Optical and NIR follow-up observations for transient objects
with Hirosima 1.5-m telescope and tutorial `how to readthe data’

広島大における突発天体の可視近赤外追跡観測とそのデータの「読み方」
Koji S. Kawabata (Hiroshima Univ)
川端 弘治 (広島大学)

1

Index• `Kanata’1.5-m Optical Telescope• Strategy of Kanata Telescope– Multi-wavelength, Multi-mode• Representative Results• Blazars and related objects• Microquasars• GRBs• IceCube events• New HinOTORI 0.5-m telescope• Summary2`Kanata’1.5-m Optical Telescope3

Higashi-Hiroshima Observatory•Found in 2006; operated by Hiroshima University•Only 25 min by car from campus (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
Kyoto

Hiroshima Univ. Campus

Hiroshima
HHOHHO(Higashi Hiroshima Observatory)

4Okayama
OAO

Osaka

Red region:
Sunny >2000hr/yrHigashi-Hiroshima Observatory: Aim
Multi-wavelength and/or Multi-band study forvariable, transient objects
Gamma-ray, X-ray and
Optical/NIR Observations
1.5m Optical/NIR telescope, Kanata (2006-)
Gamma-ray satellite (Fermi 2008-)
X-ray satellite (Suzaku 2005-, Ｈｉｔｏｍｉ 2016）© JAXA© NASA5© JAXA

GRB, XRB, AGN, etc5

HE & Opt/NIR Obs. Astronomy group
HE (X-ray and gamma-ray) Astronomy Group––––Fukazawa, Yasushi (Prof)
Mizuno, Tsunefumi (Assoc. Prof)
Takahashi, Hiromitsu (Assist. Prof)
Ohno, Masatoshi (Assist. Prof)

Optical and Near-Infrared Astronomy Group––––

Kawabata, Koji (Assoc. Prof)
Uemura, Makoto (Assoc. Prof)
Mahito Sasada (S.-A. Assist. Prof) 2018.1Masayuki Yamanaka (S.-A. Assist. Prof) 2017.5-

Specially Appointed Professor in the group– Miyama Shoken (S.-A. Prof)– Ohsugi, Takashi (S.-A. Prof)(Theoretical Astronomy group )– Kojima, Yamamoto, Okabe

Yoshida6Tanaka

Akitaya

Utsumi

Kitaguchi

Moved out recent 12 months…

OhsugiTelescope and Instruments
Nasmyth focus#2

Nasmyth focus#1

High Speed-readout
spectrograph

HOWPol 2009- (KSK+ 2008)
Opt Imaging： FoV 15′ΦOpt ImagPol： One-shot type
Spec： R~400(400-1050nm)
We-Do-Wo type Wollaston

FoV: 2.3’×2.3′
Wavelength res.: R = λ/Δλ =9-70（400-800nm）、150（430-690nm）~30 frames/sec

Cassegrain focus`Kanata’ Telescope•Successor of IR simulator ofSubaru telescope•1.5mΦ main mirror• Azimuth rotation speed : 5°/sec,
2-4 times faster than normal 1-m
size telescopes. (merit in highresponse observation (e.g. GRBs)`One-shot polarimetry’is available --- Uniquepotential for quickly-variableobject like GRB afterglows

HONIR : 2012- （Akitaya+ 2014 SPIE）
1 Optical band + 1 （future 2) NIR band (simultaneous)
Opt+NIR Imaging： FoV 10′×10′
Opt+NIR Spec： R~400-500
Opt+NIR ImagPol/SpecPol

Maximizing information by single observation
One-shot polarimetry now available
7

Double Wollaston prism for HONIR (2016.7-)
Pupil wheel• LiYF4 crystal, covering 0.45-2.3μm• Four polarization images are divided→ One-shot Polarimetry avairable for both Opt/NIR chan.

8Observational Targets with Kanata telescope 1CVs

Year (paper #)Blazars：

SNeGRBs

Others

XRBs

2010 Aug-2011 Jul(3 papers)
Follow-up obs. forFermi, MAXI, etc.

2009 Aug-2010 Jul(10 papers)
2008 Aug-2009 Jul(6 papers)
2007 Aug-2008 Jul(4 papers)
After Fermi launched,extended polarimetricmonitoring of blazars

2006Aug-2007 Jul

CVs were initial maintargets.

