MOA-II 1.8m
望遠鏡の現状と将来
1,Galactic Dark Matter (LMC & SMC)
2,Galactic structure (the Bulge)
3,Exoplanets (the Bulge)
4, GRB
5, Guest Obervation
住 貴宏 （大阪大学）
MOA collaboration
Gravitational Microlensing
star
100arcsec.
If a lens is a star,
elongation of images is an
order of 100arcsec.
Just see a star magnified
lens
observer
distortion of space due to gravity
MOA (since 1995)
（Microlensing Observation in Astrophysics）
（ New Zealand/Mt. John Observatory, Latitude： 44S, Alt: 1029m ）
1995~1998:MOA-0:0.6m,MOA-cam1(9Mpix)
1999~2005:MOA-I:0.6m,MOA-cam2(24Mpix)
2005~
:MOA-II:1.8m,MOA-cam3(80Mpix)
MOA-II1.8m telescope
（New Zealand/Mt. John Observatory at NZ, 44S ）
Mirror : 1.8m (F=2.91)
CCD : 8k x 10k pix. (MOA-cam3)
FOV : 2.2 deg.2
First light：
3/2005
Survey start： 4/2006
MOA-cam3
CCD
: 8k x 10k pix. (10 E2V CCD4482)
Pixel size: 0.58 arcsec/pix (15μm)
FOV
: 2.2 deg.2
Read out : 32 sec
MOA-II filter
Observation by MOA
•50 deg.2(50Mstars)
G.C.
1obs./night.(>MJup)
•1obs./95min.(Mjup)
1obs./47min. (Mnep)
1obs./15min. (M)
600events (2010)
http://www.massey.ac.nz/~iabond/alert/alert.html
Real-time Anomaly check at Mt.John
The planet found
on 11/9/2009
anomaly
10 events with timescale tE<２days
４７４events in 2 years
timescale： t E 
RE ( M , D)
vt
~
M / M J day
~２０days for stars
M：lens mass
MJ: Jupiter mass
D：distance
vt: velocity

tE=1.2days
~Jupiter mass
1day
Timescale tE distribution
N
 1.8
planet
abundance :~1.8 as common as stars
Mass
： 〜Jupiter mass
1.7
0.8
1.2
M planet  1.10.6 M J
Known objects
474events
Main sequence

White dwarf
Brown dwarf
Neutron star
Planetary-mass
objects
N star
Black hole
Sumi et al. 2011, Nature, 473, 7347, 349-352
Observational time&Operation rate
ゲスト観測３２時間（２０１０−２０１１）
Bulge
Operation rate = observation time / night time ≒ clear time
ゲスト観測（松岡氏、名大）
UKIDSS 赤外カタログフィールドをMOA-wideRed で観測
5分 x 347 = 32時間 （２０１０−２０１１夏）
• High z QSO 探査 ー＞宇宙再電離
• L, T型褐色矮星探査
様々な天体の二色図 (Y-J vs. I-Y)。
各赤方偏移にあるクエーサーの放射に対する銀河間空間透過率
将来計画
• Option A: カメラアップグレード
• Option B: アフリカ、南米に新望遠鏡
• WFIRST衛星(2020~)
MOA-cam4 plan
• FOV
7~10 deg.2
• Pixel size ~0.5 arcsec/pix
• Fully depleted CCD
•
•
•
現在
2011
~256M pixels (32x2kx4kCCD)= 7.04deg2
~320M pixels (40x2kx4kCCD)= 8.8deg2
~384M pixels (48x2kx4kCCD)=10.56deg2
CCD読み出し時
間
現在
計画
観測効率
32sec
16sec
1.14倍 (60秒露
出時)
長波長感
度高い
1.40倍(Redband)
32枚
(7.0平方
度)
3.20倍
量子効率（fully
depleted CCD）
CCD
(視野)
合計
10枚
(2.2平方
度)
240mm
343mm
5.10倍
Cherenkov Telescope Array (CTA)
• GRB追観測用光学望遠鏡と連携
（ナミビアor アルゼンチン）
The WFIRST Microlensing
Exoplanet Survey:
Recommended by ASTRO 2010
Decadal report
WFIRST
Kepler vs. WFIRST
WFIRST – w/ extended mission
Figures from B. MacIntosh of the ExoPlanet Task Force
Complete the census of planetary systems in the Galaxy
WFIRST’s Predicted Discoveries
~3000 exoplanets
~300 sub Earth-mass Planets,
>25 habitable planets
（0.5-10 MEarh、0.72-2.0 AU）
around FGK stars
~2000 FFP！
~190 sub Eath-mass FFP!
(>30 Earth-mass FFP！)
Free-floating rocky planets may
have liquid water, Stevenson (1999)