% AASGUIDE.TEX -- AASTeX user manual.

\documentclass[preprint2]{aastex}

\usepackage{aastexug}   % User guide style customizations

\begin{document}

\title{The \aastex\ Package\\for Manuscript Preparation}

\tableofcontents

\section{Introduction}

The American Astronomical Society (AAS) has developed an author
markup package called \aastex\ that assists authors in preparing
manuscripts that are intended for submission to the AAS-affiliated
journals.  \aastex\ can be used for other journals as well,
some of which accept \aastex\ manuscripts.

The most important aspect of the \aastex\
package is that it defines the set of commands (called \emph{markup})
that can be used to identify the structural elements of a paper.
When articles are marked up using this set of standard commands,
the papers may then be submitted electronically to the editorial
offices and fed into electronic production of the journals.

This guide contains basic instructions for creating
manuscripts using the \aastex\ markup package.
Authors are expected to be familiar with the editorial
requirements of the journals so that they can make
appropriate submissions; they should also have at least
a rudimentary knowledge of \LaTeX\ (for instance, knowing
how to set up equations using \LaTeX\ commands).
A number of useful publications about \LaTeX\ (and \TeX) are listed in
the reference section of this guide.

{\em Authors who wish to submit papers electronically to the ApJ, AJ, or
PASP are strongly encouraged to use the
\aastex\ markup package as described in this guide.}

\section{\aastex\ article markup}

This section describes the commands in the \aastex\
package that an author might enter in a manuscript that is being
prepared for
electronic submission to one of the journals.
The commands are described in roughly the same order as they
would appear in a manuscript.
The reader will also find it helpful to examine the
sample file (\verb"sample.tex") that is
distributed with the package.
Authors are reminded to check the electronic submission procedures and
the instructions to authors for the journals to which they submit their
papers.

\subsection{Preamble}\label{sec-preamble}

In \LaTeX\ manuscripts, the preamble is that portion of the file before
the \verb"\begin{document}"\  command.

\subsubsection{Getting started}

The first piece of markup in the manuscript declares the
overall style of the document.  Any commands that appear before this
markup will be ignored.
\begin{quote}
\begin{verbatim}
\documentclass{aastex}
\end{verbatim}
\end{quote}
The above example specifies the document class as
\texttt{aastex},
with the
default style, |manuscript|,
in eff\-ect.
The paper copy produced by this style file will be double-spaced.
Any tables included in the main body of the manuscript will also be
double-spaced.

Other styles are available;
they are discussed in Section~\ref{styles}.

\subsubsection{Defining new commands}

\aastex\ allows authors to define their own commands with
\LaTeX's \verb"\newcommand".
(Do not use the plain \TeX\ \verb"\def" command.)
Authors' \verb"\newcommand" definitions must be placed in the
document preamble.

In general, author-defined commands that are
abbreviations or shorthands are acceptable and can be translated, e.g.,
\begin{quote}
\begin{verbatim}
\newcommand{\lte}{local thermodynamic
	equilibrium}
\end{verbatim}
\end{quote}
However, abbreviations that attempt to define new symbols by using
\LaTeX\ commands for repositioning text or symbols tend to
cause problems during the production of the article.

Specifically, author-defined commands that use any of the commands
listed below are apt to be problematic in the conversion
procedures after the manuscript is submitted.
\begin{quote}
\verb"\hskip", \verb"\vskip",
\verb"\raise", \verb"\raisebox",
\verb"\lower", \verb"\rlap",
\verb"\kern", \verb"\lineskip",
\verb"\char", \verb"\mathchar",
\verb"\mathcode", \verb"\buildref",
\verb"\mathrel", \verb"\baselineskip"
\end{quote}
Consequently, authors are strongly discouraged from
employing them.

Extra symbols are defined for \aastex,
some specifically for an astronomical context, and others more
broadly used in math and physics.
In particular, the AMS has additional symbol fonts that are
available in a standard \LaTeX\ package (\verb"amssymb").
All of these symbols are depicted in the additional tables
supplied with this manual.

Authors are advised to consult these tables to see whether a
symbol already exists.  If it does, you should just use the
corresponding markup command; these commands are reserved.
You should \emph{not} redefine an existing command name.
When one of these commands is encountered in an electronic
manuscript, authors' redefinitions are ignored when the
manuscript is translated.

\subsubsection{Editorial information}

A number of markup commands are available for the
editorial offices to record the publication history and slug-line data
for each manuscript.
These commands are for use in the editorial and production offices only.
\begin{quote}
\begin{verbatim}
\received{<receipt date>}
\revised{<revision date>}
\accepted{<acceptance date>}

\ccc{<code>}
\cpright{<type>}{<year>}
\end{verbatim}
\end{quote}

Copyright information is specified through the commands \verb"\cpright"\
and \verb"\ccc".  The ``type'' of copyright and the corresponding year
are given in \verb"\cpright"; valid copyright types are as follows.
\begin{quote}
\begin{tabular}{l@{\quad}p{2.8in}}
\tt AAS & Copyright has been assigned to the AAS\\[.5ex]
\tt ASP & Copyright has been assigned to the ASP\\[.5ex]
\tt PD & The article is in the public domain\\[.5ex]
\tt none & No copyright is claimed for the article
\end{tabular}
\end{quote}
The copyright type is case sensitive, so the type string must be
entered exactly as given above.
The Copyright Clearing Center code may be given in the \verb"\ccc"\
command; the code is taken as regular text, so any special characters,
notably `\$', must be properly specified.

\subsubsection{Short comment on title page}

Authors who wish to include a short remark on the title page,
such as the name and date of the journal in which an article
has been scheduled, may do so with the following command.
\begin{quote}
\begin{verbatim}
\slugcomment{<text>}
\end{verbatim}
\end{quote}
In the
\texttt{manuscript} style,
such comments appear on the title page after the title and authors;
in the
\texttt{preprint} style,
they are placed at the upper right corner
of the title page.

\subsubsection{Running heads}\label{shorthead}

Authors are invited to supply running head information.
There are generally two different kinds of data in running heads;
the left head contains an author list (last
names, possibly truncated as ``et al.''), while the right head
is an abbreviated form of the paper title.  This running head
information will not appear on the \LaTeX-printed page but will be
transmitted to the copy editor for inclusion in the published version.
\begin{quote}
\begin{verbatim}
\shorttitle{<text>}
\shortauthors{<text>}
\end{verbatim}
\end{quote}
Editors and publishers impose varying requirements
on the brevity of these data.  A good rule of thumb is to limit the list
of authors to three, or use ``et al.'', and to limit the
short form of the title to 40--45 characters.
The editors may choose to modify the author-supplied
running heads.

