Within the last year ionized gas kinematics has revealed in a number of edge-on disk galaxies double-peaked emission lines. The analysis of the line profiles allows to derive individual rotation curves characteristic of two kinematically distinct gas components.
The edge-on S0 galaxy NGC 7332 has been found to have an "x-shaped" velocity curve, indicating two gas components counterrotating one with respect to the other (Plana & Boulesteix 1996).
In the inner regions of the Sc NGC 5907 Miller & Rubin (1995) observed double-valued ionized gas emissions. They attributed the higher velocity system to disk gas near the nucleus, and the lower velocity system to an outer gas ring. Although these two gas components are supposed to be spatially distinct, they are viewed superimposed along the line-of-sight on account of NGC 5907 high inclination.
The spirals NGC 5746 (Kuijken & Merrifield 1995; Bureau & Freeman 1996), NGC 5965 (Kuijken & Merrifield 1995), IC 5096 (Bureau & Freeman 1996) and NGC 2683 (Merrifield 1996) have boxy/peanut bulges and double-peaked gas line profiles. Kuijken & Merrifield (1995) explained these features as the signature of a disk non-axisymmetric potential due to the presence of a bar.
In this paper we show yet an other case of edge-on disk galaxy with a multiple-valued gas velocity curve, namely UGC 10205. For projected distances lower than from the nucleus UGC 10205 it is characterized by the presence of three kinematically distinct gaseous components, two of which give to its velocity curve a "figure-of-eight " appearance.
UGC 10205 is classified as Sa spiral by Nilson (1973) and by de Vaucouleurs et al. (1991). Its total B -band magnitude is mag (RC3) and the inclination of the galaxy deduced from the disk parameters is (Rubin et al. 1985). The distance is 132 Mpc ( Mpc-1).
© European Southern Observatory (ESO) 1997
Online publication: May 26, 1998