10. vtpdetect Parameters & Data Products Reference

This chapter lists all the vtpdetect parameters in alphabetical order for quick reference. In addition, a guide to the data products output by vtpdetect is provided.

10.1 Default Parameter File

unix% plist vtpdetect

Parameters for /soft/ciao/param/vtpdetect.par

# parameters for vtpdetect
# inputs -- can either be an image or table
        infile =                  Input file name
       expfile = none             Exposure map file name
# output
       outfile =                  Source list output file name
# processing parameters
         scale = 1                Threshold scale factor
         limit = 1e-06            Max. probability of being a false source
        coarse = 10               Minimum number of events per source
       maxiter = 10               Maximum number of iterations to allow
# SAOImage regions
      (regfile = none)            name for ASCII output region files
     (ellsigma = 3)               Size of output source ellipses (in sigmas)
         (edge = 2)               How close to edge of field to reject events
      (superdo = no)              Perform Super Voronoi Cell procedure
# probably use defaults for these...
   (maxbkgflux = 0.8)             Maximum normalized background flux to fit
   (mintotflux = 0.8)             Minimum total flux fit range
   (maxtotflux = 2.6)             Maximum total flux fit range
    (mincutoff = 1.2)             Minimum total flux cutoff value
    (maxcutoff = 3)               Maximum total flux cutoff value
       (fittol = 1e-06)           Tolerance on Possion fit
     (fitstart = 1.5)             Initial background fit starting scale factor
# user setable parameters 
      (clobber = no)              Overwrite if file exists
      (verbose = 0)               Debug level
      (logfile = stderr)          Debug file name
       (kernel = default)         Output format
# mode
         (mode = ql)

10.2 Parameter Descriptions

In the following parameter descriptions, "required=yes" indicates that the user must provide a value for the indicated parameter (e.g. infile) before the program will run. Also, the empty string (" ") is equivalent to the string none for filenames.

10.3 Data Product Descriptions

Source List File (outfile )

The primary output of vtpdetect is the FITS file of source detections. The following properties are recorded in the output file:

Data item Unit Description
RA deg Source Right Ascension
RA_ERR deg Source Right Ascension error
DEC deg Source Declination
DEC_ERR deg Source Declination error
POS(X,Y) pixel Physical coordinates
X_ERR pixel Source X position error
Y_ERR pixel Source Y position error
SRC_AREA pixel Source region area
NET_COUNTS count Net source counts
NET_COUNTS_ERR count Error in net source counts
BKG_COUNTS count Background counts (scaled to source cell)
NET_RATE count/s Source count rate
NET_RATE_ERR count/s Source count rate error
BKG_RATE count/s/pixel Background count rate
BKG_RATE_ERR count/s/pixel Background count rate error
EXPTIME s Effective exposure time
SRC_CUTOFF count/s/pixel Source flux cutoff
FSP   False source probability
EDGE_OF_FIELD   Edge-of-field flag
SHAPE   Shape of source region
R[2]   Radii of source region
ROTANG deg Rotation angle of source region
COMPONENT   Source number

ASCII Source Region File (regfile )

In addition to the source list file (outfile ), the user may also select to have a source region file (regfile ) output.

This region file is useful for subsequent input into ds9, particularly to overlay region markers over each detection; see Chapter 1, Section 1.4 for details.

The source region file from the example in Chapter 8, Section 8.2.2:

unix% more example2_out.reg

Log File (logfile )

If log is set to yes, then the log information will be written to the file indicated (vtpdetect.log in this example).

The log file from the example in Chapter 8, Section 8.2.2:

unix% more vtpdetect.log 
DEBUG: Version information -
DEBUG:     vtpdetect: 0.5.1
DEBUG:     datamodel : 1.99
DEBUG:     ascfit    : 2.2