Sydney observatory Galactic survey*
Potential for detection of extreme disk-crossing stars
Observatoire astronomique, Université Louis Pasteur, CNRS, 11 rue de l'Université, 67000 Strasbourg, France e-mail: email@example.com
2 Department of Physics, Macquarie University, Sydney 2109, New South Wales, Australia e-mail: firstname.lastname@example.org
3 Institute of Astronomy, Madingley Road, Cambridge, CB3 0HA, UK e-mail: email@example.com
Accepted: 2 May 2007
Context.First Epoch astrometric and radiometric information of a survey in the optical along the Galactic fourth quadrant is archived for further analysis in the time-domain.
Aims.A photographic survey of 1.9 106 stars down to B-magnitude 14 ± 0.5 along the galactic meridian l = (330 ± 5)°, -64° ≤ b ≤ -7° and along the galactic equator 272° ≤ l ≤ 341°, b ≤ 7°, is provided from century old astrographic plates of Sydney Observatory. Stellar candidates to investigate the Galaxy disk kinematics up to a distance of 1 kpc from the Sun are tentatively selected.
Methods.The early data are combined with late epoch observations into a set of 4.8 105 stars with significant proper motion μ ≥ 0.005´´ yr-1 and approximate color . The selection effects and the kinematical bias on the stellar system are investigated. F-G stellar candidates with a mean transverse velocity dispersion of 45 km s-1 are suggested.
Results.The spin rate of ° pc-1 of the velocity ellipsoid along its long axis is observed over half a thickness of 25 pc of the galactic disk for stars at an estimated distance D ≤ 300 pc from the Sun.
Conclusions.A catalogue of 4.8 105 stars is provided for further investigation of the galactic disk heating by transient spiral wave or by GMC encounter.
Key words: surveys / stars: kinematics
© ESO, 2007