\subsection{Starting the main body}

None of the markup that appears in the preamble actually typesets
anything; it is only a control section.
The author must include a
\begin{quote}
\begin{verbatim}
\begin{document}
\end{verbatim}
\end{quote}
command to identify the beginning of the main textual
portion of the manuscript.

\subsection{Title and author information} \label{titlepage}

Use the
\verb"\title"\
 and \verb"\author"\  commands to specify title
and author information.
Specify the author's principle affiliation with
the command \verb"\affil".
Each \verb"\author"\
 command
should be followed by a corresponding \verb"\affil"\
and optional \verb"\email"\  command.
\begin{quote}
\begin{verbatim}
\title{<text>}
\author{<name(s)>}
\affil{<affiliation>}
\affil{<address>}
\email{<email address>}
\and
\end{verbatim}
\end{quote}

Line breaks are permitted in the title if the author wishes
to specify them with the \verb"\\" command.  Long titles will
be broken automatically, so the \verb"\\" markup is not required.
If the title is explicitly broken over several lines, the
preferred style for titles in AAS and ASP journals is the so-called
``inverted pyramid'' style.  In this style, the longest line
is the first (or top) line, and each succeeding line is shorter.
The text of the title should be entered in mixed case;
it will be published in upper case or mixed case according to
the style of the publication to which the paper is submitted.
Footnotes are permissible in titles; be careful to ensure that
alternate affiliations (see below) are properly numbered if a
footnote to the title is specified.

Authors' names are given in \verb"\author"\
 commands,
and should be entered in mixed case.
Names that appear together in the author list for authors who
have the same primary affiliation should be specified in a single
\verb"\author"\  command.
Each author group (\verb"\author"\  command)
should be followed by an \verb"\affil"\  command, giving the principle
affiliation of that author.  Physical and postal address information
for the specified institution  may be included with the \verb"\affil".
The address can be broken over several lines using the
\verb"\\" command to indicate
the line breaks.
Usually, however, postal information will fit on one line.
When there is more than one \verb"\author"\  command, the last
one should be preceded by the \verb"\and"\  command.

When there is a lengthy author list, all authors' names may be
specified in a single \verb"\author"\
 command, with affiliations
specified using the \verb"\altaffilmark"\   me\-chan\-ism described below.
In this case, no \verb"\affil"\
 commands would be used, and in print the
affiliations would all be listed in a footnote block at the bottom
of the title page.

Authors often have affiliations in addition to their principle employer.
These alternate affiliations are specified with the \verb"\altaffilmark"\
 and \verb"\altaffiltext"\
 commands.
These behave like the \verb"\footnotemark"\
and |\footnotetext|  commands of \LaTeX, except there are no
optional arguments in \aastex.
\verb"\altaffilmark"\
 is appended to authors' names in the \verb"\author"\
 list and generates superscript identification numbers.
The text for the individual alternate affiliations is generated by the
\verb"\altaffiltext"\
 command.
\begin{quote}
\begin{verbatim}
\altaffilmark{<key number(s)>}
\altaffiltext{<numerical key>}{<text>}
\end{verbatim}
\end{quote}
It is up to the author to make sure that
 each \m{key number}  in his or her \verb"\altaffilmark"\
 matches the \m{numerical key} for
the corresponding \verb"\altaffiltext".

\subsection{Abstract}

The paper abstract should be enclosed in the
\texttt{abstract} environment.
\begin{quote}
\begin{verbatim}
\begin{abstract}
<abstract text>
\end{abstract}
\end{verbatim}
\end{quote}

\subsection{Keywords}

Keywords, subject headings, etc., are accommodated
as a single piece of text.
\begin{quote}
\begin{verbatim}
\keywords{<text>}
\end{verbatim}
\end{quote}
If authors supply keywords, they must be delimited by whatever
punctuation is required by the journal.
They should be specified in alphabetical order.
The \verb"\keywords"\
 command
supplies the proper leading text (``Keywords:'', ``Subject headings:'',
etc.), according to journal style.

\subsection{Comments to editors}

Authors may make notes or comments to the copy editor with the
\verb"\notetoeditor" command.
\begin{quote}
\begin{verbatim}
\notetoeditor{<text>}
\end{verbatim}
\end{quote}
This command behaves like a
footnote and appears on the bottom of the page.
\notetoeditor{Notes to the editor only appear
in the \texttt{manuscript} style.}
Output to the printed page is produced only in the
\texttt{manuscript} style.

\subsection{Sections}

The \texttt{manuscript} style for \aastex\ manuscripts supports four levels
of section headings.
\begin{quote}
\begin{verbatim}
\section{<heading>}
\subsection{<heading>}
\subsubsection{<heading>}
\paragraph{<heading>}
\end{verbatim}
\end{quote}
Section headings should be given in upper case or mixed case depending
on the style of the journal.
Note that these commands delimit sections by marking the
\emph{beginning} of each section;
there are not separate commands to identify the ends.

\subsection{Figure and table placement}   \label{place}

Generally figures and tables are not ``placed'' in the text of the
document where an author would like them to appear physically.
However, authors may indicate to the editors the preferred placement of
these items using  the \verb"\place*"\  commands.
\begin{quote}
\begin{verbatim}
\placetable{<key>}
\placefigure{<key>}
\end{verbatim}
\end{quote}
The \verb"\place*{"\m{key}\verb"}" commands are similar to the
\verb"\ref"
 command in La\TeX\
and require corresponding \verb"\label"\
 commands to link them to the
proper elements.

When used in the
\texttt{manuscript} style, the \verb"\place*"\  commands will print a short
message to the editor about figure and table placements.
In the other styles, nothing is printed.

\subsection{Acknowledgments}

\aastex\ manuscript styles support an acknowledgments section.
\begin{quote}
\begin{verbatim}
\acknowledgments
\end{verbatim}
\end{quote}
In the \aastex\ styles, acknowledgments are set off from the
concluding main body text by extra vertical space,
with no heading or type size change.

