LOTUS: a low-cost, ultraviolet spectrograph

作者：Steele I A^*; Marchant J M; Jermak H E; Barnsley R M; Bates S D; Clay N R; Fitzsimmons A; Jehin E; Jones G; Mottram C J; Smith R J; Snodgrass C; de Val Borro M

来源：Monthly Notices of the Royal Astronomical Society, 2016, 460(4): 4268-4276.

DOI：10.1093/mnras/stw1287

• instrumentation: spectrographs
• ultraviolet: general

We describe the design, construction and commissioning of a simple, low-cost long-slit spectrograph for the Liverpool Telescope. The design is optimized for near-UV and visible wavelengths and uses all transmitting optics. It exploits the instrument focal plane field curvature to partially correct axial chromatic aberration. A stepped slit provides narrow (2.5 x 95 arcsec) and wide (5 x 25 arcsec) options that are optimized for spectral resolution and flux calibration, respectively. On sky testing shows a wavelength range of 3200-6300 angstrom with a peak system throughput (including detector quantum efficiency) of 15 per cent and wavelength dependent spectral resolution of R = 225-430. By repeated observations of the symbiotic emission line star AG Peg, we demonstrate the wavelength stability of the system is < 2 angstrom rms and is limited by the positioning of the object in the slit. The spectrograph is now in routine operation monitoring the activity of comet 67P/Churyumov-Gerasimenko during its current post-perihelion apparition.

• 出版日期2016-8-21