Planetary nebula velocities in the disc and bulge of M31
Abstract
We present radial velocities for a sample of 723 planetary nebulae in the disc and bulge of M31, measured using the WYFFOS fibre spectrograph on the William Herschel Telescope. Velocities are determined using the [OIII]λ5007 emission line. Rotation and velocity dispersion are measured to a radius of 50arcmin (11.5kpc), the first stellar rotation curve and velocity dispersion profile for M31 to such a radius. Our kinematics are consistent with rotational support at radii well beyond the bulge effective radius of 1.4kpc, although our data beyond a radius of 5kpc are limited. We present tentative evidence for kinematic substructure in the bulge of M31 to be studied fully in a later work. This paper is part of an ongoing project to constrain the total mass, mass distribution and velocity anisotropy of the disc, bulge and halo of M31.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- June 2006
- DOI:
- arXiv:
- arXiv:astro-ph/0603706
- Bibcode:
- 2006MNRAS.369...97H
- Keywords:
-
- galaxies: haloes: galaxies: individual: M31: galaxies: spiral;
- galaxies: haloes;
- galaxies: individual: M31;
- galaxies: spiral;
- Astrophysics
- E-Print:
- 27 pages, accepted for publication in MNRAS