42. Virial Ratio: Direct Evaluation from Molecular Cloud Data and the Challenges of Improving Accuracy
A. Singh, C. Matzner and P. Jumper Accepted by The Astrophysical Journal
The virial ratio between kinetic and gravitational terms provides key insight into the balance of forces that confine a molecular cloud, but theclumpy and filamentary structures of resolved clouds make it difficult to evaluate this ratio in a consistent way. For clouds with resolved mapsof column density as well as a line tracer, we demonstrate that the gravitational energy can be estimated directly from observations in amanner similar to the kinetic energy. This offers improved diagnostic power and consistency. Disentangling a cloud from foreground andbackground material is a persistent challenge, for which we introduce a strategy based on Abelʼs transform. We provide proofs of principle
using simulated clouds.
to offer a relatively consistent strategy for estimating
Wcl(ß Σmap)and T , and hence αclClausius 1870
Bertordi & McKee 1992

Wcl '<latexit sha1_base64="qHucBPiZTzjDwwVeX9187qQxy/I=">AAAClnichVHLSiNBFD22jqNxxmR0I7gRg+JmQnXiMOJCRBl0I8RoHmCc0F1WYmG/7O4EtOkf8AdczGoGRMRvcCWoP+DCTxCXCm5ceNNpEJWZuU1XnTr3nlunqnTHkJ7P2E2X0t3zofdjX39i4NPnwWTqy1DJs5suF0VuG7Zb0TVPGNISRV/6hqg4rtBM3RBlfWexnS+3hOtJ21r39xyxaWoNS9Yl13yiaim1XAu4EVY9aYrdr9W6q/EgFwbfQq2Dl1ai/M9sGBQiFNZSaZZhUYy9B2oM0ogjb6eOUcUWbHA0YULAgk/YgAaPvg2oYHCI20RAnEtIRnmBEAnSNqlKUIVG7A6NDVptxKxF63ZPL1Jz2sWg3yXlGCbYNTth9+yKnbJb9vTXXkHUo+1lj2a9oxVOLXkwsvb4X5VJs4/tF9U/PfuoYybyKsm7EzHtU/COvrV/eL82W5gIJtkfdkf+f7Mbdk4nsFoP/GhVFH4hQQ+gvr3u96CUzai5THZ1Oj2/ED9FH0Yxjim67++YxzLyKNK+hzjDBS6VEWVO+aEsdUqVrlgzjFeh5J8BSMyeFg==</latexit>

2
3 GMcla
5 Rcl 軸⽐a~1-2に対して↵cl = ↵BM92 /a<latexit sha1_base64="2T+IgQAhvTgkHQi26lcBAUA6pko=">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</latexit>

Decreasing trend of BM92 with decreasing mass
and increasing column density in star-forming
molecular regions. àinterpreted in terms ofpressure-confinement on GMC scales andincipient or ongoing collapse on star cluster
formation scales

この論⽂の結果（⽅向平均）
Averaged over orientations, the energy of the sheet
is exactly π/2 times greater than the cloud energy<latexit sha1_base64="Zs9vQkle4HLSRZKODJrRVO3jHLs=">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</latexit>

