A search for co-evolving ion and neutral gas species in prestellar molecular cloud cores

Abstract

Comparison of linewidths of spectral line profiles of ions and neutral molecules have been recently used to estimate the strength of the magnetic field in turbulent star-forming regions. However, the ion (HCO+) and neutral (HCN) species used in such studies may not be necessarily co-evolving at every scale and density and may thus not trace the same regions. Here, we use coupled chemical/dynamical models of evolving prestellar molecular cloud cores including non-equilibrium chemistry, with and without magnetic fields, to study the spatial distribution of HCO+ and HCN, which have been used in observations of spectral linewidth differences to date. In addition, we seek new ion-neutral pairs that are good candidates for such observations because they have similar evolution and are approximately co-spatial in our models. We identify three such good candidate pairs: HCO+/NO, HCO+/CO, and NO+/NO.

9 pages, 5 figures, accepted for publication in ApJ

References in corpus (6)

• Gas dynamics in Massive Dense Cores in Cygnus-X
• Probing the Turbulence Dissipation Range and Magnetic Field Strengths in Molecular Clouds
• Molecular line mapping of the giant molecular cloud associated with RCW 106 - III. Multi-molecular line mapping
• Simultaneous Determination of the Cosmic Ray Ionization Rate and Fractional Ionization in DR21(OH)
• Observational Determination of the Turbulent Ambipolar Diffusion Scale and Magnetic Field Strength in Molecular Clouds
• Non-Equilibrium Chemistry of Dynamically Evolving Prestellar Cores: I. Basic Magnetic and Non-Magnetic Models and Parameter Studies

Cited by in corpus (5)

• The magnetic diffusivities in 3D radiative chemo-hydrodynamic simulations of protostellar collapse
• Comparison of Prestellar Core Elongations and Large-Scale Molecular Cloud Structures in the Lupus I Region
• Probing the Turbulence Dissipation Range and Magnetic Field Strengths in Molecular Clouds. II. Directly Probing the Ion-neutral Decoupling Scale
• Probing the Turbulent Ambipolar Diffusion Scale in Molecular Clouds with Spectroscopy
• Can we observe the ion-neutral drift velocity in prestellar cores?