Title: Optical follow-up observation for GW event S190510g using Subaru/Hyper Suprime-Cam

Abstract

Abstract A gravitational wave event, S190510g, which was classified as a binary-neutron-star coalescence at the time of preliminary alert, was detected by LIGO/Virgo collaboration on 2019 May 10. At 1.7 hours after the issue of its preliminary alert, we started a target-of-opportunity imaging observation in the Y band to search for its optical counterpart using the Hyper Suprime-Cam (HSC) on the Subaru Telescope. The observation covers a 118.8 deg2 sky area corresponding to $$11.6\%$$ confidence in the localization skymap released in the preliminary alert and $$1.2\%$$ in the updated skymap. We divided the observed area into two fields based on the availability of HSC reference images. For the fields with the HSC reference images, we applied an image subtraction technique; for the fields without the HSC reference images, we sought individual HSC images by matching a catalog of observed objects with the PS1 catalog. The search depth is 22.28 mag in the former method and the limit of search depth is 21.3 mag in the latter method. Subsequently, we performed visual inspection and obtained 83 candidates using the former method and 50 candidates using the latter method. Since we only have the one-day photometric data, we evaluated the probability of candidates being located inside the 3D skymap by estimating their distances with photometry of associated extended objects. We found three candidates are likely located inside the 3D skymap and concluded they could be a counterpart of S190510g, while most of the 133 candidates were likely to be supernovae because the number density of candidates was consistent with the expected number of supernova detections. By comparing our observational depth with a light-curve model of such a kilonova reproducing AT2017gfo, we show that early deep observations with the Subaru/HSC can capture the rising phase of the blue component of a kilonova at the estimated distance of S190510g (∼230 Mpc).

Authors:

Ohgami, Takayuki ;

• Search DOE PAGES for author "Ohgami, Takayuki"
• Search DOE PAGES for ORCID "0000-0001-6755-8285"

Tominaga, Nozomu ;

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• Search DOE PAGES for ORCID "0000-0001-8537-3153"

Utsumi, Yousuke ;

• Search DOE PAGES for author "Utsumi, Yousuke"
• Search DOE PAGES for ORCID "0000-0001-6161-8988"

Niino, Yuu ;

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Tanaka, Masaomi ;

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• Search DOE PAGES for ORCID "0000-0001-8253-6850"

Banerjee, Smaranika ;

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• Search DOE PAGES for ORCID "0000-0001-6595-2238"

Hamasaki, Ryo; Yoshida, Michitoshi ;

• Search DOE PAGES for author "Yoshida, Michitoshi"
• Search DOE PAGES for ORCID "0000-0002-9948-1646"

Terai, Tsuyoshi; Takagi, Yuhei ;

• Search DOE PAGES for author "Takagi, Yuhei"
• Search DOE PAGES for ORCID "0000-0002-9104-8979"

Morokuma, Tomoki ;

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• Search DOE PAGES for ORCID "0000-0001-7449-4814"

Sasada, Mahito ;

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• Search DOE PAGES for ORCID "0000-0001-5946-9960"

Akitaya, Hiroshi ;

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• Search DOE PAGES for ORCID "0000-0001-6156-238X"

Yasuda, Naoki; Yanagisawa, Kenshi ;

• Search DOE PAGES for author "Yanagisawa, Kenshi"
• Search DOE PAGES for ORCID "0000-0001-7592-9285"

Ohsawa, Ryou

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• Search DOE PAGES for ORCID "0000-0001-5797-6010"

Publication Date:

Thu Feb 04 00:00:00 EST 2021

Research Org.:

SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES); MEXT KAKENHI; JSPS KAKENHI

Contributing Org.:

J-GEM collaboration

OSTI Identifier:

1774692

Alternate Identifier(s):

OSTI ID: 1798508

Grant/Contract Number:  

AC02-76-SF00515; JP17H06363; JP24103003; JP26800103; JP19K14761; JP17K14255; JP20H00158; JP19H00694; JP16H02158; AC02-76SF00515

Resource Type:

Published Article

Journal Name:

Publications of the Astronomical Society of Japan

Additional Journal Information:

Journal Name: Publications of the Astronomical Society of Japan Journal Volume: 73 Journal Issue: 2; Journal ID: ISSN 0004-6264

Publisher:

Oxford University Press

Country of Publication:

Japan

Language:

English

Subject:

79 ASTRONOMY AND ASTROPHYSICS; gravitational waves; nuclear reactions; nucleosynthesis; abundances; stars: neutron