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Dependence of EGRET data from Galplot on galprop model https://galprop.stanford.edu/forum/viewtopic.php?f=20&t=55 
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Author:  henning [ Tue Jan 08, 2008 3:32 am ] 
Post subject:  Dependence of EGRET data from Galplot on galprop model 
Hi! I looked at the gammaray plots produced by galplot from the conventional and plain diffusion models fits files that I made using Galprop 50p. It seems that the lowenergy EGRET data, which in my understanding should be independent of any galprop result, change from one model to the other in the plots. I put the epsfiles and galdef and galplotdef files for thw two cases in http://accms04.physik.rwthaachen.de/~h ... ots.tar.gz Any comment would be appreciated. Henning Some output from galplot showing the differences in the EGRET spectra follows:  599298h  EGRET spectrum *E^2: E1 E2 Ebar Ibar 30 50 38.7298 0.0204328 EGRET spectrum *E^2: E1 E2 Ebar Ibar 50 70 59.1608 0.0220291 EGRET spectrum *E^2: E1 E2 Ebar Ibar 70 100 83.666 0.0261807 EGRET spectrum *E^2: E1 E2 Ebar Ibar 100 150 122.474 0.032454 EGRET spectrum *E^2: E1 E2 Ebar Ibar 150 300 212.132 0.0457423 EGRET spectrum *E^2: E1 E2 Ebar Ibar 300 500 387.298 0.0577835 EGRET spectrum *E^2: E1 E2 Ebar Ibar 500 1000 707.107 0.0672297 EGRET spectrum *E^2: E1 E2 Ebar Ibar 1000 2000 1414.21 0.0685659 EGRET spectrum *E^2: E1 E2 Ebar Ibar 2000 4000 2828.43 0.0598313 EGRET spectrum *E^2: E1 E2 Ebar Ibar 4000 10000 6324.56 0.0338678  999726h  EGRET spectrum *E^2: E1 E2 Ebar Ibar 30 50 38.7298 0.023998 EGRET spectrum *E^2: E1 E2 Ebar Ibar 50 70 59.1608 0.0248845 EGRET spectrum *E^2: E1 E2 Ebar Ibar 70 100 83.666 0.0285792 EGRET spectrum *E^2: E1 E2 Ebar Ibar 100 150 122.474 0.0344775 EGRET spectrum *E^2: E1 E2 Ebar Ibar 150 300 212.132 0.0476831 EGRET spectrum *E^2: E1 E2 Ebar Ibar 300 500 387.298 0.059519 EGRET spectrum *E^2: E1 E2 Ebar Ibar 500 1000 707.107 0.0686318 EGRET spectrum *E^2: E1 E2 Ebar Ibar 1000 2000 1414.21 0.0685217 EGRET spectrum *E^2: E1 E2 Ebar Ibar 2000 4000 2828.43 0.0598327 EGRET spectrum *E^2: E1 E2 Ebar Ibar 4000 10000 6324.56 0.0338675 
Author:  imos [ Wed Jan 09, 2008 11:59 pm ] 
Post subject:  deconvolution 
I do not know how exactly they were produced, I have to download the plots, but I guess that the regions on the sky are exactly the same. The EGRET data can be somewhat different in case if the deconvolution has been applied. The deconvolution is model dependent. It works in such a way that the model is convolved first and then the coefficients derived from a comparison of the original model and convolved model are applied to the data. The deconvolution is necessary to compare the data from different instruments, e.g., COMPTEL and EGRET, on one plot. If only EGRET data are used then the deconvolution is unnecessary; it is enough to convolve the model. Andy Strong can probably say more. * convolution usually means "convolution with the instrumental point spread function (PSF)" 
Author:  strong [ Thu Jan 10, 2008 12:43 am ] 
Post subject:  egret low energies 
yes Igor is right. Plotting a spectrum comparing model with data, one can decide either to put the instrumental response in the model curve or the data points. So we could either keep the EGRET points 'as measured' and plot the spatially convolved model, or try to correct the data points for the convolution. The latter solution was adopted so that the spectra are 'real' photon spectra and data from multiple instruments can be placed on the same plot. Since the EGRET PSF widens to low energies, the effect is maximised there, but is present at all energies at some level. Since the PSF spreads the emission, it reduces the observed intensity averaged over a given latitude range. Correcting for this increases the intensity. You can see the effect explicitly by running galplot with convolve_EGRET=0 in which case the correction is not applied. This is to be contrasted with our longitude and latitude profiles, where we DO convolve the model for direct comparison with the original EGRET data  in this case only one instrument is involved, so it is the better procedure. By the way this procedure is described in detail in our 2004 paper. 
Author:  henning [ Fri Jan 11, 2008 3:26 am ] 
Post subject:  model comparison 
I see. So is there an option in the galplotdef file to convolve the model with the EGRET PSF? In other words, what is the best way to compare two different galprop models to EGRET data in the same plot? Henning 
Author:  strong [ Fri Jan 11, 2008 6:15 am ] 
Post subject:  convolving models 
yes, in the current version there is an option to output the PSF convolved models which is done if fit_EGRET = 2 However it is probably not in the public version  if you want I can make it available. There is no possibility to show more than one galprop model on the same plot at present. 
Author:  henning [ Fri Jan 11, 2008 6:44 am ] 
Post subject:  
From what I gather from the code, there seems to be an option, fit_EGRET=2, which leads to the subroutine convolve_EGRET_HI_H2() being called. If that is not what you mean, I would be grateful if you could make the new version available. By the way, the files counts.vp0001.g006 counts.vp0001.g007 counts.vp0001.g008 which seem to contain the EGRET data above 10 GeV, that you used in your 2004 paper, are not included in my Galplot version and I have been unable to find them on the website. Henning 
Author:  strong [ Fri Jan 11, 2008 7:38 am ] 
Post subject:  convolving models 
yes you are right: if it is already in your version please try it. those nonstandard EGRET energy range (>10 GeV) files are not public, have to check with Olaf Reimer who produced them 
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