\subsection{Appendices}

When one or more appendices are needed in a paper, the point where the
main body text ends and the appendix begins must be marked
with the \verb"\appendix"\
 command.
\begin{quote}
\begin{verbatim}
\section{<body section>}
\appendix
\section{<appendix section>}
\end{verbatim}
\end{quote}
The \verb"\appendix"\
 command takes care of a number of internal
housekeeping concerns, such as identifying sections with letters
instead of numerals, resetting the equation counter, etc.
Note that the \verb"\appendix"\
 command takes no arguments.
Sections in the appendix must be headed with \verb"\section"\
 commands, as described earlier.

\subsection{Equations}

Display equations can be typeset in \LaTeX\ in many ways;
the following three are probably of greatest use in AASTeX.
\begin{quote}
\begin{verbatim}
\begin{displaymath}
\end{displaymath}

\begin{equation}
\end{equation}

\begin{eqnarray}
\end{eqnarray}
\end{verbatim}
\end{quote}
The
\texttt{displaymath}  environment
will break out a single,
unnumbered formula.  The \texttt{equation} environment does the same
thing, except that the equation is
autonumbered by \LaTeX.
To set several formul\ae\ in which vertical alignment
is required or to display a long equation across multiple lines, use the
\texttt{eqnarray} environment. Each line of the \texttt{eqnarray}
will be numbered
unless a \verb"\nonumber"\
 command is inserted
before the equation delimiter
(\verb"\\").
\LaTeX's equation counter is \emph{not} incremented when
\verb"\nonumber"\
 is used.

Authors may occasionally wish to group related equations together and
identify them with letters appended to the same equation number.
When this is desired, such related equations should still be set
in \texttt{equation} or \texttt{eqnarray} environments, whichever is
appropriate, and the grouping should then be placed within
the \texttt{mathletters} environment.
\begin{quote}
\begin{verbatim}
\begin{mathletters}
<equation> or <eqnarray>
\end{mathletters}
\end{verbatim}
\end{quote}

It is possible to override \LaTeX's automatic numbering within the
\texttt{equation} or \texttt{eqnarray} environments using
\begin{quote}
\begin{verbatim}
\eqnum{<text>}
\end{verbatim}
\end{quote}
When \verb"\eqnum"\
 is specified inside an \texttt{equation} environment,
or on a particular equation within an \texttt{eqnarray}, the text
supplied as an argument to \verb"\eqnum"\
 is used as the equation
identifier.
\LaTeX's equation counter is \emph{not} incremented when \verb"\eqnum"\
 is used.
\verb"\eqnum"\
 must be used \emph{inside} the environment.

If, as a consequence of the use of \verb"\eqnum"\
 or \verb"\nonumber",
\LaTeX's equation counter gets out of synch with the author's
intended sequence,
the counter may be reset to a particular value.
\begin{quote}
\begin{verbatim}
\setcounter{equation}{<number>}
\end{verbatim}
\end{quote}
The equation counter should be set to the number corresponding to the
last equation that was formatted; therefore, it is most appropriate for this
command to appear immediately after an \texttt{equation} or
\texttt{eqnarray} environment
ends.
The command must be used
\emph{outside} the math environments.

The \texttt{eqsecnum} style file can also be used to modify the way equations
are numbered. See Section~\ref{styles} for details.


\subsection{Citations and bibliography}   \label{bibliography}

Two options are available for symbolically marking citations
and formatting reference lists: the standard \LaTeX\ \verb"thebibliography"\
environment, and the \aastex\ \verb"references"\  environment.
Authors are strongly encouraged to use \verb"thebibliography"\
in electronic submissions.

Please note that the bibliographic data supplied by the author in
the reference list must conform to the standards of the journal.
We have elected not to burden authors with tedious markup commands
to delimit the bibliographic fields --- many of the journals that
accept \aastex\ agreed to reduce typographic overhead
(bold, italic, etc.) in reference lists \citep{Abt90}.
It is the responsibility of the author to arrange these fields in the
proper order with the correct punctuation; the information will be
typeset in roman with no size or style changes.


\subsubsection{The {\tt thebibliography} environment}   \label{bib}

The preferred method for reference management is to use \LaTeX's
\texttt{thebibliography} environment, marking citations in the body
of the paper with
\verb"\citep"\ or \verb"\citet"\
and associating references with them via \verb"\bibitem".
The \verb"\cite"-\verb"\bibitem"\
mechanism associates citations and references symbolically
while maintaining proper citation syntax within the paper.
In the \verb"\bibitem"\
command, the author specifies citation data inside
square brackets and a citation key in curly braces
for each reference.
\begin{quote}
\begin{verbatim}
\begin{thebibliography}{<dummy>}
\bibitem[<cite data>]{<key>} <bibliographic data>
   .
   .
\end{thebibliography}
\end{verbatim}
\end{quote}

Note that the argument \m{dummy} to the environment is not
used in the \aastex\ package, but is consistent with the
syntax of standard \LaTeX. It is acceptable to simply insert an
empty pair of curly braces after the \verb"\begin{thebibliography}"\
command.
The |\bibitem| command is described in detail in the next section.


\subsubsection{Specifying bibliographic and citation information}\label{spec-bib-data}

The scheme used in \aastex\ for marking citations and for specifying
bibliographic data allow us to utilize the features of the |natbib|
package \citep{Daly98}.
The |natbib| package re-implements \LaTeX's |\cite| command,
and offers greater flexibility for managing citations in the
author-year form.

All of the bibliographic data are defined in |\bibitem| commands.
\begin{quote}
\begin{verbatim}
\bibitem[<author>(<year>)]{<key>} <bibliographic data>
\end{verbatim}
\end{quote}
The square-bracketed argument of |\bibitem|
contains the \m{author} portion of the citation,
followed by the \m{year} set off in parentheses.
The parentheses are important --- please don't forget them.
The curly-bracketed argument \m{key} is the code name
by which the reference is known.

When placing citations in the text, the author should use
either a |\citep| or a |\citet| command.
\begin{quote}
\begin{verbatim}
\citep[<extra>]{<key(s)>}\\
\citet[<extra>]{<key(s)>}
\end{verbatim}
\end{quote}
The |\citep| command produces a citation that is entirely
set off by parentheses, e.g.\ (Cox 1995), while |\citet| permits
the author's name to form part of your text, e.g.\ Cox (1995).
The classic \LaTeX\ |\cite| command behaves like |\citet|.

