The astrophysics group maintains a small group of Linux
workstations for beginning graduate and undergraduate
students. These computers are in room 2169 FRH.
Students who want an account on these machines should see Aaron
A few general notes: please don't bring food or beverages into
the computer room. Please try not to touch the flat-panel
LCD screens- they will last pretty much forever if we take good
care of them, but once they get scratched there's no way to fix
Don't lock the screen on these machines if you're going to be
away from the computer room for more than a short while.
Instead please log out so that someone else can use the system.
We have 2 HP laser printers for the astrophysics group, one
black & white and one color. The black & white
printer is set as the default printer.
Basic Linux/Unix skills.
If you're a beginner, there are various web sites that give
introductory lessons on Linux commands, text editing,
one web site that has a lot of useful information.
The Scientific Linux distribution includes a lot of very useful
software, such as:
a text editor
- vi, a text editor
- LaTeX, a
document processing system optimized for mathematical and
- The gcc and
- Python, along with
various useful libraries such as numpy and matplotlib.
- OpenOffice: an
office suite including word processing and spreadsheets,
able to read MS Office file formats reasonably well
- Web browsers: mozilla and firefox
reader (from the command line, type acroread)
A note about shells: the "shell" is the command language
interpreter that interprets what you type at a terminal
prompt. The two most popular shells are bash
somewhat different syntax for scripting and for things like
setting environment variables. Bash is the default shell
for linux these days, and most linux manuals will use bash
syntax. However, a lot of astronomical software that's
been around for years has documentation written using tcsh
syntax. You can use either one and it's really a matter of
preference. If you're reading the documentation for a
program and it tells you to issue a command like "setenv X y",
that's a tcsh command. The equivalent bash command would
be "X=y; export X". Every time you start up a
new terminal window, your shell will read either the .bashrc or
the .cshrc file (if you're using bash or tcsh, respectively) in
your home directory. These files are where you put
definitions for your executable search path, aliases, and things
like that which you want to be read in every time you bring up a
Astronomical software installed
on the student computers includes:
Other useful computing
Web resources for astronomy:
- IRAF: a
general-purpose data reduction and analysis package
distributed by NOAO. IRAF has horribly cumbersome
syntax, crashes easily, and it's a pretty confusing language
to script. However, it includes a huge variety of data
reduction routines that are often the easiest and most
efficient way to perform certain tasks, and some data
reduction packages for the Hubble Space Telescope or other
observatories are written in IRAF. There are manuals here,
most of which are pretty old, but IRAF hasn't changed much
since they were written.
is a Python-based front-end for IRAF that's designed to be
more user-friendly than the standard IRAF cl
interface. Once your iraf directories are set up and
working, you can just type "pyraf" at the linux prompt to
start this up. (See the iraf setup instructions above
for additional important notes on using pyraf.)
This is an image-display program that works either as a
stand-alone or as a display tool for IRAF/PyRAF.
This is an image-processing environment and programming
language. It's a very efficient language for
astronomical data analysis and very easy to learn.
is a graphing/plotting program that can read in data from
ASCII tables, perform mathematical manipulations, and
generate publication-quality plots. The sm
homepage has a tutorial and a lot of information about using
this software is used to automatically determine world
coordinate system information for astronomical images.
- Other astronomy-specific packages installed with the
Scientific Linux distribution include the cfitsio
- The arXiv
e-print server (known to astronomers as "astro-ph").
Authors can upload electronic preprints, and each day a list
of new abstracts appears on the arXiv web site. You
can sign up for a daily email of new abstracts
too. It's good to get in the habit of at least
skimming through the list of new abstracts each day.
- The NASA
Data System (ADS). This is a web index of the
entire published astronomical literature. You can
search on author name, title or abstract content, or object
names and ADS will generate a list of publications that
match your query, including links to electronically
published articles or scanned versions of journal articles
from the pre-electronic era. There are a lot of nifty
things here, like the ability to search for papers that were
most often also read by people who read a given paper.
- The NASA/IPAC
Extragalactic Database (NED). A searchable index
of extragalactic objects including galaxies, quasars, galaxy
clusters, etc. Users can search by object name or
- The SIMBAD
database. A database of Galactic objects, useful for
finding the properties of a particular star, or for
selecting a list of stars matching known criteria.
- The MAST archive
at the Space Telescope Science Institute. This is an
multi-mission data archive that includes the Hubble Space
Telescope and many other NASA missions.
- The Sloan Digital Sky
Survey. Users can search for objects matching a
list of criteria using SQL queries and download images and
- The HEASARC
archive. A data archive of X-ray missions.
of the Day. A nice resource for pretty pictures,
and a good place to submit a picture from your own research
if you have something you want to show off to the public.
- American Astronomical
Society. Links to membership information,
meetings, grants, and more.
Society of the Pacific. Links to membership
information, publications, and an online store of
Meetings List. A list of upcoming conferences.
- The AAS Job
Register. An online listing of job offerings in
astronomy, updated monthly.