Task: zeemap Purpose: Map the magnetic field from I and V cubes Categories: profile analysis ZEEMAP tries to find the line-of-sight magnetic field splitting a transition by measuring the shift in the line owing to the Zeeman effect. Key: iin Stokes I spectral cube with channel on the first axis. Key: vin Stokes V spectral cube with channel on the first axis. Key: b Output file name for line-of-sight magnetic field. Key: d Output file name for the derivative of I/2 spectrum (op=div only). Key: be Output file name for the error in B (op=div only). Key: g Output file name for amount of residual I found in V (op=fit only). Key: blc Bottom left corner of box to be fit. Key: trc Top right corner of box to be fit. Key: freq Frequency of line in GHz, used to determine amount of splitting per Gauss. Key: op Operation code that controls how the line shift is determined - div: by dividing V by the derivative of I/2, or fit: by fitting of the derivative of I and I to V. Key: cutoff For op="div", the division will not be performed unless the derivative of I/2 is greater than cutoff. For op="fit", the fit will not be performed unless one or more channels in the I spectrum is larger in absolute value than cutoff. Key: vrms RMS deviation in V spectrum in a signal free area. This can be obtained using histo. Used for calculating error in B for op=div. Key: mode This determines the algorithms used, if operation="fit". It can consist of several flags: l Include leakage term, 2 Use 2 sided derivative approximation, m Use maximum likelihood technique, x Perform extra checks for better solutions, when using the maximum likelihood technique. Default mode=2m. Key: y corlen Correlation length. Selected window must be divisible by this number, which is the number of pixels over which you think the magnetic field might be constant. Default is 1, try maybe 2 or 4. Revision: 1.4, 2010/11/22 05:06:16 UTC

Generated by miriad@atnf.csiro.au on 21 Jun 2016