Total Observation time (hr/year)
9Observational Targets with Kanata telescope 2
2017.10-2018.2

Others(YSOs)
XRBs

Blazars/AGN

GRBs
Supernovae

山中川端
中岡

10

Number of published papers~80 papers with Kanata observation since 200711

Collaborating studies with Kanata telescope
FY 2006-2015: 105 studies (204 persons) in total
2014年度 共同研究 28件、35名• 名古屋大1件1名（X線連星フレア）、米国UCSD1件1名（X線連星多波長観測）、東京大4件4名（AGN多波長観測、近傍セイファート銀河観測、AGN分光モニター）、大阪大1件1名（TeVガンマ線フレア）、ドイツMPI 2件2名（AGN多波長観測）、米国USRA 1件1名（X線連星多波長）、英国サウサンプトン大1件1名、東工大1件2名（X線増光天体追跡観測）、韓国ソウル大1件2名（彗星偏光観測）、埼玉大1件1名（YSO多波長観測）、
ブラジル・サンパウロ大1件1名（Be星偏光分光）、香川大 1件2名（星間雲偏光）、【継続分】東京大1件2名（木曽超新星サーベイ追跡観測）、大学間連携キャンペーン観測8件8名、ポーランド ジャギーロニアン大1件1名（AGN偏光）、東京大1件2名（大質量星形成領域）、茨城大1件3名（Fermi未同定天体）2015年度 共同研究 18件、33名• 重力波対応天体捜索1件10名、韓国KASI 1件1名（活動銀河分光）、理研 1件1名（クエーサー多バンド偏光）、東北大 2件4名（木星衛星食、惑星雲赤外閃光モニター）、兵庫県立大 1件1名（皆既月食偏光）、JAXA 1件2名（金星の赤外偏光分光）、鹿児島大1件1名（ミラ型候補星分光）、【継続分】東京大4件6名（木曽超新星サーベイ追跡観測、AGN多波長観測、AGN分光モニター、大質量星形成領域）、大学間連携キャンペーン
観測4件4名、韓国ソウル大1件2名（彗星偏光観測）、ブラジル・サンパウロ大1件1名（Be星偏光分光）
12

OISTER 光赤外大学間連携 (2011-; 2017-)

埼玉大(Japan)
16 tels.
0.5-2m(Chile)1 tel.
1m(South Africa)
1 tel.
1.4m

13Strategy of Kanata Telescope

14

Discrimination from other telescopes• Transient phenomena– Requiring high response system and/or extendedobservations (being hard for large telescopes)• Multi-wavelength– Coordinated with X/Gamma-ray observations
supported by high-energy (and theoretical) people.

• Multi-mode– Simultaneous Opt/NIR observation including
polarimetry and spectroscopy, maximizing information
gaining from a single observation.

15

Multi-wavelength Observation Sample 1:
Blazars and related objects

16Blazars and related objects

cold gasjet

hot gasblack holeaccretion
disk
plasma torus

Blazars： AGN seen from jet axis
Beamed synchrotron radiation from jet dominates (thusbright)

17

SED of Blazars

Low-peak (LSP; FSRQ)

Synchrotron peakIntermediate-peak (ISP)

18

Radio

High-peak (HSP)(BL Lac objects)

Inverse Compton peak(FSRQ)

Luminosity

Relativistic beaming;brightened by δ^4 ~10,000 times

Emission from the jet dominatesfrom radio through gamma-ray;
rapid and large amplitude variability
and strongly polarized light

Fossati+98

log v (Hz)Gamma-ray

Synchrotron –Self Compton (SSC)
External Radiation Compton (ERC)

luminosity

Emission model of high energy partHigh-peak : Mrk421 Abdo+11

synchrotron

SSC

Freq [Hz]Kataoka+99

Abdo+10synchrotron

Emission at GeV regime
High-peak ： SSC
Low-peak ： ERC

ERC

Low-peak :PKS1502+106
SSC

19Freq (log v)

