The deep learning model Starduster emulates dust radiative transfer simulations, which significantly accelerates the computation of dust attenuation and emission. Starduster contains two specific generative models, which explicitly take into account the features of the dust attenuation curves and dust emission spectra. Both generative models should be trained by a set of characteristic outputs of a radiative transfer simulation. The obtained neural networks can produce realistic galaxy spectral energy distributions that satisfy the energy balance condition of dust attenuation and emission. Applications of Starduster include SED-fitting and SED-modeling from semi-analytic models.

ASPIRED reduces 2D spectral data from raw image to wavelength and flux calibrated 1D spectrum automatically without any user input (quicklook quality), and provides a set of easily configurable routines to build pipelines for long slit spectrographs on different telescopes (science quality). It delivers near real-time data reduction, which can facilitate automated or interactive decision making, allowing "on-the-fly" modification of observing strategies and rapid triggering of other facilities.

Popsynth provides an abstract way to generate survey populations from arbitrary luminosity functions and redshift distributions. Additionally, auxiliary quantities can be sampled and stored. Populations can be saved and restored via an HDF5 files for later use, and population synthesis routines can be created via classes or structured YAML files. Users can construct their own classes for spatial, luminosity, and other distributions, all of which can be connected to arbitrarily complex selection functions.

distance-omnibus computes posterior DPDFs for catalog sources using the Bayesian application of kinematic distance likelihoods derived from a Galactic rotation curve with prior Distance Probability Density Functions (DPDFs) derived from ancillary data. The methodology and code base are generalized for use with any (sub-)millimeter survey of the Galactic plane.

contaminante helps find the contaminant transiting source in NASA's Kepler, K2 or TESS data. When hunting for transiting planets, sometimes signals come from neighboring contaminants. This package helps users identify where the transiting signal comes from in their data. The code uses pixel level modeling of the TargetPixelFile data from NASA's astrophysics missions that are processed with the Kepler pipeline. The output of contaminante is a Python dictionary containing the source location and transit depth, and a contaminant location and depth. It can also output a figure showing where the main target is centered in all available TPFs, what the phase curve looks like for the main target, where the transiting source is centered in all available TPFs, if a transiting source is located outside the main target, or the transiting source phase curve, if a transiting source is located outside the main target.

Sculptor manipulates, models and analyzes spectroscopic data; the code facilitates reproducible scientific results and easy to inspect model fits. A built-in graphical user interface around LMFIT (ascl:1606.014) offers interactive control to set up and combine multiple spectral models to fully fit the spectrum of choice. Alternatively, all core functionality can be scripted to facilitate the design of spectral fitting and analysis pipelines.

GALLUMI (GALaxy LUMInosity) is a likelihood code that extracts cosmological and astrophysical parameters from the UV galaxy luminosity function. The code is implemented in the MCMC sampler MontePython (ascl:1307.002) and can be readily run in conjunction with other likelihood codes.

Find_Orb takes a set of observations of an asteroid, comet, or natural or artificial satellite given in the MPC (Minor Planet Center) format, the ADES astrometric format, and/or the NEODyS or AstDyS formats, and finds the corresponding orbit.

SPARTAN fits the spectroscopy and photometry of distant galaxies. The code implements multiple interfaces to help in the configuration of the fitting and the inspection of the results. SPARTAN relies on pre-computed input files (such as stellar population and IGM extinction), available for download, to save time in the fitting process.

Site with collection of codes and fundamental references on mean motion resonances.

Citlalicue allows you to create synthetic stellar light curves (transits, stellar variability and white noise) and detrend light curves using Gaussian Processes (GPs). Transits are implemented using PyTransit (ascl:1505.024). Python notebooks are provided to demonstrate using Citlalicue for both functions.

PSLS simulates solar-like oscillators representative of PLATO targets. It includes planetary transits, stochastically-excited oscillations, granulation and activity background components, as well as instrumental systematic errors and random noises representative for PLATO.

fiducial_flare generates a reasonable approximation of the UV emission of M dwarf stars over a single flare or a series of them. The simulated radiation is resolved in both wavelength and time. The intent is to provide consistent input for applications requiring time-dependent stellar UV radiation fields that balances simplicity with realism, namely for simulations of exoplanet atmospheres.

