AIPS HELP file for SPECURVE in 31DEC24
As of Mon Sep 16 6:12:51 2024
HELP SECTION
SPECURVE
Type: Adverb (Real array(3))
Use: Spectral index curvature defined so that the flux density goes
as
log(T(f)/T(f0) = S * log(f/f0) + C(1) * (log(f/f0))^2
+ C(2) * (log(f/f0))^3 + C(3) * (log(f/f0))^4
where S is SPECINDEX and C is SPECURVE, f0 is 1 GHz for
simplicity, and all logs are base 10. It is unlikely for you to
have reliable values for SPECURV(3); SETJY uses only through
SPECURVE(2) for the basic flux calibration sources.
Tasks:
BLCHN.....Compute closure offset corrections on a channel-by-channel
basis. Curvature value with f0 1 GHz.
BPASS.....Computes spectral bandpass correction table.
SPECURVE is used to remove curvature from the derived
bandpass amplitude spectrum. f0 is the frequency in the
UV data set header and is independent of IF and channel.
CPASS.....Computes polynomial spectral bandpass correction table
Curvature value with f0 1 GHz.
EVAUV.....Subtracts & divides a model into UV data, does statistics
on results. Spectral curvature if using SMODEL with f0
the header frequency.
SETJY.....Task to enter source info into source (SU) table.
Curvature value with f0 1 GHz.
SOUSP.....Fits SPECINDX and SPECURVE to the fluxes in an SU table
returning the values for input to BPASS.et al.
EXPLAIN SECTION