The citation \m{key} corresponds to a \m{key} in a |\bibitem| command.
During processing, information from the \m{cite data} is inserted in
the text at the location of the \verb"\cite"\ command.
Multiple citation \m{keys} are separated by commas, e.g.,
|\citep|\allowbreak
|{knuth84,|\allowbreak
|cox95,|\allowbreak
|lamport94}|.
|\citep| and |\citet| each take optional arguments that specify
\m{extra} text that is appended to the citation label,
per standard \LaTeX\ behavior.

\aastex\ uses a full |natbib| implementation.
There are more syntax options than we have described here,
and these support the whole range of arcane possibilities
for composing citations; the price is complexity.
Authors who need more flexibility should become familiar
with the |natbib| documentation.
The syntax discussed above should be sufficient for the
vast majority of cases.

It is not possible to use \verb"\bibitem"
within \aastex's \texttt{references} environment
(section~\ref{refenv}),
nor will \verb"\cite"\ commands work properly in the main body
if \verb"\bibitem" commands are absent.


\subsubsection{The {\tt references} environment}\label{refenv}

Some authors might prefer to enter citations directly
into the body of an article. If so, the |references| environment may be
used to format the reference list. The
\texttt{references}  environment
simply sets off
the list of references and adjusts spacing parameters.
\begin{quote}
\begin{verbatim}
\begin{references}
\reference{<key>}<bibliographic data>
   .
   .
\end{references}
\end{verbatim}
\end{quote}

While the
\texttt{references}  environment
remains supported in v5.0,
we anticipate that authors will prefer the stronger capabilities of
the standard \LaTeX\ |thebibliography| commands as extended by |natbib|.

\subsubsection{Abbreviations for journal names}

There are markup commands for many of the most frequently-referenced journals so  that authors may use the markup  rather than having
to look up a particular journal's abbreviation.
In principle, all the journals should be using the
same abbreviations, but it is fair to anticipate some changes in
the specific abbreviations before a system is finally settled on.  As
long as these commands are kept up to date, authors need not be
concerned about such editorial preferences and changes.
A listing of the current abbreviations appears in Table~\ref{journame}.
\begin{table}
\begin{center}
\caption{Abbreviations for Journal Names}\label{journame}
\begin{tabular}{ll}
\verb"\araa" & Annual Review of Astronomy\\
  & \hspace*{1em} and Astrophysics\\
\verb"\ao" & Applied Optics\\
\verb"\aj" & Astronomical Journal\\
\verb"\azh" & Astronomicheskii Zhurnal\\
\verb"\aap" & Astronomy and Astrophysics\\
\verb"\aapr" & Astronomy and Astrophysics Reviews\\
\verb"\apj" & Astrophysical Journal\\
\verb"\apjl" & \rule[.5ex]{2em}{.4pt}, Letters to the Editor\\
\verb"\apjs" & \rule[.5ex]{2em}{.4pt}, Supplement Series\\
\verb"\aplett" & Astrophysics Letters\\
\verb"\apspr" & Astrophysics Space Physics Research\\
\verb"\apss" & Astrophysics and Space Science\\
\verb"\aaps" & \rule[.5ex]{2em}{.4pt}, Supplement Series\\
\verb"\baas" & Bulletin of the AAS\\
\verb"\bain" & Bulletin Astronomical Inst. Netherlands\\
\verb"\gca" & Geochimica Cosmochimica Acta\\
\verb"\grl" & Geophysics Research Letters\\
\verb"\iaucirc" & IAU Circular\\
\verb"\jcp" & Journal of Chemical Physics\\
\verb"\jgr" & Journal of Geophysics Research\\
\verb"\jrasc" & Journal of the RAS of Canada\\
\verb"\memras" & Memoirs of the RAS\\
\verb"\mnras" & Monthly Notices of the RAS\\
\verb"\nat" & Nature\\
\verb"\nphysa" & Nuclear Physics A\\
\verb"\physscr" & Physica Scripta\\
\verb"\pra" & Physical Review A\\
\verb"\prb" & Physical Review B\\
\verb"\prc" & Physical Review C\\
\verb"\prd" & Physical Review D\\
\verb"\pre" & Physical Review E\\
\verb"\prl" & Physical Review Letters\\
\verb"\physrep" & Physics Reports\\
\verb"\planss" & Planetary Space Science\\
\verb"\procspie" & Proceedings of the SPIE\\
\verb"\pasj" & Publications of the ASJ\\
\verb"\pasp" & Publications of the ASP\\
\verb"\qjras" & Quarterly Journal of the RAS\\
\verb"\skytel" & Sky and Telescope\\
\verb"\solphys" & Solar Physics\\
\end{tabular}
\end{center}
\end{table}

\subsection{Figures}

\subsubsection{Electronic art}

For manuscripts that are submitted electronically, the electronic figures
themselves are generally sent as individual files to the editors
and are not included as part of the main text, although the
legends or captions for these files are included using the markup described
in Section~\ref{legends}.
Detailed information on preparing and submitting electronic art is
available in the submissions instructions for the various journals.

At this time, the most widely used means of including figures or other
types of nontextual data in electronic manuscripts is to generate such
files as Encapsulated PostScript files.\footnote{%
 PostScript is a registered trademark of Adobe Systems Incorporated.%
}%

If an author wishes PostScript figures to be included in the
pages being produced, it is necessary that
the graphics files being included conform
to the Encapsulated PostScript standard \citep{PLRM}. The
author must also have an appropriate DVI translator,
one that targets PostScript output devices.

There are several commands to use when including EPS files
in \aastex\ manuscripts. They should be placed within  the
 \texttt{figure} environment.
\begin{quote}
\begin{verbatim}
\begin{figure}
\figurenum{<text>}
\epsscale{<num>}
\plotone{<epsfile>}
\plottwo{<epsfile>}{<epsfile>}
\caption{<text>}
\end{figure}
\end{verbatim}
\end{quote}
When \verb"\figurenum" is specified inside a {\tt figure} environment,
the text supplied as an argument to \verb"\figurenum" is used as the
figure identifier.
\LaTeX's figure counter is \emph{not} incremented when \verb"\figurenum"
is used.
\verb"\figurenum" must be used \emph{inside} the {\tt figure} environment.

\verb"\plotone" inserts the graphic in the named EPS file,
scaled (in both dimensions) so that the horizontal
dimension fits in the body text width;
the vertical dimension is scaled to maintain the aspect ratio.
\verb"\plottwo" inserts two plots next to each other.
Scale factors are determined automatically from information in the
EPS file.

