MOPEX User's Guide - IRSA

MOPEX User’s Guide
The module estimates the pixel uncertainty for each pixel in the image using the following
model:
σ = σ 2
readnoise
g 2
+ σ 2
confusion
g 2
+ I
g ,
Equation 6.2
where the parameters Read Noise σreadnoise, Gain g, and Confusion Sigma σconfusion are specified
in the module settings. The last term is the Poisson noise determined by the pixel value, I.
The units of Read Noise and Confusion Sigma here are electrons. The module is designed to
work with the images in DN units. If you are working with the images in units of surface
brightness (MJy/sr; i.e. all Spitzer BCDs) then the Gain should include the conversion factor
from surface brightness units to electrons (see the INPUT for this module). The product of
this step is the uncertainty images.
6.5.5 APEX Modules: Fiducial Image Frame
Command Line Equivalent: run_fiducial_image_frame
Default Output Directory:
De pe nds On: Initial Settings; APEX Settings
Relevant Pipelines: APEX Multiframe; APEX User List Multiframe
Important Notes: Running this module will overwrite any pre-existing FIF.tbl file in the output
directory. If you are working with MIPS images and plan to use the Mosaic PRFs the n
please see the Discussion below for important information.
If you are using the mosaic.fits file from a pre-pended Mosaic pipeline as input into APEX then
you should omit this module.
PURPOSE
Point Source Extraction (APEX) 116
APEX Modules