Cooling, Gravity, and Geometry: Flow-driven Massive Core Formation

By F. Heitsch, L. Hartmann, A. Slyz, J. Devriendt, A. Burkert. 2007

156 citations recorded by the source corpus.

We study numerically the formation of molecular clouds in large-scale colliding flows including self-gravity. The models emphasize the competition between the effects of gravity on global and local scales in an isolated cloud. Global gravity builds up large-scale filaments, while local gravity, triggered by a combination of strong thermal and dynamical instabilities, causes cores to form. The dynamical instabilities give rise to a local focusing of the colliding flows, facilitating the rapid formation of massive protostellar cores of a few hundred M☉. The forming clouds do not reach an equilibrium state, although the motions within the clouds appear to be comparable to virial. The self-similar core mass distributions derived from models with and without self-gravity indicate that the core mass distribution is set very early on during the cloud formation process, predominantly by a combination of thermal and dynamical instabilities rather than by self-gravity.

Subfields: Astronomy and Astrophysics, Fluid Flow and Transfer Processes

View Paper: https://www.semanticscholar.org/paper/28ccc23007c04f050b2a18512c41dc0c8555edb6

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

In Fluid Flow and Transfer Processes

Citations in the corpus

Global hierarchical collapse in molecular clouds. Towards a comprehensive scenario (2019, background): “…is expected to produce filamentary structures, as verified in numerical simulations of collapsing sheet-like clouds (e.g. Burkert & Hartmann 2004; Hartmann & Burkert 2007; Vázquez-Semadeni et al. 2007; Heitsch et al. 2008b, 2009; Gómez & Vázquez-Semadeni 2014; Carroll-Nellenback et al. 2014).”
Physical Processes in the Interstellar Medium (2014, background): “Simulations show that clouds formed in one-dimensional flows tend to collapse gravitationally in the directions perpendicular to the flow (see e.g. Burkert & Hartmann, 2004; Heitsch et al., 2008; Vázquez-Semadeni et al., 2009).”
Analytical Theory for the Initial Mass Function: CO Clumps and Prestellar Cores (2008, result): “[15]) for subsonic turbulence and is in good agreement with the mass spectrum inferred from numerical simulations (Hennebelle&Audit 2007; Hennebelle et al. 2008; Heitsch et al. 2008).”
Cores, filaments, and bundles: hierarchical core formation in the L1495/B213 Taurus region (2013, background): “This however is not necessarily so if the L1495/B213 complex was formed by the convergence of large-scale flows, a mechanism favored by a number of theoretical considerations and numerical simulations (e.g., Elmegreen 1993; Vázquez-Semadeni et al. 2006; Hennebelle et al. 2008; Heitsch et al. 2008).”
Gravity or turbulence? Velocity dispersion–size relation (2010, background): “…& Pérault 1999) with the result that the gas cools rapidly, producing a dense, cold, turbulent cloud (Walder & Folini 1998; Koyama & Inutsuka 2002; Heitsch et al. 2005, 2006; Vázquez-Semadeni et al. 2006) which soon becomes Jeans unstable (Vázquez-Semadeni et al. 2007; Heitsch et al. 2008).”
FILAMENTARY STRUCTURE OF STAR-FORMING COMPLEXES (2009, background): “If instead both hubs and filaments arise promptly during the compression which forms the layer (VazquezSemadeni et al 2007, Heitsch et al 2008), the role of self-gravity might be to selectively preserve the ridges and valleys which most closely resemble those of modulated equilibrium.”
From the warm magnetized atomic medium to molecular clouds (2008, methodology): “Recently large multi-dimensional non-magnetic numerical simulations have been performed (Hennebelle & Audit 2007, Vázquez-Semadeni et al. 2007, Heitsch et al. 2008, the last two including self-gravity) with the aim of studying in detail the formation of dense gas from a large flow of warm neutral…”
Dynamic star formation in the massive DR21 filament (2010, background): “High velocity compressive flows form dense structures at stagnation points that may collapse to form stars/clusters (Ballesteros-Paredes et al. 2003, Vazquez-Semadeni et al. 2007, 2009, Heitsch et al. 2008).”
STAR FORMATION IN DISK GALAXIES. I. FORMATION AND EVOLUTION OF GIANT MOLECULAR CLOUDS VIA GRAVITATIONAL INSTABILITY AND CLOUD COLLISIONS (2008, background): “…(e.g. Kim, Ostriker, & Stone 2003; Shetty & Ostriker 2006; Glover & Mac Low 2007), whereas ‘bottom-up’ processes have GMCs forming via agglomeration from inelastic collisions of clouds (e.g. Kwan 1979) or from turbulent or colliding flows (e.g. Bergin et al. 2004; Heitsch et al. 2008).”
Clump morphology and evolution in MHD simulations of molecular cloud formation (2008, background): “…Koyama & Inutsuka 2002; Audit & Hennebelle 2005; Heitsch et al. 2005; Gazol et al. 2005; Vázquez-Semadeni et al. 2006, 2007; Hennebelle et al. 2007; Heitsch et al. 2008), which have shown that molecular regions can form by ther- mal instability TI (Field 1965) in the warm neutral interstellar…”
Turbulent molecular clouds (2012, methodology): “The mass spectra of non self-gravitating clumps, i.e. clumps induced by pure turbulence, have been obtained numerically by Hennebelle & Audit (2007), Heitsch et al. (2008), Dib et al. (2008), Audit & Hennebelle (2010) and Inoue & Inutsuka (2012).”
Is molecular gas necessary for star formation (2011, background): “…the issue of the assembly of cold, dense clouds of gas from the warm, neutral ISM has already been investigated by a number of authors (see e.g. Koyama & Inutsuka 2002; Audit & Hennebelle 2005; Vázquez-Semadeni et al. 2007; Heitsch et al. 2008; Heitsch & Hartmann 2008; Banerjee et al. 2009).”