------------------------------------------------------------------------
 compex.tex ApJ, Jan 2008, in press
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%astro-ph/0709.0542
\documentclass{article}

\begin{document}

%% LaTeX will automatically break titles if they run longer than
%% one line. However, you may use \\ to force a line break if
%% you desire.

\title{The Galactic center, the largest oxigen bearing organic molecule 
repository}

\author{Requena-Torres, M.A.\altaffilmark{1}\email{requena@damir.iem.csic.es}, 
Mart\'in-Pintado, J.\altaffilmark{1}\email{martin@damir.iem.csic.es},\\
Mart\'in, S.,\altaffilmark{2}\email{martin@astro.cfa.edu} \& Morris, M. R.
\altaffilmark{3}\email{morris@astro.ucla.edu}}

Instituto de Estructura de la Materia-CSIC, C\ Serrano 121, E-28006 Madrid, 
Spain}
\altaffiltext{2}{Harvard-Smithsonian Center for Astrophysics, 60 Garden 
Street, MS 78 Cambridge, MA 02138, USA}
\altaffiltext{3}{Department of Physics \& Astronomy, University of California, 
Los Angeles, CA 90095-1547, USA}


\begin{abstract}
We present the first detection of complex aldehydes and isomers in three
typical molecular clouds located within 200$\,$pc of the center of our Galaxy.
 We
find very large abundances of these complex organic molecules (COMs) in the
central molecular zone (CMZ), which we attribute to the ejection of COMs from 
grain mantles
by shocks. The relative abundances of the different COMs with respect to that
of CH$_3$OH are strikingly similar for the three sources, located in very 
different
environments in the CMZ. The similar relative abundances point toward a unique
grain mantle composition in the CMZ. Studying the Galactic center clouds and
objects in the Galactic disk having large abundances of COMs, we find that
more saturated molecules are more abundant than the non-saturated ones. We 
also
find differences between the relative abundance between COMs in the CMZ and
the Galactic disk, suggesting different chemical histories of the grain 
mantles between the two regions in the Galaxy for the complex aldehydes. 
Different possibilities for the
grain chemistry on the icy mantles in the GC clouds are briefly discussed. 
Cosmic rays can play an important role in the grain chemistry. With these new
detections, the molecular clouds in the Galactic center appear to be one of 
the
best laboratories for studying the formation of COMs in the Galaxy.
\end{abstract}

\keywords{astrochemistry --- molecular data --- ISM: molecules --- 
techniques:spectroscopic --- ISM:individual(CMZ)}

\end{document}

************************************************
Miguel Angel Requena Torres
Dpto. Astrofisica Molecular e Infrarroja
 Instituto de Estructura de la Materia(CSIC)
C\ Serrano 121
 28006, Madrid (SPAIN)
 Tel: (0034) 91 561 68 00 - Temp extension 2416
 Fax: (0034) 91 564 55 57
 http://www.damir.iem.csic.es/~requena/
************************************************