tokens: reasons for these two regimes goes far beyond the scope of this paper. Compared to ETGs, there is a higher dispersion and a less inclined slope for the LTG relation, which is more noticeable in the massive galaxy range, as was already pointed out by Georgiev et al. ( 2016 ). This indicates that the nuclei in LTGs are on average less massive at a fixed host galaxy mass than nuclei in ETGs. The weighted linear and polynomial least-squares fits are shown in Table 3 . Based on considerations that the mechanisms that are responsible for the build-up of the central massive objects are similar for nuclei and massive BHs, previous studies have discussed their possible evolutionary connection (e.g., Ferrarese et al. 2006 ; Neumayer Walcher 2012 ). For the purpose of comparison, we illustrate the black hole–galaxy mass relation from McConnell Ma ( 2013 ) with its 1 σ and 3 σ uncertainty limits. This relation was obtained from fitting the compilation of 35 ETGs with dynamical measurements of the bulge stellar mass, with mass range of 10 9 to 10 12 M ⊙ . Their sample is well populated for bulges more massive than 2 × 10 10 M ⊙ (see their Figure 3). Assuming that we can extrapolate to lower bulge masses, we see in Figure 10 that the scaling relation for BHs and their ETG hosts is similar to the relation between nuclei and their host galaxy mass down to 10 9 M ⊙ . For galaxies with lower masses, the nucleus-to-galaxy mass relation becomes flatter. Table 3 Scaling Relations Note. For the nucleus versus galaxy mass relation (), we set and . For the mass ratio ( η n ) relation as a function of galaxy mass (), we define y ≡ log( η n ) and . The mass ratio between nucleus and its host galaxy () as a function of galaxy mass is shown at the bottom panel of Figure 10 . We find a clear anticorrelation of η n versus over the entire galaxy mass range; that is, the lower the galaxy mass, the more significant becomes the nucleus. In the massive galaxy regime (), we note a large scatter in the relation, which is the main reason why previous studies assumed a constant equivalent luminosity ratio for their samples, like for instance the ACS Virgo nucleated galaxies with (Côté et al. 2006 ), for the ACS Fornax nucleated galaxies (Turner et al. 2012 ), and for LTGs (Georgiev et al. 2016 ). However, in the faint dwarf galaxy regime (), a clear and strong trend appears, reaching to η n ≃ 10% for a dwarf galaxy with a stellar mass of 10 7 M ⊙ . The four low-mass ETGs studied by Nguyen et al. ( 2017 , 2018 ) have η n values up to 1.7%, which are in agreement with the general trend. The extension of the η n versus anticorrelation toward the faint dwarf galaxy population appears to be similar for ETGs and LTGs. This, in turn, suggests that nuclei at the smallest masses are subject to localized processes that work on parsec scales within the galaxy core regions independent of galaxy type. 5.3. Comparison with Theoretical Predictions The two proposed formation scenarios for
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