruder star, were studied to determine the disk kinematic
いに関連し．筆者自身が開発した，ASW表面のOHラジカル検出法を
characteristics that can help to distinguish between these burst mechanisms. Methods. Numerical hydrodynamics simulations
用いて，λ=532nmの光子一つでOHがdesorotionすることを確認．
in the thin-disk limit were employed to model the bursts in disk environments that are expected for each burst mechanism.
Results. We found that the circumstellar
disks featuring accretion bursts can bear kinematic features that are distinct for–• 氷表面のOHは容易に電子を引き寄せ，OHになる．今回はさらに，
diﬀerent burst mechanisms, which can be useful when identifying the burst origin. The disks in the stellar encounter andclump-infall models
are characterized by tens of percent deviations from the Keplerian rotation, whie the disks in the MRI
OH–の形成がnegative
currentを誘起することを突き止め，protonmodels are characterized only a few percent deviation, which is mostly caused by the gravitational instability that fuels thetransferのmirror
imageとして100年前に予言されていたproton-hole
MRI bursts.
Velocity channel maps also show distinct kinks and wiggles, which are caused by gas disk flows that are peculiar
to each considered burst mechanism. The deviations of velocity channels in the burst-hosting disks from a symmetric patterntransfer typical(Grotthuss
mechanism)で実効的に氷内で素早く輸送される
of Kepleriandisks are strongest for the clump-infall and collision models, and carry individual features that may be
useful for the identification of the corresponding burst mechanism. The considered burst mechanisms produce a variety of light
ことを明かした．
curves with the burst amplitudes varying in the
m=2.5-3.7 limits, except for the clump-infall model wherem can reach• 低温下の氷マントルでは起こらないと思われていた関連反応が重要に
5.4, although the derived numbers may be aﬀected by a small sample and boundary conditions. Conclusions. Burst triggering
mechanisms are associated with distinct kinematic features in the burst-hosting disks that may be used for their identification.
なる可能性がある．
Abridged.

17.

planets around lambda Bootis stars such as HR 8799 and HD 169142 is also possible through the core accretion process andnot only gravitational instability [abridged]

ALMA observations of the early stages of substellar formation in the Lupus 1 and 3
molecular clouds

A. Santamaría-Miranda, I. de Gregorio-Monsalvo, A. L. Plunkett, N. Huélamo, C. López, Á. Ribas, M. R.
Schreiber, K. Mužić, A. Palau, L. B. G. Knee, A. Bayo, F. Comerón, A. Hales The dominant mechanism leading
to the formation of brown dwarfs (BDs) remains uncertain. The most direct keys to formation, which are obtained fromyounger objects (pre-BD cores and proto-BDs), are limited by the very low number statistics available. We aim to identify andcharacterize a set of pre- and proto-BDs as well as Class II BDs in the Lupus 1 and 3 molecular clouds to test their formation
mechanism. We performed ALMA band 6 (1.3 mm) continuum observations of a selection of 64 cores previously identified from
AzTEC/ASTE data (1.1 mm), along with previously known Class II BDs in the Lupus 1 and 3 molecular clouds. Surveyedarchival data in the optical were used to complement these observations. We expect these ALMA observations prove eﬃcientin detecting the youngest sources in these regions, since they probe the frequency domain at which these sources emit most of
their radiation. We detected 19 sources from 15 ALMA fields. Considering all the pointings in our observing setup, the ALMA
detection rate was ⇠23% and the derived masses of the detected sources were between ⇠0.18 and 124 MJup . We classified thesesources according to their spectral energy distribution as 5 Class II sources, 2 new Class I/0 candidats, and 12 new possible
pre-BD or deeply embedded protostellar candidates. We detected a promising candidate for a Class 0/I proto-BD source andinferred the disk dust mass of a bona fide Class II BD. The pre-BD cores might be the byproduct of an ongoing process oflarge-scale collapse. The Class II BD disks follow the correlation between disk mass and the mass of the central object that isobserved at the low-mass stellar regime. We conclude that it is highly probable that the sources in the sample are formed as ascaled-down version of low-mass star formation, although disk fragmentation may be responsible for a considerable fraction of
BDs.