Residual Feature Extraction Pipeline carries out feature extraction of residual substructure within the residual images produced by popular galaxy structural-fitting routines such as GALFIT (ascl:1104.010) and GIM2D (ascl:1004.001). It extracts faint low surface brightness features by isolating flux-wise and area-wise significant contiguous pixels regions by rigorous masking routine. The code accepts the image cubes (original image, model image, residual image) and generates several data products, such as an image with extracted features, a source extraction based segmentation map, and the background sky mask and the residual extraction mask. It uses a Monte Carlo approach-based area threshold above which the extracted features are identified. The pipeline also creates a catalog entry indicating the surface brightness and its error.

The EDI (Exoplanet Detection Identifier) Vetter Unplugged software identifies false positive transit signals using Transit Least Squares (TLS) information and has been simplified from the full EDI-Vetter algorithm (ascl:2202.009) for easy implementation with the TLS output.

EDI (Exoplanet Detection Identifier) Vetter identifies false positive transit signal in the K2 data set. It combines the functionalities of Terra (ascl:2202.008) and RoboVetter (ascl:2012.006) and is optimized to test single transiting planet signals. An easily implemented suite of vetting metrics built to run alongside TLS of EDI Vetter, EDI-Vetter Unplugged (ascl:2202.010), is also available.

TERRA (Transiting Exoearth Robust Reduction Algorithm) identifies and removes instrumental noise in Kepler photometry. This transit detection code is optimized to detect small planets around photometrically quiet stars. TERRA calculates photometry in the time domain, combs the calibrated photometry for periodic, box-shaped signals, fits promising signals, and rejects signals inconsistent with exoplanet transits.

SciCatalog handles catalogs of scientific data in a way that is easily extensible, including the ability to create nicely formatted AASTex deluxe tables for use in AAS Publishing manuscripts. It handles catalogs of values, their positive and negative uncertainties, and references for those values with methods for easily adding columns and changing values. The catalog is also backed up every time it is loaded under the assumption that it is about to be modified.

FIRE Studio is a Python interface for C libraries that project Smoothed Particle Hydrodynamic (SPH) datasets. These C libraries can, in principle, be applied to any SPH dataset; the Python interface is specialized to conveniently load and format Gadget-derivative datasets such as GIZMO (ascl:1410.003). FIRE Studio is fast, memory efficient, and parallelizable. In addition to producing "1-color" projection maps for SPH datasets, the interface can produce "2-color" maps, where the pixel saturation is set by one projected quantity and the hue is set by another, and "3-color" maps, where three quantities are projected simultaneously and remapped into an RGB colorspace. FIRE Studio can model stellar emission and dust extinction to produce mock Hubble images (by default) or to model surface brightness maps for thirteen of the most common bands (plus the bolometric luminosity). It produces publication quality static images of simulation datasets and provides interpolation scripts to create movies that smoothly evolve in time (provided multiple snapshots in time of the data exist), view the dataset from different perspectives (taking advantage of shared memory buffers to allow massive parallelization), or both.

Palettable is a library of color palettes for Python. The code is written in pure Python with no dependencies; it can be used to supply color maps for matplotlib plots, customize matplotlib plots, and to supply colors for a web application.

SUPPNet performs fully automated precise continuum normalization of merged echelle spectra and offers flexible manual fine-tuning, if necessary. The code uses a fully convolutional deep neural network (SUPP Network) trained to predict a pseudo-continuum. The post-processing step uses smoothing splines that give access to regressed knots, which are useful for optional manual corrections. The active learning technique controls possible biases that may arise from training with synthetic spectra and extends the applicability of the method to features absent in this kind of spectra.

Zwindstroom computes background quantities and scale-dependent growth factors for cosmological models with free-streaming species, such as massive neutrinos. Following the earlier REPS code (ascl:1612.022), the code uses a Newtonian fluid approximation with external neutrino sound speed to close the Boltzmann hierarchy. Zwindstroom supports multi-fluid models with distinct transfer functions and sound speeds. A flexible python interface facilitates interaction with CLASS (ascl:1106.020) through classy. There is also a Zwindstroom plugin for the cosmological initial conditions generator monofonIC (ascl:2008.024) that allows for higher-order LPT ICs for massive neutrino simulations in a single step.

