% modifications to the standard LaTeX styles
\textheight 650pt
\textwidth 460pt
\oddsidemargin 0pt
\evensidemargin 0pt
\marginparwidth 50pt
\topmargin 0pt
\brokenpenalty=10000
\sloppy
\newcommand{\entete}
  {\includegraphics[2.7cm,24.85cm][2.8cm,24.9cm]{letterhead.ps} 
  \hspace{5mm} \textsf{\scriptsize \jour  } }
\newcommand {\msun}{\mbox{M$_\odot$}}
\newcommand {\sun}{\odot}
\newcommand {\kms}{\mbox{km~s$^{-1}$}}
\newcommand {\micron}{\mbox{$\mu$m}}
\newcommand{\twelveco}{\mbox{$^{12}$CO}} 
\newcommand{\thirteenco}{\mbox{$^{13}$CO}}
\newcommand{\htwo}{\mbox{H$_2$}}
\newcommand{\htwoo}{\mbox{H$_2$O}}
\newcommand{\htwos}{\mbox{H$_2$S}}
\newcommand{\hcoplus}{\mbox{HCO$^+$}}
\newcommand{\sotwo}{\mbox{SO$_2$}}
\newcommand{\etal}{{\it et~al.\/}}
\newcommand{\AaA}[2] {{\it Astron. Astrophys.} {#1}, #2}
\newcommand{\ApJ}[2] {{\it Astrophys. J.} {#1}, #2}
\pagestyle{myheadings}
\markboth{ \hfil \protect\@date}
{\protect\@date \hfil }
\def\jour{\number\day\space\ifcase\month\or
  janvier\or f\'evrier\or mars\or avril\or mai\or juin\or
  juillet\or ao\^ut\or septembre\or octobre\or novembre\or d\'ecembre\fi
  \space\number\year}
%
% Table of contents : redefine box size for numbers (default is too small)
\def\l@subsection{\@dottedtocline{2}{1.5em}{4.3em}}
\def\l@subsubsection{\@dottedtocline{3}{3.8em}{6.2em}}
\def\l@paragraph{\@dottedtocline{4}{7.0em}{8.1em}}
\def\l@subparagraph{\@dottedtocline{5}{10em}{10em}}
%
% references environment
% \list parameters have been adjusted in the `thebibliography'
% environment to the match A&A layout of References.
\def\thebibliography#1{\section*{References\markboth
 {REFERENCES}{REFERENCES}}\list
% The \arabic{enumi} command has been removed because we don't use
% numbered citations in astronomical journals.
 {}{\setlength\labelwidth{1.4em}\leftmargin\labelwidth
 \setlength\parsep{0pt}\setlength\itemsep{0pt}
 \setlength{\itemindent}{-\leftmargin}
 \usecounter{enumi}}
 \def\newblock{\hskip .11em plus .33em minus -.07em}
 \sloppy
 \sfcode`\.=1000\relax}
\let\endthebibliography=\endlist
%
%\newenvironment{captions}
\def \captions    {\newcounter{fign}\section*{Figure Captions}
	\begin{list}{\bf Fig. \Arabic{fign}.}
	{\usecounter{fign}\setlength{\leftmargin}{0mm}
	\setlength{\itemindent}{0mm}}
	\small}
\def \endcaptions    {\end{list}\normalsize}
%
% Redefine \@cite so no square brackets are output.
% Redefine \@biblabel so the label is not output in the bibliography.
\def\@cite#1#2{{#1\if@tempswa , #2\fi}}
\def\@biblabel#1{}
\def\@listI{\leftmargin\leftmargini 
 \parsep 4pt plus 2pt minus 1pt
 \topsep \parsep \itemsep \z@}
\let\@listi\@listI
\@listi 
\def\@listii{\leftmargin\leftmarginii
 \labelwidth\leftmarginii\advance\labelwidth-\labelsep
 \parsep \z@ \topsep \z@}
\def\@listiii{\leftmargin\leftmarginiii
 \labelwidth\leftmarginiii\advance\labelwidth-\labelsep }
\def\@listiv{\leftmargin\leftmarginiv
 \labelwidth\leftmarginiv\advance\labelwidth-\labelsep}
\def\@listv{\leftmargin\leftmarginv
 \labelwidth\leftmarginv\advance\labelwidth-\labelsep}
\def\@listvi{\leftmargin\leftmarginvi
 \labelwidth\leftmarginvi\advance\labelwidth-\labelsep}
\def\labelitemi{\bf --}
\def\labelitemii{$\cdot$}
\def\labelitemiii{$\circ$}
\def\shortlist{\ifnum \@itemdepth >3 \@toodeep\else \advance\@itemdepth \@ne
\edef\@itemitem{labelitem\romannumeral\the\@itemdepth}%
\list{--}{\parsep\z@ \topsep\z@}\fi}
\let\endshortlist=\endlist