Nonisothermal filaments in equilibrium

Autor(en)

S. Recchi, Alvaro Hacar Gonzalez, A. Palestini

Abstrakt

Context. The physical properties of the so-called Ostriker isothermal

filament have been classically used as a benchmark to interpret the

stability of the filaments observed in nearby clouds. However, recent

continuum studies have shown that the internal structure of the

filaments depart from the isothermality, typically exhibiting radially

increasing temperature gradients. Aims: The presence of internal

temperature gradients within filaments suggests that the equilibrium

configuration of these objects should be therefore revisited. The main

goal of this work is to theoretically explore how the equilibrium

structure of a filament changes in a nonisothermal configuration.

Methods: We solve the hydrostatic equilibrium equation by assuming

temperature gradients similar to those derived from observations.

Results: We obtain a new set of equilibrium solutions for nonisothermal

filaments with both linear and asymptotically constant temperature

gradients. For sufficiently large internal temperature gradients, our

results show that a nonisothermal filament could present significantly

larger masses per unit length and shallower density profiles than the

isothermal filament without collapsing by its own gravity.

Conclusions: We conclude that filaments can reach an equilibrium

configuration under nonisothermal conditions. Detailed studies of both

the internal mass distribution and temperature gradients within

filaments are then needed to judge the physical state of filaments.

Organisation(en)

Institut für Astrophysik

Externe Organisation(en)

Università degli Studi di Roma La Sapienza

Journal

Astronomy & Astrophysics

Band

558

Anzahl der Seiten

5

ISSN

0004-6361

DOI

https://doi.org/10.1051/0004-6361/201321565

Publikationsdatum

10-2013

Peer-reviewed

Ja

ÖFOS 2012

103004 Astrophysik, 103003 Astronomie

Schlagwörter

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/be2e9a92-304e-447a-8999-2bc0255a6943