Multicolor Photometry of the Nearby Galaxy Cluster A119
  This paper presents multicolor optical photometry of the nearby galaxy
cluster Abell 119 (z = 0:0442) with the Beijing-Arizona-Taiwan-Connecticut
(BATC) system of 15 intermediate bands. Within the BATC viewing field of 58'*
58', there are 368 galaxies with known spectroscopic redshifts, including 238
member galaxies (called sample I). Based on the spectral energy distributions
(SEDs) of 1376 galaxies brighter than iBATC = 19:5, photometric redshift
technique and the color-magnitude relation of earlytype galaxies are applied to
select faint member galaxies. As a result, 117 faint galaxies were selected as
new member galaxies. Combined with sample I, an enlarged sample (called sample
II) of 355 member galaxies is obtained. Spatial distribution and localized
velocity structure for two samples demonstrate that A119 is a dynamically
complex cluster with at least three prominent substructures in the central
region within 1 Mpc. A large velocity dispersion for the central clump
indicates a merging along the line of sight. No significant evidences for
morphology and luminosity segregations are found in both samples. With the
evolutionary synthesis model PEGASE, environmental effect on the star formation
properties is confirmed. Faint galaxies in low-density region tend to have
longer time scales of star formation, smaller mean stellar ages, and lower
metallicities of interstellar medium, which is in agreement with the context of
hierarchical cosmological scenario.
