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Observations of magnetic fields and clustering functions in prestellar cores

Nutter, David John 2004. Observations of magnetic fields and clustering functions in prestellar cores. PhD Thesis, Cardiff University.

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In this thesis, I present SCUBA polaximetry data of three prestellar cores, L1544, L43 and L183. I also present SCUBA scan-map observations of three molecular clouds, Orion B, L1689, and RCrA. I use the Chandrasekhar-Fermi technique to measure the magnetic field strength in LI544, L43 and LI83, and find that each core is approximately magnetically critical or slightly supercritical. I measure the core mass function for prestellar cores in the Orion B molecular cloud and find that above 1 M0, the data are best fitted by a power-law of the form diV/dlog M cx M 15. The mass function has a peak at approximately 1 Mq. This core mass function is comparable with the Salpeter slope of M-1,35. I also determine the mean surface density of companions Ec(0) for the Orion B region, and find that it is best fitted by a power law of the form £c(0) oc 0 03. This is smaller than the slope of 9 6 that is typically found for young stars in most molecular clouds. However, this slope is consistent with my data at the extreme limits of my la error bars. My value of T,c(0) oc 0 3 is comparable with the slope of 9 0 2 that is found for the nearby Orion Trapezium association. I find that the L1689 molecular cloud has a comparable rate of star formation to the neighbouring and more massive LI688. In addition, the star formation in LI689 occurs in a number of filaments that are parallel both to each other, and to similar filaments in L1688. I conclude that these observations indicate that the star formation is being influenced by the nearby Sco OB2 association. I compare the RCrA data to previous surveys of the region, and discover a previously unknown Class 0 source.

Item Type: Thesis (PhD)
Status: Unpublished
Schools: Physics and Astronomy
Subjects: Q Science > QB Astronomy
ISBN: 9781303200106
Date of First Compliant Deposit: 30 March 2016
Last Modified: 19 Mar 2016 23:30

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