# Astrophysics Source Code Library

Here is a list of professional astrophysics codes. Many of the links below came from the Astrophysics Source Code Library (ASCL); the ASCL now has hundreds of codes and can be found here. The links below have been changed to reflect the new locations of the entries. See also
http://www.cfd-online.com/
http://www.astro-sim.org/
http://www-theorie.physik.unizh.ch/astrosim/code/doku.php

## Accretion Disks

DUSTY - Radiation transport in a dusty environment Ivezic, Z., Nenkova, M., & Elitzur, M.
XSTAR - A program for calculating conditions and spectra of photoionized gases Kallman, T.

## Astrochemistry

CSENV: A code for the chemistry of CircumStellar ENVelopes Mamon, G. A. http://ascl.net/0104.002

## Astrometry

StarFinder: A code for stellar field analysis Diolaiti, E. et al. http://ascl.net/0011.001

## Astronomical Databases: Miscellaneous

CHIANTI: A database for astrophysical emission line spectroscopy CHIANTI Consortium http://ascl.net/9911.004

## Astrophysics general

AMUSE: Astronphysical Multipurpose Software Environment Portegies Zwart, S, et al. http://amusecode.org

## Atomic Data

CHIANTI: A database for astrophysical emission line spectroscopy CHIANTI Consortium http://ascl.net/9911.004

## Atomic Processes

CHIANTI: A database for astrophysical emission line spectroscopy CHIANTI Consortium http://ascl.net/9911.004
CLOUDY: Numerical simulation of plasmas and their spectra Ferland, G. et al. http://ascl.net/9910.001
PopRatio: A program to calculate atomic level populations in astrophysical plasmas Silva, A. I. & Viegas, S. M. http://ascl.net/0202.001

## Black Hole Physics

BHSKY: Visual distortions near a black hole Nemiroff, R. J. http://ascl.net/9910.006

## Circumstellar Matter

CSENV: A code for the chemistry of CircumStellar ENVelopes Mamon, G. A. http://ascl.net/0104.002

## Cosmic Microwave Background

COSMICS: Cosmological initial conditions and microwave anisotropy codes Bertschinger, E. http://ascl.net/9910.004
RADPACK: A RADical compression analysis PACKage for fitting to the CMB Knox, L. http://ascl.net/9910.009
CMBFAST: A microwave anisotropy code Seljak, U. & Zaldarriaga, M. http://ascl.net/9909.004
Icosahedron: The Icosahedron Package for Pixelizing the Sphere Tegmark, M. http://ascl.net/9905.002

## Cosmology: Theory

COSMICS: Cosmological initial conditions and microwave anisotropy codes Bertschinger, E. http://ascl.net/9910.004
ANGSIZ: A general and practical method for calculating cosmological distances Helbig, P., Kayser, R., & Schramm, T. http://ascl.net/9909.002
PMcode: Particle-Mesh code for cosmological simulations Klypin, A. & Holtzman, J. http://ascl.net/9909.001
RADPACK: A RADical compression analysis PACKage for fitting to the CMB Knox, L. http://ascl.net/9910.009
CMBFAST: A microwave anisotropy code Seljak, U. & Zaldarriaga, M. http://ascl.net/9909.004

## Cosmology: Large-Scale Structure of Universe

MLAPM: Simulating Structure Formation from Collisionless Matter Knebe, A., Green, A. & Binney, J. http://ascl.net/0104.001

## Dark Matter

COSMICS: Cosmological initial conditions and microwave anisotropy codes Bertschinger, E. http://ascl.net/9910.004
PMcode: Particle-Mesh code for cosmological simulations Klypin, A. & Holtzman, J. http://ascl.net/9909.001
MLAPM: Simulating Structure Formation from Collisionless Matter Knebe, A., Green, A. & Binney, J. http://ascl.net/0104.001
CMBFAST: A microwave anisotropy code Seljak, U. & Zaldarriaga, M. http://ascl.net/9909.004

## Distance Scale

ANGSIZ: A general and practical method for calculating cosmological distances Helbig, P., Kayser, R., & Schramm, T. http://ascl.net/9909.002
SLOPES: least-squares linear regression lines for bivariate datasets Feigelson, E. http://ascl.net/9906.001

