Christopher edited Setup.tex  about 10 years ago

Commit id: 22eca25413d4925457e81ffc4418be906c59bedb

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\section{Setup}  The simulation data provided were in data cubes with 256 pixels/channels on each dimension. This represented an area of 0.26pc by 0.26pc, with a 20 km/s wide spectrum centered at the 0-1 transition of ^{13}CO and ^{12}CO.  The Common Astronomy Software Applications (CASA) is a software package that allows us to simulate observations with various interferometers and single dish telescopes. It also has tools that allow us to analyse this data.  We will be running two tasks in CASA. The first, simobserve, will simulate an observation with various specified parameters. The second, simanalyze, will deconvolve and clean the observation.  \subsection{Observation}  The data provided were in fits cubes with 256 pixels/channels on each dimension. This represented an area of 0.26pc by 0.26pc, with a 20 km/s wide spectrum centered at the 0-1 transition of ^{13}CO and 12CO. These were used as the simobserve skymodel.  When processing the synthetic images through casa, using simobserve, we assume distance of 450 pc to the source. This was chosen as it is the distance of HH46/47, a molecular outflow powered by a forming star that has been recently observed with ALMA (Arce et al. 2013).  CASA Simobserve  parameters were set as follows. Indirection, The data cube was set as  the RA skymodel,  and Dec we assume a distance  of 450 pc to  the source, source. This was chosen as it is the distance of HH46/47, a molecular outflow powered by a forming star that has been recently observed with ALMA (Arce et al. 2013). The location of the source (simobserve's "Indirection")  was set to be the same as that the location  of HH46/47: J2000 8h25m44 -51d00m00 -51d00m00.  Incell, the angular size of a pixel at the desired distance was calculated using the small angle formula. With a pixel width of ~0.001pc, and a distance to the source of 450pc the angular size of a pixle is ~0.5".