On the equilibrium of rotating filaments

TL;DR

This paper investigates how rotation affects the equilibrium structure of filaments, revealing that rotation can produce more realistic, stable filament models with shallower density profiles, aligning better with observations.

Contribution

It introduces new equilibrium solutions for rotating, pressure-truncated filaments, expanding the classical Ostriker model to include uniform and differential rotation effects.

Findings

Rotating filaments have shallower radial and column density profiles.

Centrifugal forces in rotating filaments can support larger masses.

Rotation can stabilize filaments without requiring instability.

Abstract

The physical properties of the so-called Ostriker isothermal, non-rotating filament have been classically used as benchmark to interpret the stability of the filaments observed in nearby clouds. However, such static picture seems to contrast with the more dynamical state observed in different filaments. In order to explore the physical conditions of filaments under realistic conditions, in this work we theoretically investigate how the equilibrium structure of a filament changes in a rotating configuration. To do so, we solve the hydrostatic equilibrium equation assuming both uniform and differential rotations independently. We obtain a new set of equilibrium solutions for rotating and pressure truncated filaments. These new equilibrium solutions are found to present both radial and projected column density profiles shallower than their Ostriker-like counterparts. Moreover, and for rotational periods similar to those found in the observations, the centrifugal forces present in these filaments are also able to sustain large amounts of mass (larger than the mass attained by the Ostriker filament) without being necessary unstable. Our results indicate that further analysis on the physical state of star-forming filaments should take into account rotational effects as stabilizing agents against gravity