## Elementary Particles

COSMICS: Cosmological initial conditions and microwave anisotropy codes Bertschinger, E. http://ascl.net/9910.004

## Galaxies
### Elliptical

FASTELL: Fast calculation of a family of elliptical mass gravitational lens models Barkana, R. http://ascl.net/9910.003

### Formation

MLAPM: Simulating Structure Formation from Collisionless Matter Knebe, A., Green, A. & Binney, J. http://ascl.net/0104.001
SPH_1D: Hierarchical gravity/SPH treecode for simulations of interacting galaxies Olson, K. http://ascl.net/9912.001

### Halos

MLAPM: Simulating Structure Formation from Collisionless Matter Knebe, A., Green, A. & Binney, J. http://ascl.net/0104.001

### Individual

FASTELL: Fast calculation of a family of elliptical mass gravitational lens models Barkana, R. http://ascl.net/9910.003

### Interactions

SPH_1D: Hierarchical gravity/SPH treecode for simulations of interacting galaxies Olson, K. http://ascl.net/9912.001

### Structure

FASTELL: Fast calculation of a family of elliptical mass gravitational lens models Barkana, R. http://ascl.net/9910.003

### Content

BSGMODEL: The Bahcall-Soneira Galaxy Model Bahcall, J. N. http://ascl.net/9904.001

### Structure

BSGMODEL: The Bahcall-Soneira Galaxy Model Bahcall, J. N. http://ascl.net/9904.001
EXTINCT: A Computerized Model of Large-Scale Visual Interstellar Extinction Hakkila, J., Myers, J. M., Stidman, B. J., Hartmann, D. H. http://ascl.net/9906.002

### Bursts

WINGSPAN: A WINdows Gamma-ray SPectral Analysis program Preece, R. D., Briggs, M. S., Mallozzi R. S., & Brock, M. N. http://ascl.net/9910.007
MILLISEARCH: A Search for Millilensing in BATSE GRB Data Nemiroff, Robert J. http://ascl.net/0101.001
BLOCK: A Bayesian block method to analyze structure in photon counting data Scargle, J. D. http://ascl.net/9909.005 This code is obsolete and yields approximate results; see Bayesian Blocks instead for an algorithm guaranteeing exact global optimization.

### Observations

WINGSPAN: A WINdows Gamma-ray SPectral Analysis program Preece, R. D., Briggs, M. S., Mallozzi R. S., & Brock, M. N. http://ascl.net/9910.007

### Gravitation

NBODY family of codes: Numerical Simulations of Many-body (N-body) Gravitational Interactions Aarseth, S. http://ascl.net/1102.006
COSMICS: Cosmological initial conditions and microwave anisotropy codes Bertschinger, E. http://ascl.net/9910.004
GADGET: A code for cosmological simulations of structure formation Springel, V. & Yoshida, N. http://ascl.net/0003.001

## Gravitational Lensing

FASTELL: Fast calculation of a family of elliptical mass gravitational lens models Barkana, R. http://ascl.net/9910.003
ANGSIZ: A general and practical method for calculating cosmological distances Helbig, P., Kayser, R., & Schramm, T. http://ascl.net/9909.002
MILLISEARCH: A Search for Millilensing in BATSE GRB Data Nemiroff, Robert J. http://ascl.net/0101.001
BHSKY: Visual distortions near a black hole Nemiroff, R. J. http://ascl.net/9910.006
LENSKY: Galactic Microlensing Probability Nemiroff, R. J. http://ascl.net/LENSKY

## Hydrodynamics

GADGET: A code for cosmological simulations of structure formation Springel, V. & Yoshida, N. http://ascl.net/0003.001
Pencil Code: A high-order code, especially for hydromagnetic turbulence; http://pencil-code.googlecode.com/

## Instrumentation
### Adaptive Optics

StarFinder: A code for stellar field analysis Diolaiti, E. et al. http://ascl.net/0011.001

