Follow-up Observationsof the Various Transientswith OISTER
Masayuki Yamanaka (Hiroshima Univ.),
Yasuyuki Tanaka (Hiroshima Univ. -> MATSUDA)
Tomoki Morokuma (U. of Tokyo), Kouji Ohta (Kyoto Univ.),
Ryosuke Itoh (TIT), Yousuke Utsumi (Hiroshima Univ. ->Stanford) Koji S. Kawabata, Hiroki Mori (Hiroshima Univ.) ,On the behalf of OISTER collaboration

Topics (related to IceCube event)from Optical & NIR groups in this WS
1. OISTER (introducing the telescope/instrument
properties, multi –band and –mode ToO follow ups,future prospects) by MY

2. Kanata (`How to read’ optical data, polarization?)by Kawabata-san
3. Subaru HSC + FOCAS (Exploring the IceCubeevent based on the BROS catalog, andconstraint on the redshift) by Ohta-san

Topics from MY
1. Introducing the OISTER
2. Exploring the IceCube event using Kanata(detailed matters will be talked by Kawabata-san)
3. Future prospects (Finding & Follow ups w/ Tomo-eGozen/3.8-m/OISTER)

What’s OISTER ?

Optical and Infrared Telescopes of Synergetics forEducation and Research (OISTER)
Overalls• Cooperation among Universities having optical and nearinfrared small/intermeridate (0.4 – 2.0m) telescopes• Seven positions (Postdocs/Assistant prof.) were employed ineach University. (MY, on May, 2017)• An associate prof. (H. Maehara@Kyoto) was employed tosummarize the overall among Universities• First period finished and second began in 2017 (for 5 years)

Scientific goals• Flexible and immediate follow-ups of transients and variables
including the gravitational wave and neutrino events.
• Multi –band and –mode observations using the various
instruments• Participants have right to propose observations (Externalresearchers can join as Co-I)• 6 ToOs were triggered in 2017-2018 (ongoing for 2 of 6)• Flexible operation is applied to the current observations

Telescopes

Telescope/Instrument lists (from North)
Univ.

Observatories

Telescopes

Instruments

Imaging

Spectroscopy

Polarimetry

Hokkaido

Nayoro1.6-m Pirka

MSI

UBVRI

R=150

Imaging pol.

NaCS

BVgriz

R=300

GLOWS

BVRI

R=400-500

Gunma

1.5-m

GAEOS
GIRCS
Saitama
U. TokyoTokyo tech
NagoyaKiso

JHKs

0.55-m SaCRA MuSASHI

riz

1.0-m

KWFCugriz

Tomo-e Gozenno (gri, Ha)

Akeno

50cm

MITSuMEg’RI

Okayama

50cm

MITSuME

g’RI

SAAO

1.4-m IRSF

SIRIUS/SIRPOL

JHKs

Kyoto
U. of Hyogo

R=100000

40cm
Nishi-harima

R=1000

Imaging pol.

BVRI

3.8-m

KOOLS-IFU

R=600-2000

2.0-m Nayuta

MALLS

R=600-7500

MINT

BVRI

NIC

JHKs

Telescope/Instrument lists
Univ.

Observatories

Telescopes

Instruments

Imaging

SpectraPolarimetry

Hiroshima

HHAO

1.5m Kanata

HOWPolBVRIz’+Y

R=400

Imaging pol.

HONIR

VRI+JHKs

R=600?

Imag/specpol

HSCAM

BVRI

R=20-150

KagoshimaIriki

1.0m

NIR Cam

JHKs

NAOJ

Ishigakijima

1.05m Murikabushi

MITSuMEg’RI※ 1.0m miniTAO (Tokyo) is not available※ 3.8m telescope (Kyoto) will have HSCAM on 2019?
※ Kyoto Sangyo Univ (1.3m)., Bisei Space Gard Center also participates.

We can always perform
photometry, spectroscopy, andpolarimetry in optical and NIRTimescale (intra-day)
Many telescopes @ Japan
0h (UT)24h (UT)IRSF @ South Africa
miniTAO @ Chile (not available)
HinOTORI @ Tibet (2018?)

