第４回可視赤外線観測装置技術ワークショップ
2014. 12. 3, 国立天文台三鷹すばる棟大セミナー室

東京大学木曽観測所超広視野高速CMOSカメラ
Tomo-eの開発

酒向 重行(Institute of Astronomy, the University of Tokyo)
andthe Tomo-e Gozen project team:

M. Doi, K. Motohara, T. Miyata, N. Kobayashi, T. Morokuma, H. Takahashi, R. Osawa, T. Aoki, T. Soyano, K. Tarusawa, H. Maehara, H. Mito,
Y. Nakada, S. Todo, Y. Kikuchi, (IoA, U Tokyo), F. Usui, N. Matsunaga (DoA, U Tokyo), M. Tanaka, J. Watanabe (NAOJ), N. Tominaga (KonanU), Y. Sarugaku, K. Arimatsu (ISAS/JAXA), Y. Ita, H. Onozato, T. Hanaue, H. Iwasaki (Tohoku U), S. Urakawa (Japan Spaceguard Association),
H. Kawakita, S. Kondo (Kyoto Sangyo University)

次の時代、秒角、国内、可視光、口径シーイングｍ、1

後追いでは、勝てない。

間違いなく言えること、で、何ができると言うのか？

4

Outline□ Overview of Kiso wide-field CMOS camera, Tomo-e□ Development of Tomo-e□ New science capability with Tomo-eKiso Observatory
Kiso Observatory, the University of Tokyo

the Tomoe Gozen
Kiso Observatory

KisoObservatory
Mitaka Head quarters
Institute of Astronomy

Dome for 1m telescope Established in 1974
 Open use operation
 Dark sky, 1,120m altitude
 Accommodation, Cafeteria

Kiso Observatory, Institute of Astronomy, School of Science, the University of Tokyo

Main buildingKiso 105 cm Schmidt Telescope
Kiso Observatory, the University of Tokyo

Extremely wide field telescope Field of view : φ 9 degrees
 Primary :150 cm spherical mirror

 Corrector :105 cm aperture Focal ratio :3.1

Photographic plate(36 cm x 36 cm)
used until the 1990s

Kiso Observatory, Institute of Astronomy, School of Science, the University of Tokyo

the Tomoe Gozen
Kiso ObservatoryKWFC: Kiso Wide Field Camera
Kiso Observatory, the University of Tokyo•

8 CCD chips with 8k x 8k pixels•F.O.V of 4.8 deg2 (2.2 deg. x 2.2 deg).

•Open use operation started in April 2012

Read noise•

Fully automatic observation system using queue lists

Dark current

Pixel scale
CCDs

the Tomoe Gozen
Kiso Observatory

0.946 arcsec/pix
2k x 4k MIT x 4
2k x 4k SITe x 4
5 – 10 e- (MIT),20 e- (SITe)< 5e- / hour @-100 deg

Kiso Observatory, Institute of Astronomy, School of Science, the University of Tokyo

Field of View
Kiso Observatory, the University of TokyoZTF (1.2m) , 47 deg2 (2016-)

the Tomoe Gozen
Kiso Observatory

Kiso Schmidt telescope
φ 9 deg

KWFC/Kiso
4.8 deg2, CCD

iPTF (1.2m), 7.8 deg2
Pan-STARRS (1.8m), 9 deg2
LSST (8.4m), 9.6 deg2 (2023-)

Kiso new wide-field camera
20 deg2 in φ 9 deg, CMOS

Kiso Observatory, Institute of Astronomy, School of Science, the University of Tokyo

Extremely Wide-field CMOS Camera
Kiso Observatory, the University of Tokyo

the Tomo-e Gozen Camera; Tomo-e Telescope:

Kiso 105 cm Schmidt

 Field of view : 20 deg2 in φ 9 deg Sensor:

1k x 2k CMOS sensor†

 Chips:84

 Pixel scale :1.2 arcsec/pix

 Frame rate :2 frames/sec (max) Filter :SDSS-g+r, SDSS-g, SDSS-r ‡† Driven at ordinary temperature and pressure‡ Manually exchange between filters in the daytime

Kiso Observatory, Institute of Astronomy, School of Science, the University of Tokyo

the Tomoe Gozen
Kiso Observatory

Extremely Wide-field CMOS Camera
Kiso Observatory, the University of Tokyo

the Tomoe Gozen
Kiso Observatory

the Tomo-e Gozen Camera Telescope:

Kiso 105 cm Schmidt

 Field of view : 20 deg2 in φ 9 deg Sensor:

1k x 2k CMOS sensor†

 Chips:84

 Pixel scale :1.2 arcsec/pix

 Frame rate :2 frames/sec (max) Filter :SDSS-g+r, SDSS-g, SDSS-r ‡† Driven at ordinary temperature and pressure‡ Manually exchange between filters in the daytime

Tomo-e Gozen (Lady Tomo-e, 巴御前)

born in the Kiso region in the 12th century andknown with beauty and bravery.

