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Normalization of positron fraction
https://galprop.stanford.edu/forum/viewtopic.php?f=3&t=192
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Author:  nicoviaux [ Tue Jul 22, 2014 2:39 pm ]
Post subject:  Normalization of positron fraction

Hi everyone,

I am trying to understand why and how is the normalisation for the positron fraction, here I out two papers that made a different normalization of the positron fraction, but which of them is the correct one?, :

1.- http://arxiv.org/abs/1307.6204
2.- http://arxiv.org/abs/0906.1571v3,

in the case of 1.- \kappa multiply the positron flux and then the sum of both (in the denominator), how the same \kappa can normalizate different things? and when you eliminate the DM signal, \kappa cancel, so no normalisation in that case?? very strange for me.

for 2. the authors multiply \kappa with electron flux, but I don't understand why, positron fraction is normalised? , or I need to normalise both with different coefficient?

Thanks in advance..

Nicolás

Author:  strong [ Tue Jul 22, 2014 10:45 pm ]
Post subject:  Re: Normalization of positron fraction

In 1, eq(22) indeed the same factor seems to be used for both primary electrons and secondary leptons, which seems strange since each has its independent uncertainty.
In 2, their equation (9), they are evidently assuming that only primary electrons are uncertain. The are ignoring apparently the uncertainty on secondary leptons.

In any case these are issues to ask the authors of those papers, they are not really GALPROP-specific questions. GALPROP is just used to compute the standard components, how they are used is another matter. It depends on the particular application and assumptions.

Author:  nicoviaux [ Wed Jul 23, 2014 4:55 am ]
Post subject:  Re: Normalization of positron fraction

Ok, thanks a lot.

Now, if I only use GALPROP and not a parametrisation of GALPROP for the positron fraction, I need to tramline the the positron fraction obtained from GALPROP?

Best

Nicolás

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