Changes between Version 25 and Version 26 of Durham_MDS_Testing
- Timestamp:
- Jul 16, 2009, 10:54:49 PM (17 years ago)
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Durham_MDS_Testing
v25 v26 54 54 == Comparison with SDSS - (Nigel Metcalfe) == 55 55 56 Here is a comparison of the PSFmags from the cmf files of four adjacent (arbitrarily chosen) MD07 stacks with SDSS model mags. r-band on the left, g-band on the right. Blue indicates an object flagged as a star by SDSS. I haven't rejected any images flagged as defective in any way, so this probably explains the blue points offset by 2 mags. UPDATE: looks like these offset points are stars with masked centres - note that there are brighter stars which are not masked. Is this the 'removing intermediate brightness stars as cosmic rays' problem again?56 Here is a comparison of the PSFmags from the cmf files of four adjacent (arbitrarily chosen) MD07 stacks with SDSS model mags. r-band on the top left, g-band top right, i-band bottom left. Blue indicates an object flagged as a star by SDSS. I haven't rejected any images flagged as defective in any way, so this probably explains the blue points offset by 2 mags. UPDATE: looks like these offset points are stars with masked centres - note that there are brighter stars which are not masked. Is this the 'removing intermediate brightness stars as cosmic rays' problem again? It appears particularly bad on r cells 40 and 52. 57 57 58 58 Clearly the zero-point varies from cell to cell (do we expected this? after all, no calibration has been done as far as I can tell). The r-band stellar locus also appears tighter in cell 41 than in the other r-band cells. As the are no extended source magnitudes in the cmf files, all the galaxies (black open circles) are offset.
