Nonisothermal filaments in equilibrium
- Author(s)
- S. Recchi, Alvaro Hacar Gonzalez, A. Palestini
- Abstract
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(s)
- Department of Astrophysics
- External organisation(s)
- Sapienza University of Rome
- Journal
- Astronomy & Astrophysics
- Volume
- 558
- No. of pages
- 5
- ISSN
- 0004-6361
- DOI
- https://doi.org/10.1051/0004-6361/201321565
- Publication date
- 10-2013
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103004 Astrophysics, 103003 Astronomy
- Keywords
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/be2e9a92-304e-447a-8999-2bc0255a6943