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arXiv · 2606.05237

GREX-PLUS Science Book v2

PLUS Science Team·Shunsuke Baba·Sirio Belli·Pietro Benotto·Ivan Delvecchio·Yoshinobu Fudamoto·Yuka Fujii·Yuichi Harikane·Yasuhiro Hirahara·Akio K. Inoue·Yoshiyuki Inoue·Hajime Kawahara·Taiki Kawamuro·Yui Kawashima·Lucas Kimmig·Tadayuki Kodama·Mitsuru Kokubo·Hiroyuki Kurokawa·Katsunori Kusakabe·Kosei Matsumoto·Noriyuki Matsunaga·Taro Matsuo·Yoshiki Matsuoka·Shuji Matsuura·Toru Misawa·Shota Miyazaki·Alessia Moretti·Kumiko Morihana·Takashi Moriya·Kentaro Nagamine·Kimihiko Nakajima·Hideko Nomura·Shota Notsu·Takafumi Ootsubo·Kazumasa Ohno·Giorgia Peluso·Bianca M. Poggianti·Mario Radovich·Giulia Rodighiero·Hideo Sagawa·Kazuhiro Shimasaku·Takashi Shimonishi·Ken-ichi Tadaki·Kosuke Takahashi·Michihiro Takami·Shuya Tan·Takumi Tanaka·Tsuyoshi Terai·Yoshiki Toba·Roberta Tripodi·Francesco Valentino·Benedetta Vulcani·Taihei Yano·Chikako Yasui·Stefano Zibetti
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Abstract

GREX-PLUS (Galaxy Reionization EXplorer and PLanetary Universe Spectrometer) is a mission candidate for a JAXA strategic L-class mission to be launched in the 2030s. Its primary science goals are two-fold: galaxy formation and evolution, and planetary system formation and evolution. The GREX-PLUS spacecraft will carry a telescope with a 1 m primary mirror aperture cooled down to 50 K. The two science instruments will be onboard: a wide-field camera in the 2--8 $\mu$m wavelength band and a high-resolution spectrometer with a wavelength resolution of 30,000 in the 10--18 $\mu$m band. The GREX-PLUS wide-field camera aims to detect the first generation of galaxies at redshift $z>15$. The GREX-PLUS high-resolution spectrometer aims to identify the location of the water ``snowline'' in protoplanetary disks. Both instruments will provide unique datasets for a broad range of scientific topics, including galaxy mass assembly, the origin of supermassive blackholes, infrared background radiation, molecular spectroscopy in the interstellar medium, transit spectroscopy of exoplanet atmospheres, planetary atmospheres in the Solar System, and so on. This document is the second version of a collection of scientific themes that can be achieved with GREX-PLUS. Each section in Chapters~2 and 3 is based on presentations at several GREX-PLUS Science Workshops.

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PLUS Science Team, Shunsuke Baba, Sirio Belli, Pietro Benotto, Ivan Delvecchio, Yoshinobu Fudamoto, Yuka Fujii, Yuichi Harikane, Yasuhiro Hirahara, Akio K. Inoue, Yoshiyuki Inoue, Hajime Kawahara, Taiki Kawamuro, Yui Kawashima, Lucas Kimmig, Tadayuki Kodama, Mitsuru Kokubo, Hiroyuki Kurokawa, Katsunori Kusakabe, Kosei Matsumoto, Noriyuki Matsunaga, Taro Matsuo, Yoshiki Matsuoka, Shuji Matsuura, Toru Misawa, Shota Miyazaki, Alessia Moretti, Kumiko Morihana, Takashi Moriya, Kentaro Nagamine, Kimihiko Nakajima, Hideko Nomura, Shota Notsu, Takafumi Ootsubo, Kazumasa Ohno, Giorgia Peluso, Bianca M. Poggianti, Mario Radovich, Giulia Rodighiero, Hideo Sagawa, Kazuhiro Shimasaku, Takashi Shimonishi, Ken-ichi Tadaki, Kosuke Takahashi, Michihiro Takami, Shuya Tan, Takumi Tanaka, Tsuyoshi Terai, Yoshiki Toba, Roberta Tripodi, Francesco Valentino, Benedetta Vulcani, Taihei Yano, Chikako Yasui, Stefano Zibetti. 2026-06-03. GREX-PLUS Science Book v2. https://arxiv.org/abs/2606.05237

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