We have a almost full coverage of the nebula in:
- (A) ACS f658n: relatively wide filter that passes Ha and [N II]
- (B) WFPC2 f656n: narrower filter that passes mainly Ha, with a small amount of [N II]
- (V) ACS f555w
- (Z) ACS f775w
We have much more restrictive coverage in
- (C) WFPC2 f658n: narrow filter that passes mainly [N II] with a small amount of Ha. Only the inner regions
- (D) ACS f660n: narrow filter that passes mainly [N II] Only the field around LL 2
- (M) WFPC2 f547m: medium continuum filter uncontaminated by strong lines. Only the inner regions
In an ideal world we would use (B), (C), and (M) to solve for the Ha, [N II], and continuum brightness. Call this method [I].
But we need to find a method that works with (B), (A), (V), and (Z) instead. Call this method [II].
We can check the reliability of [II] by calibrating it against [I] in the inner regions. Although, we have to be a bit careful that there are not strong trends with R(NII) and EW(Ha), since they will be different in the outer nebula.
We have a almost full coverage of the nebula in:
We have much more restrictive coverage in
In an ideal world we would use (B), (C), and (M) to solve for the Ha, [N II], and continuum brightness. Call this method [I].
But we need to find a method that works with (B), (A), (V), and (Z) instead. Call this method [II].
We can check the reliability of [II] by calibrating it against [I] in the inner regions. Although, we have to be a bit careful that there are not strong trends with R(NII) and EW(Ha), since they will be different in the outer nebula.