Kanata Blazar Photo-Polarimetry Campaign
2008-2014: 42 (13 FSRQs, 8 LSPs, 9 ISPs, and 12 HSPs）＋3 blazars have been monitored
Compared with gamma-ray with Fermi observation
Itoh et al. 2016; Ikejiri et al. 2011

Target Blazars
PKS 0048
S2 0109
MisV1436
PKS 0215
3C66A
AO 0235
SO 0324
1ES 0323
PKS 0422
QSO0454Q
1ES 0647
S5 0716BL Lac

PKS 0754
1ES 0806
OJ 49
OJ 287
S4 0954
3EG 1052
Mrk 421
RGB 1136
ON 325
ON 231
3C 273QSO1239
1ES 2344

3C279
OQ 530
PKS 1502
PKS 1510
PG 1553
Mrk 501
H1722+11
9
PKS 1749
S5 1803
3C371
1ES 1959
PKS 2155
3C454.320

Flux-color correlation
3C 454.3

PG 1553+113

Color-mag.
diagram

Color

V mag

3C 371

Ikejiri et al. 2011

`Bluer when brighter’ `Bluer when brighter’ in brighter phase (16%)(In faint phase, hot disk component is dominant)trend in the whole data(72%)
21

Flux-polarization correlation
AO 0235+164

MisV1436

OJ 49

FluxPol.
degreePol.-fluxcorr.

positive corr.

positive corr. + othernegative corr.
Ikejiri et al. 201145%
22

Rotation of Linear Polarization Angle
PKS 1510-089

3C 66AV mag

PAobs
PA180
PAshiftaround origin

around origin

around average Typically, 1020°/dayaround average

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

Variation of polarization
vector is not random but
systematically rotating 23

Non-zero averagepolarization
Ikejiri+ 2011

Multi-wavelength study in 3C 279
MW Light Curve and Opt. Polarization
γ-raySEDFlux

X-ray

OpticalOpt. Polarization

PA of Opt. Polarization
振動数[Hz]Radio

Date [MJD]
24

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

Correlation between gamma-ray and optical light

Itoh et al. 2016

Alignment of magnetic field depends on blazar type25

Active phase monitoring in CTA 102
FSRQ (z = 1.037)

Itoh, Fukazawa, Tanaka+13

Flare observed on
19 Sep 2012 Optical report (ATel #4397)
21 Sep 2012 GeV report (ATel #4409)

Started dense monitoring with
Kanata + OISTER

Two types of violent
variation in opticalpolarization observed.
Only polarization
deg. flared.
26

Both flux and pol.
deg. flared.

Multi-wavelength Observation Sample 2:
X-ray binary/microquasar

27

X-ray binary
jet synchrotron
IR OptAccretion disk
Binary including BH or NS
XTE J1118+480; Markoff et al (2001)• It has been claimed that NIR light is produced by jet. (Most X-ray
binaries locate near the milky way, and the optical light is heavily
absorbed, but NIR light is much less absorbed.)• Thus, jet can be probed by NIR observation (as well as X-ray and radioobservations)28

Outburst of blackhole binary V404 Cyg
V404 Cyg in outburst phase（Kanata/HONIR, Pirka; Tanaka+ 2016）
Conceptual SED and polarization vsfrequency for X-ray binary in active phase
光学的に薄いシンクロトロン(Jet)
Synchrotron radiation

Shahbaz+ 2016(disk)
Thermal emission

青・黒：R
赤 Ｋｓ

PA%Pol.

%Polarization

MagFlux

自己吸収
シンクロトロン

Shahbaz+ (2008)

Shahbaz+ (2008)

Kバンド付近で数十％もの大きな偏光が期待される（かも）しばらくしてから可視シンクロトロンフ
レア活動性が現れる場合もある
29

Microquasar GRS 1915+015• Superluminal motion in radio (VLBI)→ High-velocity jet → Called as microquasar• BH mass 14±4 M from NIR spectroscopic period (Greiner et al. 2001)• A time-sequential flare among X-ray, NIR and radio wavelengths isfound, explained by disk-jet model (Mirabel et al. 1998)• But, the observational material for accretion and jet physics is stillpoor.
30

GRS 1915+015: NIR and X-ray monitoring
NIR photometric monitoring.
X-ray hardness ratio suggests
this binary is in soft state atMJD 54320-54570.
Around MJD 54370, X-ray andradio flare appeared→ jet ejection
In contrast, NIR flux decreased.
(Time lag < 1d)

Possible jet ejection

NIR(Ks)Soft X

Hard X

Radio
Arai et al (2009)This NIR – X/radio anti-correlation continued during its
soft state (~250 d).
31

GRS 1915+015: NIR polarimetry

Strong, variable
polarization→ Synchrotron
radiation from jet?