Kiso Observatory, Institute of Astronomy, School of Science, the University of TokyoDetection Capability for Transient Events

10RAPTOR-Q

104

Field of View (deg2)

103

TORTORA9WIDGET

10AROMA-W
RAPTOR-A/B

12

Pi of the Sky
MASTER-Net

109

FAVOR

101012

MASTER-VMF
BOOTES

12very small telescope

102
Tomoe

[Very fast]

101

Tomoe
[Fast]

16.8

15

Tomoe

[Normal]Tomoe[Slow]

15

GW optical counter parts
Flaring stars
GRBs
Satellite, Debris
Meteors
White dwarfs
Neutron stars
Occultation of TNOs

ZTF

Tomoe

[CoAdd]LSSTPTF

22 25 202320

Skymapper

TAOS-II

10-1

1918.7

17.6Pan-STARRS

100

progressive CCD

interlaced CCD or CMOS

Blanco/Decam
Subaru/Hyper Suprime-Cam

100

101

Time scale (sec)2020

KISO/KWFC

25 22SDSS102

The numbers in the circles indicate
limiting magnitudes.

Targets of Tomo-eKiso Observatory, the University of Tokyo

the Tomoe Gozen
Kiso Observatory

Rare and Transient Phenomena
 Shock Breakout of core-collapse SN
 Explosion of Nova
 Optical follow up of Gravitational wave
 Afterglow of Gamma-ray burst

Occultation by TNO

Gamma ray burst

Neutron star marger  GW

Planet transit

 Optical candidate of fast radio burst
 X-ray time variable objects
 Transit of Exoplanet Occultation by Trans-Neptune object
 Potentially Hazardous Asteroid
 Faint meteor
Kiso Observatory, Institute of Astronomy, School of Science, the University of Tokyo

Outline□ Overview of Kiso wide-field CMOS camera, Tomo-e□ Development of Tomo-e□ New science capability with Tomo-eFocal Plane
Kiso Observatory, the University of Tokyo

480 mm12’

the Tomoe Gozen
Kiso Observatory

40’

12’
12’

2000 x 1128 pix

530 mmx 84 chips

23’12’35mm Full HD CMOS sensor

sensor / package area = 0.3• Total sky coverage 20 deg2
• Total 190 Mpixels
φ 9 degree
vignetting 0.44mag

φ 4 degree
vignetting free area

• 760 MB/exposure

Kiso Observatory, Institute of Astronomy, School of Science, the University of Tokyo

CMOS Imaging Sensor
Kiso Observatory, the University of Tokyo

the Tomoe Gozen
Kiso Observatory

Specification

35 mm full HD CMOS sensor

developed by Canon and U-Tokyo
based on products for commercialuse.

- Low dark current at Room temperature- Low readout noise in Fast frame rate

Pixels2000 x 1128

Pixel size

19 μmArchitecture

Front side illuminated + micro lens array

Surface protection

Cover glass with AR coating

Output16 ch differential analog out

Internal amplifier

G = x1, x4, x16, x64, x256

Frame rate

30 fps (max)Read out mode

Rolling read out

Power dissipation

1.8 W @30 fps

QE (Aη)0.45 @λpeak=500nm, 0.25 @λ=380, 700nm

Read out noise

2.3 e- rms @30 fps @G = x16

Dark current

0.05 e-/pix/sec @273 K

Saturation

55,000 e-/pix @G = x1
5,700 e-/pix @G = x16

Filling factor

Sensor area/Package area = 0.3Package size

60.9 mm x 44.6 mm

Kiso Observatory, Institute of Astronomy, School of Science, the University of Tokyo

