  Two brightest cluster galaxies (BCGs), namely Abell 1836-BCG and Abell
3565-BCG, were observed with the Advanced Camera for Surveys (ACS) and the
Space Telescope Imaging Spectrograph (STIS) on board the Hubble Space
Telescope. By modeling the available photometric and kinematic data, it
resulted that the mass of Abell 1836-BCG and Abell 3565-BCG are
M_bh=4.8(+0.8,-0.7)x10^9 M_sun and M_bh=1.3(+0.3,-0.4)x10^9 M_sun at 1 sigma
confidence level, respectively.