The automatic scaling may be overridden with the command
\verb"\epsscale{<num>}", where \m{num}
is in decimal units, i.e., 0.80.

%See  ``Using Encapsulated PostScript with AAS\TeX'' on
%the AAS\TeX\ V5.0 home page, \url{|http://\allowbreak
%www.aas.\allowbreak
%org/\allowbreak
%publications/\allowbreak
%aastex|},
%for information on use of the commands,
%as well as where to obtain the DVI package.

\subsubsection{Figure captions} \label{legends}

Figure captions, or legends, should be included as a group at the end
of the manuscript using either the \verb"\figcaption"\  command
or a \texttt{figure} environment for each figure in
the paper, whether or not electronic art is included.
For electronic submissions, use of \verb"\figcaption"\ is preferred.

\begin{quote}
\begin{verbatim}
\figcaption[<filename>]{<text>\label{<key>}}
\end{verbatim}
\end{quote}

The optional argument, \m{filename}, can be used to iden\-ti\-fy
the file for the corresponding figure;
\m{text} refers to the caption for that figure.  The author
may provide a \verb"\label"\ with a unique \m{key} for cross-referencing
purposes.

When the \verb"\figcaption"\  command is used, the figure
identification,
e.g., ``Figure 1,'' is generated automatically by the command itself, so
there is no need to key this information.
 There is an upper limit of seven figure captions per page.
Footnotes are \emph{not} supported for figures.

\subsection{Tables}  \label{tables}

There is support in the \aastex\ package for tables via two mechanisms:
\LaTeX's standard \texttt{table} environment
and the
\texttt{deluxetable} environment, which facilitates the formatting
of lengthy tabular material.  Tables may be
marked up using either mechanism, although use of
\texttt{deluxetable} is preferred.
Authors should \emph{not} use the \LaTeX\
\texttt{tabbing} environment
or the \verb"\hline"\
 command when preparing electronic
submissions.

\LaTeX\ permits the preparation of fairly complex tables with
arbitrary spacing, straddle heads, rules, and the like.
Authors who need to specify complicated column headings and
so forth are advised to consult the \LaTeX\ manual \citep{Lamport}.
Most of the capabilities outlined there are applicable to  the \aastex\
 table preparation environments.

\subsubsection{The {\tt deluxetable} environment}  \label{dte}

Authors are encouraged to use the
\texttt{deluxetable} environment to format their tables since it automatically
handles many formatting tasks, including table numbering and insertion
of horizontal rules. It also provides mechanisms for breaking tables and
controlling width and vertical spacing that are unavailable in the \LaTeX\
\texttt{tabular} environment.

The \texttt{deluxetable} environment
is delimited by \LaTeX's familiar
\verb"\begin"\  and \verb"\end"\  constructs.
The content consists of \m{preamble} commands and \m{table data},
the latter delimited by \verb"\startdata"\
 and \verb"\enddata".
\begin{quote}
\begin{verbatim}
\begin{deluxetable}{<cols>}
<preamble commands>
\startdata
<table data>
\enddata
\end{deluxetable}
\end{verbatim}
\end{quote}
where \m{cols} specifies the justification for each col\-umn.
One of the letters `l', `c', `r', or `p' is given for each column,
indicating flush left, centered, flush right, or justified text.
Authors are
referred to the \LaTeX\ manual \citep{Lamport} for further information.

\subsubsection{Preamble to the {\tt deluxetable}}

There are several items in the
\texttt{deluxetable} environment
that
must be given before the data for the table;
they constitute the \m{preamble} to the environment.
\begin{quote}
\begin{verbatim}
\small
\footnotesize
\scriptsize
\rotate
\tablewidth{<dimen>}
\tablenum{<text>}
\tablecolumns{<num>}
\tableheadfrac{<num>}
\tablecaption{<text>\label{<key>}}
\tablehead{<text>}
\end{verbatim}
\end{quote}

If a table is too wide for the printed page, it is permissible to change
the font size within the
\texttt{deluxetable} environment
using the
\verb"\small"\
 (11pt), the \verb"\footnotesize"\
 (10pt), or the
\verb"\scriptsize"\
 (8pt) command.

You can force a table to be set in landscape orientation
using the \verb"\rotate"\
\label{cmd-rotate} command.
The default is for \aastex\ itself to determine if landscape orientation is required.

The width of a deluxetable is defined by \verb"\tablewidth";
the default width, if this command is omitted, is the width of the body
text.
The table can be set to its natural width by specifying
a \m{dimen} of \verb"0pt".
Long tables may have a natural width that is
different for each page.  The natural width for each page will be
printed to the log file during processing;
authors may then define a fixed table width based
on this information, giving the
tables a more uniform appearance across the pages.

It is possible to override \LaTeX's automatic numbering within the
\texttt{deluxetable} environment.
When \verb"\tablenum"\
 is specified inside a \texttt{deluxetable}
preamble,
the text supplied as an argument to \verb"\tablenum"\
 is used as the
table identifier.
\LaTeX's equation counter is \emph{not} incremented when
\verb"\tablenum"\
 is used.

The caption (actually, the title) of the table is specified
in \verb"\tablecaption".
The text of \verb"\tablecaption"\
 should be brief;
explanatory notes should be specified in the end notes to the table
(see \verb"\tablecomments"\
 below).  If the caption
does not appear
centered above the table after processing, then specify the width of
the table explicitly in the \verb"\tablewidth"\
 command and rerun
\LaTeX\ on the file.   The author
may provide a \verb"\label"\ in the caption with a unique \m{key}
for cross-referencing
purposes.

  Column headings are specified with \verb"\tablehead".
Within \verb"\tablehead", each column heading can be given
in a \verb"\colhead", which will ensure that the heading
is centered
on the natural width of the column; this is the typical disposition
of column headings, and the use of \verb"\colhead"\
 is encouraged.
There should be a heading for each column, so that there are as
many \verb"\colhead"\
 commands in the \verb"\tablehead"\
 as there
are data columns.

\begin{quote}
\begin{verbatim}
\tablehead{
\colhead{<heading>} & \colhead{<heading>}}
\end{verbatim}
\end{quote}

If more complicated column headings are required,
any valid \texttt{tabular} command that constitutes a proper
head line in a \LaTeX\ table may be used.
Consult the \LaTeX\ manual \citep{Lamport} for details.

