Results 451-500 of 3598 (3503 ASCL, 95 submitted)
DarkMappy reconstructs maximum a posteriori (MAP) convergence maps by formulating an unconstrained Bayesian inference problem in order to implement hybrid Bayesian dark-matter reconstruction techniques on the plane and on the celestial sphere. These convergence maps support principled uncertainty quantification and provide hypothesis testing of structure, from which it is possible to distinguish between physical objects and artifacts of the reconstruction.
FLAGLET computes flaglet transforms with arbitrary spin direction, probing the angular features of this generic wavelet transform for rapid analysis of signals from wavelet coefficients. The code enables the decomposition of a band-limited signal into a set of flaglet maps that capture all information contained in the initial band-limited map, and it can reconstruct the individual flaglets at varying resolutions. FLAGLET relies upon the SSHT (ascl:2207.034), S2LET (ascl:1211.001), and SO3 codes to provide angular transforms and sampling theorems, as well as the FFTW (ascl:1201.015) code to compute Fourier transforms.
Given a FITS image, breizorro creates a binary mask. The software allows the user control various parameters and functions, such as setting a sigma threshold for masking, merging in or subtracting one or more masks or region files, filling holes, applying dilation within a defined radius of pixels, and inverting the mask.
DDFacet provides a wideband wide-field spectral imaging and deconvolution framework that accounts for generic direction-dependent effects (DDEs). It implements a wide-field coplanar faceting scheme and uses nontrivial facet-dependent w-kernels to correct for noncoplanarity within the facets. In the imaging and deconvolution steps, DDFacet can handle generic, spatially discrete, time-frequency-baseline-direction-dependent full polarization Jones matrices, and computes a direction dependent PSF for use in the minor cycle of deconvolution for time-frequency-baseline dependent Mueller matrices. The code also allows for the effects of time and bandwidth averaging to be explicitly incorporated into deconvolution. DDFacet has been successfully tested with data diverse telescopes such as LOFAR, VLA, MeerKAT AR1, and ATCA.
stimela provides a system-agnostic scripting framework for simulating, processing, and imaging radio interferometric data. The framework executes radio interferometry related tasks such as imaging, calibration, and data synthesis in Docker containers using Python modules. stimela offers a simple interface to packages that perform these tasks rather than doing any data processing, synthesis or analysis itself. stimela only requires Docker and Python. Moreover, because of Docker, a stimela script runs the same way (in the same isolated environment) regardless of the host machine’s settings, thus providing a user-friendly and modular scripting environment that gives general users easy access to novel radio interferometry calibration, imaging, and synthesis packages.
QuartiCal is the successor to CubiCal (ascl:1805.031). It implements a suite of fast radio interferometric calibration routines exploiting complex optimization. Unlike CubiCal, QuartiCal allows for any available Jones terms to be combined. It can also be deployed on a cluster.
killMS implements two very efficient algorithms for solving the Direction-Dependent calibration problem (also known as third generation calibration). This problem naturally arises in the Radio Interferometry Measurement Equation (RIME), but only became overwhelmingly problematic with the construction of the SKA precursors and pathfinders. Solving for the DDE calibration problem basically consists in inverting a number of non-linear equations, while the system is very large and often subject to ill conditioning. The two algorithms killMS uses are based on complex optimization techniques and exploit algorithmic shortcuts; killMS also runs an extended Kalman filter.
katdal interacts with the chunk stores and HDF5 files produced by the MeerKAT radio telescope and its predecessors (KAT-7 and Fringe Finder), which are collectively known as MeerKAT Visibility Format (MVF) data sets. The library uses memory carefully, allowing data sets to be inspected and partially loaded into memory. Data sets may be concatenated and split via a flexible selection mechanism. In addition, katdal provides a script to convert these data sets to CASA MeasurementSets.
extrapops simulates extra-galactic populations of gravitational waves sources and models their emission during the inspiral phase. The code approximately assesses the detectability of individual sources by LISA and computes the background due to unresolved sources in the LISA band using different methods. The simulated populations can be saved in a format compatible with LISA LDC. Simulations are well calibrated to produce accurate background calculations and fair random generation at the tails of the distributions, which is important for accurate probability of detectable events. extrapops uses a number of ad-hoc techniques for rapid simulation and allows room for further optimization up to almost 1 order of magnitude.
Virtual Telescope predicts the signal-to-noise and other parameters of imaging and/or spectroscopic observations as a function of telescope size, detector noise, and other factors for the Next-Generation Space Telescope.
