%                                                              aadoc.tex
% AA vers. 4.01, LaTeX class for Astronomy & Astrophysics
% documentation
%                                                 (c) Springer-Verlag HD
%-----------------------------------------------------------------------
%
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\makeatletter

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  \vspace*{-1em}%
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\setcounter{tocdepth}{2}

\begin{document}

\title{Astronomy \& Astrophysics\\Document Class V4.01}
\date{Springer Verlag}

\maketitle

\tableofcontents

\section{Getting started}

As the articles for the A\&A will be available online in different
formats -- one of these is full-text-searchable hyper-text -- we
strongly suggest you strictly obey the \LaTeX\ conventions. This will
ease the processing of your article and avoids any problems with formats
other than PostScript.

{\hfuzz=2.1pt
Please always give a \verb|\label| where possible and use \verb|\ref|
for cross-referencing. Such cross-references will be converted to
hyper-links in HTML. The \verb|\cite|- and
\verb|\bibitem|-mechanism for
bibliographic references or the use of \BibTeX\ (see
Sect.~\ref{sec:bibtex}) as well as the \verb|\object| command (see
Sect.~\ref{sec:astobjects}) is also obligatory.\par}

Please refrain from using any self-made definitions since these will get
lost during further conversion of your text. If you use typing
abbreviations, ``search and replace'' them before submitting your
article to the publisher.

\subsection{\TeX nical background information}

This document class was derived from the \LaTeXe\ \texttt{article.cls}
based on \TeX\ version 3.141 and \LaTeXe. Hence formulas and text are
typed using the standard \LaTeXe\ commands. The standard sectioning
commands are also kept. Using \texttt{aa.cls} with other versions or
implementations may cause difficulties. If this is the case, please
contact us and we will try to help you.

\section{The document structure}

\subsection{Loading the class}

To load the document class, you have to include
\begin{decl}
\verb|\documentclass{aa}|
\end{decl}
\noindent
at the beginning of your article. This replaces the former
\verb|\documentstyle| command. There is a class option \texttt{referee},
which you should set to produce the two hardcopies for the referees with
a special layout (it also provides for a list of astronomical objects --
see Sect.~\ref{sec:astobjects} below):
\begin{decl}
\verb|\documentclass[referee]{aa}|
\end{decl}


\subsection{Using PostScript fonts}

The journal to which you are planning to submit your paper is
phototypeset using the PostScript\footnote{PostScript is a trademark of
Adobe.} (PS) Times fonts. As the use of PostScript fonts results in a
slightly different page make-up from Computer Modern (CM) fonts, we
encourage you to use our document class together with the
\texttt{psnfss} package \texttt{times}. This will show you the page
make-up parallel-to-print. Ask your local \TeX pert for details.
PostScript previewing is possible on most systems. On some
installations, however, on-screen previewing may be possible only with
CM fonts.

\goodbreak
\noindent
To use PS fonts, the following CM fonts have to be replaced:

\medskip
\noindent
\begin{tabular}{ll}
\hline
CM font & corresponding PS font\\
\hline
cmr    &  Times roman\\
cmbx   &  Times bold\\
cmti   &  Times italic\\
cmtt   &  Courier\\
cmbxti &  Times bold italic\\
cmss   &  Helvetica\\
\hline
\end{tabular}

\medskip

If, for technical reasons, you are not able to use the PS fonts, it is
also possible to use our document class together with the ordinary CM
fonts. Note, however, that in this case line and page breaks will change
when we re\TeX\ your file with PS fonts, making it necessary for you to
check them again once you receive the proofs from the printer. The
additional time required for these procedures plus the additional costs
involved mean that (preferably) files \TeX ed with PS fonts should be
submitted.

\subsection{Section numbers and thesaurus codes}\label{thescode}

When your article is published, the title and author(s) will be printed
in the table of contents under the appropriate section heading (e.g.\
``Cosmology'', ``Extragalactic astronomy'', etc.). In the annual index
your article will appear under between one and six (maximum) different
subject headings (or key words). For computer storage and sorting, it is
necessary that the \emph{section number} and \emph{thesaurus code
numbers} are typeset above the title in the page proofs. This is done
with the command
\begin{decl}
\verb|\thesaurus{<section number>(<thesaurus code>; ... <thesaurus code>)}|
\end{decl}

\noindent
The list of possible thesaurus codes and their corresponding keywords is
included in the file \texttt{aa.the} together with the list of the
twelve sections. The code numbers correspond to the subject headings (or
key words) used in the annual indexes.