Evaluations of Front-side CMOS Sensor
Kiso Observatory, the University of Tokyo

the Tomoe Gozen
Kiso Observatory

Laboratory test and Test observations in U-Tokyo (2012-2013)-Readout noise
Cross talk, Hysteresis
Linearity, Dynamic range, Flatness
Photometric accuracy
Quantum efficiency, Sensitivity
Aperture ratio, Efficiency of micro lens
Dark current
Temperature dependence (20 – 60 degrees)

35mm Full HD CMOS sensor

FoV 40’ x 20’
CMOS sensor mounted on
Kiso Schmidt telescopeFirst light observations
2012/12/16-17

High dynamic range image
M42 Orion star-forming region
1/30 sec x1,000 frame x 2 bands

Long integration time image
NGC891 nearby edge-on galaxy
2 sec x100 frame x 5 dithers, V band

Kiso Observatory, Institute of Astronomy, School of Science, the University of Tokyo

Limiting Magnitude of Tomo-eKiso Observatory, the University of Tokyo

13 e-/s/pix
2.5 e0.05 e-/s/pix

w/ broad band on Kiso Schmidt in dark sky (20 mag/arcsec2)

Limiting magnitude of Tomo-eIntegration time (sec)Vmag

1/1015.3

117.2

1018.710019.9

Vmag
2120
Limiting magnitude

Background photons:
Readout noise:
Dark current at 273 K:

the Tomoe Gozen
Kiso Observatory

190.2 magdue todQE

18
17
16
15
140.1

- Higher sensitivity than CCD in tinteg < 10 sec.

S/N = 5, Seeing = 3”
wo/ readout dead time

110

Integration time [sec/frame]- Higher exposure efficiency expected in continues observations because ofzero readout time.
Kiso Observatory, Institute of Astronomy, School of Science, the University of Tokyo100

Photometric Accuracy
Kiso Observatory, the University of Tokyo

the Tomoe Gozen
Kiso Observatory

Measured photometric error- PSF on microlens array- 1.2 arcsec/pix- Sufficient over-sampling

σcount / object count [%]Seeing size: 3 arcsec
Derived from continues 100 frames

1030 fps
5 fps
1 fps

13%
2%
1%
Time variation ofatmospheric refractive index

103

104

105

object count [ADU]106

 Flux time-variation-

Photometric degradation originated from microlens array not confirmed.

-Photometric accuracy depends on a frame rate.
Kiso Observatory, Institute of Astronomy, School of Science, the University of Tokyo

Cross talk and Hysteresis
Kiso Observatory, the University of Tokyo

the Tomoe Gozen
Kiso Observatory• Cross talk in the same frame- Between separated pixels: < 10-8
- Between neighbor pixels: not measured• Hysteresis between frames
Image of α Aur (Vmag = 0.08)- A few second time scale: < 10-6
- Sub-second time scale: not measured

Good performance on cross talk and hysteresis confirmed

Kiso Observatory, Institute of Astronomy, School of Science, the University of TokyoConceptual Design of Camera System
Kiso Observatory, the University of Tokyo

the Tomoe Gozen
Kiso Observatory

 Thermal and structural design

 Mosaic mount of CMOS sensors

T = 273K, 1 atm

On a spherical surface of R = 3,300 mm

Ordinal pressure and Room temperature inside
the chassis

 Video readout circuit Optical alignment accuracy
λ = 420 nm

4.5 deg-100-50

0+50Defocus [μm]+100

Alignment accuracy of ± 100 μm required

6 arcsec (100μm)

FoV
center

16 bit 500 ksps/ch-Differential amplifiers and A/D convertors
Total power dissipation is 30 W.

Kiso Observatory, Institute of Astronomy, School of Science, the University of Tokyo

Data Handling and Storage
Kiso Observatory, the University of Tokyo

the Tomoe Gozen
Kiso Observatory

Large amount of data (760 MB/sec, 27 TB/night) is produced in 2 fps observation.
 Drastic reduction of raw data is required to record in storage.
 Base design of data handling system
Reduce raw data to 1/100 size

Telescope dome
Control room(1) Camera(1)

by cropping valuable image areaand co-adding 100 frames.

