Re: Subtracting a Galaxy template

Posted by karenacollins on Jan 27, 2024; 12:19pm
URL: http://astroimagej.170.s1.nabble.com/Subtracting-a-Galaxy-template-tp2302p2353.html

If the size of the galaxy on the detector is large enough compared to the stellar PSF, maybe try forcing the sky background annulus to be restricted to within the galaxy so that the brightness of the galaxy (plus sky) will be subtracted from the pixels within the photometric aperture. Since the galaxy brightness wouldn't be perfectly smooth, the subtraction wouldn't be precise, but might be better than attempting to subtract a version of the galaxy from another image. The small background annulus size might cause more noise than would be acceptable though.

Karen