Here is a list of programs used by the community: https://heasarc.gsfc.nasa.gov/docs/heasarc/astro-update/
IRAF Image Reduction and Analysis Facility is used for a wide range of tasks pertaining to optical and infrared data processing. There is also pyIRAF as well.
If you want to install IRAF under anaconda: https://faculty1.coloradocollege.edu/~sburns/courses/18-19/pc362/Anaconda_IRAF_install.html
Note that IRAF and pyRAF is not supported anymore.
SAO ds9 is an astronomical image viewer and manipulator. It is used widely by the community regardless of wavelength. This is a nice tutorial on how to use ds9 to examine astronomical images: https://astrobites.org/2011/03/09/how-to-use-sao-ds9-to-examine-astronomical-images/
QFitsView is a FITS file viewer similar to SAOimage, DS9, and the like. It was written using the cross-platform QT library and thus runs under Microsoft Windows as well as many flavors of UNIX and MAC OS-X.
https://www.mpe.mpg.de/~ott/QFitsView/
SExtractor, or Source Extractor, is a program that operates on a FITS image to automatically detect objects. Once sources have been identified, a variety of measurements are made including source size, shape and magnitude.
Documentation: https://sextractor.readthedocs.io/en/latest/Introduction.html
A pdf manual is available here (for a slightly older version of the code).
SExtractor for Dummies is another manual
A Unified Release of the FTOOLS and XANADU Software Packages. This includes packages of: XANADU - High-level, multi-mission tasks for X-ray astronomical spectral, timing, and imaging data analysis, FTOOLS - General and mission-specific tools to manipulate FITS files, FITSIO - Core library responsible for reading and writing FITS files, fv - General FITS file browser/editor/plotter with a graphical user interface, and XSTAR - Tool for calculating the physical conditions and emission spectra of photoionized gases.
It also includes a lot of individual mission packages for ASCA, Einstein, EXOSAT, CGRO, HEAO-1 , Hitomi, INTEGRAL, MAXI, NICER, NuSTAR, OSO-8, ROSAT , Suzaku, Swift, Vela.
https://heasarc.gsfc.nasa.gov/lheasoft/
Sherpa is the CIAO modeling and fitting application for Python made available by the Chandra X-ray Center (CXC). Development takes place at the Sherpa GitHub repository and contributions - whether new code, bug fixes, or documentation input - are welcome.
Sherpa can be used for analysis of images, spectra and time series from many telescopes, including optical telescopes such as Hubble. It can also be easily used with non-Astronomical data. Sherpa is flexible, modular and extensible. It has an IPython user interface and it is also an importable Python module. Sherpa models, optimisation and statistic functions are available via both C++ and Python for software developers wishing to link such functions directly to their own compiled code.
Sherpa supports fitting of 1-D X-ray spectra from Chandra and other X-ray missions, as well as 1-D non-X-ray data, including generic data arrays, radial profiles, and lightcurves. The options for grating data analysis include fitting the spectrum with multiple response files required for overlapping orders in LETG observations. Modeling of 2-D spatial data is fully supported, including the PSF and exposure maps. User specified models can be added to Sherpa with advanced "user model" functionality.
Fv is an easy to use graphical program for viewing and editing any FITS format image or table.
https://heasarc.gsfc.nasa.gov/docs/software/lheasoft/ftools/fv/
The Astropy Project is a community effort to develop a core package for astronomy using the Python programming language and improve usability, interoperability, and collaboration between astronomy Python packages. The core astropy package contains functionality aimed at professional astronomers and astrophysicists, but may be useful to anyone developing astronomy software. The Astropy Project also includes "affiliated packages," Python packages that are not necessarily developed by the core development team, but share the goals of Astropy, and often build from the core package's code and infrastructure.
specutils is a Python package for representing, loading, manipulating, and analyzing astronomical spectroscopic data. The generic data containers and accompanying modules provide a toolbox that the astronomical community can use to build more domain-specific packages.
https://specutils.readthedocs.io/en/stable/index.html
A Mission Count Rate Simulator. Predominantly aimed at X-ray instrumentation.
https://heasarc.gsfc.nasa.gov/cgi-bin/Tools/w3pimms/w3pimms.pl
Determine when or if an astronomical position can be viewed by a given space telescope.
If something is observable from a ground based observatory:
http://catserver.ing.iac.es/staralt/index.php
Calculate the H I Column Density for a Sky Position
https://heasarc.gsfc.nasa.gov/cgi-bin/Tools/w3nh/w3nh.pl
Interactively view tabular data of astronomical data sets.
http://www.star.bris.ac.uk/~mbt/topcat/
If you have astronomical imaging of the sky with celestial coordinates you do not know—or do not trust—then Astrometry.net is for you. Input an image and we'll give you back astrometric calibration meta-data, plus lists of known objects falling inside the field of view.
Cubeviz is a visualization and analysis toolbox for data cubes from integral field units (IFUs). It is built as part of the Glue visualiztion tool. Cubeviz is designed to work with data cubes from the NIRSpec and MIRI instruments on JWST, and will work with IFU data cubes.
https://jdaviz.readthedocs.io/en/latest/cubeviz/index.html