FRIDDA forecasts the cosmological impact of measurements of the redshift drift and the fine-structure constant (alpha) as well as their combination. The code is based on Fisher Matrix Analysis techniques and works for various fiducial cosmological models. Though designed for the ArmazoNes high Dispersion Echelle Spectrograph (ANDES), it is easily adaptable to other fiducial cosmological models and to other instruments with similar scientific goals.
JET (JWST Exoplanet Targeting) optimizes lists of exoplanet targets for atmospheric characterization by the James Webb Space Telescope (JWST). The software uses catalogs of planet detections, either simulated, or actual and categorizes targets by radius and equilibrium temperature; it also estimates planet masses and generates model spectra and simulated instrument spectra. JET then performs a statistical analysis to determine if the instrument spectra can confirm an atmospheric detection and finally ranks the targets within each category by observation time required for detection.
FALCO (Fast Linearized Coronagraph Optimizer) performs coronagraphic focal plane wavefront correction. It includes routines for pair-wise probing estimation of the complex electric field and Electric Field Conjugation (EFC) control. FALCO utilizes and builds upon PROPER (ascl:1405.006) and rapidly computes the linearized response matrix for each DM, which facilitates re-linearization after each control step for faster DM-integrated coronagraph design and wavefront correction experiments. A MATLAB implementation of FALCO (ascl:2304.004) is also available.
FALCO (Fast Linearized Coronagraph Optimizer) performs coronagraphic focal plane wavefront correction. It includes routines for pair-wise probing estimation of the complex electric field and Electric Field Conjugation (EFC) control. FALCO utilizes and builds upon PROPER (ascl:1405.006) and rapidly computes the linearized response matrix for each DM, which facilitates re-linearization after each control step for faster DM-integrated coronagraph design and wavefront correction experiments. A Python 3 implementation of FALCO (ascl:2304.005) is also available.
BatAnalysis processes and analyzes Swift Burst Alert Telescope (BAT) survey data in a comprehensive computational pipeline. The code downloads BAT survey data, batch processes the survey observations, and extracts light curves and spectra for each survey observation for a given source. BatAnalysis allows for the use of BAT survey data in advanced analyses of astrophysical sources including pulsars, pulsar wind nebula, active galactic nuclei, and other known/unknown transient events that may be detected in the hard X-ray band. BatAnalysis can also create mosaicked images at different time bins and extract light curves and spectra from the mosaicked images for a given source.
Applefy calculates detection limits for exoplanet high contrast imaging (HCI) datasets. The package provides features and functionalities to improve the accuracy and robustness of contrast curve calculations. Applefy implements the classical approach based on the t-test, as well as the parametric boostrap test for non-Gaussian residual noise. Applefy enables the comparison of imaging results across instruments with different noise characteristics.
ASSIST integrates test particle trajectories in the field of the Sun, Moon, planets, and massive asteroids, with the positions of the masses obtained from the JPL DE441 ephemeris and its associated asteroid perturber file. Using REBOUND's (ascl:1110.016) IAS15 integrator, ASSIST incorporates the most significant gravitational harmonics and general relativistic corrections and accounts for position- and velocity-dependent non-gravitational effects. The first-order variational equations are included for all terms to support orbit fitting and covariance mapping.
HaloGraphNet predicts halo masses from simulations using Graph Neural Networks. Given a dark matter halo and its galaxies, this software creates a graph with information about the 3D position, stellar mass and other properties. It then trains a Graph Neural Network to predict the mass of the host halo. Data are taken from the CAMELS hydrodynamic simulations.
pulsar_spectra provides a pulsar flux density catalog and automated spectral fitting software for finding spectral models. The package can also produce publication-quality plots and allows users to add new spectral measurements to the catalog. The spectral fitting software uses robust statistical methods to determine the best-fitting model for individual pulsar spectra.
MORPHOFIT consists of a series of modules for estimating galaxy structural parameters. The package uses SEXTRACTOR (ascl:1010.064) in forced photometry mode to get an initial estimate of the galaxy structural parameters and create a multiband catalog. It also uses GALFIT (ascl:1010.064), running it on galaxy stamps and galaxy regions from the parent image and also on galaxies from the full image using SEXTRACTOR properties as input. MORPHOFIT has been optimized and tested in both low-density and crowded environments, and can recover the input structural parameters of galaxies with good accuracy.
bajes [baɪɛs] provides a user-friendly interface for setting up a Bayesian analysis for an arbitrary model, and is specialized for the analysis of gravitational-wave and multi-messenger transients. The code runs a parameter estimation job, inferring the properties of the input model. bajes is designed to be simple-to-use and light-weighted with minimal dependencies on external libraries. The user can set up a pipeline for parameters estimation of multi-messenger transients by writing a configuration file containing the information to be passed to the executables. The package also includes tools and methods for data analysis of multi-messenger signals. The pipeline incorporates an interface with reduced-order-quadratude (ROQ) interpolants. In particular, the ROQ pipeline relies on the output provided by PyROQ-refactored.
