The Migrating Embryo Model for Disk Evolution
Shantanu Basu and Eduard I. Vorobyov / Accepted by Meteoritics and Planetary Science
http://arxiv.org/abs/1211.0625(Review論文)

Astronomy&Basu and Vorobyovof 25 – 200 AU. These models employ a barotropic relation Astrophysics
between pressure and density,

分子雲コアからの収縮で出来た円盤を考えたモデルによって幾つかの減少が説明できる。
(Basuはコアからの円盤計算の数値計算をやっている人)

1. コアから円盤への質量降着→再帰的重力不安定→クランプ形成, クランプは重力トルクで落ちる
クランプによってギャップが出来れば伴星やガス惑星も説明できる。

which makes a smooth transition from the early isothermal regime to a late adiabatic regime. So
2. さらに、クランプが複数できると小さな惑星が飛ばされて浮遊惑星も説明できる。
the treatment of thermal physics is more simplified in this model than in those presented in the
3. クランプの降着を考慮すると、高温ガスが外からうちに運ばれる
previous and subsequent sections.

4. →こういうクランプは岩石惑星の形成も説明できる。

mass star-forming region: radial velocities,
nces, and accretion properties!,!!

1 , E. Covino1 , A. Frasca2 , F. Getman1 , and L. Spezzi3

ry, via Moiariello, 16, 80131 Napoli, Italya S. Sofia, 78, 95123 Catania, Italy
Schwarzschild-Str. 2, 85748 Garching bei München, Germany
2012
ABSTRACTtal abundances, and accretion properties of members of star-forming regions is imtary formation. While infrared observations reveal the evolutionary status of the disk,
II low-mass
region:velocities,
elemental
abun- dances, andnformationThe
onChamaeleon
the propertiesof thestar-forming
central star
andradialon theaccretion
characteristics.
accretion properties
tzer c2d survey
the Chamaeleon
II dark cloud
have
provided
disk properties of aFig. 3.ofFormationof a giant protoplanetwith mass≈  5  M
J and mean  orbit  distance  ≈  55  AU.
-2ese data withoptical
spectroscopy
withElvira
theg cmaim) of
providingphysicalstellarparameKatia
Biazzo1,
Juan
Covino1,
Antonio
Frasca2,Getman1and LoredanaShown
is thegas Manuelsurface Alcal1,density(inin the600 times
600 Fedor
AU box(top panels)
and 400

Spezzi3
times 400 AU box (bottom panels) at several consecutive times after the formation of the centralstar.
ES/GIRAFFE
spectroscopicof 40 members of the Chamaeleon II starAcceptedby Astronomyobservations
and Astrophysics
http://ads.nao.ac.jp/abs/2012A%26A...547A.104B
ugh cross-correlation
technique, lithium abundances by means of curves of growth,2MASSとSpitzerのデータを使って、Chamaeleon
II darkcloudtheの若い星を解析。 widths of theFe, Al, Si, Ca,Ti, 3andNi using
code
MOOG.
FromFigure
presents
the gasthe
surfacedensitymaps (ing cm–2) inequivalenta model with initial core mass Mc =・元素組成を測定 リチウム量など。
mission lines,0.9
weMestimate
the mass accretion rates, Ṁaccmagnitude, for all theobjects.
β = 1.3
× 10–2at six evolution☉and ratio of rotational to gravitational energy
times afterII
thestars,formationof theTherotation(notes−1thatwe zoom
for the Chamaeleon
whichis disk.
peakedat "Vradis# counterclockwise= 11.4 ± 2.0 km. We
find in at
・星のradial velocity
distributionを測定。
結果は
これは、ガスの−0.82
thebottomrow).
Severalfragments
condenseintheouterpartsofthespiralarms
as
early
ge
in the∼0.1−1.0 M' mass regime, as well as a mean mass accretion rate foras 0.09
radial velocity(~10-12km/s)と速度分散(1-2km/s)と一致。
Myr after disk formation, but none of them have survived by the end of the embedded phase at. We also Hα,establish
a relationship between the He  λ7065 Å line emission and theHβなど輝線を用いて質量降着率を測定。結果
0.16
Myr when about 75% - 80% of the envelope has been accreted by the disk. They are all
driven into the sink cell via a very efficient exchange of angular momentum with the spiral arms,

f stars and gas
in Chamaeleon
II areFUconsistent.
The
spreadandin BasuṀacc 2005,
at a given
possiblyleading to multiple
Orionis bursts(Vorobyov2006) orstellar
forminggiantandicyplanets
onverycloseorbits(Nayakshin2010a,2010b).
The
byproductof theseot be ascribed entirely to short timescale variability. Analyzing the relation between
is disk expansion
to thedisk
conservation
angularmomentum.
Whenmass loading
ands, we findbursts
indications
that thedue
innerchangesoffrom
optically
thick
tothe
optically
from the envelope diminishes and the burst phase ends, this expansion is followed by transientg region to measure radial velocities through cross-correlation technique, lithium abundances by ma suitable star elemental abundances of Fe, Al, Si, Ca, Ti, and Ni using the code MOOG. From th, and the He  λ5876, λ6678, λ7065 Å emission lines, we estimate the mass accretion rates, Ṁacc , fos. We derive a radial velocity distribution for the Chamaeleon II stars, which is peaked at "Vrad # = 1
encies of Ṁacc ∝ M$1.3 and of Ṁacc ∝ Age−0.82 in the ∼0.1−1.0 M' mass regime, as well as a meeleon II of Ṁacc ∼ 7+26
× 10−10 M' yr−1 . We also establish a relationship between the He  λ7065−5Scattering of small bodies by planets: a potential origin for exozodiacal dust ?
on luminosity.
sions. TheAmy
radialvelocity
distributions
ofandstars
andThebault2
gas in Chamaeleon II are consistent. The sprea
Bonsor1,Jean-Charles
Augereau1
Philippe
about one order of magnitude and can not be ascribed entirely to short timescale variability. Analy
主系列星の周りで観測されるexozodiacal dust (赤道上空のダスト？)を説明するN体計算。
d the colors
in Spitzer c2d and 2MASS bands, we find indications that the inner disk changes from
微惑星ベルトの衝突カスケードで説明できるかどうかを考えた。
−10Ṁacc ∼ 10 M' yr−1 . Finally, the disk fraction is consistent with the age of Chamaeleon II.
(普通に考えると、観測で受かるようなダストは衝突か、輻射で飛ばされるかで寿命が短いため説明は難し

