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Title: OSCILLATING FILAMENTS. I. OSCILLATION AND GEOMETRICAL FRAGMENTATION

Abstract

We study the stability of filaments in equilibrium between gravity and internal as well as external pressure using the grid-based AMR code RAMSES. A homogeneous, straight cylinder below a critical line mass is marginally stable. However, if the cylinder is bent, such as with a slight sinusoidal perturbation, an otherwise stable configuration starts to oscillate, is triggered into fragmentation, and collapses. This previously unstudied behavior allows a filament to fragment at any given scale, as long as it has slight bends. We call this process “geometrical fragmentation.” In our realization, the spacing between the cores matches the wavelength of the sinusoidal perturbation, whereas up to now, filaments were thought to be only fragmenting on the characteristic scale set by the mass-to-line ratio. Using first principles, we derive the oscillation period as well as the collapse timescale analytically. To enable a direct comparison with observations, we study the line-of-sight velocity for different inclinations. We show that the overall oscillation pattern can hide the infall signature of cores.

Authors:
; ;  [1]
  1. University Observatory Munich, LMU Munich, Scheinerstrasse 1, D-81679 Munich (Germany)
Publication Date:
OSTI Identifier:
22661371
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 834; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COMPARATIVE EVALUATIONS; COMPUTERIZED SIMULATION; DISTURBANCES; EQUILIBRIUM; FILAMENTS; FRAGMENTATION; GRAVITATION; GRIDS; HYDRODYNAMICS; INCLINATION; MASS; OSCILLATIONS; R CODES; STARS; VELOCITY; WAVELENGTHS

Citation Formats

Gritschneder, Matthias, Heigl, Stefan, and Burkert, Andreas, E-mail: gritschm@usm.uni-muenchen.de. OSCILLATING FILAMENTS. I. OSCILLATION AND GEOMETRICAL FRAGMENTATION. United States: N. p., 2017. Web. doi:10.3847/1538-4357/834/2/202.
Gritschneder, Matthias, Heigl, Stefan, & Burkert, Andreas, E-mail: gritschm@usm.uni-muenchen.de. OSCILLATING FILAMENTS. I. OSCILLATION AND GEOMETRICAL FRAGMENTATION. United States. doi:10.3847/1538-4357/834/2/202.
Gritschneder, Matthias, Heigl, Stefan, and Burkert, Andreas, E-mail: gritschm@usm.uni-muenchen.de. Tue . "OSCILLATING FILAMENTS. I. OSCILLATION AND GEOMETRICAL FRAGMENTATION". United States. doi:10.3847/1538-4357/834/2/202.
@article{osti_22661371,
title = {OSCILLATING FILAMENTS. I. OSCILLATION AND GEOMETRICAL FRAGMENTATION},
author = {Gritschneder, Matthias and Heigl, Stefan and Burkert, Andreas, E-mail: gritschm@usm.uni-muenchen.de},
abstractNote = {We study the stability of filaments in equilibrium between gravity and internal as well as external pressure using the grid-based AMR code RAMSES. A homogeneous, straight cylinder below a critical line mass is marginally stable. However, if the cylinder is bent, such as with a slight sinusoidal perturbation, an otherwise stable configuration starts to oscillate, is triggered into fragmentation, and collapses. This previously unstudied behavior allows a filament to fragment at any given scale, as long as it has slight bends. We call this process “geometrical fragmentation.” In our realization, the spacing between the cores matches the wavelength of the sinusoidal perturbation, whereas up to now, filaments were thought to be only fragmenting on the characteristic scale set by the mass-to-line ratio. Using first principles, we derive the oscillation period as well as the collapse timescale analytically. To enable a direct comparison with observations, we study the line-of-sight velocity for different inclinations. We show that the overall oscillation pattern can hide the infall signature of cores.},
doi = {10.3847/1538-4357/834/2/202},
journal = {Astrophysical Journal},
number = 2,
volume = 834,
place = {United States},
year = {Tue Jan 10 00:00:00 EST 2017},
month = {Tue Jan 10 00:00:00 EST 2017}
}
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