\smallskip

\noindent
\textbf{Example:}
An article on ``Formation of primordial molecules" belongs to Sect.~2
(``Cosmology'') and will be listed in the annual index under the key
words ``Molecular processes'' (02.13.5) and ``Cosmology: theory''
(12.03.4). The complete coding, printed automatically in boldface at the
top of the first page, should be as follows (note that the codes within
the parentheses are separated by semicolons):
\begin{verbatim}
\thesaurus{02(02.13.5; 12.03.4)}
\end{verbatim}

\subsection{The title}

Code the title of your article as follows:
\begin{decl}
\verb|\title{<your title>}|\\
\verb|\subtitle{<your subtitle>}|
\end{decl}
\noindent
The main title and the subtitle should not be capitalized, except for
the first letter and any other words that are always capitalized.
Maths variables and symbols should be typeset as in the text.

If a long \verb|\title| or \verb|\subtitle| needs to split accross two
or more lines, please insert linebreaks (\verb|\\|).

\subsection{Names of authors}

The preferred form for each name is: initial(s) of the forename(s)
followed by the family name.
\begin{decl}
\verb|\author{<first author's name>|\\
\verb|  \and <second author's name> ...}|
\end{decl}
\noindent
If there is more than one author, the order is optional.
The names should be separated by \verb|\and|.

If the authors have different affiliations, each name has to be
followed by
\begin{decl}
\verb|\inst{<number>}|
\end{decl}
\noindent
Numbers referring to different addresses should be attached to each
author, pointing to the corresponding institute.

\subsection{Addresses}

If there is more than one address, the entries are numbered
automatically with \verb|\and|, in the order in which you type them.
Please make sure that the numbers match those placed next to the
authors' names.
\begin{decl}
\verb|\institute{<name of the first institute>|\\
\verb|\and <name of the second institute> ...}|
\end{decl}

\subsection{Footnotes to the title block}

If footnotes to the title, subtitle, author's names or institute
addresses are need\-ed, please code them with
\begin{decl}
\verb|\thanks{<text of footnote>}|
\end{decl}
\noindent
immediately after the word where the footnote indicator should be
placed. These footnotes are marked by asterisks ($\ast$). If you need
more than one consecutive footnote, use \verb|\fnmsep| to typeset the
comma separating the asterisks (see demo file).

If there is more than one author, please provide an address for offprint
requests:
\begin{decl}
\verb|\offprints{<name>}|\\
\verb|\mail{<corresponding author>}|
\end{decl}

\noindent
Stating the present address of an author is done with
\begin{decl}
\verb|\thanks{\emph{Present address:}<address>}|
\end{decl}

\subsection{Dates of receipt and acceptance}

Although the dates of receipt and acceptance of your
manuscript will be fixed by the editors and inserted
by the publisher, please type:
\begin{decl}
\verb|\date{Received <date> / Accepted <date>}|
\end{decl}
\noindent
The date is inserted later in the format \texttt{day month year}.
An example will
be given in Sect.~\ref{sec:example} on page \pageref{sec:example}.

\subsection{Typesetting the header}

Having entered the commands described in this section,
please format the complete heading of your article by typing:
\begin{decl}
\verb|\maketitle|
\end{decl}
\noindent
If you leave it out, the work done so far will produce \emph{no} text.
You will find a complete example of the beginning of an article in
Sect.~\ref{sec:example}.

\subsection{Changing the running head}

The command \verb|\maketitle| will automatically generate the running
title, deriving it from the author and title inputs. If the title is too
long for the space available, \LaTeX\ will ask you to supply a shorter
version. In this case enter
\begin{decl}
\verb|\titlerunning{<short title>}|\\
\verb|\authorrunning{<name(s) of author(s)>}|
\end{decl}
\noindent
before \verb|\maketitle|. If there are two authors, both names,
separated by an ampersand (\verb|&|, coded as \verb|\&|), should be
given; if there are more than two authors, the name of the first plus
``et al.'' should be given. The title should be shortened to a maximum
of about 60 characters, spaces ignored, following the wording of the
original title as closely as possible. If a paper has a numbered
subtitle, the main title (length permitting) should be given, followed
by the roman numeral of the subtitle. The Editors reserve the right to
modify the running head suggested by the authors, should this be
necessary.