2016. 8-10
H band (𝜆𝜆 1.6𝜇𝜇m)

Bias (fake) polarization?

H bandK bandShahbaz , et al . (2008)

廣地（2018）
広島大修論

Too strong as interstellar pol.
Synchrotron is unlikely becauseof lowerpol. at longer wavenength32

Multi-wavelength Observation Sample 3:
Gamma-ray bursts and their afterglows,
Optical counterpart of GW events

33

Afterglow of GRBs
A considerable fraction of GRBs (~30%)
show afterglows in optical wavelengths.
They are explained by synchrotron
radiation originated in an external shock
region where the relativistic jet interacts
with circumstellar matter.

Internal

afterglow

Meszaros 02
34

X-ray

Optical/NIR

Externalγ, X, Opt,
radioGRB

080413B Filgas+ 2011

Time since (sec)Expected geometry of magnetism and polarization
1.
2.

Totally random orientation of magnetism.
 Null polarization
Combination of coherent patches (scale length~ cτ). Within each patch, the magnetic field isordered. Normal jet may have ~50 patches.
 Constant polarization of ~10% (=70%/√N)2.
jet～c τpolarized

3.

(e.g., Gruzinov & Waxman 1999)

4.

Axi-symmetric polarization pattern due tocompressed, tangled magnetic field, coupledwith relativistic `beaming’ and `occultation’ ofemitting region.
 Variable polarization of p=0-10% from obliqueline of sight (e.g, Sari+ 1999; Rossi+ 2004)
Large scale ordered-magnetic field in (nothydrodynamic jet, but) Poynting-flux dominatedjet (e.g, Lyutikov+ 2003)
 Large polarization (up to ~50%)
35

jetunpol.
polarized

Polarization

3.

Time since GRB
Rossi+ 04

List of Kanata optical polarimetry for GRBs
GRB
triggert1

GCN Expos.
t3-t1 t3-t2
receive start
(s)
(s)
t2
t3

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

53

NoGRB 130427A

7:47:57

7:49:15 11:40:26 14027 13949

NoGRB 130505A

8:22:28

8:22:51 10:46:08 8643

8620

NoGRB 140629A

14:17:30 14:17:46 14:18:43

57

No

92

73

Polarized?

We have the record of earliest observation (<~100s aftergamma-ray trigger) for GRB afterglow in polarimetry(091208B, 121011A, 140629A).
36

GRB 111228A (z=0.714)

Takaki, Toma, KK+, submitted

Optical afterglow shows significant temporal polarization change.
GRB 111228A: Strongly polarized
Katsutoshi Takaki will give a talk on the study of this GRB afterglow
on third day of this GRB conference.
37

GRB 140629A (z=2.3)
T90 (15-350keV) = 75.6±12.7sec

Galactic 𝐴𝐴𝑉𝑉 = 0.022 ; upper-limit 𝑝𝑝𝑀𝑀𝑀𝑀 ~0.07%

Polarimetry began at 𝑇𝑇0 + 73 s
(22 s in rest frame)
The record of earliest polarimetry ever!

𝑝𝑝 = 1.8±1.1 % at T0+73 s to 185 s
𝑝𝑝 = 1.5±1.8 % at T0+198 s to 436 s
𝑝𝑝 = 2.8±6.4 % at T0+7456 s to 8618 s

GRB 140629A: Unpolarized (or onlyweakly polarized)
38

Takaki+, in prep.

