Authors: Alister W. Graham, Igor V. Chilingarian, Dieu D. Nguyen, Roberto Soria, Mark Durre, Duncan A. Forbes
High-redshift little red dots (LRDs) detected with the James Webb Space Telescope are considered the cores of emerging galaxies. For the first time, we compare LRDs in Mbh-M* diagrams with an array of z=0 galaxy-morphology-dependent scaling relations, along with the Mbh-M*,nsc relation for nuclear star clusters. The Mbh-M*,sph relations for spheroidal stellar systems are characterised by a nearly parallel set of quasi-quadratic (or steeper) distributions that are known to trace the `punctuated equilibrium' of galaxies, reflecting their stepwise growth in black hole mass and merger-built bulge/spheroid mass. We show that LRDs are not equivalent to nuclear star clusters, with the latter having higher Mbh/M* ratios. However, the least massive LRDs exhibit similar Mbh and M*,gal values as ultracompact dwarf (UCD) galaxies. We show that the LRDs span the Mbh-M*,gal diagram from UCD galaxies to primaeval lenticular galaxies. In contrast, spiral galaxies and the subset of major-merger-built early-type galaxies define offset relations. Additionally, we observe that low-z galaxies with active galactic nuclei align with the steep black hole scaling relations for disc galaxies defined by primarily inactive galaxies with directly measured black hole masses. Collectively, this highlights the benefits of considering galaxy morphology, which reflects their accretion and merger history, to understand the coevolution of galaxies and their black holes.