The following illustrates the required style (the colon will be inserted
by the macro):

\medskip
\noindent
\small
N. Copernicus: How active is NGC 4258?\\
E. Hertzsprung \& E.P. Hubble: Optical spectroscopy of WR stars in M33
and M31.~II\\
A.S. Eddington et al.: Infrared lines as probes of solar magnetic
features.~IV\\
C. Barbieri et al.: (RN) First HST/FOC images of the low mass companion
of the astronomic binary Gliese~623
\normalsize


\subsection{Abstract and keywords}

Proceed as follows:
\begin{decl}
\verb|\begin{abstract}|\\
\verb|<text of your abstract (summary)>|\\
\verb|\keywords{<keyword -- keyword -- keyword ...>}|\\
\verb|\end{abstract}|
\end{decl}

\noindent
For the sake of simplicity and uniformity, authors should choose not
more than six key words which are identical to those already chosen as
the thesaurus codes (see Sect.~\ref{thescode}). The heading ``Key
words'' appears automatically. The individual key words should be
separated by an en-dash (\verb|--|) with one blank before and after.

\subsection{An example of the beginning of an article}
\label{sec:example}

\begin{verbatim}
\documentclass{aa}

\begin{document}

\thesaurus{08(09.10.1; 09.13.2; 08.16.5)}

\title{Optimality relationships for $p$-cyclic SOR
  \thanks{Research supported in part by the US Air Force
    under grant no.\ AFOSR-88-0285 and
    the National Science Foundation under grant
    no.\ DMS-85-21154}\fnmsep
  \thanks{This is a second footnote}\\
  resulting in asymptotically faster convergence\\
  for the same amount of work per iteration}

\subtitle{II. An example text with infinitesimal
  scientific value\\
  whose title and subtitle may also be split}

\author{Daniel J.\,Pierce\inst{1},
  \and Apostolos Hadjidimios\inst{2}
  \thanks{\emph{Present address:}
    Department of Computer Science, Purdue University,
    West Lafayette, IN 47907, USA}
    \and Robert J.\,Plemmons\inst{3}}

\offprints{R. Plemmons}

\institute{Boeing Computer Service, P.O. Box 24346,
  MS 7L-21, Seattle, WA 98124-0346, USA
  \and Department of Mathematics, University of Ioannina,
  GR-45 1210, Ioannina, Greece
  \and Department of Computer Science and Mathematics,
  North Carolina State University, Raleigh, NC 27695-8205, USA}

\date{Received 2 November 1992 / Accepted 7 January 1993}

\maketitle

\begin{abstract}
The optimality question for block $p$-cyclic matrix
into a block $q$-cyclic form, $q < p$, results in
asymptotically faster SOR convergence for the same amount
of work per iteration. As a consequence block 2-cyclic SOR
is optimal under these conditions.
%
\keywords{interstellar medium: jets and outflows --
  interstellar medium: molecules -- stars: pre-main-sequence}
\end{abstract}
\end{verbatim}

\subsection{Acknowledgements}

For acknowledgements use the environment:
\begin{decl}
\verb|\begin{acknowlegements}|\\
\verb|\end{acknowledgements}|
\end{decl}

\subsection{Appendices}

If you enter the command
\begin{decl}
\verb|\appendix|
\end{decl}
\noindent
the sections that follow will be numbered with capital letters.

\section{Floating objects}

\subsection{Figures}\label{sec:figures}\label{sec:fig}

It is desirable for graphics inclusions to conform to certain codes of
behaviour, so that the graphics can be manipulated readily and reliably.
For that purpose graphics should be included as a PostScript file.

When a PostScript file contains a simple one-page description for the
purpose of inclusion in other documents, it is necessary that it
conformes to the encapsulated PostScript file format (EPSF). One of the
advantages of this format is that the application that includes the
file can determine the size and location of the graphic on the page
\emph{without} having to interpret any PostScript code. It is, however,
necessary to read in a portion of the data (the header of the PostScript
file) to find this information.%
\footnote{View your \texttt{.eps} file with a text editor. It is
necessary to have proper line endings in the header of the file to have
the commands recognizable for \TeX\ or \texttt{dvips}. The different end
of line representations cause problems e.g.\ when creating the
\texttt{.eps} files on a Macintosh but \TeX ing your manuscript on a
UNIX or PC operating system.}

Most graphic packages and astronomical application software support the
EPSF format. If yours does not, convert the file from another format;
for information on available software, consult your local system
administrator. Keep in mind that conversions usually reduce the quality
of the graphics and may increase the document length.

