KINEMATICS OF THE GALACTIC SUPERNOVA-REMNANTS RCW-86, MSH-15-56 AND MSH-11-61A

We have studied the kinematics of the galactic super nova remnants (SN Rs) RCW 86, MSH 15-56 and MSH 11-61A as the first step of a long term project of determination of kinematic distances to galactic SNRs with optical counterparts. We have obtained the kinematic distances to thes e nebulae. Our results on RCW 86 imply a real association between this SNR and a neighboring OB stellar association, confirming that this SN R, which is now in the Sedov phase, is probably the result of an explo sion of a Type II supernova. Furthermore, we argue against the identif ication of RCW 86 with the historical supernova AD185. We have detecte d an almost complete shell of optical filaments associated with the SN R MSH 15-56. The lame diameter derived from its kinematic distance sug gests that this SNR is in the radiative phase of evolution. Finally, w e estimate that the SNR MSH 11-61A is located at about 7 kpc from the Sun in a zone where several background and foreground nebulae at diffe rent velocities are seen in projection. Its linear diameter is 31 pc, about twice the value given by previous determinations.