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TMT Exoplanet Detection and
Characterization
周济林 (Ji-Lin Zhou)
Nanjing University, [email protected]
Credit: TMT science
2015/4/8
transit spectroscopy for XO-2. credit ESA
1
What TMT can do in
exoplanet
TMT Science book
1、Protoplanetary Disk
2、Detection & transit follow-up of Exoplanet
RV, image (Dou’s report)
3、Characterization --atmosphere
Focus on Chinese Exoplanet detection
projects
2
1.Protoplanetary disk
MIRES (Mid-Infrared Echelle Spectrometer): is a diffraction-limited, high-resolution (5000 < R <
100
000) spectrometer and imager operating at 8 – 18 μm. a separate AO system optimized for
the mid-infrared.
NIRES (Near-Infrared Echelle Spectrometer): fed by NFIRAOS, NIRES is a diffraction-limited high
resolution
(20 000 < R < 100 000) spectrometer covering 1 – 2.4 μm simultaneously.
Science:

Planet formation: Gravitational
instability or core accretion?


Disk evolution
Gap opening & planet
migration
Map out the velocity of disk
3
Classical
Planet Formation Scenario
(1) gravitational instability model
Form MMSN:
<1
Boss A.
a -1/ 4
Q » 4.4( AU
)
HR 8799 system
(2) Core accretion model

Formation of km size
planetesimals

Accretion of planetesimals
into planetary embryos

Gas accretion, giant impact
Q = pkGcå < 1
www.planet.sci.kobe-u.ac.jp
Disk-planet tidal interactions
type-II migration
type-I migration
Goldreich & Tremaine (1979),
Ward (1986, 1997), Tanaka et al. (2002)
Lin & Papaloizou (1985),....
planet’s perturbation
viscous diffusion
disk torque imbalance
viscous disk accretion
1
2
æ S ö æ M ö æ10 öæ M ö æ a ö 2
o
t mig,II » çç g,SN ÷÷ ç p ÷ ç
÷ Myr
÷ç ÷ ç
è Sg ø è M J ø è a øè M* ø è1AU ø
-3
1
See, Kley et al. 2012 Annu. Rev. Astron. Astrophys.
2.Exoplanet detection (RV)
HROS (High-Resolution Optical Spectrometer): a single-object, seeing-limited, highresolution (R = 50000 for 1 arcsec slit) optical-UV echelle spectrograph
Advantage : short time to get high SNR
Science :
(1)Down to M,L type stars (HZ more close)
(2)RM-effect
(3)Transit Follow (Kepler, TESS,…)
Tusk: target list (from transit)
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III-2. Internal structure and atmosphere of planets
Tidal inflation?
R
f ~ ( R p )2
*
J
Udry & Santos 2007
HD: 67 Me /113 Me
Jup: <12Me/320Me
Charbonneau et al. Nature 2009
16 Months of Kepler Data
Batalha et al. 2012, 1202.5852
Need choose targets!
total: 2300 planets, 20% of the stars catalogued have multiple planets.
paucity of giant planets at short periods in multiple planet systems.
3. Exoplanet atmosphere
Task:
(1) More simulation:--planet radius, location
(2) Make a list for suitable candidates
(3) Habitable Earth?
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Chinese Planet Search Projects
2.16m(NAOC)
AST3
2.4m (YNO)
SDUO
BSST(?)
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2008 data: Total of ~20,000stars, we choose ~10000 stars with precision of <2%,
We find 10 most-promising candidates.
Submitted to
ApJS
According to Kepler’s results
(transiting, P<100 days)
Photometric
accuracy
Frequency of
Exoplanets
1%
0.047%
0.5%
0.085%
N:0.038%
0.1%
0.28%
sE:0.233%
CSTAR-1
P=2.04 days
R~0.5RJ
The binned phase-folded light curve (top panel) along with the
normalized BLS periodogram (bottom panel) of one CSTAR object.
The solid line in the top panel show the best-fit transit model
南大,国台,紫台等合作
CSTAR数据: 发现了56颗双星-星表
南大,国台,紫台
我们使用CSTAR2008年观测数据进行细致的光变分析,从10,000个源中找到56颗双星
并整理成双星星表,包括15个不相接双星、6个半接双星、27个密近双星和8个未分
类的可疑双星。我们还对不相接双星计算了掩星中心时刻的变化。我们将我们的结
果与Kepler发现的双星系统做了轨道参数的统计性比较,二者有相同的分布趋势。
我们发现5颗双星处于近相接演化阶段,3颗双星具有较大偏心率,并且发现一颗双
星同时具有大偏心率与明显的掩星中心时刻变化。这些结果对双星系统的形成和演
化提供了重要的参考价值。
Yang Ming, Zhang Hui & Zhou Ji-Lin*, Zhou Xu, Liu Hui-Gen, Wang Lifang, et al., Eclipsing Binary Stars from 14.5cm
Telescope at Dome A Antactica, in preparing;
Conclusion
To join in TMT in exoplanet:
(1) Group too small and weak, more persons need
to be trained:
Disk, RV, transit, exoplanet
(2) Preliminary tusk should be assigned soon
(3) Sent young persons abroad to learn

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