The easiest way to include your \verb".eps" files is with the
\verb"graphics" package, which comes along with the standard \LaTeXe\
distribution. Include the package in the preamble of your document:
\begin{decl}
\verb|\usepackage{graphics}|
\end{decl}

To fill the whole column width, the figure has to be resized.
Therefore, the syntax to include a one-column-spanning graphic is

\begin{decl}
\verb|\begin{figure}|\\
\verb|  \resizebox{\hsize}{!}{\includegraphics{<yourfilename.eps>}}|\\
\verb|  \caption{<Your caption text...>}|\\
\verb|  \label{<Your label>}|\\
\verb|\end{figure}|
\end{decl}

\noindent
For a two-column-wide plot, substitute \verb"figure" by \verb"figure*".

A\&A also uses a third width, 12\,cm; that is, with the figure
caption at its lower right-hand side. To achieve this format, use

\begin{decl}
\verb|\begin{figure*}|\\
\verb|  \resizebox{12cm}{!}{\includegraphics{<yourfilename.eps>}}|\\
\verb|  \hfill|\\
\verb|  \parbox[b]{55mm}{|\\
\verb|    \caption{<Your caption text...>}|\\
\verb|    \label{<Your label>}}|\\
\verb|\end{figure*}|
\end{decl}

Note the use of the \verb|\label| command. All cross-referencing to the
figures should then be written as ``\dots
\verb|see Fig.~\ref{<Your label>}|''.

The A\&A macro sets all figures and tables at the top of the columns and
flush left according to layout conventions. The content and style of
your figure (line art, grey-scale etc., size of text labels and other
marks) mean that widths less than the ones given here would be more
suitable for the page layout. Please see printed editions of the A\&A
for examples. We reserve the right to change the size pre-set by you if
layout restrictions apply.

If you have colour images to be printed, please request additional
instructions by email to \verb"astro@springer.de". Otherwise, digital
colour images will appear as grey-scale images in the printed edition,
and as colour images only in the electronic edition (bear in mind
download times!).

To name your files, please use the DOS 8:3 convention to ensure
platform-independent usability. You may preferably include the
manuscript number in the file name.

\textbf{Note:} Some software packages leave a considerable margin around
the \verb".eps" figures. You may have to tune the \texttt{BoundingBox}
by hand. It can be made visible using the \verb"bb.ps" PostScript
program, which you will find on almost any FTP server.

Also, if you use the predecessors of the \texttt{graphics} bundle
(\texttt{psfig}, \texttt{epsf}) you may get difficulties in aligning the
edges of the figures with the top and the left column margins. You can
find a workaround in the demo file.

If you are not able to submit your figures (or tables) as
\verb".eps" files, make sure your submitted hard copies are of
excellent camera-ready quality and advise \LaTeX\ to reserve enough
space for your external input by using

\begin{decl}
\verb|\vspace{<preferred input-height>}|
\end{decl}

\noindent
instead of the \verb"\includegraphics" command or \verb"tabular"
environment.

\subsection{Tables}

Table columns should be set flush left. Vertical lines are normally not
necessary and should be inserted only in exceptional cases for the sake
of clarity.

For further information you will find a complete description of the
table and tabular environment in {\em \LaTeX{} User's Guide \& Reference
Manual\/} (2nd ed.), by Leslie Lamport.

The height of each table including the caption must not exceed 23.5~cm.

\subsubsection{Tables not coded with \LaTeX{}}

If you do not code your tables with \LaTeX\ but prefer to have them
reproduc\-ed separately, send them as \verb|.eps| files and proceed as
described for figures in Section~\ref{sec:figures}, but without the
\verb|\resizebox| command.

\sampleinput

\begin{verbatim}
\begin{table}
  \caption[ ]{... text of caption ...}
  \vspace{<height> cm}
\end{table}
\end{verbatim}

\noindent
The caption should always be placed above the table.

\section{References}\label{refer}\label{sec:bib}

For overall information on the reference environment see the
\emph{\LaTeX\ User's Guide \& Reference Manual}.

Journal names should be abbreviated if possible in the simplified form
or using standard abbreviations (see Appendix~\ref{app:abbr} on
p.~\pageref{app:abbr}).

\subsection{The use of \BibTeX}\label{sec:bibtex}

The use of \BibTeX{} is wide spread. Many authors have accumulated large
databases for their bibliographic references. For the A\&A we suggest
the \verb|astron.bst| \BibTeX{} style. It was developed by Sake
J.~Hogeveen from 1990 onwards. Using it you will generate your
references
in the exact A\&A format automatically via \BibTeX{} from your
bibliographic database.

You will find the \verb|astron| package on our server as well as on the
well-known sources for \TeX{} and its friends. It comes with complete
documentation (\verb|astdoc.tex|) as well as a demo file for \LaTeX{}
and an example database (\verb|example.tex|, \verb|example.bib|).

