How to get the ApJ look of your paper emulateapj.cls, version 05/12/14
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.

\documentclass{emulateapj}
or
\documentclass[onecolumn]{emulateapj}