Appendix B: CIGALE  

CIGALE data have been acquired at the 6 m telescope of SAO (Special Astrophysical Observatory, Russia) on October 27, 1995. The scanning Perot-Fabry interferometer, installed inside the pupil plane of a focal reducer which was attached to the F/4 prime focus of the telescope, gives a spectral resolution of 9000.

The detector was an intensified photon counting system (IPCS) with a pixel scale of 0.97''. The free spectral range was 606 km s^-1. The IPCS enables a rapid scan of the interferometer (each of the 32 channels were scanned typically in 18 s). The blocking interference filter was of 12 Ang, centered on the mean recession velocity of the galaxy. The total exposure was 16000 s, during poor weather transparency conditions.

Reduction of observational data (correction for phase shifting, night sky emission substraction, velocity and monochromatic maps) were done using standard methods through the ADHOC software (see Plana & Boulesteix 1996 for details). The final data were beamed $5\times5$ pixels because of the poor observational conditions.