Timescale (inter-day)https://tenki.jpWe can avoid the weather risk! (typically shows~ 1 day delay between Hiroshima and Tokyo )A science case: Dust emission inpeculiar Type Ia SN

A science case: Dust emission inpeculiar Type Ia SN
JHKs-band flux of SN
2012dn was subtractedusing the SN 2009dc(prototype SC).
We found the `NIR echo’ (flatevolution of NIR flux), bycomparing to the model(Maeda et al. 2015, Nagao etal. 2017, 2018)
Dust locates on 0.48pc to the SN
ejecta. The total dust mass was
5.5x10-4MSun assuming the carbondust

Results from OISTER ToO observations“Broad-lined Supernova 2016coi with a Helium Envelope”, YM; Nakaoka, Tatsuya; Tanaka, Masaomi etal., 2017, ApJ, 837, 1“Measurement of Interstellar Polarization and Estimation of Galactic Extinction for the Direction of Xray Black Hole Binary V404 Cygni”, Itoh, R., Tanaka, Y. T., Kawabata, K. S., et al. 2016, PASJ accepted,“OISTER optical and near-infrared observations of the super-Chandrasekhar supernova candidate SN
2012dn: Dust emission from the circumstellar shell”, YM., Maeda, K., Tanaka, M., Tominaga, N.,Kawabata, K. S., et al. 2016, PASJ, 68, 68.
“No Evidence of Intrinsic Optical/Near-infrared Linear Polarization for V404 Cygni during Its BrightOutburst in 2015: Broadband Modeling and Constraint on Jet Parameters”
Tanaka, Y. T., Itoh, R., Uemura, M., Inoue, Y., et al.,2016, ApJ, 823, 35.
“Optical and Near-infrared Polarimetry for a Highly Dormant Comet 209P/LINEAR”
Kuroda, D., Ishiguro, M., Watanabe, M., et al. 2015, ApJ, 814, 156.
“OISTER Optical and Near-Infrared Observations of Type Iax Supernova 2012Z”
YM., Maeda, K., Kawabata, K. S., Tanaka, M., Tominaga, N., et al. 2015, ApJ, 806, 191.
“Multi-wavelength Observations of the Black Widow Pulsar 2FGL J2339.6-0532 with OISTER andSuzaku” Yatsu, Y., Kataoka, J., Takahashi, Y., Tachibana, Y., Kawai, N. et al. and OISTER Team,2015, ApJ,802, 84.
“Dust from Comet 209P/LINEAR during its 2014 Return: Parent Body of a New Meteor Shower, theMay Camelopardalids”, Ishiguro, M., Kuroda, D., et al.2015, ApJL, 798, L34.
“Variable optical polarization during high state in $¥gamma$-ray loud, narrow-line Seyfert 1 galaxy 1H0323+342”, Itoh, R., Tanaka, Y. T. et al. 2014, PASJ, 66, 108.
“Dense Optical and Near-infrared Monitoring of CTA 102 during High State in 2012 with OISTER:
Detection of Intra-night "Orphan Polarized Flux Flare“”, Itoh, Ryosuke; Fukazawa, Yasushi; Tanaka,Yasuyuki T. et al. 2013, ApJ, 768L, 24

Follow ups of IceCubetransientsResearchers related to IceCube transient follow-ups
Y. Tanaka (Hiroshima U. -> MATSUDA)-> Fermi, BROS, Subaru, Blazars
T. Morokuma (Tokyo Univ.)-> OISTER, Kiso(Tomo-e Gozen, KWFC), Subaru/(HSC, FOCAS), AGN, J-GEM
R. Itoh (Tokyo In. of Tech.)-> Fermi, OISTER, BROS, MITSUME A/O, GROWTH, J-GEM, Blazars
K. Ohta (Kyoto Univ.) talk (tomorrow)-> OISTER, Blazars, Subaru/(HSC, FOCAS), 3.8m@Okayama, 40cm@Kyoto, J-GEM,Galaxies
Y. Utsumi (Hiroshima U. -> Stanford U.)-> Subar/HSC, J-GEM, HinOTORI, 1.5-m Kanata
K. S. Kawabata (Hiroshima Univ.) talk (tomorrow)-> OISTER, 1.5-m Kanata, Subaru/HSC, Supernovae, J-GEM
M. Yamanaka (Hiroshima Univ.) this talk-> OISTER, 1.5m Kanata, Supernovae

