stsdas.analysis.isophote ellipse task and bad pixels
Ramiro Simoes Lopes wrote on Feb 27, 2009
I'm fitting ellipses to images of galaxies using a bad pixel mask (dqf parameter).
I know the bad pixels are not taken into account for the geometry fitting.
My questions are:
1- I want to know if the reported fluxes in the output table include or not the flux from the bad pixels.
2- Also, what happens if I set both the inellip and the dqf parameters? I don't understand what the task is doing in this case. I expect it would use the bad pixel mask for estimating photometry only but it seems to be refitting the geometry.
Thanks for your time
Ramiro
I know the bad pixels are not taken into account for the geometry fitting.
My questions are:
1- I want to know if the reported fluxes in the output table include or not the flux from the bad pixels.
2- Also, what happens if I set both the inellip and the dqf parameters? I don't understand what the task is doing in this case. I expect it would use the bad pixel mask for estimating photometry only but it seems to be refitting the geometry.
Thanks for your time
Ramiro
Mike Fitzpatrick wrote on Feb 27, 2009
For an authoritative answer (I don't use this task) you should check with the STScI help desk (help@stsci.edu) since this is their task. However, a quick scan of the code seems to indicate that the output fluxes only take into account the valid pixels (i.e. not the dqf-flagged ones). The inellip param is supposed to apply the pre-defined ellipses and compute results from those, I'm not sure why it appears to be refitting.
-Mike
-Mike
Last post on Feb 27, 2009