Other early afterglow polarimetry
Mundell+ (2013), Nature

Polarization (%)

RINGO2
RINGO2/CAFOS
RINGO
HOWPolRINGOISAAC/FORS2
FORS1

Time from GRB (sec)Earliest afterglow is generally strongly polarized?
39

Other early afterglow polarimetry w/ HOWPol data

Polarization (%)

Mundell+ (2013), Nature
RINGO2
RINGO2/CAFOS
RINGO
HOWPolRINGOISAAC/FORS2
FORS1111228A
091208B
121024 (Wiersema+ 2014)

140629A 121011A

130427A

130505A

Time from GRB (sec)Earliest afterglow is generally strongly polarized?
－ No.
40Multi-wavelength Observation Sample 4:
Neutrino sources

41

Searching counterparts for IceCube events• Tiling observation covering error circle↓• Targeted observation for blazars within errorcircle

42

IceCube-161210A
Alert: 2016-12-10 20:07(UT)
RA: +1.1 -1.0deg
DEC: +0.45 -0.40 deg

森 修論(2018)2016-12-11 9:30-17:30 (UT)J-band imaging (tiling)

43

IceCube-170321A
BROS blazar catalog (Tanaka, Itoh, Inoue, et al.)>5000 from TGSS, PanSTARRS
Alert: 2017-03-21 07:32(UT)
RA:, DEC: ±1.2deg

2017-03-22 10:30-11:10 (UT)J-band imaging
44

森 修論(2018)

IceCube-170922A
Alert: 2017-09-22 20:54(UT)
RA: -0.8 +1.3 deg
DEC: -0.4 +0.7 deg

2017-09-23 16:10-20:20 (UT)J-band imaging

45

森 修論(2018)

~0.1mag scatters depending on
used reference star46

森 修論(2018)

IceCube-170922A: Light curve
Difference between
reference star method
and all-star method(∆~0.15mag at most)Difference between
observatory(∆~0.1mag at most)

Imcomplete flat-fielding, errors in used catalogue, instability due to observing condition,
intra-night variability, etc.
47

森 修論(2018)

IceCube-170922A: Polarization

Radio jet axis
(cf. Iinuma, Nagai’s talk)Misalignment with jet axis?

48

Polarization map of nearby stars

Multi-wavelength Observation Sample 5:
GW events49

重力波天体 同定観測ネットワーク J-GEM
PI 吉田道利（広島大）

J-GEMに参加している望遠鏡群（諸隈ほか2017）

NS-NS（BH）合体

1mクラス

8mHSC

O2ラン進行中（～2017夏）

距離100MpcでのGWイベントの光度曲線モデル（田中雅臣2017）

50

51

J-GEM obs. of thecounterpart of GW 170817:
SSS17aDecayed and reddened
quickly
Utsumi et al. 2017;
Tanaka et al. 2017;
Tominaga et al. 2017;
Subaru HSC 𝜆𝜆0.9μm、IRSF1.2μm, 2.2μm composite color image

Hiroshima Kanata 1.5m/
HONIR𝜆𝜆1.6μm
2017.08.20 19:11JST（17min after sunset, ℎ~10deg)

Nakaoka et al. 2017;
Utsumi et al. 201751

Severe to photometry from Japan

HinOTORI 0.5m telescope in Tibet, China

52

53

HinOTORI 0.5m tel.@5100m
Yomiuri2017 Nov 12

RussiaAli Obs. (NAOC)
Western Tibet

Beijing

Korea

JapanTokyo
Hiroshima

ChinaIndia

TaiwanClose to AliCPT site(IHEP/CAS)53

54

Summary• Kanata 1.5m telescope– Dedicated for transient objects/phenomana– Simultaneous optical and NIR observation (imaging, spectroscopy,polarimetry)– Supernova, Blazars, GRBs, IceCube events, GW events,..
– Be careful to reliability for errors (depending on observer/reduction
tool, etc.) - easily changing by 0.1-0.2 mag• HinOTORI 0.5m telescope– Construction finished in 2017 Oct– Proper observation will begin in late 2018 or 2019

Collaborating study with Kanata is always welcome!
Opt imaging ≦21 mag, NIR imaging ≦17-19 mag
10’x10’(HONIR) low-res. spectroscopy, polarimetry
HinOTORI 0.5m in Tibet will be available soon.
54