PISAPEAK reads in the object parameterisations file produced by PISAFIND. Using
the PISA profiling function it then transforms certain of the variables into values which are intensity
invariant for a radial stellar profile. Two of the output variables may have values of around 1.0 for
objects which are well represented by the given PISA profiling parameters. The variables produced
are the ratio of the semi-major axis of the object fit to the radius of an object whose peak intensity is
the same, but whose size is determined by the PISA profiling function (a peakedness measure).
The ratio of the integrated intensity to the peak intensity and the model object ratio. The
ellipticity (unmodified) and the absolute value of the intensity weighted cross moment
(ABS(SXY)).
The output from PISAPEAK can be used in star-galaxy separation, either by applying direct cuts in
variable values or by discrimination analysis routines such as PISAKNN.
BACKGROUND = _REAL (Read)
The frame background value (sky) as used by PISAFIND. [Global]
COMIX = _REAL (Read)
The mixture coefficient, as a fraction of the Gaussian peak, of a Lorentzian
function used to model the wings of the stellar profile. At each point in the analytical profile the
Lorentzian function is added to the Gaussian/exponential core scaled by the mixture coefficient.
[Global]
CROSS = _REAL (Read)
The crossover point, as a percentage of the Gaussian peak, where
an exponential fall-off in the analytical stellar profile takes over from the Gaussian core. The
exponential function is joined on smoothly to the Gaussian. [Global]
FINDDATA = FILENAME
(Read)
Name of the file containing the PISAFIND parameterisations. [PISAFIND.DAT]
GSIGM = _REAL (Read)
The standard deviation, in pixels, of the Gaussian core of the
analytical stellar profile. [Global]
IN = NDF (Read)
The NDF containing the objects which
have been parameterised by PISAFIND.
RESULTS = FILENAME (Write)
Name of a file
to contain the PISAPEAK results. [PISAPEAK.DAT]
THRESH = _REAL (Read)
The
detection threshold as used by PISAFIND. [Global]