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Hi folks,
I am trying to reduce some CTIO Hydra data--the first time at this for me. I'm able to run DOHYDRA just fine up until it tries to pull out the sky fibers and combine them to form a sky spectrum. It does not find any, and fails with the output:List of object spectra: obj1007
Edit the sky spectra? (yes):
Warning: No spectra selected
Warning: Cannot open image (skyobj1007)
ERROR: bus error
"ymax=INDEF, logfile=temp4, graphics="stdgraph")"
line 84: srcfibers$skysub.cl
called as: `skysub (input=obj1007.ms.fits, output=, objaps=, skyaps=30,46,65,81,111,115,116,124,125,127, objbeams=0,1, skybeams=0, skyedit=yes, combine=average, scale=none, saveskys=no, logfile=logfile)'
"saveskys=saveskys, logfile=logfile)"
line 684: srcfibers$proc.cl (hidden task)
called as: `proc (objects=obj1007, apref=Pflat_g292_f1, flat=Dflat_circle, throughput=Mflat_fit, arcs1=comp1009, arcs2=, arcreplace=, arctable=, fibers=29, apidtable=, crval=INDEF, cdelt=INDEF, objaps=, skyaps=30,46,65,81,111,115,116,124,125,127, arcaps=, objbeams=0,1, skybeams=0, arcbeams=, scattered=no, fitflat=yes, recenter=no, edit=no, trace=no, arcap=no, clean=yes, dispcor=yes, savearcs=yes, skyalign=no, skysubtract=yes, skyedit=yes, saveskys=no, splot=no, redo=no, update=yes, batch=no, listonly=no)'
"skyedit, saveskys, splot, redo, update, batch, listonly)"
line 69: hydra$dohydra.cl
called as: `dohydra ()'Here is the parameter file for DOHYDRA:
objects = "" List of object spectra
(apref = "Pflat_g292_f1") Aperture reference spectrum
(flat = "Dflat_circle") Flat field spectrum
(throughput = "Mflat_fit") Throughput file or image (optional)
(arcs1 = "comp1009") List of arc spectra
(arcs2 = "") List of shift arc spectra
(arcreplace = "") Special aperture replacements
(arctable = "") Arc assignment table (optional)\n
(readnoise = "RDNOISE") Read out noise sigma (photons)
(gain = "GAIN") Photon gain (photons/data number)
(datamax = INDEF) Max data value / cosmic ray threshold
(fibers = 29) Number of fibers
(width = 12.) Width of profiles (pixels)
(minsep = 8.) Minimum separation between fibers (pixels)
(maxsep = 15.) Maximum separation between fibers (pixels)
(apidtable = "") Aperture identifications
(crval = "INDEF") Approximate central wavelength
(cdelt = "INDEF") Approximate dispersion
(objaps = "") Object apertures
(skyaps = "30,46,65,81,111,115,116,124,125,127") Sky apertures
(arcaps = "") Arc apertures
(objbeams = "0,1") Object beam numbers
(skybeams = "0") Sky beam numbers
(arcbeams = "") Arc beam numbers\n
(scattered = no) Subtract scattered light?
(fitflat = yes) Fit and ratio flat field spectrum?
(clean = yes) Detect and replace bad pixels?
(dispcor = yes) Dispersion correct spectra?
(savearcs = yes) Save simultaneous arc apertures?
(skyalign = no) Align sky lines?
(skysubtract = yes) Subtract sky?
(skyedit = yes) Edit the sky spectra?
(saveskys = no) Save sky spectra?
(splot = no) Plot the final spectrum?
(redo = no) Redo operations if previously done?
(update = yes) Update spectra if cal data changes?
(batch = no) Extract objects in batch?
(listonly = no) List steps but don't process?\n
(params = "") Algorithm parameters
(mode = "ql") Finally, I'm running this on my Intel Mac (OS10.4) in IRAF 2.13.I'm sure this is some dumb thing that I have set wrong in a parameter somewhere, but I've beat my head against the wall for awhile on this with no luck--so hope someone more expert can help.Thanks!
Frank

Hi Frank,Frank would be the best person to answer, but I found a similar problem in an earlier message where his reply might be just what you need.See https://iraf.net/phpBB2/viewtopic.php?t=76322&highlight=dohydra+spectra+selectedCheers,
-Mike

Hi,In reviewing the link to a forum search that Mike gave I would agree that this is giving the right indication that the aperture identifications are not telling the task that there are any sky fibers. So explore how the sky fiber information is supposed to be set. I have not seen any CTIO hydra data or questions in many years. At WIYN they use keywords in the header to define the fibers.If you can't figure it out try sending a header listing from a file and tell me what documentation you are following to do the processing.Yours,
Frank Valdes