10.12 Point Spread Function Fraction Factors in the Data
Products

Caveat:  The point spread function correction factors are applied to all point source photometry products, like PPAP and PCAP, regardless of whether a background subtraction was performed or not (see Section 5.2.5). For staring mode observations without background subtraction this has to be accounted for when subtracting the separate background measurement.

The background measurement can be either a point source product of type PPAP or PCAP (in Jy):

or an extended source product of type PPAE or PCAE (in MJysr). For the conversion of in-band power to surface brightness, see Section 8.4.7:

, , are fluxes in the aperture uncorrected for point source function effects (the latter one for one single pixel of the array). is the surface brightness of the background.

Please note the following definitions with regard to application of -factors to header keywords:

1)

For PPAP and PPAE:

= 1

2)

For PCAP and PCAE staring modes:
total flux of the array is used!
=
converted flux from surface brightness has to be multiplied with number of pixels, because the solid angle is defined per pixel!
n = 9 for C100, = 4 for C200

3)

For C100 PCAP and PCAE chopped mode (PHT22):

because only the central pixel is used!
= 1
Note that is applied to the data fields PCAPSRCE for consistency with the staring mode!

4)

For C200 PCAP and PCAE chopped mode (PHT22):

= 4