How intense does the iR have to be for marking?
Is it just white or can orange/red be ok?
Welcome to RGZ, bobk47!
In general, I mark any IR source that seems to be 'brighter' than the 'red' background. Sometimes these very faint IR sources may turn out to be just 'noise', but I think it's better to err on this side than to not mark what could turn out to be a genuine IR source.
Hope this helps, and happy hunting! 😃
Hi bobk47, thanks for the question as this is a hard one to answer. As JeanTate said, anything brighter than the background red should be marked. So the infrared host galaxy can be white, orange, red.