Astronomy 920 Commissioning of the Prime Focus Imaging Spectrograph Meeting 7 SALT IRAF Package Ken Nordsieck Oct 21, 2005 Ast 920 Meeting 7

PFIS First Light Night NGC 1866 (LMC) 6290 Interference Filter 5 sec Oct 21, 2005 Ast 920 Meeting 7

Why did we go to all that expense to get large diameter etalons? Quiz Question Why did we go to all that expense to get large diameter etalons? Oct 21, 2005 Ast 920 Meeting 7

Scanning PFIS control system allows arbitrary sets of discrete steps (equal exposures) linear scan for line profiles dithering onto continuum for absorption lines Off axis, must take account of wavelength gradient due to cos θ center to edge gradient: λ(r)/ λ0 = 1/ cos θ ~ (1- .00365*(r/4’)2 ) (24 Ang at Hα) Inside “bullseye”, wavelength changed by less than resolution: D(bullseye) = 1.4’ (10,000/R)1/2 - if object larger than bullseye, extend scan to cover same wavelengths - if object not round, pays to move telescope and rescan, instead of extending scan Oct 21, 2005 Ast 920 Meeting 7

Accessing SALT IRAF package Source (environment variable $salt) Unix: /usr/local/salt MAC: /usr/local/iraf/irafext/salt cl> salt [ loads salt task ] cl> help pfis [ lists pfis commands ] cl> pfis [ loads pfis subtask ] cl> cd working directory/yyyymmdd Oct 21, 2005 Ast 920 Meeting 7

PFIS/ SALT IRAF Package Hierarchy PFIS commands PFIS/ SALT IRAF Package Hierarchy implemented lower level pprepare p pireduce r pmosaic m imcoadd pgain pbias psreduce ps pstransform t psskysub s psextract e scombine piflat psflat pswavelength pscalibrate c psstandard pbpm pscut Raw data name: Pyyyyddddssss.fits, ie P200510200079.fits "multiextension" fits file, one for each of 6 amplifiers; open in DS9 with "open other/ open mosaic IRAF" Each stage of processing prepends a letter or two Imaging: (pireduce, pmosaic) mrpP200510200097.fits Spectroscopy: (psreduce) psP2..... Oct 21, 2005 Ast 920 Meeting 7

Imaging pprepare (p) pireduce (r) check header validity, get data from calibration database pireduce (r) remove crosstalk subtract mean of overscan in each amp, trim divide by gain for each amp subtract bias, if specified subtract dark, if specified divide by flat, if specified pbias: run pireduce on bias frames, bias/ dark/ flat turned off pflat (TBI) run pireduce on flat frames, dark/ flat turned off pmosaic (m) combine amplifiers and ccd's into single fits files can now be opened as normal image by DS9 imcoadd (TBI) remove distortion combine mosaiced images, registering and removing cosmic rays Oct 21, 2005 Ast 920 Meeting 7

Spectroscopy psreduce (ps) run pireduce run pmosaic using slitmask definition file (MDF), cut into one piece for each slit (pscut) apply first guess wavelength calibration to each psflat (TBI) run psreduce on spectral flats (tungsten continuum spectrum) pswavelength identify lines and update wavelength dispersion calibration for wavecal frame pstransform (TBI) resample cut spectra onto linear wavelength vs space grid psskysub, psextract (TBI) extract to 1-d raw spectra pscalibrate compute flux cal from flux standard Oct 21, 2005 Ast 920 Meeting 7

Configuration Data Instrument configuration data: $salt/pfis/data (IRAF pfis$data) PFISamps gain and noise for ccd amps PFISxtalk crosstalk coefficients PFISgeom orientation of CCD's in mosaic PFISdistortion correct pincushion distortion of collimator (r ~ R + AR3 + BR5) PFISfilters. filter list with pointers to transmission curves in /filters PFISgratings. grating list with alignment calibration /masks. mask definition files /linelists. linelists for calibration lamps: Xe, Ne, HgAr Oct 21, 2005 Ast 920 Meeting 7