The effect of the Galactic gas distribution on the expected Cosmic Rays spectrum
Mercedes Moll\'{a}
Manuel Aguilar
Juan Alcaraz
Javier Berdugo
Jorge Casaus
Carlos D\'{\i}az
Elisa Lanciotti
Carlos Ma\~{n}\'{a}
Jes\'{u}s Mar\'{\i}n
Gustavo Mart\'{\i}nez
Carmen Palomares
Eusebio S\'{a}nchez
Ignacio Sevilla
Ana Sof\'{\i}a Torrent\'{o}
molla.tex
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% This is a sample input file for your contribution to a
% multi-author book ("proceedings-like) to be published
% by Springer Verlag.
%
% Please use it as a template for your own input, and please
% follow the instructions for the formal editing of your
% manuscript as described in the file "1readme".
%
% Please send the Tex and figure files of your manuscript
% together with any additional style files as well as the
% PS file to the editor of your book.
%
% He or she will collect all contributions for the planned
% book, possibly compile them all in one go and pass the
% complete set of manuscripts on to Springer.
%
% Vers. 07/99
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%



%RECOMMENDED%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\documentclass[runningheads]{svmult}

\usepackage{makeidx}   % allows index generation
\usepackage{graphicx}  % standard LaTeX graphics                 % for including eps-figure files
%\usepackage{subeqnar}  % subnumbers individual equations
                       % within an array
\usepackage{multicol}  % used for the two-column index
%\usepackage{cropmark}  % cropmarks for pages without
                       % pagenumbers - only needed when manuscript
                       % is printed from paper and not from data
\usepackage{physprbb}  % modified textarea for proceedings,
                       % lecture notes, and the like.
\makeindex             % used for the subject index
                       % please use the style sprmidx.sty with
                       % your makeindex program

%%upright Greek letters (example below: upright "mu")
\newcommand{\greeksym}[1]{{\usefont{U}{psy}{m}{n}#1}}
\newcommand{\umu}{\mbox{\greeksym{m}}}
\newcommand{\udelta}{\mbox{\greeksym{d}}}
\newcommand{\uDelta}{\mbox{\greeksym{D}}}
\newcommand{\uPi}{\mbox{\greeksym{P}}}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%


%OPTIONAL%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%\usepackage{amstex}   % useful for coding complex math
%\mathindent\parindent % needed in case "Amstex" is used
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%AUTHOR_STYLES_AND_DEFINITIONS%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%Please reduce your own definitions and macros to an absolute
%minimum since otherwise the editor will find it rather
%strenuous to compile all individual contributions to a
%single book file
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\begin{document}
%
\title*{ The effect of the Galactic gas distribution on the expected
Cosmic Rays spectrum}
%
%
\toctitle{The effect of the Galactic gas distribution
\protect\newline on the expected Cosmic Rays spectrum}
% allows explicit linebreak for the table of content
%
%
\titlerunning{The effect of the gas distribution on the CR spectrum}
% allows abbreviation of title, if the full title is too long
% to fit in the running head
%
\author{Mercedes Moll\'{a}
\and Manuel Aguilar
\and Juan Alcaraz
\and Javier Berdugo
\and Jorge Casaus
\and Carlos D\'{\i}az
\and Elisa Lanciotti
\and Carlos Ma\~{n}\'{a}
\and Jes\'{u}s Mar\'{\i}n
\and Gustavo Mart\'{\i}nez
\and Carmen Palomares
\and Eusebio S\'{a}nchez
\and Ignacio Sevilla
\and Ana Sof\'{\i}a Torrent\'{o}}
%
\authorrunning{Moll\'{a} et al.}
% if there are more than two authors,
% please abbreviate author list for running head
%
%
\institute{CIEMAT, Avda. Complutense 22, 28040 Madrid (Spain)}

\maketitle              % typesets the title of the contribution


\section{Introduction}

\begin{figure}[b]
\begin{center}
\includegraphics[width=0.4\textwidth,angle=-90]{mollaf1.eps}
\end{center}
\caption[]{The radial distribution of the diffuse gas atomic density
as obtained from \cite{joun6} compared
with other author's distributions as labeled in the figure}
\label{gas}
\end{figure}

Cosmic ray (CR) nuclei are accelerated particles which move randomly
through the interstellar medium (ISM), where they suffer scattering,
reacceleration and energy loss processes before reaching
Earth. Spallation processes also take place forming secondary nuclei
by fragmentation of heavier ones. Due to the impossibility of
observing directly their original direction, the determination of
possible sources where these particles originated requires the use of
codes to simulate the propagation of CR within the Galaxy. This
consists of a spiral disk with a thickness of 2h $\sim$ 200 pc, where
CR are created, and a halo with a height H, where they diffuse.

From the existing data, mostly $\rm ^{10}Be/^{9}Be$ and $\rm B/C$, it
is deduced that CR go through a mean density of $\sim 0.3$ cm$^{-3}$
(\cite{joun4,joun5}).  Since the total density of
the ISM is considered as 1 $\rm cm^{-3}$, ($\rm <n_{HI}> \sim 0.5 \,
cm^{-3}$; \cite{joun1,joun2,joun7,joun10}), 
a large effective halo and/or a local
bubble or cavity of low density are required. This result is very
dependent on the actual disk ISM density, largely uncertain. 
\cite{joun6} have very recently obtained a new map of the diffuse
gas distribution (Fig.~\ref{gas}), from which $\rm <n_{HI}> \sim 0.2
\, cm^{-3}$, a factor of 2 lower than previous estimates.


