Optical intra-day variability timescales and black hole mass of the blazars

In this paper, we have used optical intra-day variability archive data to calculate the central black hole masses and Eddington luminosities for nine blazars: 3C 66A, AO 0235+164, S5 0716+714, PKS 0735+178, OJ 287, 1215+303, 1216−010, 1308+326, PKS 1510−089, Mrk 501 and BL Lac using intra-day variability timescales and periodicity (if present). The calculated central black hole mass of these nine blazars using intra-day variability timescales are found to be in the range of 1.22–25.30 × 107 M⊙ and corresponding Eddington luminosity in the range of 1.58–32.88 × 1045 erg s−1. The black hole mass and Eddington luminosity are in the range of 0.32–31.23 × 108 M⊙ and 1.23–31.20 × 1046 erg s−1, respectively when optical Doppler factor is taken into account. The comparison show, our estimated values of black hole mass are consistent with earlier reported values. Periodicity were present in two blazars OJ 287 and 1216−010 which give the central black hole mass of these blazars in the range of 1.32–14.6 × 107 M⊙ and corresponding Eddington luminosity in the range of 1.60–19.0 × 1045 erg s−1, respectively.