Rapid reduction is required(4) Secondary server withstorage for 600 nights(3) Primary server withstorage for 10 nights(2) Control PC withstorage for 1 night

(2)

(4)

(3)

Transfer raw data Transfer raw data
in day timein night time
(27 TB/day)(27 TB/night)

Operation building

Transfer reduced datain the next night time(270 GB/day)

Kiso Observatory, Institute of Astronomy, School of Science, the University of Tokyo

Time Table for Development of Tomo-eKiso Observatory, the University of Tokyo

the Tomoe Gozen
Kiso Observatory

Tomo-e will be commissioning in 2017

Sensor development

2014/4

2015/4

2016/42017/42018/4

Sensor evaluation
Data acquisition system
ChassisAssemble
Test observation↑ commissioning↑ commissioning

Kiso Observatory, Institute of Astronomy, School of Science, the University of Tokyo

Outline□ Overview of Kiso wide-field CMOS camera, Tomo-e□ Development of Tomo-e□ New science capability with Tomo-eObservation Strategy of Tomo-e(1) 1-hour-cadence all-sky monitoring(high-cadence + very-wide-field)(2) 20-fps wide-field monitoring(very-high-cadence + wide-field)(3) Synergy with high-energy astronomy(very-wide-field + quick follow-up)(4) Near and interior Earth objects(wide-field monitoring for fast moving objects)

Field of view (square degree)

Kiso Observatory, the University of Tokyo

the Tomoe Gozen
Kiso Observatory(3)

10,000(1)1,000100

10(2)
10.01

1100

10,000Time resolution (sec)

Kiso Observatory, Institute of Astronomy, School of Science, the University of Tokyo□ 1-hour-cadence All-sky Monitoring
Kiso Observatory, the University of Tokyo

the Tomoe Gozen
Kiso Observatory

Observation plan
• All sky (10,000 deg2), 1 hour cadence• Recording period: 3 years• Observation sequence:- 4 dithers x 170 pointing- short exposure (3 sec)  readout (0 sec)  dithering (2 sec)

• Limiting magnitude: Vmag ~ 18 (1 hour cadence)

Expected results

Vmag ~ 19 (1 day cadence)

φ 9 deg x 170 pointing,
1 hour cadence, 18 mag

Bright, but Rare and Fast time-variable events• Supernovae, Neutron star mergers, AGNs, Gravity lensing• Novae, Stellar flares, Eclipsing binaries, Late type star, Exosolar planets• Bursts of comets and asteroids• Unknown transient phenomena
Kiso Observatory, Institute of Astronomy, School of Science, the University of Tokyo

High-cadence All-sky SNe survey
Kiso Observatory, the University of Tokyo

the Tomoe Gozen
Kiso Observatory• Early phase light curve to constrain SN Ia progenitor• Shock breakout of core-collapse supernovae
Estimated detection rate = 1/100 SNe

explosion at core
Absolute magnitude

progenitor> a few days

breakout-22-20-180100

200300Days since bolometric peak (days)

-16

00.5

1

Days since bolometric peak (days)• Tomo-e has 5 times higher capability than KWFC/Kiss SN survey (P.I. T. Morokuma) todetect SN shock breakouts.
• Spectroscopic data of All objects discovered by this survey can be obtained by 1 – 2m class telescopes.
Kiso Observatory, Institute of Astronomy, School of Science, the University of Tokyo

Expected detection rates of Novae and SNe
Kiso Observatory, the University of Tokyo

N. Tominaga+ 2014/10• 1 hour cadence, all-sky, 18 mag
Event

the Tomoe Gozen
Kiso Observatory

Detection rate(events/year)

Early phase of Nova

2Shock breakout of C-C SN5including M31• 1 day cadence, all-sky, 19 mag
EventDetection rate(events/year)

Discovery of Nova

10including M31

Early phase of Ia SN

1,600

Mv ~ -18 mag, 260 Mpc

Early phase of C-C SN

300

Mv ~ -16 mag, 100 Mpc

Superluminous SN

30

Mv ~ -21 mag, 1,000 Mpc

SN in Near-by Galaxy

0.5

Mv ~ -11 mag, 10 Mpc

Discovery of Faint SN

unknown

Kiso Observatory, Institute of Astronomy, School of Science, the University of Tokyo□ 20-fps Wide-field Monitoring
Kiso Observatory, the University of Tokyo

the Tomoe Gozen
Kiso Observatory

Observation plan•••••

2 deg2 (partially readout) in φ 9 deg
20 frame/sec
Continuous monitoring of 10,000 stars
Recording period: 1 year
Limiting magnitude: Vmag ~ 14
2 deg2 in φ 9 deg,
20-fps, 10,000 stars