### Detectors

XSPEC: An X-ray spectral fitting package Arnaud, K., Shafer, R., Haberl, F. & Tennant, A. http://ascl.net/9910.005
ISIS - A programmable data analysis environment, similar to IDL or matlab, with a strong emphasis on X-ray spectral analysis.
CONSKY: Sky CCD Integration Simulation Nemiroff, R. J. & Rafert, J. B. http://ascl.net/9905.001
WINGSPAN: A WINdows Gamma-ray SPectral Analysis program Preece, R. D., Briggs, M. S., Mallozzi R. S., & Brock, M. N. http://ascl.net/9910.007

### Interferometric

AIPS: Astronomical Image Processing System AIPS Team http://ascl.net/9911.003

### Photometers

IRAF: Image Reduction and Analysis Facility IRAF Team http://ascl.net/9911.002

### Spectrographs

XSPEC: An X-ray spectral fitting package Arnaud, K., Shafer, R., Haberl, F. & Tennant, A. http://ascl.net/9910.005
ISIS - A programmable data analysis environment, similar to IDL or matlab, with a strong emphasis on X-ray spectral analysis.
IRAF: Image Reduction and Analysis Facility IRAF Team http://ascl.net/9911.002
RVSAO: Digital redshifts and radial velocities Kurtz, M. J. & Mink, D. J. http://ascl.net/9912.003

## ISM
### Abundances

CLOUDY: Numerical simulation of plasmas and their spectra Ferland, G. et al. http://ascl.net/9910.001

### Atoms

CLOUDY: Numerical simulation of plasmas and their spectra Ferland, G. et al. http://ascl.net/9910.001

### Dust

DDSCAT: The Discrete Dipole approximation for Scattering and absorption of light by irregular particles Draine, B. T. & Flatau, Piotr J. http://ascl.net/0008.001
EXTINCT: A Computerized Model of Large-Scale Visual Interstellar Extinction Hakkila, J., Myers, J. M., Stidman, B. J., Hartmann, D. H. http://ascl.net/9906.002
DUSTY: Radiation transport in a dusty environment Ivezic, Z., Nenkova, M., & Elitzur, M. http://ascl.net/9911.001

### Extinction

DDSCAT: The Discrete Dipole approximation for Scattering and absorption of light by irregular particles Draine, B. T. & Flatau, Piotr J. http://ascl.net/0008.001
EXTINCT: A Computerized Model of Large-Scale Visual Interstellar Extinction Hakkila, J., Myers, J. M., Stidman, B. J., Hartmann, D. H. http://ascl.net/9906.002
DUSTY: Radiation transport in a dusty environment Ivezic, Z., Nenkova, M., & Elitzur, M. http://ascl.net/9911.001

### Molecules

RATRAN: Radiative transfer and molecular excitation in one and two dimensions Hogerheijde, Michiel & van der Tak, Floris http://ascl.net/RATRAN
CSENV: A code for the chemistry of CircumStellar ENVelopes Mamon, G. A. http://ascl.net/0104.002

## Large-Scale Structure Of The Universe

COSMICS: Cosmological initial conditions and microwave anisotropy codes Bertschinger, E. http://ascl.net/9910.004
PMcode: Particle-Mesh code for cosmological simulations Klypin, A. & Holtzman, J. http://ascl.net/9909.001
CMBFAST: A microwave anisotropy code Seljak, U. & Zaldarriaga, M. http://ascl.net/9909.004

## Line
### Formation

XSPEC: An X-ray spectral fitting package Arnaud, K., Shafer, R., Haberl, F. & Tennant, A. http://ascl.net/9910.005
ISIS - A programmable data analysis environment, similar to IDL or matlab, with a strong emphasis on X-ray spectral analysis.
CLOUDY: Numerical simulation of plasmas and their spectra Ferland, G. et al. http://ascl.net/9910.001
RATRAN: Radiative transfer and molecular excitation in one and two dimensions Hogerheijde, Michiel & van der Tak, Floris http://ascl.net/RATRAN
XSTAR: A program for calculating conditions and spectra of photoionized gases Kallman, T. http://ascl.net/9910.008
PopRatio: A program to calculate atomic level populations in astrophysical plasmas Silva, A. I. & Viegas, S. M. http://ascl.net/0202.001

