Photometric Properties of AGNs from the Absolute Spectrophotometry of De Bruyn and Sargent

Abstract

The absolute spectrophotometry of 66 AGNs (de Bruyn and Sargent, 1978) is used to compute synthetic magnitudes and colors, and K-corrections in the UBV system. In our preliminary contribution (Kalinkov et al., 1988) only some results of (U-B)s and (B-V)s colors were given. Here we use the whole observational data given by de Bruyn and Sargent. Synthetic spectra for 41 Sy1, 7 Sy1.5 and 15 Sy2 galaxies are constructed in relative units, assuming f(λ5470) = 1000. Colors and K-corrections are obtained from the synthetic spectra. The variations with the redshift are presented in the polynomial approximation form X = aizi, i = 0,1,‥, where X = (U-B)ss, (B-V)ss, KB, KV (Table 1). The largest deviation in mag. from the computed curves is denoted by Q. The relations in Table 1 are very good approximations in the corresponding redshift ranges.