2D = (1µ2 ) 1/2 3D

半径Rclの等温球
λJ=1.78Rcl
M=0.29乱流

43.
Star-forming
the periphery
the MO
supershellsurrounding
Cyg 4,
OB1 association.
( 6N
A HDIB regions
BD IM atN NC
D C S ofA NC
MC GG MOOI DIB the
NC -SBMM D ND I II.
11 ISM
162
kinematics
DI H ND M andI YSOs64M inDI theNC star
MN cluster
GOMN vdB, 130 region
BD I
T.G. 6DNID
Sitnik etN al.
G Accepted
N byS MNRAS
235 6
We present
small-scale
processes
M IN an
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ND I G study
MNO S ofA MH
GG M G feedback
A
MM M operating
NDIB inDI theNC star-forming
MN A HDIB region
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N in
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GG ofA theNC
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Cyg 4,
OB1 association.
interstellargas
R I DIB MO
MC GG around
OI theNC -SBMM D ND I The
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I dustOMN content
IN IN andI pre-stellar
MN GG populations
OG ND IM in
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new optical
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the 6-m
D DIDNS ofA NC
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GOMN vdB, 130 are analysed
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ND G andI 15
M
ND IM performed
A H with
DNC NC
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spectroscopic
NIR images)
M
N M
D mappingH
DIB inDI theNC [Sii
6DD ] doublet)O G N andI 2.5-m) H (optical
ND G and
I 315
DH B M Russian
5OMMD I telescopes
N G M
M along
G IB with
DNC theNC archival
CD G data
N ofA
SpitzerandHerschelspacetelescopes.
Analysingionizedgaskinematics
andemission
spectra,wediscoveredacompact
region
6 DNT
I 0 M C G M
N G M
M I GSMDIB D IDT B M DI H ND M I HDMMD I M
NDMHN BD Iwithsupersonic
DNC MOM ID motions.
H ND IM TheseC M motions
H ND IM may
H S be caused
OM either
DNC byS stellar
MN GG wind,
DI or a bipolar
D G outflow
ONAG
Afrom
H a protostellar
N MN GG disc.
DM Young
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wereidentified
andclassified
in
the
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under
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Twostar-forming
regions
wereidentified.
One
of
them
is
MN GG
NM
D INDADI G MMDAD DI NC
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MN A HDIB BD IM
D INDAD
4I A NC H DM aregionstar Aformation
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No Class I or II protostars or stars
The aim of this work is to continue the study ofbrighter than 23 mag are found in thisstar-forming regions in walls of an expanding
region(1) the stellar wind from
[SII]6717,6731 VLSR
supershell formed by the wind and the UV
the point source
radiation of stars in the Cyg OB1 association(2) a bipolar outfow fromthe protostellar disc of aClass 0 protostar,

6pc

44. Alignment of a circumbinary disc around an eccentric binary with application to KH 15D
J. L. Smallwood Accepted by MNRAS
We analyse the evolution of a mildly inclined circumbinary disc that orbits an eccentric orbit binary by means of smoother particle
hydrodynamic (SPH) simulations and linear theory. We show that the alignment process of an initially misaligned circumbinary discaround an eccentric orbit binary is significantly different than around a circular orbit binary and involves tilt oscillations. The more
eccentric the binary, the larger the tilt oscillations and the longer it takes to damp these oscillations. A circumbinary disc that is
only mildly inclined may increase its inclination by a factor of a few before it moves towards alignment. The results of the SPH
simulations agree well with those of linear theory. We investigate the properties of the circumbinary disc/ring around KH 15D. We
determine disc properties based on the observational constraints imposed by the changing binary brightness. We find that the
inclination is currently at a local minimum and will increase substantially before setting to coplanarity. In addition, the nodal
precession is currently near its most rapid rate. The recent observations that show a reappearance of Star B impose constraints on
the thickness of the layer of obscuring material. Our results suggest that disc solids have undergone substantial inward drift andsettling towards to disc midplane. For disc masses ~ 0.001M⊙, our model indicates that the level of disc turbulence is low ≪ 0.001.
Another possibility is that the disc/ring contains little gas.

retrograde
progradetest particle

45. Magnetic stability of massive star forming clumps in RCW 106
Shohei Tamaoki et al. Accepted by Astrophysical Journal Letters
The RCW 106 molecular cloud complex is an active massive star-forming region where a ministarburst is taking place. We examined its
magnetic structure by near-IR polarimetric observations with the imaging polarimeter SIRPOL on the IRSF 1.4 m telescope. The global
magnetic field is nearly parallel to the direction of the Galactic plane and the cloud elongation. We derived the magnetic field strength of~ 100‒1600 μG for 71 clumps with the Davis-Chandrasekhar-Fermi method. We also evaluated the magnetic stability of these clumps
and found massive star-forming clumps tend to be magnetically unstable and gravitationally unstable. Therefore, we propose a newcriterion to search for massive star-forming clumps. These details suggest that the process enhancing the clump density without anincrease of the magnetic flux is essential for the formation of massive stars and the necessity for accreting mass along the magnetic
field lines.

D=3.6kpc
M=6x10^6Msol
Mcl~10^3Msol
ministarburst
D-C-F Method

71クランプ100~1600μG

Angular Dispersion Function
H-band vectors within 2′, ~2‒3 times theclump R, from the clump center to makethe fit.

