Comprehensive analysis of RGU photometry in the direction to M5

Abstract

The RGU-photographic investigation of an intermediate latitude field in the direction to the Galactic center is presented. 164 extra-galactic objects, identified by comparison of Minnesota and Basel charts, are excluded from the program. Also, a region with size 0.104 square-degrees, contaminated by cluster (M5) stars and affected by background light of the bright star HD 136202 is omitted. Contrary to previous investigations, a reddening of $E(B-V)=0.046$, corresponding to E(G-R)=0.07 mag is adopted. The separation of dwarfs and evolved stars is carried out by an empirical method, already applied in some of our works. A new calibration for the metallicity determination is used for dwarfs, while the absolute magnitude determination for stars of all categories is performed using the procedures given in the literature. There is good agreement between the observed logarithmic space density histograms and the galactic model gradients. Also, the local luminosity function agrees with Gliese's (1969) and Hipparcos' (Jahreiss & Wielen 1997) luminosity functions, for stars with $2<M(G)\le 8$ mag. For giants, we obtained two different local space densities from comparison with two Galactic models, i.e. $D^{\ast }(0)=6.63$, close to that of Gliese (1969), and $D^{\ast }(0)=6.79$. A metallicity gradient, $d[Fe/H]/dz=-0.20$ dex/kpc, is detected for dwarfs (only) with absolute magnitudes $4<M(G)\le 6$, corresponding to a spectral type interval F5-K0.

arXiv comment17 pages, including 13 figures and 3 tables, accepted for publication in PASA

References in corpus (4)

• Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds
• A catalogue of [Fe/H] determinations : 1996 edition
• Early evolution of the Galactic halo revealed from Hipparcos observations of metal-poor stars
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Cited by in corpus (5)

• Absolute magnitudes for late-type dwarf stars for Sloan photometry
• Galactic model parameters for field giants separated from field dwarfs by their 2MASS and V apparent magnitudes
• Volume limited dependent Galactic model parameters
• Separation of dwarf and giant stars with ROTSE-IIId
• Analysis of UBV Photometry in Selected Area 133