Spectrograph SPEM in the Nasmyth focus
Characteristics of the spectrograph
| Collimator | f/16, D = 80 mm |
| Maksutov camera | f/2.5 |
| Diffracting gratings | 651 and 1200 Grooves/mm (150×150 mm) |
| Dispersion near Hα line with grating of 651 gr/mm | 1.76 Å/pixel; 2465 Å per frame |
| Spectral resolution with the entrance slit width of 3″ and with grating of 651 gr/mm | 7.5 Å |
| Scale | 0.78 arcsec/pixel |
| Exposure for Seyfert galaxies of 13-14m with grating of 651 gr/mm | 15-20 minutes (S/N > 100) |
Detector - CCD camera SPEC-10 (Roper Scientific, USA)
Characteristics
| Readnoise | 1.50 ADU = 2.98 e- |
| Gain | 1.99 e-/ADU |
| QE | 95% Max. at λ5500 Å |
| Geometry | 1340×100 pixels, 20×20 μm |
| Well Depth | 262,000 e- |
| Dynamic resolution | 16 bits, 100 kHz |
| Cooling | up to -100°C, regardless of ambient |