The luminosity function around isolated spiral galaxies |
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Authors: | IMorgan R MSmith SPhillipps |
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Institution: | Department of Physics and Astronomy, University of Wales College of Cardiff, PO Box 913, Cardiff CF2 3YB; Department of Physics, University of Bristol, Tyndall Avenue, Bristol BS8 ITL |
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Abstract: | We determine the companion galaxy luminosity function (LF) for regions around isolated spiral galaxies. If we assume that any excess in the galaxy number counts in the vicinity of a spiral galaxy is due to galaxies at the same distance, then a system LF can be determined from the variation of excess numbers with apparent magnitude. By studying the excess over many field 'centre' galaxies, a good statistical accuracy can be obtained for the companion galaxy LF. Since redshift information is not required for the faint galaxies, it is possible to sample further down the LF as compared with redshift surveys. For 23 primary galaxies of known redshift, we find a dwarf satellite Schechter LF with a characteristic magnitude M V *( D )??19 and a faint-end slope α=?1.7, down to MV =?14 ( H 0=50 km s?1 Mpc?1). |
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Keywords: | galaxies: clusters: general galaxies: evolution galaxies: luminosity function mass function galaxies: spiral cosmology: observations |
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