Do the PN Kinematics Follow the Absorption Line Stellar Kinematics?
If the distribution of PNe follows light, the PNe can be considered as faithful tracers also for the stellar kinematics. A test of this is to compare the rotation velocities v and velocity dispersions obtained from PN radial velocities with those from ALS, taking into account the greater smoothing of the PN velocity field due to spatial averaging. Mendez used his sample of 535 PN velocities in NGC 4697 for a simple comparison [2]. His sample, restricted to a stripe around the major axis, indeed followed the rotation seen in the ALS data; however, the number of PNe per mean velocity point is ~ 10 and so the errors are large, ~ 50 km s-1. Similarly, the PN velocity dispersions in major axis sectors were consistent with the ALS dispersions within ~ 20 km s-1. In such a case the PN velocities and the ALS velocity measurements can be simply combined in modelling the stellar kinematics. Even the incompleteness in the center does not present a problem, because the probability of losing a PN a
Related Questions
- What follow up actions might the Child Abuse Report Line (CARL) staff suggest to education and care notifiers and how should this happen?
- How Saturated Are Absorption Lines in the Broad Absorption Line Quasar PG 1411+442?
- How Saturated Are Absorption Lines in the Broad Absorption Line Quasar PG 1411+442?
- Do the PN Kinematics Follow the Absorption Line Stellar Kinematics?
- What property of atoms causes line emission (and absorption)?
- What property of atoms causes line emission (and absorption)?