Characterizing the line emission from molecular clouds. Stratified random sampling ofPerseus cloud• theLupus1,3の分子雲に対しAzTEC/ASTE
data (1.1mm)で同定されたコア64個をALMAでサーベイ
M. Tafalla, A. Usero, A. Hacar Context. The traditional approach to characterize the structure of molecular clouds is to
map their line emission. Aims. We aim to test and apply a stratified random sampling technique that can characterize the• 19個をALMAで検出．クラス分け
line emission from molecular clouds more eﬃciently than mapping. M ethods. We sampled the molecular emission from the
Perseus cloud using the H2 column density as a proxy. We divided the cloud into ten logarithmically spaced column density• Class
II BDに関しては，中心星質量と円盤質量の相関を確認．BD形成はlow mass starbins, and we randomly selected ten positions from each bin. The resulting 100 cloud positions were observed with the IRAM
30m telescope, covering the 3mm-wavelength band and parts of the 2 and 1mm bands. Results. We focus our analysis on 11
formationのスケールダウンバージョンらしいmolecular species
detected toward most column density bins. In all cases, the line intensity is tightly correlated with the H2column density. For the CO isotopologs, the trend is relatively flat, while for high-dipole moment species such as HCN, CS, andHCO+ the trend is approximately linear. We reproduce this behavior with a cloud model in which the gas density increases
with column density, and where most species have abundance profiles characterized by an outer photodissociation edge and20.

the absence of experimental methods for in situ detection of radicals. Because OH radicals can be easily produced in interstellar
conditions by not only the photolysis and/or ion bombardments of H2O but also the reaction of H and O atoms, they arethought to be one of the most abundant radicals on ice dust. In this context, the development of a close monitoring method ofOH radicals on the ASW surface may help to elucidate the chemical reactions occurring on the ASW surface.

Distinguishing between diﬀerent mechanisms of FU-Orionis-type luminosity outbursts

Eduard I. Vorobyov, Vardan G. Elbakyan, Hauyu Baobab Liu, Michihiro Takami Aims. Accretion and luminosity
bursts triggered by three distinct mechanisms: the magnetorotational instability in the inner disk regions, clump infall ingravitationally fragmented disks and close encounters with an intruder star, were studied to determine the disk kinematiccharacteristics that can help to distinguish between these burst mechanisms. Methods. Numerical hydrodynamics simulationsin the thin-disk limit were employed to model the bursts in disk environments that are expected for each burst mechanism.
Results. We found that the circumstellar disks featuring accretion bursts can bear kinematic features that are distinct for
diﬀerent burst mechanisms, which can be useful when identifying the burst origin. The disks in the stellar encounter andclump-infall models are characterized by tens of percent deviations from the Keplerian rotation, whie the disks in the MRI
models are characterized only a few percent deviation, which is mostly caused by the gravitational instability that fuels the
MRI bursts. Velocity channel maps also show distinct kinks and wiggles, which are caused by gas disk flows that are peculiar
to each considered burst mechanism. The deviations of velocity channels in the burst-hosting disks from a symmetric patterntypical of Keplerian disks are strongest for the clump-infall and collision models, and carry individual features that may be
useful for the identification of the corresponding burst mechanism. The considered burst mechanisms produce a variety of light
curves with the burst amplitudes varying in the
m=2.5-3.7 limits, except for the clump-infall model wherem can reach
5.4, although the derived numbers may be aﬀected by a small sample and boundary conditions. Conclusions. Burst triggering
mechanisms are associated with distinct kinematic features in the burst-hosting disks that may be used for their identification.
Abridged.