ords. accretion,accretion disks – stars: pre-main sequence – stars: low-mass – stars: abundances –い。)

inematics アイディア：外側に置いた微惑星ベルトが惑星によって散乱されて内側に飛ばされることで観測を説明す
and dynamics – open clusters and associations: individual: Chamaeleon IIction

る。
結果：低質量惑星が複数いると説明できるかもしれない。

references therein). In addition, theHigh SiO abundance in the HH212 protostellar jet
important to understand the planef accretion properties of members of star-forming the efficiency of dispersal of circ
S. Cabrit1, C. Codella2,3, F. Gueth4 and A. Gusdorf1Rs) is important for our understanding of stellar to depend on stellar metallicity i
Accepted
by A&A,infrared
Letters to theEditor
ry formation.
Whileobservations
provide tion of planetesimals around stars
on the structureof the circumstellar disk, the ac- (Ercolano & Clarke 2010). Simult
http://arxiv.org/abs/1211.1258
erties can be retrieved from photometry and spec- cretion rates and elemental abunda
HH212 ; jetの根本がSiOで見えている天体で、jetの起源は円盤からの磁気遠心力起源(molecular)を示唆してng primary
diagnostics, such as UV excess emis- ters are therefore crucial to shed liいる。この論文ではSiOの量にさらなる制限を与える。
Gullbring今までの制限：bipolar
et al. 1998; Rigliaco
et al. 2011a), the in disk
dispersal(inclinationand planetaryform
jet のピーク位置は500-1000AU, systemic 10km/s= 最大速度150km/s
4°
mer continuumand Balmer jump (e.g., Gullbringを仮定)、幅<90AU、opening angle < 4-6°、
The Chamaeleon II (hereafter
Herczeg &Hillenbrand2008;
Rigliaco et al. 2011b),
低速jet: systemic 6 km/sのbow-shockも見えている。->
slow wide-angle jet をprefer -> 時期遠心力の方がy tracers,説明できる。
like hydrogen recombination lines (Hα, tance of 178 ± 18 pc (Whittet et9, Paβ, Brγ),and the He , Ca , Na  lines (e.g., main clouds of the Chamaeleon com
今回の注目点：Siが原子で存在しているか、分子で存在しているかどうか。
extends over ∼2 deg2 in the sky (st al. 1998a,b;
Natta radius
et al.
2006; Fang etlaunchingal. 2009;
dust sublimation~ 0.2AUであるので、jetpointの位置が中心星に近ければsiliconが原子とal. 2011b;して気相にいる。
Antoniucci et al. 2011). The rate at which review). The population of Cha IIstar accretes from disk material has been found to T Tauri stars (CTTSs), ∼ten weakは elemental siliconの10-40%以上であることがわかった。
ly scale 今回の結果：SiOwith the squareof the stellar mass and to an intermediate-mass Herbig Ae s
これは、従来のMHD wind + dusty/dust free chemical 計算とは合わない。(そんなにたくさんSiOは出てこなh age (see,e.g., Herczeg & Hillenbrand 2008, and e.g., Garcia Lopez et al. 2011),
い)ので、challengingだ。
(Alcalá et al. 2008, and reference
objects, and references therein) an FLAMES(GIRAFFE+UVES)ATLASGAL— Compact source observations
catalogue: 330 < l collected< 21 degrees
Large Telescope (VLT; Paranal, Chile). Program (Spezzi et al. 2008, and reference
Y. Contreras1,2, F. Schuller2,3, J.S. Urquhart2, T. Csengeri2, F. Wyrowski2, H. Beuther4, S.
the five SFRs included in the Spi
A).
Bontemps5, L. Bronfman1, T. Henning4, K.M. Menten2, P. Schilke6, C.M. Walmsley7,8, M. Wienen2, J.
Tackenberg4 andH. Linz4–7, and Appendices
A andB are available in electronic program “From Molecular Cores toEvans et al. 2003; Young et al. 2005://www.aanda.org
http://arxiv.org/abs/1211.0741
Article published by EDP Sciences

Inner Galactic Planeのサブミリ観測のカタログ。観測に使用したのはLABOCAで、波長は870μm(345GHz)。
6639個のcompact sourceを発見。IRAS,MSXカタログとのマッチングも行った。赤外で受かっている(星形成をしている)クランプもたくさんあるが、そうでない冷たいガスクランプの情報も含んでいるので、大質量星形成の若い段階を見るのにこのカタログは適しています。