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

Abstract

We used 1627 faint (15.5< R<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 chisquared. Our model includes a double exponential for the stellar disk with scaleheights h_1 and h_2 and a power law halo with exponent alpha. 24480 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), h_1=300 pc, h_2=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%.

16 pages, 10 figures, submitted to Astronomy and Astrophysics

References in corpus (6)

• The Ghost of Sagittarius and Lumps in the Halo of the Milky Way
• Starcounts Redivivus. IV. Density Laws Through Photometric Parallaxes
• Early galaxy evolution from deep wide field star counts. II. First estimate of the thick disc mass function
• The Subdwarf Luminosity Function
• The Luminosity Function Of Field Galaxies And Its Evolution Since z=1
• The Millennium Galaxy Catalogue: Star counts and the Structure of the Galactic Stellar Halo

Cited by in corpus (13)

• The stellar halo of the Galaxy
• Contamination by field late-M, L and T dwarfs in deep surveys
• Towards a fully consistent Milky Way disc model: Part 1 The local model based on kinematic and photometric data
• The Information Of The Milky Way From 2MASS Whole Sky Star Count: The Structure Parameters
• Galactic longitude dependent Galactic model parameters
• The Stellar Halo in the Inner Milky Way: Predicted Shape and Kinematics
• Estimation of Galactic Model Parameters and Metalicity Distribution in Intermediate Latitudes with SDSS
• Estimation of Absolute Magnitude-dependent Galactic Model Parameters In Intermediate Latitude With SDSS and SCUSS
• Estimation of Galactic model parameters with the SDSS and metallicity distribution in two fields in the anti-centre direction of the Galaxy
• Comment on ``General Relativity Resolves Galactic Rotation Without Exotic Dark Matter'' by F.I. Cooperstock & S. Tieu
• Astrophysics in 2006
• CADIS has seen the Virgo overdensity and parts of the Monoceros and `Orphan' streams in retrospect
• Multi-object spectroscopy of stars in the CoRoT fields II: The stellar population of the CoRoT fields IRa01, LRa01, LRa02, and LRa06