\section{Computed Models and Results} 

\begin{figure}[b]
\centerline{%
\begin{tabular}{c@{\hspace{2pc}}c}
\includegraphics[width=0.4\textwidth,angle=0]{mollaf2a.eps} &
\includegraphics[width=0.4\textwidth,angle=0]{mollaf2b.eps}\\
\end{tabular}}
\caption[]{The spectra of a) $\rm ^{10}Be/^{9}Be$, and b) of $\rm
B/C$.  Models are represented by lines as labeled}
\label{bebc}
\end{figure}
We now use the GALPROP code, developed by \cite{joun8,proc1}, 
to compute how CR propagates.  The model includes a
realistic diffuse gas radial distribution (\cite{joun3}).
A halo height $H=1-5$ kpc is obtained, depending of the model.  
Results for $\rm ^{10}Be/^{9}Be$ and $\rm B/C$ are shown with 
dashed lines in Fig.~\ref{bebc} a) and b), respectively, for 
a diffusion model with $H=1$ kpc.

We now change the old HI distribution with the new one.  The dotted
lines in Fig.2 represent the same model using this new distribution.
It is evident that it is not yet valid.  The solid lines correspond to
a new good enough model, with a halo height $\rm H=0.5$ kpc. This
implies that CR diffuse mostly in the disk closer to the sources than
it was deduced before.  This result agrees with \cite{joun9}
who obtain distances as short as 500 pc between the source and the
Sun, from the ACE radionuclide measurements.

\begin{thebibliography}{8.}
\addcontentsline{toc}{section}{References}

\bibitem{joun1}Dickey, J. M. \& Lockman, F.J. 1990, A.R.A.A.,
\textbf{28}, 215
\bibitem{joun2}Ferri\'{e}rre, K. 1998, ApJ., \textbf{497}, 759
\bibitem{joun3}Gordon, M.A.  \& Burton, W.B. 1976, ApJ., \textbf{208},
346
\bibitem{joun4} Jones, F.~C., Lukasiak, A., Ptuskin, V., \& Webber, W.
\ 2001, ApJ, \textbf{547}, 264
\bibitem{joun5}Maurin, D., Donato, F., Taillet, R. \& Salati, P. 2001,
ApJ., \textbf{555}, 585
\bibitem{joun6}Nakanishi, H. \& Sofue, Y.  2004, PASJ, \textbf{55},
191
\bibitem{joun7}Olling, R.~P.~\& Merrifield, M.~R.\ 2001, MNRAS, 
\textbf{326}, 164
\bibitem{joun8}Strong \& Moskalenko 1998, ApJ, \textbf{509}, 212
\bibitem{proc1}Strong \& Moskalenko 2003, 28 IRC Conf., 1921
\bibitem{joun9}Yanasak, N.E., Wiedenbeck, M. E., Mewaldt, R.A. et
al. 2001, ApJ., \textbf{563}, 768 
\bibitem{joun10}Wolfire, M.~G., McKee, C.~F., Hollenbach, D., et al.\
2003, ApJ, \textbf{587}, 27

\end{thebibliography}


%INDEX%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Please check with the editor of your book whether he plans to
% include a "mutual" subject index - if so, please code your entries
% in the standard syntax. For your own purposes you may print your
% "personal" index by using the following commands:
%
%\clearpage
%\addcontentsline{toc}{section}{Index}
%\flushbottom
%\printindex
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\end{document}


astro-ph0411692.extracted_bib
\begin{thebibliography}{8.}
\addcontentsline{toc}{section}{References}

\bibitem{joun1}Dickey, J. M. \& Lockman, F.J. 1990, A.R.A.A.,
\textbf{28}, 215
\bibitem{joun2}Ferri\'{e}rre, K. 1998, ApJ., \textbf{497}, 759
\bibitem{joun3}Gordon, M.A.  \& Burton, W.B. 1976, ApJ., \textbf{208},
346
\bibitem{joun4} Jones, F.~C., Lukasiak, A., Ptuskin, V., \& Webber, W.
\ 2001, ApJ, \textbf{547}, 264
\bibitem{joun5}Maurin, D., Donato, F., Taillet, R. \& Salati, P. 2001,
ApJ., \textbf{555}, 585
\bibitem{joun6}Nakanishi, H. \& Sofue, Y.  2004, PASJ, \textbf{55},
191
\bibitem{joun7}Olling, R.~P.~\& Merrifield, M.~R.\ 2001, MNRAS, 
\textbf{326}, 164
\bibitem{joun8}Strong \& Moskalenko 1998, ApJ, \textbf{509}, 212
\bibitem{proc1}Strong \& Moskalenko 2003, 28 IRC Conf., 1921
\bibitem{joun9}Yanasak, N.E., Wiedenbeck, M. E., Mewaldt, R.A. et
al. 2001, ApJ., \textbf{563}, 768 
\bibitem{joun10}Wolfire, M.~G., McKee, C.~F., Hollenbach, D., et al.\
2003, ApJ, \textbf{587}, 27

\end{thebibliography}