On the behalf of OISTER collaboration

From Morokuma san’s slide

Counterpart Search Strategy@optical (see also Ohta-san’s talk)日本天文学会2018春季年会

2018/03/14-17

From Morokuma san’s slideFrom Morokuma san’s slide

3 objects was observed by Kanata,but the variation was not detected

BROS catalog will beintroduced by Ohta-san

日本天文学会2018春季年会

2018/03/14-17

Road to EM Counterpart Discovery of IceCube-170922A
From Morokuma-san’s slide
IceCube alert (GCN 21916): 2017/09/22, 20:54:30 (UT)
7 BROS sources within IceCube-170922A error region
TXS 0506+056 variability detected with Kanata/HONIR on 2017/09/24
Y. Tanaka & TM talked during Subaru ToO observations at remote observing room andnoticed LAT variability…(no special care about Subaru…)
found Fermi/LAT (gamma, ATel #10791, Tanaka+), ASAS-SN (opt) variabilities==> multi-wavelength follow-up
optical/NIR imaging, spectroscopy, polarization: incl. MITSuME, Kiso, Nayuta, Kanata,IRSF (OISTER) + Subaru (TM+ in prep.)blue-when-brighter trend: not special
R.A. 05 09 25.964
Decl. +05 41 35.33
no detailed studies yet about variability behavior
ASAS-SN long-term light curve (V-band, 0.5um)
1,000 days

3/23

2MASSKanata/HONIRJ-band
日本天文学会2018春季年会

2018/03/14-17

1

3/23 - 3/24 9

Telescopes we used through theOISTER framework
40cm@Kyoto

1.5-m Kanata@Hiroshima

2.0-m Nayuta@Hyogo1.0-m schmidt@Kiso (U. of Tokyo)
Optical Photometry

1.4-m IRSF
@SAAO (Nagoya U.)
NIR photometry

0.5-m MITSuME@Akeno (TIT)
Optical PhotometryOISTER Multi –bandand –mode follow up
results
RJ w/ polarimetry(Kanata/HONIR@Hiroshima)g’RI(0.5m MITSuME@Akeno)
JHKs (IRSF@SAAO)
V (40cm@Kyoto)

Flux, color~”almost constant”
Polarization degree
decreases(will be talked byKawabata-san)

S5 0716+06

Short-term andlarge-amplitude variationof BL Lac objects

0.6 mag

Gupta et al.
2012

We do not find`significantly’
Large-amplitude
brigtening

BL Lac

0.8 mag

Villata et al.
2002

Spectra = redshift (see Ohta san’s talk)Featureless..

1.5m Kanata/HOWPolFuture prospects

Follow-up of transient
discovered by “Tomo-e Gozen”
Discovery

spectroscopy

Photometry(polarization)

Wide-field transient survey
w/ Tomo-e Gozen
From Sako-san’s slideWide-field transient survey
w/ Tomo-e Gozen
From Sako-san’s slideWide-field transient survey
w/ Tomo-e Gozen
All-sky survey (~10000 deg2) will be
performed @ <1 day cadence-> We can research all light curves ofBROS catalog blazars…

Detection limit
from Osawa-san’s slideSynergy of follow ups(for the case of supernovae…)

IceCube transients (BL Lac??)Flux, color~“almost constant”

Spectra~no (weak) feature-> difficult to give a
constrainton theredshift

Polarization ??

No polarization observations for first 10 days
We focus on the `flux variation`in order to discover the `newtransient’
However, BL Lac objects are
known to exhibit the rapid
polarization variation (see Itohet al. 2016)

Currently, polarization shows large variation ??

Summary• We have performed the follow-up observations ofvarious transients thourgh OISTER.
• We used various instruments to get the multi –bandand –mode observational data.
• We performed the follow ups of IceCube 170922A
through OISTER ToO program.
• The flux and color variation show almost constant..
• Current observations show the large variation ofpolarization ?? (preliminary)• We will construct the new framework for `prompt’
follow-ups of transients discovered by `Tomo-e Gozen’.
The follow-up will also be done using Kyoto 3.8 m(KOOLS-IFU) and OISTER telescopes.