SatGen generates satellite-galaxy populations for host halos of desired mass and redshift. It combines halo merger trees, empirical relations for galaxy-halo connection, and analytic prescriptions for tidal effects, dynamical friction, and ram-pressure stripping. It emulates zoom-in cosmological hydrosimulations in certain ways and outperforms simulations regarding statistical power and numerical resolution.
The SIDM model combines the isothermal Jeans model and the model of adiabatic halo contraction into a simple semi-analytic procedure for computing the density profile of self-interacting dark-matter (SIDM) haloes with the gravitational influence from the inhabitant galaxies. It agrees well with cosmological SIDM simulations over the entire core-forming stage and up to the onset of gravothermal core-collapse. The fast speed of the method facilitates analyses that would be challenging for numerical simulations.
Delphes simulates a fast multipurpose detector response. The simulation includes a tracking system, embedded into a magnetic field, calorimeters and a muon system. The Delphes framework is interfaced to standard file formats (e.g. Les Houches Event File or HepMC) and outputs observables such as isolated leptons, missing transverse energy and collection of jets that can be used for dedicated analyses. The simulation of the detector response takes into account the effect of magnetic field, the granularity of the calorimeters and sub-detector resolutions. Visualization of the final state particles is also built-in using the corresponding ROOT library.
The FastJet package provides fast native implementations of many sequential recombination algorithms, including the longitudinally invariant kt longitudinally invariant inclusive Cambridge/Aachen and anti-kt jet finders. It also provides a uniform interface to external jet finders via a plugin mechanism. FastJet also includes tools for calculating jet areas and performing background (pileup/UE) subtraction and for jet substructure analyses.
EvoEMD evaluates cosmic evolution with or without an early matter dominated (EMD) era. The framework includes global parameter, particle, and process systems, and different methods for Hubble parameter calculation. EvoEMD automatically builds up the Boltzmann equation according to the user's definition of particle and process,solves the Boltzmann equation using 4th order Runge-Kutta method with adaptive steps tailored to cosmology application, and caches the collision rate calculation results for fast evaluation.
Scri manipulates time-dependent functions of spin-weighted spherical harmonics. It implements the BMS transformations of the most common gravitational waveforms, including the Newman-Penrose quantity ψ4, the Bondi news function, the shear spin coefficient σ, and the transverse-traceless metric perturbation h, as well as the remaining Newman-Penrose quantities ψ0 through ψ3.
spinsfast is a fast spin-s spherical harmonic transform algorithm, which is flexible and exact for band-limited functions. It permits the computation of several distinct spin transforms simultaneously. Specifically, only one set of special functions is computed for transforms of quantities with any spin, namely the Wigner d matrices evaluated at π/2, which may be computed with efficient recursions. For any spin, the computation scales as O(L^3), where L is the band limit of the function.
Pandora searches for exomoons by employing an analytical photodynamical model that includes stellar limb darkening, full and partial planet-moon eclipses, and barycentric motion of planet and moon. The code can be used with nested samplers such as UltraNest (ascl:1611.001) or dynesty (ascl:1809.013). Pandora is fast, calculating 10,000 models and log-likelihood evaluation per second (give or take an order of magnitude, depending on parameters and data); this means that a retrieval with 250 Mio. evaluations until convergence takes about 5 hours on a single core. For searches in large amounts of data, it is most efficient to assign one core per light curve.
Comparing galaxies across redshifts via cumulative number densities is a popular way to estimate the evolution of specific galaxy populations. nd-redshift uses abundance matching in the ΛCDM paradigm to estimate the median change in number density with redshift. It also provides estimates for the 1σ range of number densities corresponding to galaxy progenitors and descendants.
PyCom provides function calls for deriving the optimal communication scheme to maximize the data rate between a remote probe and home-base. It includes models for the loss of photons from diffraction, technological limitations, interstellar extinction and atmospheric transmission, and manages major atmospheric, zodiacal, stellar and instrumental noise sources. It also includes scripts for creating figures appearing in the referenced paper.
