[vsnet-grb-info 22093] LIGO/Virgo S190425z: J-GEM optical follow-up observations with Subaru/FOCAS

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  24192
SUBJECT: LIGO/Virgo S190425z: J-GEM optical follow-up observations with Subaru/FOCAS
DATE:    19/04/25 17:56:25 GMT
FROM:    Mahito Sasada at Hiroshima University  <sasadam at hiroshima-u.ac.jp>

Sasada, M., Akitaya, H., Nakaoka, T. (Hiroshima U.), Yoshida, M. (NAOJ/Subaru),
Tanaka, M. (Tohoku U.), Tominaga N., Ohgami, T., Kaneko A. (Konan U.),
Itoh, R. (Bisei Astronomical Observatory), Sekiguchi, Y. (Toho U.),
Utsumi, Y. (Stanford U./SLAC), Morokuma, T., Niino, Y., Ohsawa, R. (U.
of Tokyo),
Murata, K. L. (Tokyo Tech), on behalf of J-GEM collaboration


We report our optical imaging observations of galaxies in the
localization region of the BNS gravitational wave event S190425z (The
LIGO Scientific Collaboration and the Virgo Collaboration, 2019, GCN,
24168) using the Faint Object Camera and Spectrograph (FOCAS; 6 arcmin
field-of-view in diameter; Kashikawa et al. 2002, PASJ, 54, 819) on
the 8.2-m Subaru telescope. We started our observations at UT
2019-04-25 11:46, about 3.5 hours after the event.

We observed 154 galaxies in total. The target galaxies are selected
from the list of potential host galaxies for this event (Dalya et al.
2019, GCN, 24171) around the central coordinate of the localization of
the gamma-ray pulses detected with INTEGRAL/SPI-ACS (Minaev et al.
2019, GCN, 24170). The list of the galaxies we observed is shown in
the table below.

We took ten-second r-band images for each galaxy with typical 5-sigma
depths of 23-24 mag. The obtained images are compared with the
Pan-STARRS r-band images (Chambers et al., 2016, arXiv:1612.05560)
with similar or slightly shallower depths compared to our FOCAS
images. In these galaxies, we find no apparent transient objects that
are not registered in the IAU Transient Name Server
(https://wis-tns.weizmann.ac.il).

Galaxy name               RA Dec
2MASS16522624+2319575     16:52:26.24 +23:19:57.5
NGC6051                   16:04:56.70 +23:55:58.3
NGC6062                   16:06:22.80 +19:46:40.6
60191                     17:23:26.11 +23:38:39.5
NGC6308                   17:11:59.72 +23:22:48.3
57296                     16:09:15.67 +25:42:45.0
56144                     15:49:57.32 +20:48:18.6
UGC10138                  16:01:40.23 +21:21:10.6
UGC10153                  16:03:19.52 +20:38:12.5
57607                     16:14:57.83 +21:56:17.9
58028                     16:24:15.15 +20:11:00.9
56443                     15:56:33.64 +20:03:08.2
56713                     16:01:28.67 +22:25:39.6
NGC6203                   16:40:27.38 +23:46:29.1
57072                     16:05:29.16 +19:56:31.7
2MASS16313806+2047366     16:31:38.06 +20:47:36.6
58396                     16:30:47.15 +20:21:19.3
NGC6233                   16:50:15.72 +23:34:47.4
1683153                   16:32:58.94 +23:11:51.0
1745822                   16:09:51.84 +25:41:11.6
59087                     16:50:14.26 +23:26:28.4
58322                     16:29:17.35 +20:21:53.3
58537                     16:34:53.70 +23:12:42.2
UGC10224                  16:08:50.23 +22:02:33.4
2MASS18405128+2334077     18:40:51.28 +23:34:07.7
58006                     16:23:40.08 +24:28:26.6
1695642                   16:22:57.30 +23:53:35.9
1631905                   16:16:11.90 +20:36:45.1
UGC10834                  17:24:32.84 +20:23:53.0
1612380                   16:00:30.52 +19:59:07.0
55776                     15:40:37.22 +20:33:44.7
56150                     15:49:59.28 +20:48:20.6
UGC10260                  16:11:57.87 +20:55:24.4
NGC6075                   16:11:22.56 +23:57:54.5
57272                     16:08:33.84 +21:04:52.3
1635109                   15:44:24.00 +20:45:09.5
214459                    16:06:00.72 +20:50:50.2
2MASS16060593+2047032     16:06:05.93 +20:47:03.2
2MASS16072060+2058306     16:07:20.60 +20:58:30.6
3089913                   16:06:16.28 +21:03:49.2
PGC1626696                12:03:48.25 +20:24:58.9
56856                     16:03:17.78 +21:35:30.5
56706                     16:01:25.27 +21:55:57.5
1661347                   16:04:50.77 +21:59:23.3
214390                    15:35:04.81 +23:28:45.7
56084                     15:48:33.88 +22:58:20.8
57085                     16:05:36.81 +22:11:10.8
56652                     16:00:38.21 +22:32:37.0
57526                     16:13:25.54 +21:54:33.8
SDSSJ153858.32+234650.8   15:38:58.33 +23:46:50.8
2MASS16073961+2220315     16:07:39.61 +22:20:31.5
1671243                   16:05:23.40 +22:30:27.6
IC4573                    15:42:12.27 +23:48:00.5
57116                     16:05:58.62 +22:37:55.9
57420                     16:11:20.97 +22:22:31.3
56853                     16:03:13.71 +23:00:29.5
UGC10236                  16:10:05.09 +22:39:01.1
56252                     15:52:02.13 +23:44:02.7
UGC10066                  15:51:36.87 +23:47:24.1
1688132                   16:03:44.45 +23:28:55.4
57542                     16:13:46.01 +22:55:07.9
57472                     16:12:20.33 +23:00:07.0
56175                     15:50:38.65 +20:22:54.7
1623900                   16:04:43.49 +20:19:25.3
56534                     15:58:33.94 +20:11:06.3
UGC10060                  15:51:06.90 +20:12:09.2
3089914                   16:18:24.75 +20:53:23.9
1686786                   15:10:28.49 +23:24:14.4
PGC1689724                15:11:16.57 +23:34:20.9
2MASS16182990+2209489     16:18:29.90 +22:09:48.9
1684230                   15:50:20.24 +23:15:32.7
1690340                   15:43:51.42 +23:36:26.5
1668320                   16:19:07.19 +22:21:07.7
55690                     15:38:59.04 +23:46:54.0
1672257                   16:17:11.69 +22:33:46.9
57493                     16:12:42.77 +22:59:02.7
2MASS16141210+2307136     16:14:12.10 +23:07:13.6
57263                     16:08:23.52 +23:28:24.7
57265                     16:08:22.57 +23:28:46.7
56963                     16:04:36.61 +23:39:47.3
1691288                   16:04:59.95 +23:39:30.4
57021                     16:05:02.50 +23:40:08.5
56958                     16:04:33.46 +23:50:16.3
57003                     16:04:50.57 +23:58:30.3
57014                     16:04:59.47 +23:58:12.3
56887                     16:03:41.89 +24:05:42.5
1692398                   16:12:07.70 +23:43:04.9
UGC10256                  16:11:30.77 +23:48:42.3
56991                     16:04:46.81 +24:16:43.2
1694999                   16:12:14.17 +23:51:28.9
57105                     16:05:49.61 +24:10:32.8
1705857                   16:03:14.25 +24:22:23.2
57406                     16:11:14.38 +24:13:29.5
1717114                   16:04:16.27 +24:48:44.4
UGC10160                  16:03:54.24 +25:00:38.0
57029                     16:05:11.46 +24:57:36.7
56949                     16:04:35.57 +25:11:23.3
57293                     16:09:06.46 +24:52:13.0
1686035                   16:36:40.62 +23:21:36.5
58712                     16:39:41.29 +23:30:53.4
58345                     16:29:44.04 +23:21:10.6
UGC10320                  16:18:07.32 +21:03:58.9
58744                     16:40:50.93 +23:39:34.0
58371                     16:30:13.32 +23:04:11.1
58050                     16:24:45.01 +23:57:54.3
58363                     16:30:02.71 +23:21:16.1
56249                     15:52:05.66 +20:08:42.7
58360                     16:29:53.36 +20:13:57.6
60508                     17:34:06.29 +23:31:09.2
1642211                   16:21:09.60 +21:04:30.3
56874                     16:03:28.01 +20:17:32.3
PGC058850                 16:43:36.19 +20:13:53.8
1621936                   16:47:43.70 +20:15:48.6
56961                     16:04:35.71 +25:43:14.3
57893                     16:21:04.24 +21:20:26.3
NGC6201                   16:40:14.41 +23:45:55.0
58042                     16:24:34.15 +21:11:41.3
2MASS15503893+2023227     15:50:38.93 +20:23:22.7
1736488                   16:10:48.42 +25:26:12.6
60430                     17:31:15.29 +23:35:01.8
1614726                   15:57:32.18 +20:03:12.8
57765                     16:18:05.32 +21:33:12.9
NGC6062B                  16:06:18.93 +19:45:47.2
58415                     16:31:06.58 +23:49:57.7
1673429                   16:20:44.20 +22:38:00.7
2MASS16345531+2034432     16:34:55.31 +20:34:43.2
2MASS16320391+2045519     16:32:03.91 +20:45:51.9
57752                     16:17:49.42 +20:41:28.9
1638586                   16:27:04.49 +20:54:35.2
1685163                   16:33:32.29 +23:18:43.4
57391                     16:10:52.39 +22:37:32.2
1603948                   16:13:55.38 +19:44:45.9
56282                     15:52:43.13 +20:13:59.8
1692904                   16:52:11.03 +23:44:39.6
UGC10525                  16:44:04.21 +23:23:52.1
60413                     17:30:34.99 +23:37:28.9
57290                     16:09:07.26 +21:52:03.7
59153                     16:52:17.31 +23:18:01.5
2MASS16302400+2026011     16:30:24.00 +20:26:01.1
1667049                   16:02:25.59 +22:17:02.5
59213                     16:53:53.83 +20:35:51.8
1628794                   16:25:52.24 +20:29:19.8
57283                     16:08:58.14 +19:49:25.5
1657664                   16:19:02.35 +21:48:22.7
1632425                   16:25:00.27 +20:38:04.5
1612760                   15:57:33.04 +19:59:43.8
1688390                   16:29:48.38 +23:29:45.6
1664646                   16:05:13.92 +22:09:32.6
1610658                   16:05:32.29 +19:56:04.8
1727092                   16:11:38.16 +25:09:11.6
1736885                   16:03:52.36 +25:26:48.6
2MASS16282647+2341107     16:28:26.47 +23:41:10.7
3089915                   16:20:34.24 +21:12:08.7
1699245                   16:11:35.70 +24:04:35.6