Changes between Version 6 and Version 7 of fullforce_SAStest2
- Timestamp:
- Mar 31, 2014, 2:11:11 PM (12 years ago)
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fullforce_SAStest2
v6 v7 5 5 6 6 There we presented plots that send to indicate that the full force results provided a much 7 better match to SDSS model fits than the psphotStack results for de Vaucouleurs models (dev ) There was some scepticism that7 better match to SDSS model fits than the psphotStack results for de Vaucouleurs models (dev model) There was some scepticism that 8 8 the difference was so great. In particular the validity of the [http://svn.pan-starrs.ifa.hawaii.edu/trac/ipp/attachment/wiki/fullforce_SAStest1/ddevrad_hist_comparison.jpg plot] 9 9 was doubted. … … 11 11 It turns out that this scepticism was justified. The ddevrad values for the stack photometry were incorrect (the difference in units between the sdss value (arcseconds) and the IPP values (pixels) was not accounted for. Upon further review we discovered that the wrong stacks (label SAS.20130620) were used for that investigation rather than the SAS 32 stacks (label SAS.20130703). 12 12 13 In order to examine the results in more detail we re-ran the full force pipeline on a subset of the SAS skycells, selecting only deV models for forced photometry. Recall that by default the "best" of the three models fit during stack photometry is used. The skycells chosen were near the center 13 In order to examine the dev model results in more detail we re-ran the full force pipeline on a subset of the SAS skycells. To improve statistics we changed 14 the system to selecting only dev models for forced photometry rather than the usual method of choosing the best model. The skycells processed were near the center 14 15 of the SAS field: 332 < ra < 336, -3 < dec < 3. 15 16 16 Here isthe difference between the SDSS model radius devRad_r*0.25 and the psphotStack and psphotFullForce values for EXT_WIDTH_MAJ for for dev galaxies17 (devFrac_r == 1.0). 17 Here are the difference between the SDSS model radius devRad_r*0.25 and the psphotStack and psphotFullForce values for EXT_WIDTH_MAJ for for dev galaxies 18 (devFrac_r == 1.0). Bright galaxies are SDSS r magnitude < 20. 18 19 19 20 [[Image(ddevrad_stack.jpg)]] [[Image(ddevrad_forced.jpg)]] … … 23 24 [[Image(ddevrad_comparison.jpg)]] 24 25 26 We find that the lowest chi squared fit is shifted slightly to the left indicating that we get a larger raidus. Interestingly this effect is larger for the bright objects. 27 28 Here is the plot of the magnitude differences. 29 30 [[Image(ddevmag.jpg)]] 31 32