The \verb"\tablecolumns{"\m{num}\verb"}" command
is necessary if the author has
multi-line column headings produced by \verb"\tablehead"\
 or other \LaTeX\
commands and is using either the \verb"\cutinhead"\
 or \verb"\sidehead"\
markup (see below).  The \m{num} is
set to the true number of columns in the
table.  The command must come before the \verb"\startdata"\
 command.

It is possible that a complicated table heading will overflow
the vertical space allotted for the table heading.
The fraction of the page allocated
for the table heading may be changed with \verb"\tableheadfrac".
The \m{num} argument to \verb"\tableheadfrac"\
 should be the
decimal fraction of the page used for heading information.
The default value is 0.1, meaning that 10\% of the page height
is reserved for the table heading.  It should rarely be necessary
to change this value.

\subsubsection{Content of the {\tt deluxetable}}

After the table title and column headings are specified,
data rows can be entered.
Data rows are delimited with the \verb"\startdata"\
 and \verb"\enddata"\
 commands.
The end of each row is indicated with the standard \LaTeX\ \verb"\\" command.
Data cells within a row of the table are separated with \& (ampersand) characters.
\begin{quote}
\begin{verbatim}
\startdata
<data line>\\
<cell>&<cell>&<cell>\\
<more data lines>
\enddata
\end{verbatim}
\end{quote}

Column alignment within the data columns can be adjusted with the \TeX\
\verb"\phantom{"\m{string}\verb"}" command,
where \m{string} can be any character, e.g., \verb"\phantom{$\arcmin$}".
A blank character of width \m{string} is then inserted in the table.
Four commands have been predefined for this purpose.
\begin{quote}
\begin{tabular}{l@{\quad}p{2in}}
{\verb"\phn"%
} & {phantom numeral 0-9}\\
{\verb"\phd"%
} & {phantom decimal point}\\
{\verb"\phs"%
} & {phantom $\pm$ sign}\\
{\verb"\phm{"\m{string}\verb"}"} & {generic phantom}\\
\end{tabular}
\end{quote}

Extra vertical space can be inserted between rows with an optional argument to the
\verb"\\" command; the argument is a dimension
and may be specified in any units that are legitimate in \LaTeX.
\begin{quote}
\begin{verbatim}
\\[<dimen>]
\end{verbatim}
\end{quote}

In a table, it may happen that several rows of data are
associated with a single object or item;
such logical groupings should not be broken across pages.
In such cases, the *-form of the |\\| command can be used to
keep the current line with the next line (``Keep with Next'').
\begin{quote}
\begin{verbatim}
<table row>\\*
<next table row>
\end{verbatim}
\end{quote}
An unlimited number of table rows can be held together in a block in this way.

The journals often require that table cells that contain  no data
be explicitly marked.  This is to differentiate such cells from
blank cells, which are frequently interpreted as implicitly
repeating the entry in the corresponding cell in the row preceding.
Data elements for which there are no data should contain
a \verb"\nodata"\
 command; an appropriate symbol will be placed in
that data element.
\begin{quote}
\begin{verbatim}
\nodata
\end{verbatim}
\end{quote}

Within the deluxetable body, two kinds of ``specialty'' heads are
recognized.  A cut-in head is a piece of text that is centered on the
table width;
it is spaced above and below from the data rows that precede and
follow it; there may be rules associated with it, depending on the
journal or manuscript style.  All of these formatting particulars
are managed by the style files.  The author need only specify that the
text be centered with a \verb"\cutinhead"\
 command.
Similarly, a side head is a piece of text that is left-justified.

\begin{quote}
\begin{verbatim}
\cutinhead{<text>}
\sidehead{<text>}
\end{verbatim}
\end{quote}

Table footnotes (more properly, table \emph{endnotes})
may be used in the \texttt{deluxetable} environment;
their use is described in detail in the Section
 \ref{tabfoot} below.

\subsubsection{The {\tt table} environment}

Tables may also be marked and composed using the \texttt{table} environment.
\begin{quote}
\begin{verbatim}
\begin{table}
\end{table}
\end{verbatim}
\end{quote}
The
\texttt{table}\ environment
encloses not only the tabular
material but also any title (caption) or footnote information
associated with the table.

Titles or captions for tables are indicated with
\begin{quote}
\begin{verbatim}
\caption{<text>\label{<key>}}
\end{verbatim}
\end{quote}
Tables will be identified with arabic numerals, e.g., ``Table 2'';
the identifying text, including the number, is generated automatically
by \verb"\caption".
 The author
may provide a \verb"\label"\ in the caption with a unique \m{key}
for cross-referencing
purposes.

Tabular information is typeset within the
\texttt{tabular} environment:
\begin{quote}
\begin{verbatim}
\begin{tabular}{<cols>}
\end{tabular}
\end{verbatim}
\end{quote}
where \m{cols} specifies the justification for each column.
One of the letters `l', `c', or `r' is given for each column,
indicating left, center, or right justification.
Consult the \LaTeX\ manual \citep{Lamport} for details about using
the
\texttt{tabular} environment
to prepare tables.
Each \texttt{tabular} table must appear within a \texttt{table}
environment. There should be only one \texttt{tabular} table per
\texttt{table}
environment.
If the journal requests manuscripts with only one table per page,
the author may need to insert a \verb"\clearpage"\
 command after
especially short tables.

There is a table line command for use in \texttt{tabular}
environments.
\begin{quote}
\verb"\tableline"
 \end{quote}
This command produces the horizontal rule(s) between the column headings
and the body of the table.
Authors are discouraged from using \verb"\hline".
In addition, the use of vertical rules should be avoided.

As with the \texttt{deluxetable} environment, it
 is possible to override \LaTeX's automatic numbering within the
\texttt{table} environment using \verb"\tablenum".
\verb"\tablenum"\
 must be used \emph{inside} the \texttt{table}
environment.



