Return a new catalog which is a subset of objects selected
        using the input cut array.

        NOTE: This is really a *selection* (i.e., objects are retained if the value of 'cut' is True)

def applyCut(self, cut):
        """
        Return a new catalog which is a subset of objects selected
        using the input cut array.

        NOTE: This is really a *selection* (i.e., objects are retained if the value of 'cut' is True)
        """
        return Catalog(self.config, data=self.data[cut])