Okayama-3.8m optical - near infrared telescope Kouji OHTA (Kyoto - - PowerPoint PPT Presentation

Okayama-3.8m

• ptical - near infrared telescope

Kouji OHTA (Kyoto Univ.)

May 22, 2019 AMON WS@Chiba

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Chiba

(you are here)

Kyoto Okayama

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Okayama site

Okayama Astrophysical Observatory, National Astronomical Observatory, Japan (picture taken in 2012)

188cm telescope

Our observatory site

Observable nights ~60% Seeing ~ 1.5”-2” Weather condition is almost the best in Japan Night sky is not very dark

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Site as of 2012

Okayama 3.8m telescope

nickname: Seimei（晴明※） telescope

Kyoto University

As of Sep, 2018

Opening ceremony Feb, 2019

(still under development)

※named after famous ancient astrologer

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Unique Features of the 3.8m

• 1. Segmented mirrors (petal type)

inner 6 segments + outer 12 segments

• 2. Mirror fabrication by

mainly grinding (and polishing)

• 3. Light weight torus structure

=> rapid slewing slew speed 3-4 deg/sec

• Pointing accuracy ~3” rms

=> ~5” rms

• Two Nathmyth foci available

Almost handmade telescope still under development

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Another unique feature：longitude

○： >3m opt-NIR telescopes (general purpose)

○ ○

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Instrument currently working

• KO

KOOLS-IFU IFU

• Low
• w/intermediate disp

spersi sion

• n op
• ptical sp

spectrog

• graph

(KO KOOLS) fed b by fiber bundle type IF IFU KOOLS spectrograph IFU FoV:15”Φ １fiber FoV：0.9”φ

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KOOLS-IFU: performance

＊FOV: 15”Φ ＊Wavelength coverage: 4000-10000 A ＊Spectral resolution: λ/Δλ ~ 500-2000 depending on grism ＊Limiting magnitude: Spec:S/N~10, 18－19AB mag w/ 30min (seeing ~ 1.5”) currently ~17 mag

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(i) GRB GCN notice (e-mail/socket) positional accuracy is ~3” w/SWIFT XRT => automatic telescope slewing if the pointing accuracy is <3”, the IFU can catch the target (partly archived) (ii) Neutrino, GW candidates by OISTER/J-GEM (incl. Kanata/Tomoe-Gozen) => 3.8m telescope

Transient target supply (plan)

Instrument under development

(related to MMA)

Sim imult ltan aneous m mult lti-ba band d opt ptic ical al i imag ager + NIR im imag ager

NIR J/(Hs) sensor g-band CMOS r-band CMOS

Light from the telescope

i(/z/Y)-band CMOS

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Simultaneous Opt-NIR multi-band camera: Expected performance Opt: FoV： 6’x11’ 0.34”/pix Band: g, r, i, (z, y) (5000-9000A) Sensor: CMOS SN~10 ~23 mag (V) w/10min NIR： FoV：2.9’x2.9’ Band: J-band (1.2um), very short H-band SN? (I don’t have info…)

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Simultaneous Opt-NIR multi-band camera: Schedule Opt: 2019FY fabrication 2020FY observation (hopefully) Future plan: low/intermediate dispersion spectroscopy w/ grism(s) NIR： 2019-20FY fabrication 2021FY observation (hopefully)

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Operation of 3.8m telescope

• Obse

serving g runs s st started from

• m March 2019

as s a phot

• ton
• n bucke

ket t telesc scop

• pe
• Exc

xcept for

• r engi

gineering t g time,

• Ha

Half of

• f the m

machine time i is s use sed f for

• r op
• pen u

use se for

• r

Japanese se com

• mmunity
• Th

The ot

• ther half of
• f the machine t

time is s for

• r Ky

Kyot

• to
• Un

Univ

• We accept Ta

Targe get of

• f Oppor
• rtunity ob
• bse

servation

• ns

s w/prop

• pos
• sal base

se

• Tw

Two

• se

semest sters: s: A: A:Jan-Jun, B: B:Jul-Dec

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Summary

• We

hav ave c constructe ted d a a new 3 3.8 .8m ( (Seim imei) ) tele lescope pe.

• Once w

we g get ta target c can andi dida dates, , we w wil ill l be be ab able le t to m mak ake o

• pt

ptic ical al s spe pectroscop

• pic

ic or mult lti-ba band im d imag agin ing (i (in f future) ) obs bserva vatio ions qu quic ickly ly.

• But st

stil ill l unde der ad adju justment and d de deve velo lopm pment

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