How to get the ApJ look of your paper emulateapj.cls, version 04/17/13
11/10/09: Two major changes:
1. ApJ has moved its publishing to IOP and they have slightly changed the formatting. To implement these changes, call emulateapj with the iop option, use
\documentclass[iop]{emulateapj}
Other available options:
[chicago] - (default) typeset as was done in the University of Chicago Press
[twocolumn] - (default) two-column mode
[onecolumn] - main text in one-column mode
[apj]       - typeset as for main journal
[apjl]      - (default) typeset as for ApJ Letters 
[tighten]   - some adjustments to approximate grid typesetting
[numberedappendix]   - number appendix sections as A, B, etc
[appendixfloats]  - use separate numbering for floats within appendix
[twocolappendix]  - make appendix in two-col mode in a two-col paper
[revtex4]   - force using revtex4
2. Starting from version 11/10/2009, emulateapj tries to load revtex4-1 if present on the system. This may cause small changes in typesetting for old documents. If you want full compatibility, please download the last version based on revtex4, emulateapj-rtx4.cls, and bundle it with your TeX source code.
2/9/03: MAJOR CHANGE: Emulateapj is completely rewritten. This version adds the use of single-column floats (figures, tables and footnotes) in the two-column mode. All standard LaTeX/AASTeX environments such as {figure}, {table}, {figure*}, {table*} and {deluxetable} (and {deluxetable*} added here) should work as expected. Enjoy.

Download emulateapj.cls and use it instead of aastex.cls. 

\documentclass{emulateapj}
or
\documentclass[onecolumn]{emulateapj}
(see header for other options)
Emulateapj uses revtex4.cls, download it also if you don't have it already.

The old versions of this package are emulateapj5.sty (package to be used with aastex.cls) and emulateapj.sty (package to be used with article class).

The user needs to use \documentclass{aastex} and then \usepackage{emulateapj5}.

The apjfonts.sty can be used for Times typefaces. It works under old latex 2.09 and new LaTeX 2e.

Some TeX installations (e.g. teTeX) will find all the font files used by apjfonts.sty. If, however, your LaTeX/dvips complains about not finding some fonts, you will have to install them: download apjfonts.tar.gz, unpack and read INSTALL.

If you have any questions, email alexey@head-cfa.harvard.edu