Search

We present measurements of the spectral response function of commercially-available Nikon 35mm photographic camera lenses for use in astronomical instrumentation. Our motivation for this work stems from the fact that several astronomical imaging systems have been deployed or proposed using this type of commercial lens. We have performed measurements of the relative and absolute spectral response function of five commercially-available photographic lenses. These measurements show that these lenses generally have >50% throughput across the entire optical window of 400nm < λ < 800nm.

We present results from the spectrophotometric calibration of the new E2V CCD camera on the Swope telescope and of RetroCam on the DuPont Telescope. We measured the relative sensitivity of each pixel vs wavelength over the whole wavelength sensitivity range of each camera, for all the filters that will be used during the 5 years of the CSP2 survey. We used a tunable light source and fiber delivery system conceived and built in our lab to achieve +/-1% precision calibration from 300nm to 1100nm and +/-3% from 1100nm to 1800nm. Achieving this relatively high precision at low light levels was made possible by using Si, Ge and InGaAs photodiodes coupled to custom high gain amplifiers. Comparison of these results to results obtained 3 years before, allowed us to confirm that the intrinsic transmission bandpass of the filters has not changed over time but that the mirror reflectivity and the introduction of a new CCD camera drastically changed the total telescope sensitivity. The analysis of the spatial response of the new E2V CCD vs wavelength also shows a slight gradient in the color response of the CCD both in the UV and Infrared.

The Visible Integral-Field Replicable Unit Spectrograph (VIRUS) instrument will be installed at the Hobby-Eberly Telescope† in the near future. The instrument will be housed in two enclosures that are mounted adjacent to the telescope, via the VIRUS Support Structure (VSS). We have designed the enclosures to support and protect the instrument, to enable servicing of the instrument, and to cool the instrument appropriately while not adversely affecting the dome environment. The system uses simple HVAC air handling techniques in conjunction with thermoelectric and standard glycol heat exchangers to provide efficient heat removal. The enclosures also provide power and data transfer to and from each VIRUS unit, liquid nitrogen cooling to the detectors, and environmental monitoring of the instrument and dome environments. In this paper, we describe the design and fabrication of the VIRUS enclosures and their subsystems.

We present a conceptual design for a low resolution optical spectrograph for the Astronomical Observatory of Cordoba 1.54m telescope. The simple instrument is required to cover a broad wavelength range (4000A

The Visual Integral-Field Replicable Unit Spectrograph (VIRUS) instrument is a baseline array 150 identical fiber fed optical spectrographs designed to support observations for the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX). The collimator subassemblies of the instrument have been assembled in a production line and are now complete. Here we review the design choices and assembly practices used to produce a suite of identical low-cost spectrographs in a timely fashion using primarily unskilled labor.