SPIE Astronomical Telescopes + Instrumentation 2012 : Paper 8446-270

Kiyoshi Sakimoto(a), Hiroshi Akitaya(b,*), Takuya Yamashita(c), Koji S. Kawabata(b),Hidehiko Nakaya(c), Hisashi Miyamoto(d), Tatsuya Harao(a), Ryosuke Itoh(a), Risako Matsui(a),Yuki Moritani(b), Asami Nakashima(e,c), Takashi Ohsugi(b,a), Mahito Sasada(f), Katsutoshi Takaki(a),Issei Ueno(a), Takahiro Ui(a,c), Takeshi Urano(a), and Michitoshi Yoshida(b)Photo by R. Ito(a) Department of Physical Science, School of Science, Hiroshima University, (b) Hiroshima Astrophysical Science Center,
Hiroshima University, (c) National Astronomical Observatory of Japan, (d) Molex Japan Co., Ltd., (e) The University of Tokyo,(f) Kyoto University(*) Presenter of this poster : H. Akitaya ( akitaya@hiroshima-u.ac.jp )[1] Kanata Telescope and HONIR
Kanata Telescope

Table 1: Basic parameters of HONIRIR Arm #2
Optical Arm IR Arm #1(in future)
Wavelength(μm)
0.5-1.0
1.45(1.15[1])-2.40
1.15-1.35
FOV &10’ x 10’ ;TBD
sampling
0.29”/pixel
FOV size at
the telescope
53.8 mm sq.
TBD
focus
FOV size on
30.7 mm sq.
40.9 mm sq.
TBD
the detector
B[2], V, Rc, Ic,Filters
Y, J, H[3], Ks[3]H, Ksz’, Y
CCD
HgCdTe VIRGO
Detector(HamamatsuTBD(Raytheon)
Photonics)

HONIR (Hiroshima Optical andNear-Infrared camera) (Fig. 2; Table 1) 1.5-m Ritchy-Cretien telescope at HigashiHiroshima Observatory (Hiroshima AstrophysicalScience Center, Hiroshima University) (Fig. 1)
 Noteworthy observational results especially on
variable objects such as blazers, super novae,and gamma-ray bursts.

 A brand-new instrument for the Kanata
telescope (Cassegrain focus; F/12.3).
 Obtaining three band information among
0.5–2.4 μm simultaneously with a 10 arcmin
sq. FOV.
 Spectroscopy and polarimetry (imaging- andspectro-polarimetry) are also available.
 Development History
2007: development start.
2009: NIR 1ch imaging mode installation
2011: 2ch (optical×1, NIR×1) simultaneous
imaging mode installation. (current)
future: spectroscopy and polarimetry mode,the second NIR arm installation.

Higashi-Hiroshima
Observatory
N: +34.4°, E: +132.8°
Alt: 503mDetector
formatFig. 2: HONIR on the telescope

Fig. 1: Kanata telescope and Higashi-Hiroshima observatory[2] Design and Specifications of HONIR

Fig. 5: Design of theYLF Wollaston prism.

Fig. 6: Block diagram of the detector
system.

Controlsystem

Messia 5+MFront2

Messia 5+MACS2

Readoutports

44 (16 in future)

Readout rate

133 kHz234 kHz

Frame rate
(sec/frame)

17.4

4.5

Conv. factor(e-/ADU)

1.54-2.15

3.4

Readout
noise (e- rms)

~8~170-240

Fig. 7: Focal mask turret.

Fig. 8: Optical shutter unit.