Expected results
Very bright, but Rare and Very Fast time-variable events• Stellar occultations by Solar system objects- Duration time: a few 100 msec, Rate: a few dozen events/year• Optical counterparts of Fast Radio Bursts- Duration time: ~10 msec, Rate: 0.5 events/day (when brightest case)•X-ray variable objects: AGNs, YSOs, stellar flares
Kiso Observatory, Institute of Astronomy, School of Science, the University of Tokyo

by Totani-san (privatecommunication). Note, thisflux estimation contains aninaccuracy of 7 orders.

Stellar occultations by TNOs
Kiso Observatory, the University of Tokyo

the Tomoe Gozen
Kiso Observatory• TNOs (Trans Neptune Objects) keep composition in pre-solar age.
• Bodies with km-size are important.
• It is too small to detect them even with large telescopes.

 Stellar occultations
 Fast (20 fps) wide-field monitoring by Tomo-e
A few events/year

Size and distanceof TNOs

300 msec
http://hubblesite.org/newscenter/archive/releases/2009/33/image/c/format/web_print/
Kiso Observatory, Institute of Astronomy, School of Science, the University of Tokyo□ Synergy with High-energy Astronomy
Kiso Observatory, the University of Tokyo

Gravitational wave detector
KAGRA
N-N merger?
N-B merger?
Core collapse SN?
Magnetar?

Neutrino detector
Super-Kamiokannde

the Tomoe Gozen
Kiso Observatory

Gamma-ray telescope
SWIFT, Fermi, MAXI

Nearby Supernova

Gamma-ray burst

External trigger
w/ error of arrival direction: a few degrees

Optical wide-field follow-up by Tomo-eKiso Observatory, Institute of Astronomy, School of Science, the University of Tokyo

Gravitational Wave Counterpart
Kiso Observatory, the University of Tokyo

the Tomoe Gozen
Kiso Observatory

Detectable distance < 250 – 300 Mpc
for GW from Neutron Star merger

Collapsar, Long GRB
NS/BH formation< 10 Mpc for GW

Magnetar Flare, Short GRB
NS oscillation< 10kpc for GW

Neutron Star Merger, Short GRB?
NS-NS/NS-BH< 200 Mpc for GW
KI 01, Kashiyama & KI 11

GEO600/UK-GR

KAGRA/JAPANTomo-eLIGO x2/USA

VIRGO/FR-IT

LIGO- India
In prop.

LIGO- Australia
In prop.

 Error circle of arrival direction of GW ~φ 5 deg Tomo-e can follow-up GW events with φ 9 deg

Estimation of arrival direction of gravitational wave.
Hayama (NAOJ) 2012

Kiso Observatory, Institute of Astronomy, School of Science, the University of Tokyo□ Near and Interior Earth Objects
Observation plan
• Phenomena in background• During other surveys

Expected results• Faint meteor (sporadic and meteor shower)- Rate: a few dozen events/min- Brightness distribution of meteors.
- Is the power law extended to faint meteors?

Log10 Cumulative Flux (particles m-2 s-1 2π str-1)

Kiso Observatory, the University of Tokyo

the Tomoe Gozen
Kiso Observatory??

Hughes 1978

Log10 Particles Mass of Meteor (g)• Fast moving NEOs including PHA (Potentially Hazardous Asteroid)- Moving speed: 10-100 arcmin/sec- Such fast moving asteroids are not detected by CCDs with an ordinal FoV and exposure time.
Kiso Observatory, Institute of Astronomy, School of Science, the University of Tokyo

Summary
Kiso Observatory, the University of Tokyo

the Tomoe Gozen
Kiso Observatory

Kiso Wide-field CMOS camera : Tomo-e Telescope: Field of view : Sensor: Frame rate : Commissioning : Outstanding issue:

Kiso 105 cm Schmidt
20 deg2 in φ 9 deg
84 CMOS chips
2 frames/sec (max)2017
Data handling and storage

Scientific strategies
 1-hour-cadence all-sky monitoring 20-fps wide-field monitoring
 Synergy with high-energy astronomy Near and interior Earth objects

Rare and Transient Phenomena
Sub-second Time-domain

Kiso Observatory, Institute of Astronomy, School of Science, the University of Tokyo