Astrophysics Source Code Library

Making codes discoverable since 1999

Welcome to the ASCL

The Astrophysics Source Code Library (ASCL) is a free online registry for source codes of interest to astronomers and astrophysicists, including solar system astronomers, and lists codes that have been used in research that has appeared in, or been submitted to, peer-reviewed publications. The ASCL is indexed by the SAO/NASA Astrophysics Data System (ADS) and Web of Science and is citable by using the unique ascl ID assigned to each code. The ascl ID can be used to link to the code entry by prefacing the number with (i.e.,

Most Recently Added Codes

2020 Oct 20

[ascl:2010.003] stsynphot: synphot for HST and JWST

An extension to synphot (ascl:1811.001), stsynphot implements synthetic photometry package for HST and JWST support. The software constructs spectra from various grids of model atmosphere spectra, parameterized spectrum models, and atlases of stellar spectrophotometry. It also simulates observations specific to HST and JWST, computes photometric calibration parameters for any supported instrument mode, and plots instrument-specific sensitivity curves and calibration target spectra.

2020 Oct 19

[ascl:2010.002] GSpec: Gamma-ray Burst Monitor analyzer

GSpec analyzes the Fermi mission's Gamma-ray Burst Monitor (GBM) data via a user-interactive GUI. The software provides a seamless interface to XSPEC (ascl:9910.005). It allows users to create their own Python scripts using the included libraries, and to define additional data reduction techniques, such as background fitting/estimation and data binning, as Python-based plugins. It is part of a larger effort to produce a set of GBM data tools to allow the broader community to analyze all aspects of GBM data, including the continuous data that GBM produces. GSpec is similar to RMfit (ascl:1409.011), a GUI-based spectral analysis code that specializes in the analysis of GBM trigger data, and is intended to eventually replace that IDL package.

2020 Oct 15

[ascl:2010.001] MBF: MOLSCAT 2020, BOUND, and FIELD for atomic and molecular collisions

MOLSCAT, which supercedes MOLSCAT version 14 (ascl:1206.004), performs non-reactive quantum scattering calculations for atomic and molecular collisions using coupled-channel methods. Simple atom-molecule and molecule-molecule collision types are coded internally and additional ones may be handled with plug-in routines. Plug-in routines may include external magnetic, electric or photon fields (and combinations of them).

The package also includes BOUND, which performs calculations of bound-state energies in weakly bound atomic and molecular systems using coupled-channel methods, and FIELD, a development of BOUND that locates values of external fields at which a bound state exists with a specified energy. Though the three programs have different applications, they use closely related methods, share many subroutines, and are released with a single code base.

2020 Oct 12

[submitted] DYnamics, Age and Metallicity Indicators Tracing Evolution (DYNAMITE)

DYNAMITE (DYnamics, Age and Metallicity Indicators Tracing Evolution) is a triaxial dynamical modelling code for stellar systems, which is developed at the University of Vienna. It is based on existing codes for Schwarzschild modelling in triaxial systems. The power and innovation of DYNAMITE lies in the easy-to-use object oriented Python wrapper. This makes it simple to extend the scope of pre-existing triaxial Schwarzschild codes with a number of new features, including (i) discrete kinematics, (ii) more flexible descriptions of line-of-sight velocity distributions, (iii) modelling of stellar population information, (iv) more efficient steps through parameter space, and (v) using GPU acceleration.

2020 Oct 02

[submitted] Exoplanet Detection Map Calculator (Exo-DMC)

The Exoplanet Detection Map Calculator (Exo-DMC) is a Monte Carlo tool for the statistical analysis of exoplanet surveys results.

It combines the information on the target stars with instrument detection limits to estimate the probability of detection of companions within a user defined range of masses and physical separations, ultimately generating detection probability maps.

2020 Sep 30

[ascl:2009.025] Binary-Speckle: Binary or triple star parameters

Binary-Speckle reduces Speckle or AO data from the raw data to deconvolved images (in Fourier space), to determine the parameters of a binary or triple, and to find limits for undetected companion stars.

[ascl:2009.024] MSL: Mining for Substructure Lenses

MSL applies simulation-based inference techniques to the problem of substructure inference in galaxy-galaxy strong lenses. It leverages additional information extracted from the simulator, then trains neural networks to estimate likelihood ratios associated with population-level parameters characterizing dark matter substructure. The package including five high-level scripts which run the simulation and create samples, combing multiple simulation runs into a single file to use for training, then train the neural networks. After training, the estimated likelihood ratio is tested, and calibrated network predictions are made based on histograms of the network output.

[ascl:2009.023] DASTCOM5: JPL small-body data browser

DASTCOM5 is a portable direct-access database containing all NASA/JPL asteroid and comet orbit solutions, and the software to access it. Available data include orbital elements, orbit diagrams, physical parameters, and discovery circumstances. A JPL implementation of the software is available at

[ascl:2009.022] Harmonia: Hybrid-basis inference for large-scale galaxy clustering

Harmonia combines clustering statistics decomposed in spherical and Cartesian Fourier bases for large-scale galaxy clustering likelihood analysis. Optimal weighting schemes for spherical Fourier analysis can also be readily implemented using the code.

[ascl:2009.021] Chrono: Multi-physics simulation engine

Chrono is a physics-based modelling and simulation infrastructure implemented in C++. It can handle multibody dynamics, collision detection, and granular flows, among many other physical processes. Though the applications for which Chrono has been used most often are vehicle dynamics, robotics, and machine design, it has been used to simulate asteroid aggregation and granular systems for astrophysics research. Chrono is written in C++; a Python version, PyChrono, is also available.