This documentation is not intended as an introduction to \BibTeX, nor to
\LaTeX. You are assumed to be familiar with both and the combination of
them. If you are not, \BibTeX\ is documented by its author, Oren
Patashnik. The manual comes with each distribution of \BibTeX. It
explains how \BibTeX\ should be used, and how style files can be created
or adapted.

If you only want to use the \verb|astron| bibliography style, the
information in {\em A \BibTeX{} Style for Astronomical Journals}
(\verb|astdoc.tex|) and the \LaTeX\ {\em User's Guide and Reference
Manual\/} is sufficient.

For the online hyper-text versions of A\&A articles the \verb|astron|
style will automatically generate a uniform 19-digit code to provide a
unique and traceable representation of a bibliographic reference
following the SIMBAD and NED convention for bibliographic reference
coding (Bibcode). It will be used to check the existence of an abstract
and to enable linking to the astrophysics data system abstract servers.

After downloading and installing the \verb|astron| package you can make
use of your bibliographic database, leaving the selection and formatting
of the references up to \BibTeX{} and \LaTeX. For that just add the line
\begin{decl}
\verb|\usepackage{astron}|
\end{decl}
\noindent
to your preamble and the following code where the reference section is
to appear:
\begin{decl}
\verb|\bibliographystyle{astron}|\\
\verb|\bibliography{mnemonic,example}|
\end{decl}

\subsection{References made without \BibTeX}

If you cannot use \BibTeX{} see the \emph{\LaTeX{} User's Guide \&
Reference Manual}, for general information on the reference environment.

Journal names should still be abbreviated to the standard abbreviations
(see Appendix~\ref{app:abbr}).

\subsection{Citations in the text}

References are normally cited in the text by placing the name(s) and the
year, without any comma between them, in parentheses. If there are two
authors for one citation, both names should be given, separated by an
ampersand (\&). If there are more than two authors, only the first name
should be given, followed by ``et al.''. Commas should be used only to
separate two or more years linked with one author (author group). If two
or more citations are made in one set of parentheses, they should be
separated by a semi-colon. If more than one citation for a particular
author (author group) is made for the same year, ``a'', ``b'', ``c'',
etc. should be added to the year. If citations are made within the
normal running text, only the year(s) should be placed in parentheses.
The following examples illustrate the required style:

\smallskip

\begin{quotation}
\noindent
(Copernicus 1986), (Copernicus \& Galilei 1988)\\
(Hubble et al. 1985; Newton et al. 1987; Ptolemaus \& Copernicus 1988a,
1988b, 1992)\\
Recently Galilei et al. (1991, 1992) showed that $\ldots$
\end{quotation}

\smallskip

\noindent
Authors' initials are permitted only in exceptional cases; for example,
to distinguish between two authors with the same surname. Each
literature citation made in the text should have a corresponding entry
in the {\it References} at the end of the paper (see
Sect.~\ref{sec:reflist} below). For frequently cited papers an
abbreviated form of citations is recommended, e.g., Paper I, Paper II
(if appropriate) or by the initial letters of the authors' surnames.

\subsection{The reference list}\label{sec:reflist}

The reference list should contain all the references cited in the text,
ordered alphabetically by surname (with initials following). If there
are several references to the same first author, they should be entered
according to the following scheme:
\begin{enumerate}
\item One author: chronologically
\item Author, one co-author: alphabetically by co-author, then
chronologically
\item Author, two or more co-authors: chronologically.
\end{enumerate}

Please always use the \LaTeX\ conventions of \verb|\bibitem| with a
label, together with \verb|\cite|. This is necessary to produce
hyper-links in the HTML version of your paper.

\sampleinput

\begin{verbatim}
The results in this section are a refined version of
Caraveo (\cite{caraveo}); the minimality result
of Proposition~14 was the first of its kind.
\end{verbatim}

Then the \verb|\bibitem| entry of the \verb|thebibliography| environment
should read as follows.