[3] Observational Results
Imaging (Fig. 9)

 Optical arm : Fully-depleted back-illuminated CCD(Hamamatsu Photonics K. .K.; Kamata+06)
 IR arm #1: HgCdTe VIRGO array (Raytheon)
 The integrated control system Messia 5 (Nakaya+06a)
operates a front-end electronics MFront2 (Nakaya+06b,12)
for the CCD and MACS2 (Nakaya+98) for the HgCdTe
VIRGO array (Fig. 6).
 Current performance is summarized in Table 2. Readout
noise of the HgCdTe array is too large at present and to be
reduced.
 A new control system for the HgCdTe VIRGO array is underdevelopment (16 ports parallel readout, low readout noise,etc.) based on the readout electronics for the Kiso WideField Camera (KWFC) (Sako+12; paper 8446-251 in thisFig. 4: Optical components on the optical bench.
conference.)
Table 2: Detector performance.
HgCdTe(2k×2k)[1] Until the installation of IR Arm #2 (current); [2] partiallytransparent at 0.4-0.5μm; [3] to be moved to the IR Arm #2
after its installation.

 Four rotating turrets (filters, focal masks, etc.; Fig. 7): The stepping
motors and bump sensors are controlled by the integrated controlsystem Motionnet (Nippon Pulse Motor Co., Ltd.).
 Optical shutter (Fig. 8): A shutter plate with a rectangular aperture
driven by a linear actuator travels on the entrance window on thechamber. Exposure time stability is better
than 0.1 msec (at minimum 0.3 sec exposure).

(2) Detectors

CCD(2k×4k)TBD(4) Other Features(1) Optics
 A reimaging optical system with three branchedarms (0.5-1.0, 1.15-1.35, and 1.45-2.40 μm) splitby two dichroic mirrors (Fig. 3, 4).
(*) Only two arms (0.5-1.0 and 1.15-2.40 μm)
with one DM are available at present.
 10 arcmin sq.FOV; 0.29"/pix sampling.
 Designed for operation at 85 K.
 Spectroscopy (future extension) :Grisms (BK7 or S-FTM16) will be installed ineach of the arms for low dispersion (R~350)
spectroscopy. Installation of additional grisms
for higher dispersion (R~700) and lower
dispersion (R~30) are also planned.
 Polarimetry (future extension) :Fig. 3: Optical design.
A rotatable super-achromatic half-wave plate,a barred lattice shape focal mask or slit, and an
LiYF4 (YLF; Perrin+08) Wollaston prism (Fig. 5)
will be installed.

2048×4096 2048×2048 pix;
pix; 15μm /pix
20μm/pix(3) Cryogenics

 The optical bench in a vacuum
chamber (0.96 x 0.96 x 0.63 m;
welded Al alloy) is cooled down
to and kept at 60-70 K by a single
stage Gifford-McMahon cycle
refrigerator (140W@70K).
 After 6 days evacuation andcooling, the temperature andpressure are kept at suitablelevels (60-70 K and < 10-5 Torr,respectively) for 36 days at least(at -5~+15 deg C environment).

 Image size : 0.9" fwhm (NIR) or 1.7" fwhm (optical) at the center of FOV (incl.
seeing and telescope tracking error.) Blurring at the edges → to be solved by re-alignment of the lenses.
Photometry (Fig. 10)
 NIR light curve of the young stellar object (mJ~11.7 mag); photometric precisionof 0.01-0.02 mag.

Fig. 9: Pseudo-color composite images. (a) M42 (V, J, Fig. 10: NIR light curve of theKs; 9’.2×9’.8), (b) NGC891 (V, RC, IC; 6’.2×9’.5) , (c)young stellar object MM Mon.
NGC891 (J, H, Ks).
60sec×5 dithering for each[4] Future Prospects

data point.

 2012-2013 autumn/winter : spectroscopy and polarimetry functions installation.
 2014 or later ? : the second NIR arm (IR arm #2) installation.

References
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One day in the control room of theobservatory …

Oliva et al. (1997) A&AS, 123, 179.
Kamata et al. (2006) Proc. SPIE, 6276, 62761U.
Nakaya et al. (1998), Proc. SPIE, 3354, 368.
Nakaya et al.(2006a), PASP, 118, 478.
Nakaya et al.(2006b), Proc. SPIE, 6269, 62693G.
Nakaya et al.(2012). PASP, 124, 485.
Web page:
Sako et al. (2012), Proc. SPIE, 8446 (in this conference). http://hasc.hiroshima-u.ac.jp/instruments/honir/