銀河⾯に平⾏

46. Is there more than meets the eye? Presence and role of submicron grains in debris discs
Philippe Thebault and Quentin Kral Accepted by Astronomy and Astrophysics
The presence of sub-micron grains has been inferred in several debris discs, usually because of a blue colour of the spectrum inscattered light or a pronounced silicate band around 10μm, even though these particles should be blown out by stellar radiation pressure
on very short timescales. So far, no fully satisfying explanation has been found for this apparent paradox. We investigate the possibility
that the observed abundances of sub-micron grains could be naturally produced in bright debris discs, where the high collisional activity
produces them at a rate high enough to partially compensate for their rapid removal. We also investigate to what extent this potential
presence of small grains can affect our understanding of some debris disc characteristics. We used a numerical collisional code to follow
the collisional evolution of a debris disc down to sub-micron grains far below the limiting blow-out size sblow. We considered compact
astrosilicates and explored different configurations: A and G stars, cold and warm discs, bright and very bright systems. We thenproduced synthetic spectra and spectral energy distributions, where we identified and quantified the signature of unbound sub-micron
grains.We find that in bright discs (fractional luminosity >~10−3) around A stars, the number of sub-micron grains is always high enoughto leave detectable signatures in scattered light where the disc colour becomes blue, and also in the mid-IR (10 ≤ λ ≤ 20μm), where
they boost the disc luminosity by at least a factor of 2 and induce a pronounced silicate solid-state band around 10μm. We also showthat with this additional contribution of sub-micron grains, the spectral energy distribution can mimic that of two debris belts separated
by a factor of ~ 2 in radial distance. For G stars, the effect of s ≤ sblow grains remains limited in the spectra although they dominate thegeometrical cross section of the system. We also find that for all considered cases, the halo of small (bound and unbound) grains that
extends far beyond the main disc contributes to ~ 50% of the flux up to λ ~ 50μm wavelengths.

47. A centrally concentrated sub-solar mass starless core in the Taurus L1495 filamentary complex
Kazuki Tokuda et al. Accepted by PASJ
The formation scenario of brown dwarfs is still unclear because observational studies to investigate its initial condition are quite limited.
Our systematic survey of nearby low-mass star-forming regions using the Atacama Compact Array (aka Morita array) and the IRAM 30 m
telescope in 1.2 mm continuum has identified a centrally concentrated starless condensation with the central H2 volume density of ~106
cm−3, MC5-N, connected to a narrow (width ~0.03 pc) filamentary cloud in the Taurus L1495 region. The mass of the core is ~0.2-0.4 M⊙,
which is an order of magnitude smaller than typical low-mass prestellar cores. Taking into account a typical core to star formation
efficiency for prestellar cores (~20-40%) in nearby molecular clouds, brown dwarf(s) or very low-mass star(s) may be going to be formedin this core. We have found possible substructures at the high-density portion of the core, although much higher angular resolution
observation is needed to clearly confirm them. The subsequent N2H+ and N2D+ observations using the Nobeyama 45 m telescope haveconfirmed the high-deuterium fractionation (~30%). These dynamically and chemically evolved features indicate that this core is on theverge of proto-brown dwarf or very low-mass star formation and an ideal source to investigate the initial conditions of such low-mass
objects via gravitational collapse and/or fragmentation of the filamentary cloud complex.

48. On the Mass Function, Multiplicity, and Origins of Wide-Orbit Giant Planets
Kevin Wagner, Daniel Apai, and K. M. Kratter Accepted by ApJ
A major outstanding question regarding the formation of planetary systems is whether wide-orbit giant planets form differently thanclose-in giant planets. We aim to establish constraints on two key parameters that are relevant for understanding the formation of wideorbit planets: 1) the relative mass function and 2) the fraction of systems hosting multiple companions. In this study, we focus on
systems with directly imaged substellar companions, and the detection limits on lower-mass bodies within these systems. First, we
uniformly derive the mass probability distributions of known companions. We then combine the information contained within thedetections and detection limits into a survival analysis statistical framework to estimate the underlying mass function of the parent
distribution. Finally, we calculate the probability that each system may host multiple substellar companions. We find that 1) thecompanion mass distribution is rising steeply toward smaller masses, with a functional form of N ∝ M−1.3±0.3, and consequently, 2)
many of these systems likely host additional undetected sub-stellar companions. Combined, these results strongly support the notionthat wide-orbit giant planets are formed predominantly via core accretion, similar to the better studied close-in giant planets. Finally,
given the steep rise in the relative mass function with decreasing mass, these results suggest that future deep observations should unveil
a greater number of directly imaged planets.