NWelch uses Welch's method to estimate the power spectra, complex cross-spectrum, magnitude-squared coherence, and phase spectrum of bivariate time series with nonuniform observing cadence. For univariate time series, users can apply the Welch's power spectrum estimator or compute a nonuniform fast Fourier transform-based periodogram. Options include tapering in the time domain and computing bootstrap false alarm levels. Users may choose standard 50%-overlapping Welch's segments or apply a custom-made segmentation scheme. NWelch was designed for Doppler planet searches but may be applied to any type of time series.

CHIME/FRB instrument has recently published a catalog containing about half of thousand fast radio bursts (FRB) including their spectra and several reconstructed properties, like signal widths, amplitudes, etc. We have developed a model-independent approach for the classification of these bursts using cross-correlation and clustering algorithms applied to one-dimensional intensity profiles, i.e. to amplitudes as a function of time averaged over the frequency. This approach is implemented in frbmclust package, which is used for classification of bursts featuring different waveform morphology.

GA Galaxy fits models of interacting galaxies to synthetic data using a genetic algorithm and custom fitness function. The genetic algorithm is real-coded and uses a mixed Gaussian kernel for mutation. The fitness function incorporates 1.) a direct pixel-to-pixel comparison between the target and model images and 2.) a comparison of the degree of tidal distortion present in the target and model image such that target-model pairs which are similarly distorted will have a higher relative fitness. The genetic algorithm is written in Python 2.7 while the simulation code (SPAM: Stellar Particle Animation Module) is written in Fortran 90.

nProFit analyzes surface brightness profiles. It obtains the best-fit structural, scale, and shape parameters of star clusters in Hubble Space Telescope images of nearby galaxies. The code fits dynamical models and can derive physically-relevant parameters. Among these are central volume and luminosity densities, total masses and luminosities, central velocity dispersions, core radius, half-light radius, tidal radius, and binding energy.

disnht computes the absorption spectrum for a user-defined distribution of column densities. The input is a file including the array of column density values; a python routine is provided that can make logarithmic distribution of column density that can be used as an input. Other optional inputs are a cross-section file that includes the 2-d array [energy, cross-section]; a script is provided for computing cross sections for different abundance model for the interstellar medium (solar values). Other boolean flags can be used for input and output description, rebin, plot or save.

MAGRATHEA solves planet interiors and considers the case of fully differentiated interiors. The code integrates the hydrostatic equation in order to determine the correct planet radius given the mass in each layer. The code returns the pressure, temperature, density, phase, and radius at steps of enclosed mass. The code support four layers: core, mantle, hydrosphere, and atmosphere. Each layer has a phase diagram with equations of state chosen for each phase.

COWS (COsmic Web Skeleton) implements the cosmic filament finder COsmic Web Skeleton (COWS). Written in Python, the cosmic filament finder works on Hessian-based cosmic web identifiers (such as the V-web) and returns a catalogue of filament spines. The code identifies the medial axis, or skeleton, of cosmic web filaments and then separates this skeleton into individual filaments.

statmorph calculates non-parametric morphological diagnostics of galaxy images (e.g., Gini-M_{20} and CAS statistics), and fits 2D Sérsic profiles. Given a background-subtracted image and a corresponding segmentation map indicating the source(s) of interest, statmorph calculates the following morphological statistics for each source:
- Gini-M20 statistics;
- Concentration, Asymmetry and Smoothness (CAS) statistics;
- Multimode, Intensity and Deviation (MID) statistics;
- outer asymmetry and shape asymmetry;
- Sérsic index; and,
- several shape and size measurements associated to the above statistics, such as ellipticity, Petrosian radius, and half-light radius, among others.

