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arXiv · 1904.09697

The Hyper Suprime-Cam SSP Transient Survey in COSMOS: Overview

Naoki Yasuda·Masaomi Tanaka·Nozomu Tominaga·Ji-an Jiang·Takashi J. Moriya·Tomoki Morokuma·Nao Suzuki·Ichiro Takahashi·Masaki S. Yamaguchi·Keiichi Maeda·Masao Sako·Shiro Ikeda·Akisato Kimura·Mikio Morii·Naonori Ueda·Naoki Yoshida·Chien-Hsiu Lee·Sherry H. Suyu·Yutaka Komiyama·Nicolas Regnault·David Rubin
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Abstract

We present an overview of a deep transient survey of the COSMOS field with the Subaru Hyper Suprime-Cam (HSC). The survey was performed for the 1.77 deg$^2$ ultra-deep layer and 5.78 deg$^2$ deep layer in the Subaru Strategic Program over 6- and 4-month periods from 2016 to 2017, respectively. The ultra-deep layer shows a median depth per epoch of 26.4, 26.3, 26.0, 25.6, and 24.6 mag in $g$, $r$, $i$, $z$, and $y$ bands, respectively; the deep layer is $\sim0.6$ mag shallower. In total, 1,824 supernova candidates were identified. Based on light curve fitting and derived light curve shape parameter, we classified 433 objects as Type Ia supernovae (SNe); among these candidates, 129 objects have spectroscopic or COSMOS2015 photometric redshifts and 58 objects are located at $z > 1$. Our unique dataset doubles the number of Type Ia SNe at $z > 1$ and enables various time-domain analyses of Type II SNe, high redshift superluminous SNe, variable stars, and active galactic nuclei.

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Naoki Yasuda, Masaomi Tanaka, Nozomu Tominaga, Ji-an Jiang, Takashi J. Moriya, Tomoki Morokuma, Nao Suzuki, Ichiro Takahashi, Masaki S. Yamaguchi, Keiichi Maeda, Masao Sako, Shiro Ikeda, Akisato Kimura, Mikio Morii, Naonori Ueda, Naoki Yoshida, Chien-Hsiu Lee, Sherry H. Suyu, Yutaka Komiyama, Nicolas Regnault, David Rubin. 2019-04-22. The Hyper Suprime-Cam SSP Transient Survey in COSMOS: Overview. https://doi.org/10.1093/pasj%2Fpsz050

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