High Dispersion Spectrograph (HDS) for the Subaru Telescope

Abstract

We present the design and performance of the High Dispersion Spectrograph (HDS) of the Subaru Telescope. HDS is an echelle spectrograph located at the Nasmyth focus of the telescope. The collimated beam size is 272 mm, and the echelle is 300 mm by 840 mm in total size ($31.6 \,\mathrm{gr} \,\mathrm{mm}^{-1}, R=2.8$). HDS has two cross-dispersing gratings with $400 \,\mathrm{gr} \,\mathrm{mm}^{-1}$ and $250 \,\mathrm{gr} \,\mathrm{mm}^{-1}$, which are optimized for the blue and red wavelength regions, respectively. The camera is of the catadioptric type system, consisting of three corrector lenses and a mirror. Two EEV-CCD’s with $4100 \times 2048$ pixels and a pixel size of 13.5 ${\mu \mathrm {m}}$ are used as the detector. A standard configuration with a ${0\rlap {.}{}^{\mathrm {\prime \prime }}4}$ slit gives a spectral resolution of $R=90000$, and a narrower slit width enables higher resolution of up to $R \sim 160000$. The spectrograph has sensitivities from 3000 ${Å}$ to 1 ${\mu \mathrm {m}}$, and one exposure covers a range of 1500–2500 ${Å}$, depending on the wavelength region. The throughput of the telescope and the spectrograph, including the efficiency of the detector, is about 13% in 5000–6000 ${Å}$ and about 8% at 4000 ${Å}$. The stability of the spectrograph and scattered light level are also reported.

Chemical abundances of giant stars in NGC 5053 and NGC 5634, two globular clusters associated with the Sagittarius dwarf spheroidal galaxy?

“…1) with the cluster values confirms that the target is a cluster member. Two bright red giant stars in NGC 5634 were spectroscopically observed at the Subaru telescope on 2009 March 3 with the High Dispersion Spectrograph (HDS, Noguchi et al 2002) in Echelle mode (program ID: S09A-026). The targets were selected from the photometry of Bellazzini et al (2002, hereafter B02), and their ID numbers, coordinates, and magnitudes are given in Table 1.…”

Chemical compositions of six metal-poor stars in the ultra-faint dwarf spheroidal galaxy Boötes I

“…The high-resolution spectra of six bright red giants were obtained with the Subaru Telescope High Dispersion Spectrograph (HDS; Noguchi et al 2002) Table 1 with observation details. We applied CCD on-chip binning (2 × 2 pixels), resulting in a resolving power of R = λ/δλ = 40 000.…”

6Li/7Li estimates for metal-poor stars

“…Spectra were taken for eight metal-poor stars with the High Dispersion Spectrograph (HDS, Noguchi et al 2002) mounted on the Subaru 8.2 m-telescope on the nights of May 17−19, 2005 (UT). Results for five stars are presented here; the observations of three other stars were not completed in this run to achieve the data quality required for this study.…”