Astrophysics |
Authors: Jessica Bower
The balance between ordered rotation and pressure support is a central feature of gaseous galacticdisks, yet a one-variable measure such as V /σ does not fully describe how that balance changeswithin individual galaxies. This paper investigates whether gas pressure support is organized byrotational coherence alone or by a coupled dependence on dynamical organization and radial struc-ture. The rotational organization parameter is defined as Rorg = (Vrot/σ)2, and the fractionalpressure-support measure as F = (V 2c − V 2rot)/V 2c . Across observational samples, increasing rota-tional organization is associated with decreasing pressure support at the population level. A candi-date transition near Rorg ≃ 84 successfully identifies highly organized systems in an independentWHISP holdout sample, but it fails as a universal physical boundary when tested against regular,low-Rorg H i disks. Radially resolved LITTLE THINGS data further show that a one-variable localrelation between F and Rorg cannot describe all galaxies: the sign of the within-galaxy trend variesfrom system to system. Introducing independently measured radial structure resolves much of thisinconsistency. For the primary resolved sample, F/(1 − F) ∝ R−0.91org (r/Rd)1.82, with R2 ≃ 0.87when galaxy-specific normalization is allowed. Leave-one-galaxy-out prediction improves relativeto an organization-only model in 13 of 17 systems. An independent KAT-7 sample preserves therelative two-variable structure, although not its exact coefficient strength. Finally, the frameworkis tested against NIHAO hydrodynamic simulations in which the circular velocity is derived di-rectly from the simulation potential, breaking the observational asymmetric-drift circularity. Thelocked two-variable predictor retains the expected positive direction in all four simulated galaxiesand improves prediction relative to Rorg alone. The result is interpreted as an empirical StructuralGovernance Framework: the equilibrium partition between ordered rotation and gas pressure sup-port is jointly organized by rotational state and radial disk structure. The relation is not presentedas a universal fundamental law or immutable constant
Comments: 21 Pages.
Download: PDF
[v1] 2026-09-23 15:30:25
Unique-IP document downloads: 29 times
ai.Vixra.org is a AI assisted e-print repository rather than a journal. Articles hosted may not yet have been verified by peer-review and should be treated as preliminary. In particular, anything that appears to include financial or legal advice or proposed medical treatments should be treated with due caution. ai.Vixra.org will not be responsible for any consequences of actions that result from any form of use of any documents on this website.
Add your own feedback and questions here:
You are equally welcome to be positive or negative about any paper but please be polite. If you are being critical you must mention at least one specific error, otherwise your comment will be deleted as unhelpful.