Multicolor Photometry Study of the Galaxy Cluster A2589: Dynamics,
  Luminosity Function and Star Formation History
  In this paper we present a multicolor photometry for A2589 ($z=0.0414$) with
15 intermediate bands in the Beijing-Arizona-Taiwan-Connecticut (BATC) system
which covers an optical wavelength range from 3000 \AA\ to 10000 \AA. The
spectral energy distributions (SEDs) for more than 5000 sources are achieved
down to {\it V} $\sim$ 20 mag in about 1 deg$^{2}$ field. A2589 has been also
covered by the Sloan Digital Sky Survey (SDSS) in photometric mode only. A
cross-identification of the BATC-detected galaxies with the SDSS photometric
catalog achieves 1199 galaxies brighter than $i=19.5$ mag, among which 68
member galaxies with known spectroscopic redshifts are found. After combining
the SDSS five-band photometric data and the BATC SEDs, the technique of
photometric redshift is applied to these galaxies for selecting faint member
galaxies. The color-magnitude relation is taken as a further restriction of
early-type cluster galaxies. As a result, 106 galaxies are newly selected as
member galaxies. Spatial distribution of member galaxies shows a north-south
elongation which agrees with the X-ray brightness profile and the orientation
of central cD galaxy, NGC 7647. No substructures are detected on the basis of
positions and radial velocities of cluster galaxies, indicating that A2589 is a
well-relaxed system. The luminosity function of A2589 exhibits a peak at $M_{R}
\sim -20$ mag and a dip at $M_{R} \sim -19 $ mag. The low-density outer regions
are the preferred habitat of faint galaxies. With the evolutionary population
synthesis model, PEGASE, the environmental effect on the star formation
properties for 68 spectroscopically confirmed member galaxies is studied. The
outlier faint galaxies tend to have longer time scales of star formation,
shorter mean stellar ages, and lower metallicities of interstellar medium,
which can be interpreted in the context of hierarchical cosmological scenario.
