  Recently, many gravitational wave events from compact binary mergers have
been detected by LIGO. Determining the final mass and spin of the remnant black
holes (RBHs) is a fundamental issue and is also important in astrophysics. In
this paper, unified models for predicting the final mass and spin of the RBHs
from compact binary mergers is proposed. The models achieve a good accuracy
within the parameter range of interest. In addition, the rotational energy of
the RBHs is also studied which is relevant to the electromagnetic counterparts
of the mergers. It is found the distribution of the rotational energy of the
RBHs from different types of mergers of compact binary has its own
characteristics, which might help identify the electromagnetic counterparts
associated with the mergers.
