How extracted flux depends on parameters in pipeline

For optimal extraction the pipeline uses to parameters, the aperture radius and the PSF radius.

Here's how the flux level changed with PSF radius for the setting hi-med, 396cm-1, slit6.
Also plotted is the theoretical captured flux of a certain slit width, in arcsec, for a seeing of 2.5"

More later

Absolute fluxes from the pipeline in HI-MED at 6um

We've observed the 1640cm-1 hi-med setting repeatedly.

Series 1:
AFGL 2591                 520 Jy
Vega

Series 4
AFGL 2136, 174 Jy (150 Jy Indriolo)
NGC 7538 IRS1, 92 Jy (100 Jy Indriolo)
Mon R2 IRS3, 179 Jy  (150 Jy Indriolo)
W3 IRS 5, 161 Jy, (200 Jy Indriolo)
Sirius, 349 Jy

Series 5
BN, 200 Jy, Indriolo
Sirius, 349 Jy

Series 6
Europa, --
Polaris, 55 Jy

Series 7
Europa
Polaris, 55 Jy

This post is supposed to bring together all these observations to see if we're getting reasonable absolute fluxes. I've put ISO and model fluxes beside the targets above.

Using the 3.1 factor for converting ergs s-1 cm-1 SR-1 (cm-1)-1 to Jy, here's the out of the box, continuum level fluxes of these objects.

However, the blackbody is known to be mis-represented because of the additional contribution of scattered light from the KRS5 lens. It was removed prior to series 6.
With the lens in the BB, the setpoint of 260K has a flux equivalent to 277 K, in the lab.
(add reference to blogger post)
When removed, the same setpoint has a flux equivalent to 272 K.

Since the pipeline assumes scaling to blackbody counts of a 260 K source, this acts to reduce the absolute flux values. For 277K that factor is 1.75. For 272K the factor is 1.5.

Absolute Fluxes from Pipeline
object   mode    slit  series actualflux correctedpipeflux
AFGL2591 nod-on  4     1      520        

AFGL2591 nod-off 4 series1

Converting from ergs s-1 cm-1 SR-1 (cm-1)-1 to Jy

The pipeline puts the flux into flux density units as a default [ergs s-1 cm-1 SR-1 (cm-1)-1. To get it to Jy for point sources, apply this conversion

flux_Jy = flux_pipeline x (pixelscale_in_arcsec)^2 x 78.4023.

For pixscale = 0.2", this is

flux_Jy = 3.136 x flux_pipeline

The 78.4 comes from converting sq arcsec to steradians (pi /180/3600)^2 and multiplying by 1x10^21/ 2.99792458x10^8 m/s)

I can't say I understand it.