赤外線高分散ラボ:Laboratory of Infrared High-resolution spectroscopy

about WINERED

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About WINERED

WINERED (Warm INfrared Echelle spectrograph to Realize Extreme Dispersion and sensitivity) is a near-infrared high-resolution spectrograph developed by LiH. WINERED is a PI-type instrument. It was used with the 3.58m New Technology Telescope (NTT) at the La Silla Observatory, ESO, in 2017 and 2018. Observations with the Magellan Clay 6.5m telescope are being prepared aiming to make the first observing run in 2020 June. WINERED has three distinctive features: warm optics (no cold stop), wide spectral coverage (0.90−1.35 μm), and high sensitivity (the efficiency as high as 50%). WINERED has three observing modes: "WIDE" (R≡ λ/Δ λFWHM=28,000) plus “HIRES-Y” and “HIRES-J” (R=68,000).



Instrumental Facts

1. Warm optics with no cold stop

(ⅰ) Optics are at room temperature except for the infrared camera system (camera lenses and an infrared array).
(ⅱ) Beneficial to reduce time and cost for development, alignment, and maintenance.


2. Wide spectral coverage

Achieved by a combination of decent optical design with a cross-dispersed echelle and a large format infrared array (2k x 2k).



3. High sensitivity

<High throughput>

  • Gratings with high diffraction efficiency
  •  - WIDE mode: replica echelle grating by Newport Co. (~83%), VPH cross-disperser (~86%).
     - HIRES-Y&J modes: high-blazed echelle gratings by Canon Inc. (>70%), VPH cross-dispersers (~90%).
  • Extremely-low reflection BBAR: R < 0.5% per lens surface.
  • The minimum number of optical elements: no-use of white pupil optics.
  • High Q.E. of an array: 1.7μm cut-off HAWAII-2RG (~86% @1.23μm).

  • <Low noise>

  • Low readout noise: σr= 5.3 e- (NDR=32). Low-dark noise: σ d < 2 e- (900sec)
  • Suppressed ambient thermal background (0.05e- /sec/pix @280 K) with custom thermal-cut filters .

  • 4. PI-type spectrograph

  • Compact [1.8m(L) x 1.1m(W) x 1.0m(H)] and light weight [~250kg].
  • Attachable to any telescopes with a Nasmyth focus (slower than f/11).
  • Planned to be at Magellan Clay 6.5m telescope, LCO (Chile) from 2020 and proposals to use the WINERED with the Magellan are very welcome.