Highly Sensitive, Non-cryogenic NIR High-resolution Spectrograph, WINERED

Abstract WINERED is a novel near-infrared (NIR) high-resolution spectrograph (HRS) that pursues the highest possible sensitivity to realize high-precision spectroscopy in NIR as optical wavelength range. covers 0.9–1.35 μ m ( z , Y and J -bands) with three modes (Wide mode two Hires modes) at maximum spectral resolutions of R = 28,000 70,000. For fulfilling objective, designed an unprecedentedly high instrument throughput (up 50% including quantum efficiency array) times or more than other existing optical/NIR HRSs. This mainly realized by combination non-white pupil no fiber-fed configuration design, moderate (optimized) coverage, high-throughput gratings. Another prominent feature “warm” despite for infrared (IR) observations. Such non-cryogenic (no cold stop) IR finally became custom-made thermal-cut filter 10 −8 class, 1.7 cutoff HAWAII-2RG array, baffle reducing direct thermal radiation array into solid angle f /2. The background suppressed below 0.1 photons pixel −1 s even wide band under environment 290 K. had been installed 3.58 New Technology Telescope La Silla Observatory, ESO, since 2017. Even intermediate size telescope, was confirmed provide limiting magnitude (for SNR 30 8 hr. integration time) 16.4 mag Wide 15.1 mode, respectively, natural seeing conditions. These sensitivities are comparable those NIR-HRSs attached 8–10 class telescopes AO. type spectrographs may become critical not only currently on-going extremely large reduce developing cost time but also smaller extend their lives long programs.