A. Autophot

Autophot uses IRAF's digiphot "daophot" routines; all we've done is automated the procedure a bit. Our autophot.cl script does the calling of the other scripts, image by image. Autophot will characterize the frame, do some preliminaries, pick PSF stars, and do the PSF-fitting of all the stars it found on the frame. These tasks are described in the next sub-sections.

"Autophot" updates the headers for read-noise and gain based upon where and when the data were taken; i.e., the read-noise was much elevated on the Kitt Peak Mosaic camera during September-October 2000. All of that is hardwired into "getgain".

Note that autophot itself has no parameters: the assumption is that everything in the current subdirectory is going to get photometered.

Before running the autophot script, the IRAF packages digiphot and daophot must be loaded. (Autophot also defines the apphot psffit task, so it can be run from daophot.) Autophot does an unlearn on the daophot parameters, with the belief that each routine will set the things that need resetting. You must also "set imtype="imh"" in your login.cl file; just typing it at the cl prompt will not be sufficient.

autophot.cl makes use of:

• getgain.cl, which figures out which gain and read-noise to use for each chip.
• character3.cl, which puts the saturation value, the gain, the readnoise, the name of the time-stap, the name of the filter key word, and then determines the fwhm, mode of the sky, sigma of the sky, datamin, and datamax, and also puts those in the header. It makes use of the FORTRAN code
  • pickone.f, which determines the best fwhm to be used with fitpsf.
  • pickround.f, which determines the best "roundness" based upon the output of the first run of daofind.
  • radmode.f, which deterines the modal value for the fwhm's.
• prelim.cl, which runs daofind and phot on the images.
• pickem3var.cl, which selects suitable stars for making a PSF, and then makes one. It relies upon the FORTRAN programs
  • phil2select.f (catchy name, huh?), which selects stars that way that Phil might select them. One could hope.
  • fwhmed.f, which keeps potential PSF stars iff their fwhm are within 15% of the value determined by character3 above.
  • mode3pick.f which seems to do the actual PSF star selection.
• stetson.cl, which runs allstar, runs daofind on the subtracted image, runs phot on the new stars, merges the mag files, and then runs allstar again.
• unsat.cl, which goes through and find cases where allstar actually fit saturated stars. (Why this happens is sort of a complicated story. Ask me about it some time.) It generates a new allstar file (*.als.3). It uses:
  • a href="ftp://ftp.lowell.edu/pub/massey/survey/edals.f">edals.f, a FORTRAN program that does something or another.