Running summarizing tools on a new article

Abstract: Black hole mass ($M_\text{BH}$) scaling relations are typically derived using the properties of a galaxy's bulge and samples dominated by (high-mass) early-type galaxies. Studying late-type galaxies should provide greater insight into the mutual growth of black holes and galaxies in more gas-rich environments. We have used 40 spiral galaxies to establish how $M_\text{BH}$ scales with both the total stellar mass ($M_{\rm*,tot}$), and the disk's stellar mass, having measured the spheroid (bulge) stellar mass ($M_{\rm*,sph}$) and presented the $M_{\rm BH}$-$M_{\rm*,sph}$ relation in Paper I. The relation involving $M_{\rm*,tot}$ may be beneficial for estimating $M_\text{BH}$ from either pipeline data or at higher redshift, conditions that are not ideal for the accurate isolation of the bulge. A symmetric Bayesian analysis finds $M_{\rm BH}\propto M_{\rm *,tot}^{3.05\pm0.53}$. The scatter from the regression of $M_\text{BH}$ on $M_{\rm*,tot}$ is $0.68$ dex, cf. $0.54$ dex for $M_\text{BH}$ on $M_{\rm*,sph}$ and $0.57$ dex for $M_\text{BH}$ on $σ_*$. The slope is $>2$ times that obtained using core-Sérsic early-type galaxies, echoing a similar result involving $M_{\rm*,sph}$, and supporting a varied growth mechanism among different morphological types. This steeper relation has consequences for galaxy/black hole formation theories, simulations, and predicting black hole masses. We caution that (i) a $M_\text{BH}$-$M_{\rm*,tot}$ relation built from a mixture of early- and late-type galaxies will find an arbitrary slope of approximately 1 to 3, with no physical meaning beyond one's sample selection; and (ii) evolutionary studies of the $M_\text{BH}$-$M_{\rm*,tot}$ relation need to be mindful of the galaxy types included at each epoch. We additionally update the $M_{\rm*,tot}$-(face-on spiral arm pitch angle) relation.