• CALC_SCUBA2_FCF

CALC_SCUBA2_FCF

Description

A simple PICARD recipe to calculate FCFs for one or more given sources. The results are written to a log file called log.fcf.

The FCFs are calculated from the input images - no processing is done beforehand. By default four FCFs are derived:

1. ARCSEC - the FCF is derived (in Jy/sq arcsec/pW) from the total flux within an aperture;
2. BEAM - the FCF is derived (in Jy/beam/pW) from the fitted peak flux;
3. BEAMEQUIV - the FCF is derived (in Jy/beam/pW) from the peak of a gaussian with the same total flux as derived by aperture photometry;
4. BEAMMATCH - the FCF is derived (in Jy/beam/pW) from the fitted peak flux after processing with a matched filter.

Two more may be written if the AUTOPHOTOM flag is true (ARCSEC_AP and BEAMEQUIV_AP).

By default this recipe only works on known calibration sources. However, the user may specify the source flux at 850 and/or 450 um by using recipe parameters called FLUX_850 and FLUX_450 respectively. The fluxes for different sources may be specified by appending the target name (in upper case with spaces removed), e.g. FLUX_850.HLTAU.

A log file is written containing a variety of information about the data and the values calculated (unless LOGFILE = 0).

Notes

The input data must have units of pW. If the units are anything else the recipe assumes the data are already calibrated, and subsequent processing will probably fail in undesireable ways.

If run on multiple sources and fluxes are given in the parameter file, warnings will be issued about unsupported parameters. These warnings may safely be ignored as they relate to the recipe parameters specifying the fluxes for the sources not being processed by the current pass through the recipe.

The map size must be at least AUTOPHOTOM_OUTER times the aperture radius if AUTOPHOTOM is true.

Available recipe parameters

• APERTURE_RADIUS
  • radius of aperture (in arcsec) for masking out source (otherwise 30 arcsec)
• AUTOPHOTOM

  • use KAPPA autophotom for aperture photometry

• AUTOPHOTOM_INNER
  • scale factor (in terms of aperture radius) for inner radius of annulus used for background estimate (default is 1.25)
• AUTOPHOTOM_OUTER
  • scale factor for outer radius of annulus used for background estimate (default is 2)
• FLUX_450
  • Source flux density at 450 um in Jy. Source-specific values may be given by appending the source name in upper case with spaces removed.
• FLUX_850
  • Source flux density at 850 um in Jy. Source-specific values may be given by appending the source name in upper case with spaces removed.
• LOGFILE
  • Flag to denote whether to write results to a log file at the end of processing - default is 1 (write a log file)