Overview

Profit is a GUI (graphical user interface) tool for displaying and analyzing high- and moderate-resolution spectra. Although designed with high-resolution ($R > 300$) X-ray spectra in mind, profit will also work reasonably well with CCD resolution data ($R \sim 50$) and will work with spectra in other wavebands as well. Profit can read spectra in a number of formats, including simple ASCII text. It allows users to identify emission lines, to convert an identified line into velocity units using a user-selected wavelength, to store (and restore) individual spectra, to fit lines to gaussians, and other features. Profit is meant to handle the ``exploratory'' phase of analysis, although it has some powerful features. Combining the velocity function with the ability to store and plot multiple features, it is very easy to see if lines from a particular ion or isosequence are systematically red- or blue- shifted, asymmetrical, or broadened.

Profit's GUI is based on ROOT (http://root.cern.ch), a multifunctional library developed at CERN for high energy physics analysis. ROOT was chosen because it is well-supported and designed to handle histogram data smoothly. Although ROOT features and functions are used ``behind the scenes'' in profit, the user does not need to have any familiarity with ROOT to use profit, and in fact, ROOT users might find profit incomplete as we have removed many features in order to make a simple and robust tool. Profit runs natively on a variety of systems, including Linux, Mac OS X, and Solaris.

This manual describes profit version 1.0. We plan to continue developing profit to add functionality, and welcome suggestions from users as to what features would be most useful. Requests, bug reports, and questions can be submitted at the Feedback form on the profit web site, http://heasarc.gsfc.nasa.gov/docs/software/profit/; this can also be found at http://heasarc.gsfc.nasa.gov/cgi-bin/Feedback.