Antarctic 10‐m Terahertz Telescope Project
Nario Kuno
University of Tukuba
Naomasa Nakai1, Masumichi Seta2, Tom Nitta1, Makoto Nagai1,Hiroaki Imada1, Yutaro Sekimoto3, Kazuo Sorai4
and Antarctic astronomy consortium
1University of Tsukuba.
2Kwansei Gakuin University.
3National Astronomical Observatory of Japan.
4Hokkaido University.

Outline
1. Astronomy from Antarctica
2. Antarctic 10‐m Terahertz Telescope Project
2.1 Science targets
2.2 Specifications of 10‐m telescope
2.3 Schedule1. Astronomy from Antarctica

Plateau of Antarctica (>3000m)⇒ Good place for astronomical observations
Dome F (3810m)(Japan)Ridge A (4050m)(USA)
Dome A (4090m)(China)South Pole (2835m)(USA)

Dome C (3230m)(France & Italy)

Advantages of Antarctica for Astronomy (1)• Temperature is lowest on Earth@Dome Fuji

(Yamauchi et al. 2003)⇒ Infrared sky background is lowest (2.2‐30μm)

Advantages of Antarctica for Astronomy (2)• Temperature is lowest on Earth⇒ Precipitable water vapor (PWV) is lowest
StationDome A

PWV
Winter 25%
0.10 mm

Dome C0.15
South Pole 0.23
Chajnantor 0.35
(Chile)Mauna Kea 1.0

Winter 50%
0.14 mm
0.24
0.32
0.60
1.5

(W. Saunders, et al. 2009 PASP 121, 976)
(H.Yang, et al. 2010 PASP 122, 490)

⇒ Most transparent sky (3μm‐3mm)

6Sky transmission (calculations)
THz

Submm
300μm

150μm 100μm

Dome Fuji
200K, 0.10mm

60μm

Wave length

Winter 25%

Dome Fuji
200K, 0.14mm
Winter 50%
Optical depth=1Mauna Kea
270K, 1.5mm
Winter 50%

Frequency
Chajnantor（Chile）
260K, 0.60mm

7Advantages of Antarctica for Astronomy (3)• High stability of the sky background

Optical depth

Chajnantor
Chile（5000 m）

South pole（2840 m）

Mauna Kea
Hawaii（4000 m）

860 GHz = 350 μm(Peterson etc 2003 PASP 115, 383)

8

Advantages of Antarctica for Astronomy (4)• Wind is not strong(Wind degrades pointing accuracy of telescope)
Dome Fuji

Syowa:6.5m/s

Chile(5000m): Average 6.1m

Asuka F
13m/s

Dome Fuji
5.8m/s⇒ Good telescope pointing

F

Wind speed (m/s)
9Antarctica
Dome F (3810m)(Japan)Ridge A (4050m)(USA)
Dome A (4090m)(China)South Pole (2835m)(USA)

Dome C (3230m)(France & Italy)*Concordia Station

French‐Italian Concordia Station@Dome C
Hosting capability
Summer: 80 (incl. « summer camp »)Winter: 16 (2 for our project?)2. Antarctic 10‐m Terahertz
Telescope Project2.1 Science targets
Survey of distant galaxies– Submm galaxies• found at submm (dust thermal emission)
but dark in optical⇒ Young distant galaxies
obscured by interstellar
dust⇒ evolution of galaxies

Survey at Summ & THz

Color: OpticalContour: Submm(Blain et al. 2002)• Submm & THz observations of submm galaxies– Dust thermal emission– Redshifted by cosmic expansion• Flux measurements in Wien regime– Redshift/Distance– Dust temperature

Atomic and molecular emission lines

Atomic and molecular emission lines• [CI]：diffuse molecular gas → molecular cloud formation• High excitation CO lines：warm and dense gas → star forming region• [NII]：good indicator of star formation rate
Wide area mapping：Milky Way, nearby molecular clouds⇒ evolutionary process of interstellar medium[NII]
Main sequence star

CORed giantProtostar

Molecular cloud[CI]Atomic gas

Planetary Nebula

Supernova

SN remnant
Black hole, Neutron starWhite dwarf2.2 Specifications of 10‐m Telescope
••••
•
•

