Changes between Version 5 and Version 6 of GalaxyParameters

Timestamp:

Dec 3, 2014, 3:13:42 PM (12 years ago)

Author:

bills

Comment:

--

GalaxyParameters

@@ -15 +15 @@
 The program used to make these measurements is called GIM2D. It is performed on the results of processing by SExtractor.
 Since the indices consist of sums of absolute values of the residuals a positive signal will result even in the prescence of noise.
-So the algorithm subtracts off radomly selected "background pixels" which in the GIM2D program are chosen from the SExtractor
+So the algorithm subtracts off randomly selected "background pixels" which in the GIM2D program are chosen from the SExtractor
 segmentation image. 
 
-A later paper published in [http://adsabs.harvard.edu/abs/2009A&A...508.1141S 2009] defined the parameter S2 = Rt + Ra.
+A later paper published in [http://adsabs.harvard.edu/abs/2009A&A...508.1141S 2009] defined the parameter S2 = Rt + Ra
+where Rt and Ra are measured for 2 half light radii.
 In [http://adsabs.harvard.edu/abs/2011ApJS..196...11S 2011] Simard, et al. applied these methods to SDSS images.
 
@@ -29 +30 @@
 
 2. Next if the source's model is not the Sersic model fit, the model is temporarily changed to make it so.
-The indices consist of sums over a specific radius. Following Simard 2011 the radius chosen is 2 times the half light radius for which
+The indices consist of sums over a specific radius. Following Simard 2009 and 2011 the radius chosen is 2 times the half light radius for which
 the value that we have chosen is the major axes of the Sersic fit.
 
@@ -37 +38 @@
 the source's pixels is made as well.
 
-4. The sersic model is subtracted 
+4. The Sersic model is subtracted from the images.
 
-5. The sums in the formulas for RT and RA are performed.
+5. The sums in the formulas for Rt and Ra are performed.
 
 The new code was used in psphotStack for SAS.37.