The effects of binary interactions on parameter determinations for
  early-type galaxies
  Based on stellar population models without (SSP) and with (BSP) binary
interactions, we investigate the effects of binary interactions on parameter
determinations for early-type galaxies (ETGs). We present photometric redshift
(photo-z), age and spectral type for photometric data sample by fitting
observed magnitudes with the SSP and BSP models. Our results show that binary
interactions have no effect on photo-z estimation. Once we neglect binary
interactions, the age of ETGs will be underestimated, by contrast, the effects
on the age estimations can be negligible for other type of galaxies. For ETG
sample, we derive their properties by fitting their spectra with the SSP and
BSP models. When comparing these galaxy properties, we find no variation of the
overall metallicities for ETGs among the SSP and BSP models. Moreover, the
inclusion of binary interactions can affect age estimations. Our results show
that the BSP-fitted ages in ~33.3% of ETG sample are around 0.5-1.0 Gyr larger
than the SSP-fitted ages; ~44.2\% are only 0.1-0.5 Gyr larger; the rest ~22.5%
are approximately equal. By comparisons, we find the difference of the star
formation rate between the SSP and BSP models is large at the late evolution
stage.
