Disentangling the Galaxy at low Galactic latitudes
| Autor: | Angela Bragaglia, D. S. Davis, Jason S. Kalirai, Michele Cignoni, Monica Tosi |
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| Jazyk: | angličtina |
| Rok vydání: | 2008 |
| Předmět: |
Field (physics)
STAR CLUSTER SURVEY Population MODELS FOS: Physical sciences THICK DISC Galaxy : structure Star count Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics DWARF Astrophysics::Solar and Stellar Astrophysics education Astrophysics::Galaxy Astrophysics Luminosity function (astronomy) Physics COUNTS education.field_of_study extinction Astrophysics (astro-ph) Hertzsprung-Russell (HR) diagram dust extinction Galaxy : disc Galaxy : stellar content COLOR-MAGNITUDE DIAGRAMS POPULATIONS COMPONENT Astronomy and Astrophysics Galaxy Stars Photometry (astronomy) Space and Planetary Science Astrophysics::Earth and Planetary Astrophysics dust Open cluster |
| Popis: | We have used the field stars from the open cluster survey BOCCE, to study three low-latitude fields imaged with the Canada-France-Hawaii telescope (CFHT), with the aim of better understanding the Galactic structure in those directions. Due to the deep and accurate photometry in these fields, they provide a powerful discriminant among Galactic structure models. In the present paper we discuss if a canonical star count model, expressed in terms of thin and thick disc radial scales, thick disc normalization and reddening distribution, can explain the observed CMDs. Disc and thick disc are described with double exponentials, the spheroid is represented with a De Vaucouleurs density law. In order to assess the fit quality of a particular set of parameters, the colour distribution and luminosity function of synthetic photometry is compared to that of target stars selected from the blue sequence of the observed colour-magnitude diagrams. Through a Kolmogorov-Smirnov test we find that the classical decomposition halo-thin/thick disc is sufficient to reproduce the observations--no additional population is strictly necessary. In terms of solutions common to all three fields, we have found a thick disc scale length that is equal to (or slightly longer than) the thin disc scale. Comment: Accepted for publication on MNRAS |
| Databáze: | OpenAIRE |
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