Gaussian Process Cross-Correlation (GPCC) uses Gaussian processes to estimate time delays for reverberation mapping (RM) of Active Galactic Nuclei (AGN). This statistically principled model delivers a posterior distribution for the delay and accounts for observational noise and the non-uniform sampling of the light curves. Written in Julia, GPCC quantifies the uncertainty and propagates it to subsequent calculations of dependent physical quantities, such as black hole masses. The code delivers out-of-sample predictions, which enables model selection, and can calculate the joint posterior delay for more than two light curves. Though written for RM, the software can also be applied to other fields where cross-correlation analysis is performed.
Blobby3D performs Bayesian inference for gas kinematics on emission line observations of galaxies using Integral Field Spectroscopy. The code robustly infers gas kinematics for regularly rotating galaxies even if the gas profiles have significant substructure. Blobby3D also infers gas kinematic properties free from the effects of beam smearing (where beam smearing is the effect of the observational seeing spatially blurring the gas profiles), which has significant effects on the observed gas kinematic properties, particularly the observed velocity dispersion.
naif extracts frequencies and respective amplitudes from time-series, such as that of an orbital coordinate. Based on the Numerical Analysis of Fundamental Frequencies (NAFF) algorithm and written in Python, naif offers some improvements, particularly in computation time. It also offers functions to plot the power-spectrum before extraction of each frequency, which can be useful for debugging particular orbits.
SeeKAT is a Python implementation of a novel maximum-likelihood estimation approach to localizing transients and pulsars detected in multiple MeerKAT tied-array beams at once to (sub-)arcsecond precision. It reads in list of detections (RA, Dec, S/N) and the beam PSF and computes a covariance matrix of the S/N value ratios, assuming 1-sigma Gaussian errors on each measurement. It models the aggregate beam response by arranging beam PSFs appropriately relative to each other and calculates a likelihood distribution of obtaining the observed S/N in each beam according to the modeled response. In addition, SeeKAT can plot the likelihood function over RA and Dec with 1-sigma uncertainty, overlaid on the beam coordinates and sizes.
The Python code line_selections reads synthetic "full" spectra and elemental spectra, automatically identifies the detectable lines at a given resolution (provided the linelist used to compute the spectra), and returns a table containing various properties of the lines (e.g., purity, central wavelength, and depth). The code then stores the information in a pandas DataFrame. line_selections demonstrates where chemical information is present in a stellar spectrum, and allows the user to optimize observational strategies, such as choosing resolution and spectra windows, as well as analysis codes with the application of high-quality masks.
World Observatory visualizes S/N-versus-cost tradeoffs for large optical and near-infrared telescopes. Both mid-latitude and Arctic/Antarctic sites can be considered; the intent is a simple simulation to grow intuition for where major capital costs lie relative to key observatory design choices, and against expected scientific performance at various sites. User-defined unit costs for (a possibly "effective") roadway, enclosure, aperture, focal length, and adaptive optics can be scaled up for polar sites, and down for better seeing and lower sky brightness in K-band. Observatory models and results are immediately displayed side-by-side. Either point-source-detection S/N or recovery of bulge-to-total ratios in a simulated galaxy survey are divided by the total project cost, thus providing a universal metric.
The cysgp4 Cython-powered package wraps the C++ SGP4 Library for computing satellite positions from two-line elements (TLE). It provides similar functionality as the sgp4 Python package, though also works well with arrays of TLEs and/or observing times and makes use of multi-core platforms (via OpenMP) to improve processing times.
HDMSpectra computes the decay spectrum for dark matter with masses above the scale of electroweak symmetry breaking, down to Planck scale and including all relevant electroweak interactions. The code determines the distribution of stable states for photons, neutrinos, positrons, and antiprotons.
Diffmah approximates the growth of individual halos as a simple power-law function of time, where the power-law index smoothly decreases as the halo transitions from the fast-accretion regime at early times to the slow-accretion regime at late times. The code has a typical accuracy of 0.1 dex for times greater than one billion years in halos of mass greater than 10e11 M_sun. Diffmah self-consistently captures the mean and variance of halo mass accretion rates across long time scales, and it generates Monte Carlo simulations of cosmologically-representative and differentiable halo histories.
DSPS synthesizes stellar populations, leading to fully-differentiable predictions for galaxy photometry and spectroscopy. The code implements an empirical model for stellar metallicity, and it also supports the Diffstar (ascl:2302.012) model of star formation and dark matter halo history. DSPS rapidly generates and simulates galaxy-halo histories on both CPU and GPU hardware.
