- Long_bsample is used (Nod & Shuffle uses mos_bsample) to define the background
- have to do each one individually
gm> gsex stgsgtN20040911S0116
- Found better traces if aperture width is changed to include wings, if needed (:upper, :lower or can change ap_width individually with 'y)
- Note: once an image has been processed with gsextract, it is necessary to delete the corresponding database files ("./database/") before re-reducing the image with different background subtraction parameters. Otherwise, the old parameter values in the database will silently override the user-specified values.
(outprefix = "e") Output prefix (refimages = "") Reference images for tracing apertures *(apwidth = 2) Extraction aperture in arcsec (diameter) (fl_inter = yes) Run interactively? (find = yes) Define apertures automatically? (recenter = yes) Recenter apertures? (trace = yes) Trace apertures? (tfunction = "chebyshev") Trace fitting function (torder = 3) Trace fitting function order *(tnsum = 10) Number of dispersion lines to sum for trace *(tstep = 50) Tracing step *(weights = "variance") Extraction weights (none|variance) *(clean = yes) Detect and replace bad pixels? *(lsigma = 3.) Lower rejection threshold for cleaning *(usigma = 3.) Upper rejection threshold for cleaning *(background = "fit") Background subtraction method (bfunction = "chebyshev") Background function *(border = 1) Order of background fit *(long_bsample = "*") LONGSLIT: backgr sample regions, WRT aperture *(mos_bsample = 0.5) MOS: fraction of slit length to use (bkg+obj) *(bnaverage = -10) Number of samples to average over (bniterate = 2) Number of rejection iterations (blow_reject = 2.5) Background lower rejection sigma (bhigh_reject = 2.5 Background upper rejection sigma (bgrow = 0.) Background rejection growing radius (pix)