(CORE-U), HASC and Kanata telescope

Koji S. Kawabata (Hiroshima University)

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CORE-U

Core of Research for the Energetic Universe, Hiroshima Univ.

広島大学 極限宇宙研究拠点

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Mission of CORE-U

“Core of Research for the Energetic Universe (CORE-U)” is also one such COE, and consists of research groups involved in cosmology, astrophysics and particle physics.

• To carry out advanced studies and human resource development through joint research with domestic and overseas groups as well as individual researchers.

• To unify each core member’s research and perform comprehensive studies on the evolution of the early universe, super-dense astronomical objects such as neutron stars and black holes, and ultra-high-energy phenomena such as supernovae and gamma-ray bursts.

• To develop unique research projects, such as the construction of an original miniaturized satellite, and the creation new interdisciplinary research areas in cooperation with researchers in fields such as Humanities, Social Sciences, Education and Engineering.

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HASCHiroshima Astrophysical Science Center

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HASC : Brief History

２００４．３ 1.5-m Optical telescope of NAOJ (IR simulator of 8.2-m Subaru Telescope) given to Hiroshima Univ.

２００４．４ HASC found as a Joint Education and Research Facility on Campus for the center of construction and management of new astronomical observatory hosting the 1.5-m telescope.

２００６．５ Construction of Higashi-Hiroshima Observatory

and renewal of 1.5-m `Kanata’ telescope completed.

１９９７－２０００ High-energy astronomy group found in Faculty of Science in Hiroshima Univ., contributed to GLAST(Fermi), ASKA, Astro-E2(Suzaku) satellites.

２００５．７ Suzaku (Astro-E2) X-ray satellite launched.

２００８．６ Fermi (GLAST) Gamma-ray satellite launched.

２０１６．２ Hitomi (Astro-H) X-ray satellite launched.

Opt

& N

IR O

bs.

© JAXA© JAXA © NASA

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Multi-wavelength and/or Multi-band study for variable, transient astronomical sources

Gamma-ray, X-ray andOptical/NIR Observations（Kanata tel., Fermi, Suzaku, Hitomi..)

Gamma-ray bursts (GRBs), Supernovae, Novae, Cataclysmic variables, X-ray binaries, Young Stellar ObjectsBlazars and AGNsOther transient objects (including Comets, Exoplanet transits)

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Organization

Faculty of Science

:

HASC

【Optical & NIR astronomy div】

【X-ray and γ-ray astronomy div】

【Theoretical astronomy div】

High-Energy Astrophysics Group【X-ray and γ-ray astronomy】

Theoretical astrophysics group

Hiroshima University

Theoretical particle physics group

Experimental quark physics group

Faculty branch Joint Education and Research Facility branch

Management of Higashi-Hiroshima Observatory and optical telescopes

© NASA

Contribution to developments and operations of X-ray and gamma-ray satellites, balloon missions.

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Organization

Faculty of Science

:

HASC

【Optical & NIR astronomy div】

【X-ray and γ-ray astronomy div】

【Theoretical astronomy div】

High-Energy Astrophysics Group【X-ray and γ-ray astronomy】

Theoretical astrophysics group

Hiroshima University

Theoretical particle physics group

Experimental quark physics group

Faculty branch Joint Education and Research Facility branch

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Kanata 1.5-m Telescope

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Higashi-Hiroshima Observatory

•Altitude 503m above sea level•~40% observable nights •Better seeing condition (median FWHM ~1.2 arcsec)•Sky brightness R=19-20 mag/arcsec2 in dark nights

Hiroshima Univ. Campus

HHO

(Higashi Hiroshima Observatory)

Osaka

KyotoOkayamaOAOHiroshima

HHO

Red region: Sunny >2000hr/yr

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Instruments

High Speed-readout spectrographFoV: 2.3’×2.3′Wavelength res.: R = λ/Δλ =

9-70（400-800nm）、

150（430-690nm）

~30 frames/secCassegrain

Nasmyth#2HOWPol 2009-Optical 1 bandImaging： FoV 15′ΦImaging Pol： One-shot Spec： R~350(400-1050nm)

Nasmyth#1

`Kanata’ Telescope•Successor of IR simulator of Subaru telescope•1.5mΦ main mirror• Azimuth rotation speed : 5°/sec, 2-4 times faster than normal 1-m size telescopes. (merit in high-response observation (e.g. GRBs)

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HONIR: Hiroshima Optical and Near-InfraRed camera

Akitaya, Moritani, Ui, et al. SPIE Proc. (2014)Ui, Sako, Yamashita, et al. SPIE Proc. (2014)Sakimoto, Akitaya, Yamashita, et al. SPIE Proc. (2012)

Optical Ch. IR Ch.

FoV 10′× 10′

Pixel size, and format

15μm×15μm、 2k×4k 20μm×20μm、 2k×2k

Pixel scale 0.30 ″/ pixel 0.30 ″/ pixel

Mode Imaging, Spectroscope, Imaging polarimetry, Spectropolarimetry

Wavelength range

0.5-1.0μm 1.15-1.35μm(IR2)、1.45-2.4μm(IR1)

Filters B, V, R, I, Y, O58-OC Y, J, H, Ks, 1.3μm-OC

Grisms Grism (R~400) Grism_S, Grism_L (R~400)

Polarizers Wollaston prism (LiYF4) , Double Wollaston prism (LiYF4), Superachromatic half-wave plate (Pancharatbum-type)

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NIR HCT array（～80K）

Opt CCD（173K）

Filt.Prism wheel

Filt.Prism w

heel Pupil wheel

Mask wheel

Cooler head

HONIR Mechanical Structure

Body (room temp)

Cold box（～65K）

Incident light from telescope1.

