Description
We present our optical multicolor photometry for the nearby cluster of galaxies A2255 with 13 intermediate filters in the Beijing-Arizona-Taiwan-Connecticut (BATC) system (see Cat. II/262), which cover an optical wavelength range from 3000 to 10000{AA}. The spectral energy distributions (SEDs) in the optical band for more than 7000 sources are achieved down to V~20 in a field of 58'x58' entered on this rich cluster. A2255 has been observed by the Sloan Digital Sky Survey (SDSS) down to V~17.5 spectroscopically and r'~22.0 photometrically. A method of combining the SDSS photometric data in five broad bands and the BATC SEDs is then explored. A sample of 254 galaxies with known redshifts in the region of A2255 is constructed for testing the reliability of the method of combining SEDs. Our application of the technique of photometric redshift on this sample shows that the combined SEDs with higher resolution could lead to a more accurate estimate of photometric redshift. Based on 214 spectroscopically confirmed member galaxies, spatial and dynamical properties of this cluster are studied.
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