Splitting the lentils: Clues to galaxy/black hole coevolution from the discovery of offset relations for non-dusty versus dusty (wet-merger-built) lenticular galaxies in the Mbh-M*,spheroid and Mbh-M*,galaxy diagrams

This work advances the (galaxy morphology)-dependent (black hole mass, M-bh)-(spheroid/galaxy stellar mass, M-*) scaling relations by introducing "dust bins' for lenticular (S0) galaxies. Doing so has led to the disco v ery of M-bh-M-*,M-sph and M-bh -M-*,M-gal relations for dusty S0 galaxies - built by major wet mergers and comprising half the S0 sample - offset from the distribution of dust-poor S0 galaxies. The situation is reminiscent of how major dry mergers of massive S0 galaxies have created an offset population of ellicular and elliptical galaxies. For a given Mbh, the dust-rich S0 galaxies have 3-4 times higher M-*,M-sph than the dust-poor S0 galaxies, and the steep distributions of both populations in the M bh -M-*,M-sph diagram bracket the M-bh alpha M(*,sph )(2 .27+/-0.48)relation defined by the spiral galaxies, themselves reno vated through minor mergers. The new relations offer refined means to estimate Mbh in other galaxies and should aid with: (i) constructing (galaxy morphology)-dependent black hole mass functions; (ii) estimating the masses of black holes associated with tidal disruption events; (iii) better quantifying evolution in the scaling relations via impro v ed comparisons with high z data by alleviating the pickle of apples versus oranges; (iv) mergers and longwa velength gra vitational wa ve science; (v) simulations of galaxy/black hole coevolution and semi-analytic works inv olving galaxy speciation; plus (vi) facilitating impro v ed e xtrapolations into the intermediate-mass black hole landscape. The role of the galaxy's environment is also discussed, and many potential projects that can further explore the morphological divisions are mentioned.