### Identification

XSPEC: An X-ray spectral fitting package Arnaud, K., Shafer, R., Haberl, F. & Tennant, A. http://ascl.net/9910.005
ISIS - A programmable data analysis environment, similar to IDL or matlab, with a strong emphasis on X-ray spectral analysis.
WINGSPAN: A WINdows Gamma-ray SPectral Analysis program Preece, R. D., Briggs, M. S., Mallozzi R. S., & Brock, M. N. http://ascl.net/9910.007

### Data Analysis

AIPS: Astronomical Image Processing System AIPS Team http://ascl.net/9911.003
ISIS: A method for optimal image subtraction Alard, C. & Lupton, R. http://ascl.net/9909.003
XSPEC: An X-ray spectral fitting package Arnaud, K., Shafer, R., Haberl, F. & Tennant, A. http://ascl.net/9910.005
ISIS - A programmable data analysis environment, similar to IDL or matlab, with a strong emphasis on X-ray spectral analysis.
StarFinder: A code for stellar field analysis Diolaiti, E. et al. http://ascl.net/0011.001
SLOPES: least-squares linear regression lines for bivariate datasets Feigelson, E. http://ascl.net/9906.001
FTOOLS: A general package of software to manipulate FITS files FTOOLS Team http://ascl.net/9912.002
IRAF: Image Reduction and Analysis Facility IRAF Team http://ascl.net/9911.002
RVSAO: Digital redshifts and radial velocities Kurtz, M. J. & Mink, D. J. http://ascl.net/9912.003
MILLISEARCH: A Search for Millilensing in BATSE GRB Data Nemiroff, Robert J. http://ascl.net/0101.001
BLOCK: A Bayesian block method to analyze structure in photon counting data Scargle, J. D. http://ascl.net/9909.005 This code is obsolete and yields approximate results; see Bayesian Blocks instead for an algorithm guaranteeing exact global optimization.
WINGSPAN: A WINdows Gamma-ray SPectral Analysis program Preece, R. D., Briggs, M. S., Mallozzi R. S., & Brock, M. N. http://ascl.net/9910.007
Icosahedron: The Icosahedron Package for Pixelizing the Sphere Tegmark, M. http://ascl.net/9905.002
SAOimage: A utility for displaying astronomical images in the X11 window environment VanHilst, M. & Mink, D. http://ascl.net/0003.002

### N-Body Simulations

NBODY family of codes for numerical simulations of many-body (N-body) gravitational interactions Aarseth, S. http://ascl.net/1102.00
GADGET: A code for cosmological simulations of structure formation Springel, V. & Yoshida, N. http://ascl.net/0003.001

### Numerical

RATRAN: Radiative transfer and molecular excitation in one and two dimensions Hogerheijde, Michiel & van der Tak, Floris http://ascl.net/RATRAN
SPH_1D: Hierarchical gravity/SPH treecode for simulations of interacting galaxies Olson, K. http://ascl.net/9912.001
BLOCK: A Bayesian block method to analyze structure in photon counting data Scargle, J. D. http://ascl.net/9909.005 This code is obsolete and yields approximate results; see Bayesian Blocks instead for an algorithm guaranteeing exact global optimization.

### Statistical

ISIS: A method for optimal image subtraction Alard, C. & Lupton, R. http://ascl.net/9909.003
SLOPES: least-squares linear regression lines for bivariate datasets Feigelson, E. http://ascl.net/9906.001
RADPACK: A RADical compression analysis PACKage for fitting to the CMB Knox, L. http://ascl.net/9910.009
BLOCK: A Bayesian block method to analyze structure in photon counting data Scargle, J. D. http://ascl.net/9909.005 This code is obsolete and yields approximate results; see Bayesian Blocks instead for an algorithm guaranteeing exact global optimization.
SLstats: Statistics module for the S-Lang interpreter Davis, J. E. http://space.mit.edu/cxc/software/slang/modules/stats/

