[vsnet-grb-info 25121] LIGO/Virgo S200225q: no counterpart candidate in SVOM/GWAC observations
GCN Circulars
gcncirc at capella2.gsfc.nasa.gov
Wed Feb 26 18:42:49 JST 2020
TITLE: GCN CIRCULAR
NUMBER: 27221
SUBJECT: LIGO/Virgo S200225q: no counterpart candidate in SVOM/GWAC observations
DATE: 20/02/26 09:41:33 GMT
FROM: Jirong Mao at Yunnan Obs <jirongmao_obs at ynao.ac.cn>
J. Mao (YNAO), N. Leroy (IJCLab), X. G. Wang (GXU), D. Corre (IJCLab),
J. Y. Wei (NAOC)
report on behalf of the SVOM Multi Messenger Astronomy and GWAC teams
(http://www.svom.fr/en/svom-mma-and-gwac-team):
We observed 6 (~900 square deg) sky regions to cover the skymap of the
advanced LIGO/Virgo trigger S200225q (GCN # 27193), with SVOM/GWAC,
at Xinglong Observatory. SVOM/GWAC is equipped with two sets of
wide angle cameras:
- FFOV cameras (FOV~900 square degrees/camera, aperture = 3.5 cm),
- JFOV cameras (FOV~150 square degrees/camera, aperture = 18 cm).
SVOM/GWAC currently comprises 4 FFOV cameras and 16 JFOV cameras,
working in the unfiltered band. The observations are operated in
time-series mode, taking one exposure every 25 seconds
(20s exposure + 5s readout). The observed and processed regions enclosed
an estimated 56.5% of the probability of the advanced LIGO/Virgo skymap.
Images were taken between ~5.5 hours and ~6.5 hours
after the GW trigger time. The coordinates of the 6 sky regions
observed and their observation times and covered probability are
listed below:
Id Ra Dec start (UTC) end (UTC) Proba. Cam.
1 05:56:47.7 65:08:15 2020-02-25 11:42:19 2020-02-25 12:33:05 0.001 JFOV
2 07:26:34.3 52:57:54 2020-02-25 11:34:41 2020-02-25 12:02:57 0.197 JFOV
3 06:34:13.4 31:32:25 2020-02-25 11:03:34 2020-02-25 11:31:49 0.142 JFOV
4 06:19:52.5 30:20:19 2020-02-25 11:03:45 2020-02-25 11:31:57 0.085 JFOV
5 07:28:23.2 63:59:54 2020-02-25 12:36:01 2020-02-25 12:36:25 0.165 JFOV
6 07:04:46.5 36:07:24 2020-02-25 11:48:36 2020-02-25 12:32:32 0.170 JFOV
The sky coverage map is available at:
http://cmm.svom.cn/gwpub/O3/S200225q/S200225q.png
(user:svomo3 pwd:gwo3).
Weather conditions were hazy during the observations. An average 3-sigma
limiting magnitude of 16 mag in the R band was obtained in the single
frames. No credible new source was detected by our online pipeline during
follow-up observations. A more detailed image analysis including
co-addition is ongoing with our offline pipeline to search for transient
candidates.
More information about the vsnet-grb-info
mailing list