level An offset (DC) level. noise Noise (gaussian distribution). point A point source. gaussian An elliptical or circular gaussian. gauss3 3D elliptical or circular gaussian (for cubes). disk An elliptical or circular disk. j1x J1(x)/x function jet Jet model with power law brightness. shell 2D projection of an optically-thin spherical shell comet 2D projection of a parent molecule in comet. cluster standard isothermal 2D projection for cluster gas. powerlaw standard power-law model j0 J0 Bessel function for holography work
Object Type SPAR values ----------- ----------- level offset noise rms point amp,x,y gaussian amp,x,y,bmaj,bmin,pa gauss3 amp,x,y,z,bmaj,bmin,pa,bz disk amp,x,y,bmaj,bmin,pa j1x amp,x,y,bmaj,bmin,pa jet amp,x,y,bmaj,bmin,pa shell amp,x,y,bmaj comet amp,x,y,scalelength cluster amp,x,y,core radius powerlaw amp,x,y,r_1,index1 j0 amp,x,y,r_1
Here "offset" is the offset level, "rms" is the rms value of the noise, "amp" is the normally peak value of the object (but see options=totflux below), "x" and "y" are the offset positions (in arcsec) of the object relative to the reference pixel, "z" is the absolute pixel position on the third axis, "bmaj" and "bmin" are the major and minor axes FWHM (in arcsec), "pa" is the position angle of the major axis (in degrees), and "bz" is the FWHM (in pixels) in the 3rd dimension. The position angle is measured from north towards east. The default is an object of unit amplitude, at the reference pixel, with a FWHM of 5 arcsec in x and y and 5 pixels in z. For powerlaw the scale length defaults to 5 arcsec as well and the power-law index defaults to 1. For j0, the default scale length is 5 arcseconds although significant image manipulation after-the-fact is necessary to make this object useful for holography. Comet scalelength, and cluster core radius are in arcsec units. Jet model has brightness with power law index bmaj and bmin along major and minor axes.
totflux Interpret the "amp" values in the spar keyword as total integrated flux densities (Normally the "amp" parameters are interpretted as peak values).