HII regions and high-mass starless clump candidates II. Fragmentation and induced star
at 0.025 pc scale: An ALMA continuum study• FUformation
Ori型星のメカニズムを区別する方法をシミュレーションをもとに考察

S. Zhang, A. Zavagno, A. López-Sepulcre, H. Liu, F. Louvet, M. Figueira, D. Russeil, Y. Wu, J. Yuan, T. G.
S. Pillai The ionization feedback from HII regions modifies the properties of high-mass starless clumps (HMSCs,
of several• アクリーションバーストの場合は，他のメカニズムでは見られないkinematicalfeaturesを示すはず
hundred to a few thousand solar masses with a size of 0.1-1 pc), such as temperature and turbulence, on the clump scale. The
question of whether the presence of HII regions modifies the core-scale fragmentation and star formation in HMSCs remains to
be explored. We aim to investigate the diﬀerence of 0.025 pc-scale fragmentation between candidate HMSCs that are strongly
impacted by HII regions and less disturbed ones. We also search for evidence of mass shaping and induced star formation in
the impacted HMSCs. Using the ALMA 1.3 mm continuum with a resolution of 1.3", we imaged eight candidate HMSCs,
including four impacted by HII regions and another four situated in the quiet environment. The less-impacted HMSCs are21.

5.4, although the derived numbers may be aﬀected by a small sample and boundary conditions. Conclusions. Burst triggering
mechanisms are associated with distinct kinematic features in the burst-hosting disks that may be used for their identification.
Abridged.

HII regions and high-mass starless clump candidates II. Fragmentation and induced starformation at 0.025 pc scale: An ALMA continuum study

S. Zhang, A. Zavagno, A. López-Sepulcre, H. Liu, F. Louvet, M. Figueira, D. Russeil, Y. Wu, J. Yuan, T. G.
S. Pillai The ionization feedback from HII regions modifies the properties of high-mass starless clumps (HMSCs, of several
hundred to a few thousand solar masses with a size of 0.1-1 pc), such as temperature and turbulence, on the clump scale. The
question of whether the presence of HII regions modifies the core-scale fragmentation and star formation in HMSCs remains to
be explored. We aim to investigate the diﬀerence of 0.025 pc-scale fragmentation between candidate HMSCs that are strongly
impacted by HII regions and less disturbed ones. We also search for evidence of mass shaping and induced star formation in
the impacted HMSCs. Using the ALMA 1.3 mm continuum with a resolution of 1.3", we imaged eight candidate HMSCs,
including four impacted by HII regions and another four situated in the quiet environment. The less-impacted HMSCs are
selected on the basis of their similar mass and distance compared to the impacted ones to avoid any possible bias linked to theseparameters. A total of 51 cores were detected in eight clumps, with three to nine cores for each clump. Within our limited
sample, we did not find a clear diﬀerence in the 0.025 pc-scale fragmentation between impacted and non-impacted HMSCs,
even though HII regions seem to aﬀect the spatial distribution of the fragmented cores. Both types of HMSCs present a thermalthfragmentation with two-level hierarchical features at the clump thermal Jeans length thand
0.3
J,clumpJ,clump . The ALMA
emission morphology of the impacted HMSCs AGAL010.214-00.306 and AGAL018.931-00.029 sheds light on the capacities of
HII regions to shape gas and dust in their surroundings and possibly to trigger star formation at 0.025 pc-scale in HMSCs.
Future ALMA surveys covering a large number of impacted HMSCs with high turbulence are needed to confirm the trend of
fragmentation indicated in this study.

•

High Mass Starless Clumps (HMSCs)がHII領域から与えられるフィードバックの影響を調査•

ALMA 1.3mm連続波イメージにより，8つのHMSCsの構造調査，4つはHII領域の影響大のもの• 内部に0.025pcのコアを計51個同定，HII領域の影響有無は見出せるほど明瞭な違いを生んでいなかった
8