English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We develop a detailed chemical network relevant to the conditionscharacteristic of prestellar core collapse. We solve the system oftime-dependent differential equations to calculate the equilibrium abundancesof molecules and dust grains, with a size distribution given by size-bins forthese latter. These abundances are used to compute the different non-idealmagneto-hydrodynamics resistivities (ambipolar, Ohmic and Hall), needed tocarry out simulations of protostellar collapse. For the first time in thiscontext, we take into account the evaporation of the grains, the thermalionisation of Potassium, Sodium and Hydrogen at high temperature, and thethermionic emission of grains in the chemical network, and we explore theimpact of various cosmic ray ionisation rates. All these processessignificantly affect the non-ideal magneto-hydrodynamics resistivities, whichwill modify the dynamics of the collapse. Ambipolar diffusion and Hall effectdominate at low densities, up to n_H = 10^12 cm^-3, after which Ohmic diffusiontakes over. We find that the time-scale needed to reach chemical equilibrium isalways shorter than the typical dynamical (free fall) one. This allows us tobuild a large, multi-dimensional multi-species equilibrium abundance table overa large temperature, density and ionisation rate ranges. This table, which wemake accessible to the community, is used during first and second prestellarcore collapse calculations to compute the non-ideal magneto-hydrodynamicsresistivities, yielding a consistent dynamical-chemical description of thisprocess.

A chemical solver to compute molecule and grain abundances and non-ideal MHD resistivities in prestellar core collapse calculations