READMX,'IMAGET',H,W,F,q,noise,b,net,r,wrange=wrange, $
orange=orange,/uncalib,/noisecal
IMAGET | FITS file name (including extension). |
H | FITS main header, a string array. The VICAR label will be included. |
W | Wavelengths (Å, computed from the starting wavelength and increment stored in the MXLO file. |
F | Fluxes (erg cm-2 s-1 Å-1 ). |
q | Quality flags (``'' flags). These are bit encoded. See Section 7.2.2 for a description of the values. |
noise | Noise vector. These are error estimates based on the high dispersion noise model for the pixels in the extraction slit. They are specified in FN units but may be calibrated using the /noisecal keyword described below. |
b | Chebyshev fit to the background, scaled to the net fluxes. |
net | Net fluxes (``flux numbers''). |
r | Ripple-corrected net fluxes (``flux numbers''). |
wrange | A 2-element vector giving the starting and ending wavelength (in Angstroms) to be extracted. |
orange | A 1- or 2-element vector specifying the range of orders to be extracted. If both orange and wrange are specified, READMX extracts the orders specified by orange, and trims the wavelengths according to wrange. Generally, the keywords should not be specified together. To see the complete spectrum for a given order, use READMX with orange equal to a single order number. |
uncalib | By default, READMX removes points which are uncalibrated (i.e., points are removed where the nu flag value is -2). Specifying /uncalib causes all extracted points to be extracted (although, when multiple orders are requested, the orders will still be spliced together |
noisecal | By default, the noise vector is returned in FN units (i.e., like the net and ripple-corrected net flux vectors). Specifying /noisecal causes the noise vector for each extracted order to be multiplied by the ratio of the absolute flux to the net flux, thereby giving it the same units as the absolute flux vector. Note: this vector is left uncalibrated because the project felt it was not an accurate estimate of the error in the extracted fluxes. Users are cautioned not to rely to heavily on the calibrated noise vector as an error estimate. |
See high dispersion examples of READMX in Table 4.2. Note WRITEMX has not yet been modified to support high dispersion NEWSIPS files.
Expression | Definition |
---|---|
readmx,'swp20246.mxhi',h,w,f |
extract wavelengths and fluxes and be prompted for wavelength range. |
readmx,'lwp11367.mxhi',h,w,f,q,noise, $ wrange=[2790,2810] | Read a region of a high dispersion spectrum containing Mg II. |
readmx,'lwp12345.mxhi',h,w,f,q,cn, $ orange=100,/uncalib,/noisecal plot,w,f errbar,w,f,w*0,cn,psy=1 | Reads all data from order 100, calibrates the noise vector, and plots results with error bars based on the noise vector. |