Other
Scientific paper
Aug 1997
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1997esasp.402..721h&link_type=abstract
Proceedings of the ESA Symposium `Hipparcos - Venice '97', 13-16 May, Venice, Italy, ESA SP-402 (July 1997), p. 721-726
Other
16
Scientific paper
We use the Hipparcos survey to derive an improved model of the local galactic structure. The availability of parallaxes for all the stars permits direct determination of stellar distributions, eliminating the basic indeterminacy of classical methods based on star counts. The observed joint distribution of parallaxes, colours and apparent magnitudes is well reproduced by a density model of the Bahcall-Soneira type but with modified luminosity/colour distribution and scale heights. The best fit to the data is obtained with a density law perpendicular to the plane that is intermediate between the two classical forms, the exponential and the sech^2 (isothermal). The solar distance from the plane is found to be low compared to previous estimates, especially those based on optical star counts. The Hipparcos survey was intended to be a complete sample of some 50000 stars, limited by apparent magnitude and colour. In reality, the faint part of the survey is incomplete, and the completeness factor is depending on many variables that are hard to reproduce in a model. The much more complete and homogeneous sample offered by the Tycho Catalogue can be used to constrain the model for the fainter stars.
Flynn Chris
Holmberg Johan
Lindegren Lennart
No associations
LandOfFree
Towards an Improved Model of the Galaxy does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Towards an Improved Model of the Galaxy, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Towards an Improved Model of the Galaxy will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1879421