AN ATLAS OF HIGH-RESOLUTION LINE-PROFILES OF SYMBIOTIC STARS .1. COUDE ECHELLE SPECTROMETRY OF SOUTHERN OBJECTS AND A CLASSIFICATION-SYSTEMOF H-ALPHA LINE-PROFILES

Emission lines of 59 southern symbiotic and related stars were observe d on 194 spectra taken with the Coude Echelle Spectrometer attached to the 1.4 m Coude Auxiliary Telescope of the European Southern Observat ory. On the basis of multiple Gaussian fits to emission and absorption components of the H alpha line profile, the starlike (S) and dusty (D ) symbiotics are each classified into three spectroscopic subtypes. Su btype S-1 shows a fairly narrow emission profile with no prominent abs orption, S-2 shows a clear absorption feature superimposed on the broa d emission, S-3 has a strong absorption feature which reaches at least to the continuum level. Radial velocities of the central emission com ponent are generally redshifted as compared to those of the optically thin nebular lines. This indicates that the blue wing of the emission is weakened by an overlying absorption component caused by a massive w ind. Among the 8 objects of subtype S-3 are the five known recurrent n ovae with giant companions and two symbiotic stars, PU Vul and AS 296, which are undergoing prolonged outbursts. Objects of subtype D-1 show a strong, narrow H alpha emission profile, those of D-2 a slightly as ymmetric profile with a prominent emission component on the blueward s ide of H alpha, which in most cases can be attributed to He II 6560, t hose of D-3 have a broad profile with a central absorption feature. Th e morphological classification of the S and D subtypes corresponds to a physical classification in terms of a wind model. In S-type symbioti cs, wind strength increases, and wind velocity decreases with increasi ng subtype. In types D-1 and D-2 the H alpha line originates in a tenu ous nebula, while the wind in the D-3 subtype is slow and very massive , as it is in S-3. The generally large radial velocity dispersions ind icate membership of the majority of symbiotic stars in the old disc or halo population. The objects with the smallest velocity dispersion ar e those of subtypes S-3 and D-3. These presumably youngest symbiotics show the largest mass loss rates and the smallest wind velocities.