\subsubsection{Table footnotes} \label{tabfoot}

\aastex\ supports footnotes (endnotes) that are associated with tables;
this support applies to both the
\texttt{deluxetable}  environment
and the standard \LaTeX\ \texttt{table} environment.
Footnotes for tables are usually identified by lowercase letters
rather than num\-bers.
Marking and assigning associated text is achieved with
the \verb"\tablenotemark"\
 and \verb"\tablenotetext"\
 commands, which function like the  \verb"\altaffilmark"\
 and \verb"\altaffiltext"\
 (see Section~\ref{titlepage} above).
The \verb"\tablenote"\-|text|
 must be specified
\emph{after} the \verb"\end{tabular}"\  or \verb"\enddata"\  and before
the enclosing \verb"\end{table}"\  or \verb"\end{deluxetable}".
\begin{quote}
\begin{verbatim}
\tablenotemark{<alpha key>}
\tablenotetext{<alpha key>}{<text>}
\end{verbatim}
\end{quote}
Note that the \m{alpha key} in the \verb"\tablenotemark"\
should be the same as the
\m{alpha key} for the corresponding \m{text}.
It is the responsibility of the author to make the correspondence
correct.

Sometimes authors tabulate materials which have corresponding
references,
and it may be desirable to associate these references with the table
rather than (or in addition to) the formal reference list.
Also, authors may occasionally wish to append a
short paragraph of explanatory
notes that pertain to the entire table, but which are different than
the caption. \aastex\ offers two special kinds of endnotes for these
purposes.
\begin{quote}
\begin{verbatim}
\tablerefs{<reference list>}
\tablecomments{<text>}
\end{verbatim}
\end{quote}

Like the \verb"\tablenotetext" command, these commands should be
 specified after the \verb"\end{tabular}" or \verb"\enddata" and before
the enclosing \verb"\end{table}" or \verb"\end{deluxetable}".

\subsection{Miscellaneous}

\subsubsection{Ionic species and chemical bonds}

When discussing atomic species, ionization levels can be indicated
with the following command.
\begin{quote}
\begin{verbatim}
\ion{<element>}{<level>}
\end{verbatim}
\end{quote}
The ionization state is specified as the second argument,
and should be given as a numeral.
For example, \ion{Ca}{3} is specified by typing \verb"\ion{Ca}{3}".

For single, double, and triple chemical bonds, use the following macros.
\begin{quote}
\begin{verbatim}
\sbond
\dbond
\tbond
\end{verbatim}
\end{quote}




\subsubsection{Fractions}

\aastex\ contains commands that permit authors to specify alternate
forms for fractions.
\LaTeX\ will set fractions in displayed math as built-up fractions;
however, it is sometimes desirable to use case fractions in
displayed equations.
In such instances, one should use \verb"\case"\
rather than \verb"\frac", although authors submitting
manuscripts electronically
will generally find it unnecessary to use any markup other than the
standard \LaTeX\ \verb"\frac".

\begin{center}
\renewcommand{\arraystretch}{1.4}
\begin{tabular}{@{}llc@{}}
Built-up & \verb"\frac{1}{2}" & $\displaystyle\frac{1}{2}$ \\[.5ex]
Case     & \verb"\case{1}{2}" & $\case{1}{2}$ \\
Shilled  & \verb"1/2" & $1/2$ \\
\end{tabular}
\end{center}

The \aastex\ package also contains a collection of assorted macros
for symbols and abbreviations specific to an astronomical context.
These are commonly useful and also somewhat difficult for authors
to produce themselves because fussy kerning is required.
See the \anchor{symbolapp.pdf}{symbols pages} provided as
a separate attachment with this manual.
Most of these commands can be used in both running text and math.
\verb"\lesssim"\  and \verb"\gtrsim"\  can only be used in math mode.

\subsubsection{Celestial objects}

Celestial objects should be marked by the author to facilitate
post-processing of articles for the astronomical catalog databases.
\begin{quote}
\begin{verbatim}
\objectname[<catalog ID>]{<text>}
\end{verbatim}
\end{quote}
This command has no effect in printed manuscripts.
When your article contains |\objectname| commands,
the publisher can pass along a list of ``objects in article''
to database personnel, and software can construct queries
to those databases in the online editions.

In the future, it may be useful for the author to specify a
particular catalog with an identifier.
At this time, however, the optional \verb"<catalog ID>"
argument is ignored, and need not be supplied.

\subsubsection{Hypertext constructs}

The \verb"\anchor"\ \label{cmd-anchor} command is a general-purpose
hypertext link tag, associating \verb"<text>" in the manuscript with
the specified resource (\verb"<href>").
\begin{quote}
\begin{verbatim}
\anchor{<href>}{<text>}
\end{verbatim}
\end{quote}
\verb"<href>"\ is specified as a \emph{full} URI, including the
\verb"scheme:"\  designator (|http:|, |ftp:|, etc.).

The \verb"\url" command supports the special case where an author
wishes to express a URL in the text.
\begin{quote}
\begin{verbatim}
\url{<text>}
\end{verbatim}
\end{quote}

The \verb"\email"\  command is used to identify email addresses
anywhere in the manuscript.
The argument is the pertinent email address;
please do \emph{not} prepend the \verb|mailto:| part.
\begin{quote}
\begin{verbatim}
\email{<address>}
\end{verbatim}
\end{quote}
This command should be used to indicate authors' email addresses
in author lists at the beginning of manuscripts.
The \aastex\ v4.0 command, \verb"\authoremail", is superseded
by \verb"\email".

\subsection{Concluding the file}

The last command in the electronic manuscript file should be the
\begin{quote}
\begin{verbatim}
\end{document}
\end{verbatim}
\end{quote}
command, which appears after all the material in the paper.
This command directs the formatter to perform assorted termination
activities and finish processing.

\section{Style options}   \label{styles}

The default style option is the |manuscript| style. This style will
produce double-spaced pages printed in a single column at the width
of the page.

Two preprint styles are also available.
The \texttt{preprint} style offers a single-spaced alternative for
manuscripts.
This style is similar to the |manuscript| style,
but it is single-spaced, and it is possible to use a smaller typeface.
Sometimes, it is desirable for preprints
to be set in two columns with running heads.
The \texttt{preprint2} style option achieves this.
These two style options are discussed further below.