\sampleinput
\begin{verbatim}
\begin{thebibliography}{}  % (do not forget {})
\bibitem[1995]{caraveo}
  Caraveo, P.: 1995, Isolated Neutron Stars and Their Emission
  throughout the Electric Magnetic Spectrum. In: 17th
  Texas Symposium on Relativistic Astrophysics and Cosmology,
  Bohringer H., Morfill G.E., Tr\"umper J. (eds.), Ann. of NY
  Academy of Sciences, vol. 759, 246
\bibitem[1995]{day}
  Day, C., Arnaud, K., Ebisawa, K., et al., 1995,
  The ABC guide to
  ASCA Data Reduction, NASA Goddard Space Flight Center
\bibitem[1994]{goldwurm}
  Goldwurm, A., Cordier, B., Paul, J., et al., 1994,
  Nature 371, 589
\bibitem[1988]{white}
  White, N.E., Stella, L., Parmar, A.N., 1988, in press
\end{thebibliography}
\end{verbatim}
\goodbreak
\sampleoutput
\begin{thebibliography}{}
\bibitem[1995]{caraveo}
Caraveo, P.: 1995, Isolated Neutron Stars and Their Emission
throughout the Electric Magnetic Spectrum. In: 17th
Texas Symposium on Relativistic Astrophysics and Cosmology,
Bohringer H., Morfill G.E., Tr\"umper J. (eds.), Ann. of NY
Academy of Sciences, vol. 759, 246
\bibitem[1995]{day}
Day, C., Arnaud, K., Ebisawa, K., et al., 1995, The ABC guide to
ASCA Data Reduction, NASA Goddard Space Flight Center
\bibitem[1994]{goldwurm}
Goldwurm, A., Cordier, B., Paul, J., et al., 1994, Nature 371, 589
\bibitem[1988]{white}
White, N.E., Stella, L., Parmar, A.N., 1988, in press
\end{thebibliography}

\section{General typing rules}

\subsection{Fine tuning of the text}\label{finetune}

The following should be used to improve the readability of the text:

\medskip
\noindent
\begin{tabular}{@{}l@{\hspace{.5cm}}p{.7\textwidth}}
\verb|\,|    & a thin space, e.g.\ between thousands in numbers with
               more than 5 digits; a line division will not be made
               following this space,\\
\verb|--|    & en-dash; two hyphens, without a space at either end,\\
\verb*| -- | & Please note: in \TeX, {\tt --- } gives an em-dash
               ``---''; Springer does not use this, but rather
               the shorter en-dash {\it with} spaces, i.e.\ space,
               two hyphens, for an en-dash, space, to give a
               ``Springer em-dash''.\\
\verb|-|     & hyphen; no space at either end,\\
\verb|$-$|   & minus, in the text {\em only},\\
\verb|~|     & fixed space, e.g.\ between parts of names.
\end{tabular}

\medskip
\noindent
Their use is best explained in the following example.

\sampleinput

\begin{verbatim}
20\,000 km, 1\,000\,000 s, NGC 468\,324
1950--1985, p.~11--21
this -- written on a computer -- is now printed
signal-to-noise ratio, early-type, metal-poor, non-relativistic
$-30$ K, $-5^{\circ}$C
Dr.~h.c.~Rockefeller-Smith and Prof.~Dr.~Mallory
\end{verbatim}

\sampleoutput

\begin{flushleft}
20\,000 km, 1\,000\,000 s, NGC 468\,324\\
1950--1985, p.~11--21\\
this -- written on a computer -- is now printed\\
signal-to-noise ratio, early-type, metal-poor, non-relativistic\\
$-30$ K, $-5^{\circ}$C\\
Dr.~h.c.~Rockefeller-Smith and Prof.~Dr.~Mallory
\end{flushleft}

\subsection{Special typefaces}

Normal type (roman) need not be specified. \emph{Emphasize}
(\verb|\emph{Emphasize}|) should be used for emphasis in the text.

In addition, there are the following commands.

\begin{decl}
  \verb|\vec{Symbol}|
\end{decl}

\goodbreak
\noindent
Vectors may only appear in math mode. Examples are:

\smallskip

\verb|$\vec{A} \times \vec{B} \cdot \vec{C}$|,

\smallskip

\noindent
which yields
$\vec{A}\times\vec{B}\cdot\vec{C}$ and

\smallskip

\verb|$\vec{A\/}^{\rm T} \otimes \vec{B} \otimes \vec{\hat D}$|,

\smallskip

\noindent
which yields $\vec{A\/}^{\rm T} \otimes \vec{B} \otimes \vec{\hat D}$.

\begin{decl}
  \verb|\tens{Symbol}|
\end{decl}

\noindent
Tensors may only appear in math mode. Example: \verb|\tens{ABC}| yields
$\mathsf{ABC}$.

\begin{decl}
\verb|\ion{<element symbol>}{<degree of ionization>}|
\end{decl}

\noindent
The degree of ionization in the \verb|\ion| command has to be given as
lower case roman numerals (e.g.\ \verb|\ion{H}{ii}| which yields H\,{\sc
ii}).

\begin{decl}
\verb|\element[<electrical charge>][<number of nucleons>]|\\
\verb|    [<number of protons>][<number of neutrons>]{<element symbol>}|
\end{decl}

\noindent
Note, that if you want to have for example $^{13}\mathrm{C}$,
the last two optional arguments may be omitted: \verb|\element[][13]{C}|.

