XMM-Newton Science Analysis System


asmooth (asmooth-2.32.1) [xmmsas_20230412_1735-21.0.0]

Output Files

All outputs are arrays in FITS datasets.

1. outset: The smoothed image. This has data type REAL32. Attributes (and DSS, if present) are copied from the input image.

2. (Optional) outtemplateset: this is only available from smoothstyle=`adaptive'. The array has data type REAL32. The value of a given pixel of outtemplateset is the characteristic width (sigma value) of the gaussian convolver which was used to smooth the corresponding pixel of inset. This facility doesn't offer any advantages over the smoothstyle=`withset' and I will eventually delete it.

3. (Optional) outconvolversset: this is only available from smoothstyle=`adaptive' and is written in conjunction with outindeximageset. The sequence of convolver images used in the adaptive smoothing is written to a cube or 3-dimensional array of REAL32 data type, named CONV_000. (It is recommended that outindeximageset and outconvolversset be the same dataset.) Convolver arrays which are smaller than the largest convolver array are padded to the maximum size with zeros. The first two dimensions of the cube record the now common $x$ and $y$ dimensions of these arrays; the third dimension records their position in the sequence.

4. (Optional) outindeximageset: this is only available from smoothstyle=`adaptive' and is written in conjunction with outconvolversset. The index image is written to a 2-dimensional array, of INTEGER32 data type, named INDEXIMG. (It is recommended that outindeximageset and outconvolversset be the same dataset.) Its values correspond to the sequence position of the corresponding convolver: the $i$th convolver in the sequence stored in outconvolversset was used to smooth those portions of the image for which the outindeximageset value is also $i$.

5. (Optional) outvarianceset: this records the variances (squares of standard deviations) in the smoothed image. Equation 2 shows how these values are calculated. The array has data type REAL32.

6. (Optional) badmaskset: this ought to be a boolean array but the best I can manage at the moment is INTEGER8. Non-zero values are taken to indicate TRUE. Values are set TRUE where the task was unable to evaluate the fraction in equation 4 because the denominator was close to zero.