The \texttt{eqsecnum} style file can be used to modify the way equations
are numbered.
Normally, equations are numbered sequentially through the
entire paper, starting over at ``(A1)'' if there is an appendix.
If \texttt{eqsecnum} appears in the \texttt{documentclass} command,
equation num\-bers will be sequential through each section and will be
formatted ``(sec-eqn),'' where ``sec'' is the current section number and
``eqn'' is the number of the equation within that section.
\begin{quote}
\begin{verbatim}
\documentclass[eqsecnum]{aastex}
\end{verbatim}
\end{quote}

A \verb"flushrt.sty"\  file option is available for authors that prefer to
have their margins left and right justified.
The
\texttt{preprint2} style
is flush right by default,
but the
\texttt{manuscript} and
\texttt{preprint} styles are ragged right by default.
\begin{quote}
\begin{verbatim}
\documentclass[eqsecnum,flushrt]{aastex}
\end{verbatim}
\end{quote}

\subsection{Preprint format}

A single-column preprint format can be specified with the
\texttt{preprint} style option:
\begin{quote}
\begin{verbatim}
\documentclass[preprint]{aastex}
\end{verbatim}
\end{quote}
The size of the typeface used is under author control by way of
\LaTeX's \m{nn}\texttt{pt} class options
(where \m{nn} is 10, 11, or 12).
Use of 10 point type is not recommended with the
\texttt{preprint} style.

Authors may wish to adjust vertical spacing within a preprint,
for instance, double-spacing text while single-spacing tables.
Authors who want to alternate between single and double
spacing in the manuscript may use the following commands.
\begin{quote}
\begin{verbatim}
\singlespace
\doublespace
\end{verbatim}
\end{quote}
\verb"\singlespace"\  sets the vertical spacing to a smaller value,
while \verb"\doublespace"\  invokes double-spacing.

\subsection{Two-column format}

The
\texttt{preprint2} style
has the principle function of providing two-column formatting.
\begin{quote}
\begin{verbatim}
\documentclass[preprint2]{aastex}
\end{verbatim}
\end{quote}
It is important to remember
that text lines are considerably shorter when two of them are typeset
side by side on a page.  Long equations, wide tables and figures, and
the like, may not typeset in this format without some adjustments.
The expenditure of great effort to adapt copy and markup for
two-column pages is counterproductive.
Remember that the main
goal of this package is to produce draft
(or referee) format pages;
it is the responsibility of the editors and publishers to
produce publication-format papers for the journals.

The
\texttt{preprint2} style
sets the article's front matter---the title, author, abstract,
and keyword material---on a separate page at full text width.
The body of the article is set in a two-column page grid,
the appendices in a one-column page grid,
and the bibliography in a two-column page grid.
This manual was prepared using the \texttt{preprint2} style.

The author may supply \LaTeX's \verb"\twocolumn"\  or |\onecolumn|
commands whenever desired.
Be aware, however, that using explicit column-switching commands can
cause formatting problems.

\section{Additional documentation}  \label{docs}

The preceding explanation of the markup commands in the
\aastex\ package has merit for defining syntax, but many
authors will prefer to examine the sample papers that are
included with the style files.
The files of interest are described below.

A comprehensive example employing nearly all of the capabilities
of the package (in terms of markup as well as formatting)
is in \verb"sample.tex".
This file is annotated with comments that describe
the purpose of most of the markup.
\verb"sample.tex"\ has three tables: two marked up using the
\texttt{deluxetable} environment
and another table using the \LaTeX\ \texttt{table}
environment.

In \verb"table.tex", a complex but short example of the
\texttt{deluxetable} environment
demonstrates some of the techniques
that can be used to generate complex column headings and to align
variable-width columns.
Here the \LaTeX\ \verb"\multicolumn" command is used to span a heading
over several columns.  When \verb"\multicolumn" is used along with the
\verb"\cutinhead" command, the \verb"\tablecolumns" command must be used to specify
the number of columns in the table---otherwise the \verb"\cutinhead" command
will not work properly.
This table also makes use of the \verb"\phn" command to better align some of the
columns.

This user guide (\verb"aasguide.tex")
is also marked up with the \aastex\ package,
although it is not exemplary as a scientific paper.

Many of the markup commands described in the preceding
sections are standard \LaTeX\ commands. The reader who is
unfamiliar with their syntax is referred to the \LaTeX\
manual \citep{Lamport}, or any of several other guides
by \citet{Kopka99}, \citet{Goossens94}, and \citet{Hahn93}.

Authors who wish to know the ins and outs of \TeX\ itself
should read the \emph{\TeX book} \citep{Knuth}, probably more than once.
There is a good deal of information about typography in general
in this resource.  Many details of mathematical typography are
discussed in \emph{Mathematics into Type} by \citet{Swanson}.

\section{Acknowledgments}

\aastex\ was designed and written by Chris Biemesderfer in 1988.
Substantial revisions were made by Lee Brotzman and Pierre
Landau when the package was updated to v4.0.
\aastex\ was rewritten as a \LaTeXe\ class by Arthur Ogawa
when v5.0 was created.
The documentation has benefited from revisions by
Jeannette Barnes and Sara Zimmerman.

\begin{thebibliography}{}

\bibitem[Abt(1990)]{Abt90}
  Abt, H.  1990, \apj, 357, 1 (editorial)

\bibitem[Adobe(1999)]{PLRM}
  Adobe Systems, Inc.  1999,
  \anchor{http://www.adobe.com/prodindex/postscript/}
  {PostScript Language Reference Manual} (Reading, MA: Addison-Wesley)

\bibitem[Daly(1998)]{Daly98}
  Daly, P. 1998, \emph{Natural Sciences Citations and References}
  (\texttt{natbib} package documentation)

\bibitem[Goossens, Mittelbach, and Samarin(1994)]{Goossens94}
  Goossens, M., Mittelbach, F., and Samarin, A. 1994,
  \emph{The \LaTeX\ Companion} (Reading, MA: Addison-Wesley)

\bibitem[Hahn(1993)]{Hahn93}
  Hahn, J. 1993,  \emph{\LaTeX\ for Everyone}
  (Englewood Cliffs, NJ: Prentice-Hall)

\bibitem[Knuth(1984)]{Knuth}
  Knuth, D. 1984, \emph{The \TeX book} (Reading, MA: Addison-Wesley).
  \newblock Revised to cover \TeX3, 1991.

\bibitem[Kopka and Daly(1999)]{Kopka99}
  Kopka, H. and Daly, P. 1999,  \emph{A Guide to \LaTeX},
  3rd edition, (Reading, MA: Addison-Wesley)

\bibitem[Lamport(1994)]{Lamport}
  Lamport, L. 1994, \emph{\LaTeX: A Document Preparation System\/},
  2nd edition, (Reading, MA: Addison-Wesley)

\bibitem[Swanson(1979)]{Swanson}
  Swanson, E. 1979, \emph{Mathematics into Type}
  (Providence, RI: American Mathematical Society)

\end{thebibliography}

\end{document}