AltaiPony de-trend light curves from Kepler, K2, and TESS missions, and searches them for flares. The code also injects and recovers synthetic flares to account for de-trending and noise loss in flare energy and determines energy-dependent recovery probability for every flare candidate. AltaiPony uses K2SC (ascl:1605.012), AstroPy (ascl:1304.002) and lightkurve (ascl:1812.013) in addition to other common codes, and extensive documentation and tutorials are provided for the software.

fermi-gce-flows uses a machine learning-based technique to characterize the contribution of modeled components, including unresolved point sources, to the GCE. It can perform posterior parameter estimation while accounting for pixel-to-pixel spatial correlations in the gamma-ray map. On application to Fermi data, the method generically attributes a smaller fraction of the GCE flux to unresolved point source-like emission when compared to traditional approaches.

tellrv measures absolute radial velocities for low-resolution NIR spectra. It uses telluric features to provide absolute wavelength calibration, and then cross-correlates with a standard star. Observations of a standard star are included for convenience; the code also requires both the telluric and non-telluric-corrected spectra.

dark-photons-perturbations determines constraints from Cosmic Microwave Background photons oscillating into dark photons, and from heating of the primordial plasma due to dark photon dark matter converting into low-energy photons in an inhomogeneous universe.

AllStarFit analyzes optical and infrared images and includes functions for:
- object detection and image segmentation using the ProFound package (ascl:1804.006);
- PSF determination using the ProFit package (ascl:1612.004) to fit multiple stars in the field simultaneously; and
- galaxy modelling with ProFit, using the previously determined PSF and user-specified models.

AllStarFit supports a variety of optimization methods (provided by external packages), including maximum-likelihood and Markov chain Monte Carlo (MCMC).

FitsMap visualizes astronomical image and catalog data. Implemented in Python, the software is a simple, lightweight tool, requires only a simple web server, and can scale to over gigapixel images with tens of millions of sources. Further, the web-based visualizations can be viewed performantly on mobile devices.

BLOSMapping determines the line-of-sight component of magnetic fields associated with molecular clouds. The code uses Faraday rotation measure catalogs along with an on-off approach based on relative measurements to estimate the rotation measure caused by molecular clouds. It then uses the outputs from a chemical evolution code along with extinction maps to determine the line-of-sight magnetic field strength and direction.

AstroToolBox identifies and classifies astronomical objects with a focus on low-mass stars and ultra-cool dwarfs. It can search numerous catalogs, including SIMBAD (measurements & references), AllWISE, Gaia, SDSS, among others, evaluates spectral type for main sequence stars including brown dwarfs, and provides SED fitting for ultra-cool and white dwarfs. AstroToolBox draws Gaia color-magnitude diagrams (CMD) with overplotted M0-M9 spectral types, and can draw Montreal Cooling Sequences on the white dwarf branch of the Gaia CMD. The tool can also blink images from different epochs in an image viewer, thus allowing visual identification of the motion or variability of objects. The software displays time series (static or animated) using infrared and optical images of various surveys and contains a photometric classifier. It also includes astrometric calculators and converters, an ADQL query interface (IRSA, VizieR, NOAO) and a batch spectral type lookup feature that uses a CSV file with object coordinates as input. The ToolBox also has a file browser linked to the image viewer, which makes it possible to check a large list of objects in a convenient way, and can save interesting finds in an object collection for later use.

EzTao models time series as a continuous-time autoregressive moving-average (CARMA) process. EzTao utilizes celerite (ascl:1709.008), a fast and scalable Gaussian Process Regression library, to evaluate the likelihood function. On average, EzTao is ten times faster than other tools relying on a Kalman filter for likelihood computation.

JexoSim 2.0 (JWST Exoplanet Observation Simulator) simulates exoplanet transit observations using all four instruments of the James Webb Space Telescope, and is designed for the planning and validation of science cases for JWST. The code generates synthetic spectra that capture the full impact of complex noise sources and systematic trends, allowing for assessment of both accuracy and precision in the final spectrum. JexoSim does not contain all known systematics for the various instruments, but is a good starting point to investigate the effects of systematics, and has the framework to incorporate more systematics in the future.

HoloSim-ML performs beam simulation and analysis of radio holography data from complex optical systems. The code uses machine learning to efficiently determine the position of hundreds of mirror adjusters on multiple mirrors with few micron accuracy.