AART (Adaptive Analytical Ray Tracing) exploits the integrability properties of the Kerr spacetime to compute high-resolution black hole images and their visibility amplitude on long interferometric baselines. It implements a non-uniform adaptive grid on the image plane suitable to study black hole photon rings (narrow ring-shaped features, predicted by general relativity but not yet observed). The code implements all the relevant equations required to compute the appearance of equatorial sources on the (far) observer's screen.
The RADEX Line Fitter provides a Python 3 interface that calls RADEX (ascl:1010.075) to make a non-LTE fit to a set of observed lines and derive the column density of the molecule that produced the lines and optionally also the molecular hydrogen (H2) number density or the kinetic temperature of the molecule. This code requires RADEX to be installed locally.
AMICAL (Aperture Masking Interferometry Calibration and Analysis Library) processes Aperture Masking Interferometry (AMI) data from major existing facilities, such as NIRISS on the JWST, SPHERE and VISIR from the European Very Large Telescope (VLT) and VAMPIRES from SUBARU telescope. The library cleans the reduced datacube from the standard instrument pipelines, extracts the interferometrical quantities (visibilities and closure phases) using a Fourier sampling approach, and calibrates those quantities to remove the instrumental biases. In addition, two external packages (CANDID and Pymask) are included to analyze the final outputs obtained from a binary-like sources (star-star or star-planet); these stand-alone packages are interfaced with AMICAL to quickly estimate scientific results (e.g., separation, position angle, contrast ratio, and contrast limits) using different approaches.
UBER (Universal Boltzmann Equation Solver) solves the general form of Fokker-Planck equation and Boltzmann equation, diffusive or non-diffusive, that appear in modeling planetary radiation belts. Users can freely specify the coordinate system, boundary geometry and boundary conditions, and the equation terms and coefficients. The solver works for problems in one to three spatial dimensions. The solver is based upon the mathematical theory of stochastic differential equations. By its nature, the solver scheme is intrinsically Monte Carlo, and the solutions thus contain stochastic uncertainty, though the user may dictate an arbitrarily small relative tolerance of the stochastic uncertainty at the cost of longer Monte Carlo iterations.
MADCUBA analyzes astronomical datacubes and multiple spectra from various astronomical facilities, including ALMA, Herschel, VLA, IRAM 30m, APEX, GBT, and others. These telescopes, and in particular ALMA, generate extremely large datacubes (spatial, spectral and polarization). This software combines a user-friendly interface and powerful data analysis system to derive the physical conditions of molecular gas, its chemical complexity and the kinematics from datacubes. Built using the ImageJ (ascl:1206.013) infrastructure, MADCUBA visualizes astronomical datacubes with thousands on spectral channels, and datasets with thousands of spectra; it also identifies molecular species using publicly available molecular catalogs. It can automatically derive the physical parameters of the molecular species: column density, excitation temperature, velocity and linewidths and provides the best non-linear least-squared fit using the Levenberg-Marquardt algorithm, among other tasks.
This library of scripts provides a simple interface for running the CLASS software from GILDAS (ascl:1305.010) in a semi-automatic way. Using these scripts, one can extract and organize spectra from data files in CLASS format (for example, .30m and .40m), reduce them, and even combine or average them once they are reduced. The library contains five Python scripts and two optional Julia scripts.
RichValues transforms numeric values with uncertainties and upper/lower limits to create "rich values" that can be written in plain text documents in an easily readable format and used to propagate uncertainties automatically. Rich values can also be exported in the same formatting style as the import. The RichValues library uses a specific formatting style to represent the different kinds of rich values with plain text; it can also be used to create rich values within a script. Individual rich values can be used in, for example, tuples, lists, and dictionaries, and also in arrays and tables.
swyft implements Truncated Marginal Neural Radio Estimation (TMNRE), a Bayesian parameter inference technique for complex simulation data. The code improves performance by estimating low-dimensional marginal posteriors rather than the joint posteriors of distributions, while also targeting simulations to targets of observational interest via an indicator function. The use of local amortization permits statistical checks, enabling validation of parameters that cannot be performed using sampling-based methods. swyft is also based on stochastic simulations, mapping parameters to observational data, and incorporates a simulator manager.
FCFC (Fast Correlation Function Calculator) computes correlation functions from pair counts. It supports the isotropic 2-point correlation function, anisotropic 2PCF, 2-D 2PCF, and 2PCF Legendre multipoles, among others. Written in C, FCFC takes advantage of three parallelisms that can be used simultaneously, distributed-memory processes via Message Passing Interface (MPI), shared-memory threads via Open Multi-Processing (OpenMP), and single instruction, multiple data (SIMD).
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