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Observations of high mass star formation using BLAST and Herschel

In this thesis, I present BLAST observations of the Carina Nebula and Herschel observations of NGC7538. I use the source extracting routine CSAR to identify 172 source in Carina and 94 sources in NGC7538. I fit SEDs to all the sources and calculate their mass, luminosity, temperature and radius. For the Carina Nebula I find a mass range of 20 – 10 4M¯, a luminosity range of 10 2 – 10 5 L¯, a temperature range of 16 – 28 K, and source radii range of 0.3 – 3.2 pc. For NGC7538 I find a mass range of 5 – 10 3M¯, a luminosity range of 5 – 10 3 L¯, a temperature range of 10 – 40K and a source radii range of 0.1 – 2 pc. I cross - check the source extraction method using the routine, GETSOURCES. This algorithm found a total of 621 sources in NGC7538. The GETSOURCES catalogue is filtered to removed sources which are present in two or less wavelengths. This filtered catalogue then has a good correlation with the CSAR catalogue. Using both catalogues a robust source list of 75 sources is created from sources found by both routines. I plot the mass against radius for both the Carin Nebula and NGC7538. For Carina the data are best fitted by M / R1.8 which is comparable to the Larson relation of M / R2. In NGC7538 I find no relation. I find no temperature dependence in the Carina Nebula with any other source property but find a weak relation between temperature and luminosity in NGC7538. Both regions show a relation of L / M. I find a relation between radius and Luminosity per unit volume where smaller sources have a higher luminosity per unit volume and the larger sources have a lower value. I find sources with a luminosity per unit volume less then 1L¯pc−3 tend to lie in the less dense regions of the nebulae and sources with a luminosity per unit volume greater then 3.5L¯pc−3 lie in the denser regions where the more evolved sources tend to be. This could show that the luminosity per unit volume can trace the evolutionary status of sources in a region.

Identiferoai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:567155
Date January 2011
CreatorsHarry, Sarah
PublisherCardiff University
Source SetsEthos UK
Detected LanguageEnglish
TypeElectronic Thesis or Dissertation
Sourcehttp://orca.cf.ac.uk/14483/

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