exfits is a simple tool to perform extractions on HST STIS 2D FITS spectra. It supports an equal-weighted row extraction, or a mesa weighting function. exfits can also trace a FITS image, providing a reasonable guess for the row corresponding to a star.
exfits can be run as an interactive shell, or entirely from the command line, in batch mode.
Usage: exfits [OPTION...] [FILE]
`exfits' is a program designed to perform extractions on 2D spectra from FITS
files.
exfits has two primary modes: batch and interactive. When run without
arguments, or when using the `-i' switch, exfits will be run interactively.
Otherwise, the program can be run with command-line input only. There are
currently six extraction types:
`-c' Mesa-shaped extraction across floating-point rows
`-s' Box-shaped extraction across integer rows
`-t' Box-shaped vertical extraction with integer rows
`-e -c' Echelle mode mesa-shaped extraction across floating-point rows
`-e -s' Echelle mode box-shaped extraction across integer rows
`-e' Echelle mode extraction of all rows
2D Echelle spectra can be extracted in either normal or Echelle mode
('-e'). In Echelle mode the row numbers are treated relative to each
order and each order is written to a separate file.
The extraction types including '-c' can take up to three parameters. For a
non-Echelle FITS file, omitting the central row causes the programto perform a
trace which automatically chooses the brightest row in thefile for the center.
exfits records its doings in a log file, which defaults to `exfits.log' in the
current working directory. exfits will also write cspec-compatible text files,
with appropriate headers commented with the `#' character.
-c PLATW,BASEW[,CENTER] Extract with careful method, specify mesa plateau,
base, and optionally row center. If the center is
not specified, a trace will determine the center.
-e Extract data in Echelle mode. (Fails if the input
FITS are not properly formated Echelle data)
-f, --fits Output FITS image.
-i, --interactive Enter interactive terminal session.
-l FILE File to write session log to. Default is
`exfits.log'
-o FILE Output extraction data to FILE. Default is
stdout.
-s MINROW,MAXROW Row bounds (integer) for simple extraction
(inclusive).
-t MINCOL,MAXCOL Extract vertically, with an integer range of
columns.
-u, --unifspec Output unifspec instead of the default text.
-v, --verbose Display info about extraction, default if
interactive.
-?, --help Give this help list
--usage Give a short usage message
-V, --version Print program version
This software requires installation of the NASA FITSIO libraries. Install this first:
This software also requires two custom libraries developed for the Treasury Project:
After downloading, successfully compiling, and installing those libraries you are ready to download and compile exfits: