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

Okayama-3.8m optical - near infrared telescope Kouji OHTA (Kyoto Univ.) May 22, 2019 AMON WS@Chiba 1

Chiba (you are here) Okayama Kyoto 2

Okayama site Observable nights ~60% Seeing ~ 1.5” - 2” Our observatory site Weather condition is almost the best in Japan Night sky is not very dark 188cm Okayama Astrophysical telescope Observatory, National Astronomical Observatory, Japan Site as of 2012 (picture taken in 2012) 3

Okayama 3.8m telescope nickname: Seimei （晴明 ※ ） telescope Kyoto University Opening ceremony ※ named after famous ancient astrologer Feb, 2019 (still under development) 4 As of Sep, 2018

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 5

Another unique feature ： longitude ○ ○ ○： >3m opt-NIR telescopes (general purpose) 6

Instrument currently working • KO KOOLS-IFU IFU • Low ow/intermediate disp spersi sion on op optical sp spectrog ograph (KO KOOLS) fed b by fiber bundle type IF IFU IFU FoV:15”Φ １ fiber FoV ： 0.9”φ KOOLS spectrograph 7

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 8

Transient target supply (plan) (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 9

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 Light from the telescope g-band CMOS i(/z/Y)-band CMOS r-band CMOS 10

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…) 11

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) 12

Operation of 3.8m telescope • Obse serving g runs s st started from om March 2019 as s a phot oton on bucke ket t telesc scop ope • Exc xcept for or engi gineering t g time, • Ha Half of of the m machine time i is s use sed f for or op open u use se for or Japanese se com ommunity • Th The ot other half of of the machine t time is s for or Ky Kyot oto o Un Univ • We accept Ta Targe get of of Oppor ortunity ob obse servation ons s w/prop opos osal base se • Tw Two o se semest sters: s: A: A:Jan-Jun, B: B:Jul-Dec 13

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 opt ptic ical al s spe pectroscop opic 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 14