------------------------------------------------------------------------
 galpos.tex PRL, Aug 2006, in press
Date: Wed, 16 Aug 2006 17:33:25 -0400
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% astro-ph/0512411

\documentclass[
aps,     %  American Physical Society
prl,                    %  Physical Review Letters
showpacs,               %  Displays PACS after abstract
superscriptaddress,     %  Authors' addresses linked with superscripts
nofootinbib,            %  Does not treat footnotes as references
twocolumn,              %
floatfix,
nobalancelastpage]{revtex4}
\usepackage{graphicx}
\usepackage{epstopdf}
\usepackage{natbib}
\linespread {0.97}

\begin{document}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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\title{\large
Stringent Constraint on Galactic Positron Production
% Making Milky Way Positrons Without Artificial Ingredients
\normalsize}

\author{John F. Beacom}
%\email{beacom@mps.ohio-state.edu}
\affiliation{Department of Physics, The Ohio State University, 
Columbus, Ohio
43210, USA}
\affiliation{Department of Astronomy, The Ohio State University, 
Columbus, Ohio
43210, USA}
\author{Hasan Y{\"u}ksel}
%\email{yuksel@mps.ohio-state.edu}
\affiliation{Department of Physics, The Ohio State University, 
Columbus, Ohio
43210, USA}

\date{15 December 2005; minor revisions, 24 July 2006}

\begin{abstract}
The intense 0.511 MeV gamma-ray line emission from the Galactic Center 
observed by INTEGRAL requires a large annihilation rate of 
nonrelativistic positrons.  If these positrons are injected at even 
mildly relativistic energies, higher-energy gamma rays will also be 
produced.   We calculate the gamma-ray spectrum due to inflight 
annihilation and compare to the observed diffuse Galactic gamma-ray 
data.  Even in a simplified but conservative treatment, we find that 
the positron injection energies must be $\lesssim 3$ MeV, which 
strongly constrains models for Galactic  positron production.
\end{abstract}



-- 
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John Beacom
Assistant Professor
Department of Physics and Department of Astronomy
Ohio State University
email: beacom@mps.ohio-state.edu
phone: (614) 247 - 8102
fax:   (614) 292 - 7557
Dept. of Physics, OSU, 191 W. Woodruff Ave., Columbus, OH 43210
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