## Plasmas

XSPEC: An X-ray spectral fitting package Arnaud, K., Shafer, R., Haberl, F. & Tennant, A. http://ascl.net/9910.005
ISIS - A programmable data analysis environment, similar to IDL or matlab, with a strong emphasis on X-ray spectral analysis.
CLOUDY: Numerical simulation of plasmas and their spectra Ferland, G. et al. http://ascl.net/9910.001
XSTAR: A program for calculating conditions and spectra of photoionized gases Kallman, T. http://ascl.net/9910.008
WINGSPAN: A WINdows Gamma-ray SPectral Analysis program Preece, R. D., Briggs, M. S., Mallozzi R. S., & Brock, M. N. http://ascl.net/9910.007
PopRatio: A program to calculate atomic level populations in astrophysical plasmas Silva, A. I. & Viegas, S. M. http://ascl.net/0202.001

## Radiation Mechanisms: Non-Thermal

XSPEC: An X-ray spectral fitting package Arnaud, K., Shafer, R., Haberl, F. & Tennant, A. http://ascl.net/9910.005
ISIS - A programmable data analysis environment, similar to IDL or matlab, with a strong emphasis on X-ray spectral analysis.
WINGSPAN: A WINdows Gamma-ray SPectral Analysis program Preece, R. D., Briggs, M. S., Mallozzi R. S., & Brock, M. N. http://ascl.net/9910.007

## Radiation Mechanisms: Thermal

XSPEC: An X-ray spectral fitting package Arnaud, K., Shafer, R., Haberl, F. & Tennant, A. http://ascl.net/9910.005
ISIS - A programmable data analysis environment, similar to IDL or matlab, with a strong emphasis on X-ray spectral analysis.
CLOUDY: Numerical simulation of plasmas and their spectra Ferland, G. et al. http://ascl.net/9910.001
XSTAR: A program for calculating conditions and spectra of photoionized gases Kallman, T. http://ascl.net/9910.008
WINGSPAN: A WINdows Gamma-ray SPectral Analysis program Preece, R. D., Briggs, M. S., Mallozzi R. S., & Brock, M. N. http://ascl.net/9910.007

## Radiative Transfer

DDSCAT: The Discrete Dipole approximation for Scattering and absorption of light by irregular particles Draine, B. T. & Flatau, Piotr J. http://ascl.net/0008.001
CLOUDY: Numerical simulation of plasmas and their spectra Ferland, G. et al. http://ascl.net/9910.001
RATRAN: Radiative transfer and molecular excitation in one and two dimensions Hogerheijde, Michiel & van der Tak, Floris http://ascl.net/RATRAN
DUSTY: Radiation transport in a dusty environment Ivezic, Z., Nenkova, M., & Elitzur, M. http://ascl.net/9911.001

## Radio Continuum: General

AIPS: Astronomical Image Processing System AIPS Team http://ascl.net/9911.003

## Radio Lines: General

AIPS: Astronomical Image Processing System AIPS Team http://ascl.net/9911.003

## Relativity

BHSKY: Visual distortions near a black hole Nemiroff, R. J. http://ascl.net/9910.006

## Scattering

DDSCAT: The Discrete Dipole approximation for Scattering and absorption of light by irregular particles Draine, B. T. & Flatau, Piotr J. http://ascl.net/0008.001

## Stars
### Abundances

SPECTRUM: A stellar spectral synthesis program Gray, R. O. http://ascl.net/9910.002

### Atmospheres

CHIANTI: A database for astrophysical emission line spectroscopy CHIANTI Consortium http://ascl.net/9911.004
SPECTRUM: A stellar spectral synthesis program Gray, R. O. http://ascl.net/9910.002

### Circumstellar Matter

DUSTY: Radiation transport in a dusty environment Ivezic, Z., Nenkova, M., & Elitzur, M. http://ascl.net/9911.001

### Fundamental Parameters

SPECTRUM: A stellar spectral synthesis program Gray, R. O. http://ascl.net/9910.002

### General

CONSKY: Sky CCD Integration Simulation Nemiroff, R. J. & Rafert, J. B. http://ascl.net/9905.001

### Imaging

StarFinder: A code for stellar field analysis Diolaiti, E. et al. http://ascl.net/0011.001

### Individual

SPECTRUM: A stellar spectral synthesis program Gray, R. O. http://ascl.net/9910.002