\subsection{Footnotes}

Footnotes end with a full stop.
Footnotes within the text should be coded as
\begin{decl}
\verb|\footnote{<text>}|
\end{decl}
\noindent
with \emph{no} blank before \verb|\footnote|.

\subsection{Mathematical formulas}

All equations that you are refering to with \verb|\ref| must have the
corresponding \verb|\label| -- please use this mechanism only.
Punctuate a displayed equation in the same way as ordinary text.

Note that the sizes of the parentheses or other delimiter symbols used
in equations should ideally match the height of the formulas being
enclosed. This is automatically taken care of by the following \LaTeX{}
commands, e.g.\ \ \verb|\left(| \quad or \quad \verb|\left[| \quad and
\quad \verb|\right)| \quad or \quad \verb|\right]|.

\subsubsection{Italic and roman type in the math mode}

In math mode \LaTeX{} treats all letters as though they were
mathematical or physical variables; hence they are typeset in italics.
However, any textual elements within formulas should be set in roman.
Roman should also be used for subscripts and superscripts \emph{in
formulas} where these are merely labels and not in themselves variables,
e.g.

\medskip
\noindent
\begin{tabular}{lcl}
\verb|$T_\mathrm{eff} =|&&\\
\verb|  5\,10^{9} \mathrm{K}$| &\quad produces\quad&
$T_\mathrm{eff} = 5\,10^{9} \mathrm{ K}$\\
\verb|$T_\mathrm{K}$| &\quad produces\quad& $T_\mathrm{K}$ (K = Kelvin)\\
\verb|$m_\mathrm{e}$| &\quad produces\quad& $m_\mathrm{e}$ (e = electron)
\end{tabular}

\medskip
However, do not use roman if the subscripts or superscripts represent
variables, e.g.\ $\sum_{i=1}^{n} a_{i}$.

Please ensure that \emph{physical units} (e.g.\ pc, erg s$^{-1}$ K,
cm$^{-3}$, W m$^{-2}$ Hz$^{-1}$, m kg s$^{-2}$ A$^{-2}$) and {\em
abbreviations} such as Ord, Var, GL, SL, sgn, const.\ are always set in
roman type with an appropriate inter-word spacing. To ensure this use
the \verb|\mbox| command: \verb|\mbox{Hz}|. On p.\ 44 of the {\em
\LaTeX{} User's Guide \& Reference Manual\/} (2nd ed.) by Leslie Lamport
you will find the names of common mathe\-matical functions, such as log,
sin, exp, max and sup. These should be coded as \verb|\log|,
\verb|\sin|, \verb|\exp|, \verb|\max|, \verb|\sup| and will then
automatically appear in roman.

In order to distinguish ``d'' used as the ``differential sign'' and
``e'' used as the ``exponential function'' from normal variables, set
these letters in roman if used in this context.

Chemical symbols and formulas should be set in roman, e.g.\ Fe not $Fe$,
H$_{2}$O not {\em H$_{2}$O\/}, H$\alpha$ not {\em H${\alpha}$}.

\subsection{Astronomical objects}\label{sec:astobjects}

SIMBAD the astronomical database and ALADIN the interactive deep
sky mapping facility at CDS Strasbourg create anchors for
astronomical objects cited in the A\&A. To facilitate their indexing
you, being best placed to start the proces, should surround
any astronomical object in your text as well as in small tables with the
command
\begin{decl}
\verb|\object{<objectname>}|
\end{decl}
This command simply prints out its argument and adds the thus marked
element to the list of hyper-linked astronomical objects and should be
repeated for each object.

In the \texttt{referee} version of your article the list of your objects
will automatically appear at the end (after the references).
For the final (two-column) version you could use the command
\verb|\listofobjects| directly before the end of your document to get
the list of known objects printed. \LaTeX\ will write an auxiliary file
with the extension \texttt{obj} to prepare that list.

