[vsnet-grb-info 22200] LIGO/Virgo S190426c: J-GEM optical/NIR follow-up observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  24299
SUBJECT: LIGO/Virgo S190426c: J-GEM optical/NIR follow-up observations
DATE:    19/04/27 20:03:16 GMT
FROM:    Yuu Niino at University of Tokyo  <yuuniino at ioa.s.u-tokyo.ac.jp>

Niino, Y., Morokuma, T., Ohsawa, R., Sako, S., Shikauchi, M. (U. of Tokyo), 
Yanagisawa, K. (NAOJ), 
Takagi K., Nakaoka, T., Sasada, M.(Hiroshima U.),
Saito, T. (Nishi-Harima Astronomical observatory), 
Itoh, R. (Bisei Astronomical Observatory), 
Ohta, K. (Kyoto U.), 
Utsumi, Y. (Stanford U./SLAC), 
Sekiguchi, Y. (Toho U.), 
Tominaga, N. (Konan U.), 
on behalf of J-GEM collaboration

We report our optical and near-infrared imaging observations for the gravitational wave event S190426c that has a non-zero probability to be a NS-BH merger. 

We performed 180 deg2 wide-field imaging survey, using the Tomo-e Gozen camera on the 105-cm Kiso Schmidt telescope, a very wide-field (20 deg2 field-of-view) optical CMOS imager (Sako et al. 2018, SPIE, 10702, 107020J). The observations started about 19 hours after the GW detection. A typical limiting magnitude is about 20 mag (no filter). Data reduction is in progress. 

We also performed galaxy-targeted observations for 33 galaxies (see the table below) selected from the GLADE catalog (Dalya et al. 2016) in the probability skymap of S190426c using the following telescopes/instruments.
- 91 cm Okayama Astrophysical Observatory NIR Wide‐Field Camera 
  (OAOWFC, J-band, Yanagisawa, K., et al. 2014, Proc. SPIE, 9147, 91476D, 
  Yanagisawa, K., et al. 2016, Proc. SPIE, 9908, 99085D)
- 150 cm Kanata telescope at Higashi-Hiroshima Observatory and HONIR, a 2 color imager in Rc and H bands (Akitaya et al. 2014, 9147, 91474O)
- 200 cm Nayuta telescope at Nishi-Harima Astronomical Observatory 
  and Nishiharima Infrared Camera (NIC)

We found no apparent transient objects in these galaxies 
to the 5 sigma limiting magnitudes listed below.


         galid   ra dec    J H R NoFilt      K obsid
GL204400+531432  310.9979 53.2423  17.08 -- --      -- -- OAOWFC
GL221519+843451  333.8273 84.581     -- -- -- 99.99     -- Kiso Schmidt
GL232822+852913  352.0922 85.4869     -- 99.99 99.99 --     -- Kanata-HONIR
GL233253+853017   353.222 85.5048   -- 15.35 17.65 --     -- Kanata-HONIR
GL002228+854955     5.617 85.8321 17.33  17.24 -- -- 99.99        Nayuta
GL011607+845904   19.0275 84.9843   -- -- -- --  99.99 Nayuta
GL235357+842524  358.4862 84.4233     -- -- -- 99.99    -- Kiso Schmidt
GL233600+852510  353.9992 85.4196     -- -- 17.65 --     -- Kanata-HONIR
GL235923+834710  359.8466 83.7861     -- 99.99 -- --     -- Kanata-HONIR
GL223741+844405  339.4209 84.7347     -- -- -- 99.99    -- Kiso Schmidt
GL215853+832141  329.7229 83.3614     -- -- -- 99.99    -- Kiso Schmidt
GL214359+841507  325.9938 84.2519     -- -- -- 18.29     -- Kiso Schmidt
GL222416+864727  336.0676 86.7909     -- -- -- 99.99     -- Kiso Schmidt
GL205538+853151  313.9084 85.5307     -- -- -- 99.99     -- Kiso Schmidt
GL233600+852604  353.9975 85.4346     -- 15.35 17.65 --     -- Kanata-HONIR
GL201328+463031  303.3651 46.5087  17.57 -- --      -- -- OAOWFC
GL221751+832357  334.4629 83.3993     -- -- -- 99.99     -- Kiso Schmidt
GL205927+845437  314.8623 84.9103     -- -- -- 99.99     -- Kiso Schmidt
GL224440+824209  341.1686 82.7026     -- -- -- 18.95     -- Kiso Schmidt
GL225030+824531  342.6235 82.7586     -- -- -- 19.00     -- Kiso Schmidt
GL201355+462212  303.4775 46.3701  17.57 -- --      -- -- OAOWFC
GL235428+842518  358.6179 84.4217     -- -- -- 99.99    -- Kiso Schmidt
GL223827+872835  339.6125 87.4764     -- -- -- 17.11     -- Kiso Schmidt
GL180154+865139  270.4751 86.8608     -- -- -- 17.75     -- Kiso Schmidt
GL233512+852612  353.7982 85.4366     -- 15.35 17.65 --     -- Kanata-HONIR
GL215728+854334  329.3673 85.7262     -- -- -- 15.99     -- Kiso Schmidt
GL194045+874800   295.188 87.7998   -- -- -- 17.69     -- Kiso Schmidt
GL150924+865350  227.3519 86.8972     -- -- -- 99.99     -- Kiso Schmidt
GL211419+871821  318.5808 87.3058     -- -- -- 17.59     -- Kiso Schmidt
GL204129+862633  310.3714 86.4425     -- -- -- 99.99     -- Kiso Schmidt
GL233452+852734  353.7174 85.4593     -- 15.35 17.65 --     -- Kanata-HONIR
GL173106+875633  262.7764 87.9426     -- -- -- 18.29     -- Kiso Schmidt
GL212800+853445  321.9959 85.5793     -- -- -- 18.29     -- Kiso Schmidt

Note that a limiting mag = 99.99 is due to failure in our real-time data analysis.