### Pre-Main-Sequence

DUSTY: Radiation transport in a dusty environment Ivezic, Z., Nenkova, M., & Elitzur, M. http://ascl.net/9911.001

### Variables

CONSKY: Sky CCD Integration Simulation Nemiroff, R. J. & Rafert, J. B. http://ascl.net/9905.001

### Atmosphere

CHIANTI: A database for astrophysical emission line spectroscopy CHIANTI Consortium http://ascl.net/9911.004

### Gamma-Rays

WINGSPAN: A WINdows Gamma-ray SPectral Analysis program Preece, R. D., Briggs, M. S., Mallozzi R. S., & Brock, M. N. http://ascl.net/9910.007

### Surveys

CONSKY: Sky CCD Integration Simulation Nemiroff, R. J. & Rafert, J. B. http://ascl.net/9905.001

## Techniques
### Image Processing

ISIS: A method for optimal image subtraction Alard, C. & Lupton, R. http://ascl.net/9909.003
StarFinder: A code for stellar field analysis Diolaiti, E. et al. http://ascl.net/0011.001
FTOOLS: A general package of software to manipulate FITS files FTOOLS Team http://ascl.net/9912.002

### Interferometric

AIPS: Astronomical Image Processing System AIPS Team http://ascl.net/9911.003

### Photometric

StarFinder: A code for stellar field analysis Diolaiti, E. et al. http://ascl.net/0011.001
IRAF: Image Reduction and Analysis Facility IRAF Team http://ascl.net/9911.002
CONSKY: Sky CCD Integration Simulation Nemiroff, R. J. & Rafert, J. B. http://ascl.net/9905.001
SAOimage: A utility for displaying astronomical images in the X11 window environment VanHilst, M. & Mink, D. http://ascl.net/0003.002

### Radial Velocities

RVSAO: Digital redshifts and radial velocities Kurtz, M. J. & Mink, D. J. http://ascl.net/9912.003

### Radar Astronomy

AIPS: Astronomical Image Processing System AIPS Team http://ascl.net/9911.003

### Spectroscopic

XSPEC: An X-ray spectral fitting package Arnaud, K., Shafer, R., Haberl, F. & Tennant, A. http://ascl.net/9910.005
ISIS - A programmable data analysis environment, similar to IDL or matlab, with a strong emphasis on X-ray spectral analysis.
CHIANTI: A database for astrophysical emission line spectroscopy CHIANTI Consortium http://ascl.net/9911.004
SPECTRUM: A stellar spectral synthesis program Gray, R. O. http://ascl.net/9910.002
IRAF: Image Reduction and Analysis Facility IRAF Team http://ascl.net/9911.002
RVSAO: Digital redshifts and radial velocities Kurtz, M. J. & Mink, D. J. http://ascl.net/9912.003
WINGSPAN: A WINdows Gamma-ray SPectral Analysis program Preece, R. D., Briggs, M. S., Mallozzi R. S., & Brock, M. N. http://ascl.net/9910.007

## Telescopes

CONSKY: Sky CCD Integration Simulation Nemiroff, R. J. & Rafert, J. B. http://ascl.net/9905.001

## Ultraviolet: General

CHIANTI: A database for astrophysical emission line spectroscopy CHIANTI Consortium http://ascl.net/9911.004
IRAF: Image Reduction and Analysis Facility IRAF Team http://ascl.net/9911.002
SAOimage: A utility for displaying astronomical images in the X11 window environment VanHilst, M. & Mink, D. http://ascl.net/0003.002

## X-Rays
### General

XSPEC: An X-ray spectral fitting package Arnaud, K., Shafer, R., Haberl, F. & Tennant, A. http://ascl.net/9910.005
ISIS - A programmable data analysis environment, similar to IDL or matlab, with a strong emphasis on X-ray spectral analysis.
FTOOLS: A general package of software to manipulate FITS files FTOOLS Team http://ascl.net/9912.002
XSTAR: A program for calculating conditions and spectra of photoionized gases Kallman, T. http://ascl.net/9910.008

### Stars

XSTAR: A program for calculating conditions and spectra of photoionized gases Kallman, T. http://ascl.net/9910.008