\subsection{Signs and characters}

You may need to use special signs. The available ones are listed in the
{\em \LaTeX{} User's Guide \& Reference Manual\/} (2nd ed.). We have
created further common astronomy symbols:

\medskip
\noindent
\begin{tabular}{lll|lll}
\hline
In & Explanation & Out & In & Explanation & Out\\
\hline
\verb|\sun|      & sun symbol            & $\sun$        &
\verb|\fs|       & fraction of second    & \fs\\
\verb|\degr|     & degree                & $\degr$       &
\verb|\fdg|      & fraction of degree    & \fdg\\
\verb|\diameter| & diameter              & \diameter     &
\verb|\fp|       & fraction of period    & \fp\\
\verb|\sq|       & square                & \squareforqed &
\verb|\farcs|    & fraction of arcsecond & \farcs\\
\verb|\fd|       & fraction of day       & \fd           &
\verb|\farcm|    & fraction of arcmin    & \farcm\\
\verb|\arcsec|   & arcsecond             & \arcsec &
\verb|\fh|       & fraction of hour      & \fh           \\
\verb|\arcmin|   & arcminute             & \arcmin &
\verb|\fm|       & fraction of minute    & \fm           \\
\hline
\end{tabular}
\renewcommand{\arraystretch}{1}

\appendix
\section{Simplified abbreviations of frequently used
journals}\label{app:abbr}

\begin{flushleft}
\begin{tabular}{ll}
AJ       & Astronomical Journal (the)\\
ARA\&A   & Annual Review of\\
&Astronomy and Astrophysics\\
AZh      & Astronomiceskij Zhurnal\\
A\&A     & Astronomy and Astrophysics\\
&(Letters indicated by number)\\
A\&AR    & Astronomy and Astrophysics Review (the)\\
A\&AS    & Astronomy and Astrophysics\\
&Supplement Series\\
Acta Astron.       & Acta Astronomica\\
Acta Astron.~Sin.  & Acta Astronomica Sinica\\
Afz      & Astrofizica\\
ApJ      & Astrophysical Journal (the)\\
&(Letters indicated by number)\\
ApJS     & Astrophysical Journal Supplement Series (the)\\
Ap\&SS   & Astrophysics and Space Science\\
Ark.~Astron.       & Arkiv for Astronomi\\
Astron.~Nachr.     & Astronomische Nachrichten\\
Aust.~J.~Phys.     & Australian Journal of Physics\\
Aust.~J.~Phys.& Australian Journal of Physics\\
\quad Astrophys.~Suppl.&Astrophysics Supplement\\
BAAS     & Bulletin of the American Astronomical Society\\
C.~R.~Acad.~Sci.~Paris & Comptes Rendus de l'Acad\'{e}mie des Science\\
Chin.~Astron.          & Chinese Astronomy\\
IAU Circ.              & International Astronomical Union, Circular\\
Icarus  & Icarus\\
Ir. Astron.~ J.   & Irish Astronomical Journal\\
J.~R.~Astron.~Soc.~Can. & Journal of the Royal Astronomical Society of\\
&Canada\\
JA\&A    & Journal of Astronomy and Astrophysics\\
MNRAS    & Monthly Notices of the Royal Astronomical\\
&Society\\
Mem.~R.~Astron.~Soc.   & Memoirs of the Royal Astronomical Society\\
Mem.~Soc.~Astron.~Ital. & Memorie della Societa Astronomica Italiana\\
Mitt.~Astron.~Ges.      & Mitteilungen der Astronomischen Gesellschaft\\
Mon.~Notes  & Monthly Notes of the Astronomical Society\\
\quad Astron.~Soc.~S.~Afr.& of Southern Africa\\
Nat      & Nature\\
Observatory & Observatory (the)\\
PASJ     & Publications of the Astronomical Society\\
&of Japan
\end{tabular}


\begin{tabular}{ll}
PASP     & Publications of the Astronomical Society\\
& of the Pacific\\
PASPC    & Ditto, Conference Proceedings\\
Phil.~Trans.~R.~Soc.~London,  & Philosophical Transactions of the \\
\quad Ser.~A  &Royal Society of London, Series A\\
Proc.~Astron.~Soc.~Aust.  & Proceedings of the Astronomical Society\\
&of Australia\\
QJRAS    & Quarterly Journal of the Royal \\
&Astronomical Society\\
Rev.~Mex.~Astron.~Astrofis.  & Revista Mexicana de Astronomia\\
&y Astrofisica\\
Ric.~Astron.~Specola~Vaticana & Ricerche Astronomiche. Specola Vaticana\\
Sci      & Science\\
Sci.~Am. & Scientific American\\
Sky Telesc. & Sky and Telescope\\
Space Sci.~Rev. & Space Science Reviews\\
SvA      & Soviet Astronomy
\end{tabular}
\end{flushleft}

\end{document}
