W. J. Maciel -
Abstract #104
A NEW DETERMINATION OF THE ROTATION CURVE FROM GALACTIC DISK PLANETARY NEBULAE
W. J. Maciel, L. G. Lago
Rev. Mex. Astron. Astrof. 41, 383-388 (2005) The galactic rotation curve is determined on the basis of a large sample of planetary nebulae with known radial velocities. Four distance scales are adopted and the curve is established for galactocentric distances of 4 to 14 kpc, approximately, adopting Ro = 8.5 kpc for the galactocentric distance of the LSR. The main conclusions are: (i) there is no indication of a measurable decrease of the rotation curve beyond the solar circle; (ii) there are no important differences among the statistical distance scales considered, irrespective of the "short" or "long" nature of the scale, even though individual nebulae can have very different distances according to the different scales, and (iii) the derived curves are similar to the rotation curve derived from HII regions, taking into account the fact that PN are generally older objects and have larger velocity components perpendicular to the galactic plane.
