The black hole mass-stellar velocity dispersion correlation: bulges versus pseudo-bulges

We investigate the correlation between the supermassive black holes (SMBHs) mass (M-bh) and the stellar velocity dispersion (sigma(*)) in two types of host galaxies: the early-type bulges (disc galaxies with classical bulges or elliptical galaxies) and pseudo-bulges. In the form log (M-bh/M-circle dot) = alpha + beta log (sigma(*)/200 km s(-1)) , the best-fitting results for the 39 early-type bulges are the slope beta = 4.06 +/- 0.28 and the normalization alpha = 8.28 +/- 0.05 ; the best-fitting results for the nine pseudo-bulges are beta = 4.5 +/- 1.3 and alpha = 7.50 +/- 0.18 . Both relations have intrinsic scatter in log M-bh of less than or similar to 0.27 dex. The M-bh-sigma(*) relation for pseudo-bulges is different from the relation in the early-type bulges over the 3 sigma significance level. The contrasting relations indicate the formation and growth histories of SMBHs depend on their host type. The discrepancy between the slope of the M-bh-sigma(*) relations using different definition of velocity dispersion vanishes in our sample, a uniform slope will constrain the coevolution theories of the SMBHs and their host galaxies more effectively. We also find the slope for the 'core' elliptical galaxies at the high-mass range of the relation appears steeper (beta similar or equal to 5-6) , which may be the imprint of their origin of dissipationless mergers.