2 ｍ

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Wedged Double Wollaston prism

Generally, two or four exposures at different position angles of polarizer/retarder are necessary for derivation of Stokes I, Q, U parameters in optical polarimetry

Oliva 1997, A&AS, 123, 589

But, introducing a `Double wedged Wollaston prism’ (Oliva 1997) at the pupil position, we can obtain I, Q, U parameters from a single exposure.

Inci

dent

ligh

tPu

pil i

mag

e

Pupi

l im

age

eo

eo

Four

bea

ms

→ One-shot polarimetry

Narrow-field typeMgF2+SiO2

Wide-field typeCalcite

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Double Wollaston prism for HONIR (2016.7-)

• LiYF4 crystal, covering 0.45-2.3μm • Four polarization images are devided

→ One-shot Polarimetry avairable for both Opt/NIR chan.

Pupil wheel

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HOWPol

Field of View 15’ diameter ( imaging mode)

Wavelength 450nm-1100nm

Mode Wide-field imaging (15’ circle)

Imaging polarimetry (Capability of one-shot polarimetry)

Spectroscopy (λ/d_λ~ 350)

Spectropolarimetry

Detector Two 2k-4k back-illuminated, fully-depleted CCDs (Hamamatsu)

Hiroshima One-shot Wide-field Polarimeter

Kawabata et al. 2008, SPIE Proc., 7014, 70144L

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Observational Targets with Kanata telescope

Blazars/AGN

Supernovae

GRBsXRBs

Others(YSOs)

2014 Aug – 2015 Jul

Polarimetry: Most of high-energy objects (Blazars/AGN, GRBs, XRBs) and a part of YSOs are polarimetrically observed.

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Number of Refereed Papers using Kanata Telescope

54 papers

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Prompt polarimetry observations of GRB afterglows

GRB trigger

t1

GCN receive

t2

Expos. start t3

t3-t1 (s)

t3-t2 (s)

Polarized?

GRB 091208B 9:49:58 9:50:24 9:52:27 149 123 Yes

GRB 111228A 15:44:43 15:45:33 15:47:25 162 112 Yes

GRB 121011A 11:15:30 11:16:09 11:17:02 92 53 No

GRB 130427A 7:47:57 7:49:15 11:40:26 14027 13949 No

GRB 130505A 8:22:28 8:22:51 10:46:08 8643 8620 No

GRB 140629A 14:17:30 14:17:46 14:18:43 73 57 No

When we received GRB trigger, optical polarimetry to it automatically begin with Kanata telescope. We successfully obtained earliest phase data (<~200s after gamma-ray trigger) (091208B, 121011A, 140629A).

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GRB 111228A (z=0.714)

Optical afterglow shows significant temporal polarization change.GRB 111228A: Strongly polarized

Takaki, Toma, KK+, submitted

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GRB 140629A (z=2.3)

Takaki+, in prep.

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Other early afterglow polarimetry

Mundell+ (2013), NaturePo

lariz

atio

n (%

)RINGO2

RINGO

RINGOHOWPol

RINGO2/CAFOS

ISAAC/FORS2FORS1

Earliest afterglow is generally strongly polarized?

Time from GRB (sec)

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Other early afterglow polarimetry w/ HOWPol data

Mundell+ (2013), NaturePo

lariz

atio

n (%

)RINGO2

RINGO

RINGOHOWPol

RINGO2/CAFOS

ISAAC/FORS2FORS1

121011A 130427A

130505A

140629A

111228A

Time from GRB (sec)

Earliest afterglow is generally strongly polarized?－ No.

121024 (Wiersema+ 2014)091208B

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Blazars

cold gas

accretion disk

hot gasjet

black hole

Blazars are believed to be AGN seen along the jet axis.→ Synchrotron radiation would dominate the flux at

IR/optical wavelengths

plasma torus

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Frequency [Hz]

Flux

Abdo+ 10, Hayashida+ 12; Itoh private comm.

SED

Multi-wavelength study in 3C 279

Radio

Optical

Opt. Polarization

PA of Opt. Polarization

X-ray

γ-ray

Date [MJD]

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Rotation of Linear Polarization AnglePKS 1510-089 3C 66A

V mag

Non-zero average polarization

PAobs

PA180

PAshift

around origin

around average

around origin

around averageTypically, 10-20°/day

QU-diagram

Variation of polarization vector is not random but systematically rotating

Our dense monitoring (every ~3 days) revealed hidden characteristics of variation of polarization vector.

Ikejiri+ 2011

Polarimetry of high-energy objects with Kanata tel. See talks by Yasu Tanaka and Ryosuke Itoh.

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Future Projects of HASC

• 50cm Telescope at Tibet (5100m above sea level)

• SGMAP project: Optical Polarimetry Survey in Northern Hemisphere Talk by KSK (tomorrow)

Coming soon!

• “Astronomical Polarimetry 2019” (1995: USA, 2004: USA,Hawaii, 2008: Canada,Quebec, 2014: France)

To be held in Hiroshima on 5 days in 2019 May Let’s meet together again!!