49. APEX Observations of the CO Envelope around the Young FUor-type Star V883 Ori
J.A. White et al. Accepted by ApJ
The accretion-driven outbursts of young FU Orionis-type stars may be a common stage of pre-main sequence evolution and can have asignificant impact on the circumstellar environment as it pertains to the growth of solids and eventually planets. This episodic accretion isthought to be sustained by additional gas in-falling from the circumstellar envelope and disk. We present APEX observations of the CO gas
in the envelope around V883 Orionis, a young outbursting star. The observations mapped the 12CO (4‒3), 12CO (3‒2), and 13CO (3‒2) lines
with the FLASH+ instrument and the 12CO (6‒5) line with the SEPIA instrument. We detected high signal-to-noise emission extending out
to radii >10000 au and calculated integrated fluxes of 1100 Jy km s−1 for 12CO (6‒5), 2400 Jy km s−1 for 12CO (4‒3), 1600 Jy km s−1 for
12CO (3‒2), and 450 Jy km s−1 for 13CO (3‒2). We used the thermo-chemical code PRODIMO to test several models and find the data are
best described by an envelope structure with Menv ≈ 0.2‒0.4 M⊙ and a mass-infall rate of ˙Minf = 1‒2 × 10−6 M⊙ yr−1. We infer thatthe observed envelope and outflow structure around V883 Ori could be caused by multiple outbursts, consistent with episodic accretion.

50. The Ophiuchus DIsk Survey Employing ALMA (ODISEA): Disk Dust Mass Distributions across Protostellar
Evolutionary Classes
Jonathan Williams et al. Accepted by Astrophysical Journal Letters
As protostars evolve from optically-faint/infrared-bright (Class I) sources to optically-bright/infrared-faint (Class II) the solid material intheir surrounding disks accumulates into planetesimals and protoplanets. The nearby, young Ophiuchus star-forming region contains
hundreds of protostars in a range of evolutionary states. Using the Atacama Large Millimeter Array to observe their millimeter continuum
emission, we have measured masses of, or placed strong upper limits on, the dust content of 279 disks. The masses follow a log-normal
distribution with a clear trend of decreasing mass from less to more evolved protostellar infrared class. The (logarithmic) mean Class I disk
mass, M = 3.8M⊕, is about 5 times greater than the mean Class II disk mass, but the dispersion in each class is so high, σlogM ≃ 0.8 − 1,that there is a large overlap between the two distributions. The disk mass distribution of flatspectrum protostars lies in between Class I and
II. In addition, three Class III sources with little to no infrared excess are detected with low disk masses, M ≃ 0.3M⊕. Despite the clear
trend of decreasing disk mass with protostellar evolutionary state in this region, a comparison with surveys of Class II disks in other regions
shows that masses do not decrease monotonically with age. This suggests that the cloud-scale environment may determine the initial disk
mass scale or that there is substantial dust regeneration after 1Myr.
Class ごとの⽐較

Class II同⼠の⽐較

51. Enlarging habitable zones around binary stars in hostile environments
Bethany A. Wootton and Richard J. Parker Accepted by MNRAS
Habitable zones are regions around stars where large bodies of liquid water can be sustained on a planet or satellite. As many stars
form in binary systems with non-zero eccentricity, the habitable zones around the component stars of the binary can overlap and beenlarged when the two stars are at periastron (and less often when the stars are at apastron). We perform N-body simulations of theevolution of dense star-forming regions and show that binary systems where the component stars originally have distinct habitablezones can undergo interactions that push the stars closer together, causing the habitable zones to merge and become enlarged.
Occasionally, overlapping habitable zones can occur if the component stars move further apart, but the binary becomes more eccentric.
Enlargement of habitable zones happens to 1‒2 binaries from an average initial total of 352 in each simulated star-forming region, anddemonstrates that dense star-forming regions are not always hostile environments for planet formation and evolution.