UAGS spectrograph
To implement the method of obtaining the spectra of extended astronomical objects in the wavelength range of 360-1000 nm and intermediate spectral resolution, the Universal Astronomical Grating Spectrograph (UAGS) of the Zeiss-1000 telescope is used. The spectrograph is a standard UAGS, manufactured by Carl Zeiss (Jena) for photographic spectroscopy of celestial objects wich was modernized by the observatory staff.
The appearance of the spectrograph mounted on the telescope.
The spectrograph is mounted in the Cassegrain focus of the telescope. The appearance of the spectrograph mounted on the telescope is shown in the photo.
To obtain the spectra, the diffraction gratings R325, R400, R1302 are used. Their parameters are given in Table 1.
The spectrum is recorded using the CCD detector (EEV 42-40, 2048×2048, 13.5×13.5 μm) mounted on the Schmidt-Cassegrain camera (F = 150 mm). The spectra are obtained without binning in the (high, norm) mode, which corresponds to the readout sampling of 0.52e/ADU, readout noise of about 2e and the scale along the slit of 1.35/px.
To make the wavelengths calibration of the spectrum, a He+Ne+Ar source of line spectrum is used.
The object is captured in the slit of the spectrograph and then guided (by the offset star) by the image of the field surrounding the object with a size of 5×4 angular minutes.
Table 1.
| Name | strokes/mm | Spectral range | Variance | Spectral resolution |
| [A] | [A/px] | [A] | ||
| R325 | 325 | 3700-7500 | 2.5 | 7.5 |
| R400 | 400 | 3600-8000 | 2.1 | 6.3 |
| R1302 (fi = 43d10′) | 1302 | 3880-6300 | 0.5 | 1.5 |
| R1302 (fi = 53d) | 1302 | 5750-7050 | 0.7 | 2.1 |
The efficiency of the spectrograph with the R325 grating is shown in the Figure 1 (s = 4, seeing = 2.5, clear!).
Fig. 1. The efficiency of the spectrograph with the R325 grating.
Bibliography:
1. Afanasiev V.L., Burenkov A.N., Vlasyuk V.V., Drabek S.V., “Large-aperture spectrograph of the primary focus of the 6-m telescope. User's Guide”, SAO RAS Report 234, 1995.
2. Afanasiev V.L., Vlasyuk V.V., Dodonov S.N., Drabek S.V., “Multi-pupil spectrograph MPFS. User's Guide”, SAO RAS Report 235, 1995.
3. A.I. Shapovalova, L. C. Popovic, S. Collin, A.N. Burenkov, V.H. Chavushyan, N.G. Bochkarev, Benitez, D. Dultzin-Hacyan, N. Borisov, L. Carrasco, J. Leon-Tavares, A. Mercado, J.R. Valdes, V.V. Vlasuyk, and V.E. Zhdanova, “Long-term variability of the optical spectra of NGC 4151: I. Light curves and flux correlations”, 2008, A&A, 486, 99-112.
Responsible for the method: A.N. Burenkov.