The Astrophysics Source Code Library (ASCL) is a free online registry and repository 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 ascl.net (i.e., ascl.net/1201.001).
SHELLFISH (SHELL Finding In Spheroidal Halos) finds the splashback shells of individual halos within cosmological simulations. It uses a command line toolchain to produce human-readable catalogs. It requires a configuration file that describes the layout of the particle snapshots and halo catalog and which halos to measure the splashback shell for; once that is provided, Shellfish takes care of the rest. It supports numerous particle catalog types, including gotetra, Gadget-2, and Bolshoi, all text column-based halo catalogs, and consistent-trees merger trees.
JOFILUREN analyzes and de-noises scientific data and is useful for studying and reducing the physical effects of particle noise in particle-mesh computer simulations. It uses wavelets, which can efficiently remove noise from cosmological, galaxy and plasma N-body simulations. Written in Fortran, the code is portable and can be included in grid-based N-body codes. JOFILUREN can also be applied for removing noise from standard data, such as signals and images.
Vela.jl performs Bayesian pulsar timing and noise analysis. It supports narrowband and wideband TOAs along with most commonly used pulsar timing models. The code provides an independent, efficient, and parallelized implementation of the full nonlinear pulsar timing and noise model and includes a Python binding (pyvela). One-time operations such as data file input, clock corrections, and solar system ephemeris computations are performed by pyvela with the help of the PINT (ascl:1902.007) pulsar timing package.
DMCalc estimates the Dispersion Measure (DM) of wide-band pulsar data in psrfits format. It uses PSRCHIVE (ascl:1105.014) tools to get ToAs and then uses TEMPO2 (ascl:1210.015) for DM fitting. A median absolute deviation (MAD) based ToA rejection algorithm is implemented in the code to remove large outlier ToAs using Huber Regression. Although the code has been used for analyzing uGMRT wide-band data, DMCalc can in principle be used for any pulsar dataset.
TempoNest performs a Bayesian analysis of pulsar timing data, which allows for the robust determination of the non-linear pulsar timing solution simultaneously with a range of additional stochastic parameters. This includes both red spin noise and dispersion measure variations using either power law descriptions of the noise, or through a model-independent method that parameterizes the power at individual frequencies in the signal. It uses the Bayesian inference tool MultiNest (ascl:1109.006) to explore the joint parameter space, while using Tempo2 (ascl:1210.015) as a means of evaluating the timing model. TempoNest allows for the analysis of additional stochastic signals beyond the white noise described by the TOA error bars that may be present in the data.
The highly optimized Kotekan framework processes streaming data. Written in a combination of C/C++, it is primarily designed for use on radio telescopes and was originally developed for the CHIME project. It is similar to radio projects such as GNUradio (ascl:2504.029) or Bifrost (ascl:1711.021), though has a greater focus on efficiency and throughput. Kotekan is conceptually straightforward: data is carried through the system in a series of ring buffer objects, which are connected by processing blocks which manipulate the data, and optional metadata structures can be passed alongside the streaming data.
The GNU Radio toolkit provides signal processing blocks to implement software radios. A software radio performs signal processing in software instead of using dedicated integrated circuits in hardware. The benefit is that since software can be easily replaced in the radio system, the same hardware can be used to create many kinds of radios for many different communications standards. GNU Radio can be used with readily-available low-cost external RF hardware to create software-defined radios and to simulate wireless communications.
jaxoplanet is a functional-programming-forward implementation of many features from the exoplanet and starry packages built on top of JAX (ascl:2111.002). It includes fast and robust implementations of many exoplanet-specific operations, including solving Kepler’s equation, and computing limb-darkened light curves. Built on top of JAX, jaxoplanet has first-class support for hardware acceleration using GPUs and TPUs, and integrates seamlessly with modeling tools such as NumPyro and Flax (ascl:2504.026).
picasso makes predictions for the thermodynamic properties of the gas in massive dark matter halos from gravity-only cosmological simulations. It combines an analytical model of gas properties as a function of gravitational potential with a neural network predicting the parameters of said model. Written in Python, it combines an implementation of the gas model based on JAX (ascl:2111.002) and Flax (ascl:2504.026), and models that have been pre-trained to reproduce gas properties from hydrodynamic simulations.
Flax provides a flexible end-to-end user experience for JAX users; its NNX is a simplified API that creates, inspects, debugs, and analyzes neural networks in JAX. It has first class support for Python reference semantics, enabling users to express their models using regular Python objects. Flax NNX is an evolution of the previous Flax Linen API.