Diameter：> 10m
Surface accuracy：< 20μm
Frequency：200GHz‐1.3THz
Field of view：1°
Pointing accuracy：2″
Tracking accuracy：0.5″
Angular resolution（10m）200GHz800GHz1.3THz37″

9.3″5.8″

Wide Field Radio Camera• MKID(Microwave Kinetic Inductance Detector)– NEP =ିଵ଼720 pixel – 220 GHz

220 GHz Beam pattern(Nitta et al. 2013)

Wide Field Radio Camera

600 pixels
FOV～0.1°

3000 pixels• 410GHz, 850GHz, 1.3THz– simultaneous observations

20,000 pixels
FOV～1°

Heterodyne receivers• 230GHz、450GHz、800GHz、1THz、1.3THz– Tsys: ~280K@500GHz, ~600K@800GHz• 2 polarization/2 band simultaneous observation• Single beam ⇒ multi‐beamCO(4‐3), [CI]3P1‐3P0
CO(7‐6), [CI]3P2‐3P1
CO(8‐7)
CO(11‐10)
NII

Advantages of Antarctica 10‐m Telescope• vs. ALMA (@Chile)– Better transmission and stability of sky ⇒ THz obs.
– Wide field of view (1°vs. 1’) ⇒ Wide area mapping• vs. Hershel (Satellite)– 10m vs. 3.5m
⇒ Higher spatial resolution⇒ galaxy survey：lower confusion limit⇒ star forming region：more distant dense core– （upgrade of instruments is possible）

2.4 Schedule• 2016• 2017• 2018• 2019• 2020• 2021• 2022• 2023

Budget request
Design & Fabrication
Construction @ Univ. of Tsukuba
Test & Adjustment
Transport to Antarctica
Construction @Dome C

Antarctic astronomy consortium＊Univ. of Tsukuba＊Tohoku Univ.
＊National Institute of Polar Research＊National Astronomical Observatory of Japan＊Kwanseigakuin Univ. ＊Hokkaido Univ.
＊Saitama Univ.
＊Rikyyo Univ.
＊Kanazawa Univ.
＊Nihon Univ.
＊Niigata Institute of Technology＊Japan Aerospace Exploration Agency＊Fukushima National College of Technology

Difficulties in Antarctica (1)• Low temperature ⇒ ice/frost

Durand et al. (2008)

Difficulties in Antarctica (2)• Accumulation of snow
⇒ high‐floored

AST/RO (Tothill et al. 2007)
10 years later• SPT @south pole（2007～）（USA）（South Pole Telescope）– Diameter：10m– Bolometer array– 90GHz, 150GHz, 230GHz– CMB、SZ、submm galaxies

• COCHISE @ Dome C （2010～）（Italy）（Cosmological Observations at Concordia with
Highsensitivity Instrument for Source Extraction）– D：2.6m– 200μm‐3mm– 2ch bolometer
＠2mm、1.25mm– CMB(Sabbatini et al. 2011)• HEAT @ Ridge A （2012～）（USA, Astralia）（High Elevation Antarctic Terahertz Telescope)– Remote observations（no station）– D：62㎝– 492GHz, 809GHz– CO、[CI]、([CII])

http://soral.as.arizona.edu/HEAT/instrument/

アンテナ基礎• 吹きだまり ⇒ 高床
• 基地との位置関係– どこに雪がたまるか？
AST/RO (Tothill et al. 2007)
10年後

SPT（South Pole Telescope）

• 安定な基礎が作れるか？

（金 極地研）• COCHISE

霜対策– 赤外線ヒーター＋ブロワ―＋電熱線ヒーター（Durand et al. 2008）• SPT– パネルの裏のヒーターで常に外気より1‐2度高めに暖めているPrecipitable water vapor
APEX (Chajnantor) 2012
APEX (Chajnantor) 2013
Ridge A, 2013

Chajnantor (Chile)

810GHz@Ridge A
Ridge Ａ (Antarctica)
Median (Winter )0.13mmSummer

WinterKulesa (2013)

Optical depth

Optical depth

Dome Fuji

220GHz@Dome Fuji
measured in 2006 and 2009 summer

Atacama（Chile 5000m）

SummerIshii et al. (2010)？

Winter36

Stability of sky background
860 GHz = 350 μm

South pole

(Peterson et al. 2003 PASP 115, 383)

Chajnantor

Excellent!
→ important for continuum
observations and interferometer
Mauna Kea37