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dc.contributor.authorWurster, James
dc.contributor.authorBate, Matthew
dc.contributor.authorPrice, Daniel J
dc.date.accessioned2018-04-19T09:05:21Z
dc.date.issued2018-04-19
dc.date.updated2018-04-14T08:07:39Z
dc.description.abstractWe present results from radiation non-ideal magnetohydrodynamics (MHD) calculations that follow the collapse of rotating, magnetized, molecular cloud cores to stellar densities. These are the first such calculations to include all three non-ideal effects: ambipolar diffusion, Ohmic resistivity, and the Hall effect. We employ an ionization model in which cosmic ray ionization dominates at low temperatures and thermal ionization takes over at high temperatures. We explore the effects of varying the cosmic ray ionization rate from ζcr = 10−10 to 10−16 s−1. Models with ionization rates ≳10−12 s−1 produce results that are indistinguishable from ideal MHD. Decreasing the cosmic ray ionization rate extends the lifetime of the first hydrostatic core up to a factor of 2, but the lifetimes are still substantially shorter than those obtained without magnetic fields. Outflows from the first hydrostatic core phase are launched in all models, but the outflows become broader and slower as the ionization rate is reduced. The outflow morphology following stellar core formation is complex and strongly dependent on the cosmic ray ionization rate. Calculations with high ionization rates quickly produce a fast (≈14 km s−1) bipolar outflow that is distinct from the first core outflow, but with the lowest ionization rate, a slower (≈3−4 km s−1) conical outflow develops gradually and seamlessly merges into the first core outflow.en_GB
dc.description.sponsorshipJW and MRB acknowledge support from the European Research Council under the European Commission's Seventh Framework Programme (FP7/2007- 2013 grant agreement no. 339248). DJP and JW were funded by Australian Research Council grants FT130100034 andDP130102078. The calculations for this paper were performed on the University of Exeter Supercomputer, a DiRAC Facility jointly funded by STFC, the Large Facilities Capital Fund of BIS, and the University of Exeter. We used splash (Price 2007) for the column density figures.en_GB
dc.identifier.doi10.24378/exe.264
dc.identifier.urihttp://hdl.handle.net/10871/32503
dc.language.isoenen_GB
dc.publisherUniversity of Exeteren_GB
dc.relation.urlhttp://hdl.handle.net/10871/31265
dc.rightsCC BY 4.0en_GB
dc.subjectmagnetic fields – MHD – methods: numerical – stars: formationen_GB
dc.titleThe collapse of a molecular cloud core to stellar densities using radiation non-ideal magnetohydrodynamics (dataset)en_GB
dc.typeDataseten_GB
dc.date.available2018-04-19T09:05:21Z
dc.descriptionThis is all the data created for Wurster, Bate & Price (2018a). This dataset was created using the SPHMD code sphNH, which included v1.2.1 of the NICIL library (Wurster 2016) to calculate the non-ideal MHD coefficients. The data and important files have been uploaded; the data files can be read with either sphNG, or with the graphics programme Splash. The file are named such that number at the end of `collapse' indicates the negative of the cosmic ray ionisation rate. If this number is followed by `a` or `b', then this data set was created to reproduce data accidentally deleted from the primary set without the 'a'. If it is followed by 'imp', it uses the implicit resistivity. The subsequent two numbers are the dump numbers contained within this file. If the subsequent term is 'sup', then this is the supplementary material, including executables, plotting scripts, etc... The data for the aligned model and implicit model will be uploaded in a latter data set.en_GB
dc.descriptionThe article associated with this dataset is located in ORE at: http://hdl.handle.net/10871/31265en_GB
dc.identifier.journalMonthly Notices of the Royal Astronomical Societyen_GB
dc.rights.urihttp://creativecommons.org/licenses/by/4.0


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