The Fast Template Periodogram extends the Generalised Lomb Scargle periodogram (Zechmeister and Kurster 2009) for arbitrary (periodic) signal shapes. A template is first approximated by a truncated Fourier series of length H. The Nonequispaced Fast Fourier Transform NFFT is used to efficiently compute frequency-dependent sums. Template fitting can now be done in NlogN time, improving existing algorithms by an order of magnitude for even small datasets. The FTP can be used in conjunction with gradient descent to accelerate a non-linear model fit, or be used in place of the multi-harmonic periodogram for non-sinusoidal signals with a priori known shapes.

The l1 periodogram searches for periodicities in unevenly sampled time series. It can be used similarly as a Lomb-Scargle periodogram, and retrieves a figure which has a similar aspect but has fewer peaks due to aliasing. It is primarily designed for the search of exoplanets in radial velocity data, but can be also used for other purposes. The principle of the algorithm is to search for a representation of the input signal as a sum of a small number of sinusoidal components, that is a representation which is sparse in the frequency domain. Here, "small number" means small compared to the number of observations.

wpca, written in Python, offers several implementations of Weighted Principal Component Analysis and uses an interface similar to scikit-learn's sklearn.decomposition.PCA. Implementations include a direct decomposition of a weighted covariance matrix to compute principal vectors, and then a weighted least squares optimization to compute principal components, and an iterative expectation-maximization approach to solve simultaneously for the principal vectors and principal components of weighted data. It also includes a standard non-weighted PCA implemented using the singular value decomposition, primarily to be useful for testing.

hankl implements the FFTLog algorithm in lightweight Python code. The FFTLog algorithm can be thought of as the Fast Fourier Transform (FFT) of a logarithmically spaced periodic sequence (= Hankel Transform). hankl consists of two modules, the General FFTLog module and the Cosmology one. The latter is suited for modern cosmological application and relies heavily on the former to perform the Hankel transforms. The accuracy of the method usually improves as the range of integration is enlarged; FFTlog prefers an interval that spans many orders of magnitude. Resolution is important, as low resolution introduces sharp features which in turn causes ringing.

GRIT (Gravitational Rigid-body InTegrators) simulaties the coupled dynamics of both spin and orbit of N gravitationally interacting rigid bodies. The code supports tidal forces and general relativity correction are supported, and multiple schemes with different orders of convergences and splitting strategies are available. Multiscale splittings boost the simulation speed, and force evaluations can be parallelized. In addition, each body can be set to be a rigid body or just a point mass, and the floating-point format can be customized as float, double, or long double globally.

BayesicFitting fits models to data. Data in this context means a set of (measured) points x and y. The model provides some (mathematical) relation between the x and y. Fitting adapts the model such that certain criteria are optimized. The BayesicFitting toolbox also determines whether one model fits the data better than another, making the toolbox particularly powerful. The package consists of more than 100 Python classes, of which one third are model classes. Another third are fitters in one guise or another along with additional tools, and the remaining third is used for Nested Sampling.

The O'TRAIN package identifies transients in astronomical images based on a Convolutional Neural Network (CNN). It works on images from different telescopes and, through the use of Docker, can be deployed on different operating systems. O'TRAIN uses image cutouts containing real and false transients provided by the user to train a CNN algorithm implemented with Keras. Built-in diagnostics help to characterize the accuracy of the training, and a trained model is used to classify any new cutouts.

Optab, written in Fortran90, generates ideal-gas opacity tables. It computes opacity based on user-provided chemical equilibrium abundances, and outputs mean opacities as well as monochromatic opacities, thus providing opacity tables that are consistent with one's equation of state for radiation hydrodynamics simulations. For convenience, Optab also provides interfaces for FastChem (ascl:1804.025) or TEA (ascl:1505.031) for computing chemical abundances.

deeplenstronomy simulates large datasets for applying deep learning to strong gravitational lensing. It wraps the functionalities of lenstronomy (ascl:1804.012) in a convenient yaml-style interface to generate training datasets. The code can use built-in astronomical surveys, realistic galaxy colors, real images of galaxies, and physically motivated distributions of all parameters to train the neural network to create a simulated dataset.