Galactic structure from the Calar Alto Deep Imaging Survey (CADIS)

Free access article

Issue		A&A Volume 443, Number 3, December I 2005


Page(s)		929 - 943
Section		Galactic structure, stellar clusters and populations
DOI		http://dx.doi.org/10.1051/0004-6361:20041393

A&A 443, 929-943 (2005)
DOI: 10.1051/0004-6361:20041393

Galactic structure from the Calar Alto Deep Imaging Survey (CADIS)

S. Phleps^{1, 2}, S. Drepper¹, K. Meisenheimer¹ and B. Fuchs³

¹ Max-Planck-Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany
² Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ, UK
e-mail: sp@roe.ac.uk
³ Astronomisches Rechen-Institut, Mönchhofstr. 12-14, 69115 Heidelberg, Germany

(Received 2 June 2004 / Accepted 13 August 2005 )

Abstract
We used 1627 faint ( $15.5\leq R\leq 23$ ) stars in five fields of the Calar Alto Deep Imaging Survey (CADIS) to estimate the structure parameters of the Galaxy. The results were derived by applying two complementary methods: first by fitting the density distribution function to the measured density of stars perpendicular to the Galactic plane, and second by modelling the observed colors and apparent magnitudes of the stars in the field, using Monte Carlo simulations. The best-fitting model of the Galaxy is then determined by minimising the C-statistic, a modified $\chi^2$ . Our model includes a double exponential for the stellar disk with scaleheights h₁ and h₂ and a power law halo with exponent $\alpha$ . $24\,480$ different parameter combinations have been simulated. Both methods yield consistent results: the best fitting parameter combination is $\alpha=3.0$ (or $\alpha=2.5$ , if we allow for a flattening of the halo with an axial ratio of (c/a)=0.6), h₁=300 pc, h₂=900 pc, and the contribution of thick disk stars to the disk stars in the solar neighbourhood is found to be between 4 and 10%.

Key words: Galaxy: structure

SIMBAD Objects

What is OpenURL?

The OpenURL standard is a protocol for transmission of metadata describing the resource that you wish to access. An OpenURL link contains article metadata and directs it to the OpenURL server of your choice. The OpenURL server can provide access to the resource and also offer complementary services (specific search engine, export of references...). The OpenURL link can be generated by different means.

If your librarian has set up your subscription with an OpenURL resolver, OpenURL links appear automatically on the abstract pages.
You can define your own OpenURL resolver with your EDPS Account. In this case your choice will be given priority over that of your library.
You can use an add-on for your browser (Firefox or I.E.) to display OpenURL links on a page (see http://www.openly.com/openurlref/). You should disable this module if you wish to use the OpenURL server that you or your library have defined.