Lithium depletion in G and K dwarfs |
| |
| Authors: | Minoru Umezu Hideyuki Saio |
| |
| Institution: | Department of Astronomy, School of Earth and Environmental Sciences, Seoul National University, Seoul 151-742, Korea; Departamento de Física, Universidad de Concepción, Casilla 160-C, Concepción, Chile |
| |
| Abstract: | We present deep wide-field (16.4×16.4 arcmin2) Washington CT 1 CCD surface photometry of the giant elliptical galaxy NGC 4472, the brightest member of the Virgo cluster. Our data cover a wider and deeper field than any previous CCD photometry. A single King model does not give a good fit to the surface brightness profiles of NGC 4472, but they can be fitted approximately using two King models: with the separate models representing the inner and outer regions . Surface brightness profiles for the outer region can also be fitted approximately by a de Vaucouleurs law. There is clearly a negative colour gradient within 3 arcmin of NGC 4472, in the sense that the colour gets bluer with increasing radius. The slope of the colour gradient for this region is derived to be Δ μ ( C ? T 1)=?0.08 mag arcsec?2 for Δ log r =1, which corresponds to a metallicity gradient of ΔFe/H]=?0.2 dex. However, the surface colour becomes gradually redder with increasing radius beyond 3 arcmin. A comparison of the structural parameters of NGC 4472 in C and T 1 images has shown that there is little difference in the shapes of ellipses observed using isochromes or isophotes. In addition, photometric and structural parameters of NGC 4472 have been determined. |
| |
| Keywords: | galaxies: abundances galaxies: clusters: individual: Virgo galaxies: elliptical and lenticular cD galaxies: fundamental parameters galaxies: individual: NGC 4472 galaxies: photometry |
|
|
