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[ascl:1806.030] foxi: Forecast Observations and their eXpected Information

Using information theory and Bayesian inference, the foxi Python package computes a suite of expected utilities given futuristic observations in a flexible and user-friendly way. foxi requires a set of n-dim prior samples for each model and one set of n-dim samples from the current data, and can calculate the expected ln-Bayes factor between models, decisiveness between models and its maximum-likelihood averaged equivalent, the decisivity, and the expected Kullback-Leibler divergence (i.e., the expected information gain of the futuristic dataset). The package offers flexible inputs and is designed for all-in-one script calculation or an initial cluster run then local machine post-processing, which should make large jobs quite manageable subject to resources and includes features such as LaTeX tables and plot-making for post-data analysis visuals and convenience of presentation.

[ascl:1010.002] fpack: FITS Image Compression Program

fpack is a utility program for optimally compressing images in the FITS data format. The associated funpack program will restore the compressed file back to its original state. These programs may be run from the host operating system command line and are analogous to the gzip and gunzip utility programs, except that they are specifically optimized for FITS format images and offer a wider choice of compression options.

fpack uses the tiled image compression convention for storing the compressed images. This convention can in principle support any number of of different compression algorithms; currently GZIP, Rice, Hcompress, and the IRAF pixel list compression algorithms have been implemented.

The main advantages of fpack compared to the commonly used technique of externally compressing the whole FITS file with gzip are:

- It is generally faster and offers better compression than gzip.
- The FITS header keywords remain uncompressed for fast access.
- Each HDU of a multi-extension FITS file is compressed separately, so it is not necessary to uncompress the entire file to read a single image in a multi-extension file.
- Dividing the image into tiles before compression enables faster access to small subsections of the image.
- The compressed image is itself a valid FITS file and can be manipulated by other general FITS utility software.
- Lossy compression can be used for much higher compression in cases where it is not necessary to exactly preserve the original image.
- The CHECKSUM keywords are automatically updated to help verify the integrity of the files.
- Software that supports the tiled image compression technique can directly read and write the FITS images in their compressed form.

[ascl:2311.010] FPFS: Fourier Power Function Shaplets

FPFS (Fourier Power Function Shaplets) is a fast, accurate shear estimator for the shear responses of galaxy shape, flux, and detection. Utilizing leading-order perturbations of shear (a vector perturbation) and image noise (a tensor perturbation), the code determines shear and noise responses for both measurements and detections. Unlike methods that distort each observed galaxy repeatedly, the software employs analytical shear responses of select basis functions, including Shapelets basis and peak basis. FPFS is efficient and can process approximately 1,000 galaxies within a single CPU second, and maintains a multiplicative shear estimation bias below 0.5% even amidst blending challenges.

[ascl:2001.004] FragMent: Fragmentation techniques for studying filaments

FragMent studies fragmentation in filaments by collating a number of different techniques, including nearest neighbour separations, minimum spanning tree, two-point correlation function, and Fourier power spectrum. It also performs model selection using a frequentist and Bayesian approach to find the best descriptor of a filament's fragmentation. While the code was designed to investigate filament fragmentation, the functions are general and may be used for any set of 2D points to study more general cases of fragmentation.

[ascl:2109.010] Frankenstein: Flux reconstructor

Frankenstein (frank) fits the 1D radial brightness profile of an interferometric source given a set of visibilities. It uses a Gaussian process that performs the fit in <1 minute for a typical protoplanetary disc continuum dataset. Frankenstein can perform a fit in 2 ways, by running the code directly from the terminal or using the code as a Python module.

[ascl:2306.018] FRB: Fast Radio Burst calculations, estimations, and analysis

FRB performs calculations, estimations, analysis, and Bayesian inferences for Fast Radio Bursts, including dispersion measure and emission measure calculations, derived properties and spectrums, and Galactic RM.

[ascl:2011.011] frbcat: Fast Radio Burst CATalog querying package

frbcat queries and downloads Fast Radio Burst (FRB) data from the FRBCAT Catalogue web page, the CHIME-REPEATERS web page and the Transient Name Server (TNS). It is written in Python and can be installed using pip.

[submitted] frbmclust: Model-independent classification of events from the first CHIME/FRB Fast Radio Burst catalog

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.

[ascl:1911.009] frbpoppy: Fast radio burst population synthesis in Python

frbpoppy conducts fast radio burst population synthesis and continues the work of PSRPOP (ascl:1107.019) and PsrPopPy (ascl:1501.006) in the realm of FRBs. The code replicates observed FRB detection rates and FRB distributions in three steps. It first simulates a cosmic population of one-off FRBs and allows the user to select options such as models for source number density, cosmology, DM host/IGM/Milky Way, luminosity functions, and emission bands as well as maximum redshift and size of the FRB population. The code then generates a survey by adopting a beam pattern using various survey parameters, among them telescope gain, sampling time, receiver temperature, central frequency, channel bandwidth, number of polarizations, and survey region limits. Finally, frbpoppy convolves the generated intrinsic population with the generated survey to simulate an observed FRB population.

[ascl:2106.028] FRBSTATS: A web-based platform for visualization of fast radio burst properties

FRBSTATS provides a user-friendly web interface to an open-access catalog of fast radio bursts (FRBs) published up to date, along with a highly accurate statistical overview of the observed events. The platform supports the retrieval of fundamental FRB data either directly through the FRBSTATS API, or in the form of a CSV/JSON-parsed database, while enabling the plotting of parameter distributions for a variety of visualizations. These features allow researchers to conduct more thorough population studies while narrowing down the list of astrophysical models describing the origins and emission mechanisms behind these sources. Lastly, the platform provides a visualization tool that illustrates associations between primary bursts and repeaters, complementing basic repeater information provided by the Transient Name Server.

[ascl:1906.003] FREDDA: A fast, real-time engine for de-dispersing amplitudes

FREDDA detects Fast Radio Bursts (FRBs) in power data. It is optimized for use at ASKAP, namely GHz frequencies with 10s of beams, 100s of channels and millisecond integration times. The code is written in CUDA for NVIDIA Graphics Processing Units.

[ascl:1610.014] Freddi: Fast Rise Exponential Decay accretion Disk model Implementation

Freddi (Fast Rise Exponential Decay: accretion Disk model Implementation) solves 1-D evolution equations of the Shakura-Sunyaev accretion disk. It simulates fast rise exponential decay (FRED) light curves of low mass X-ray binaries (LMXBs). The basic equation of the viscous evolution relates the surface density and viscous stresses and is of diffusion type; evolution of the accretion rate can be found on solving the equation. The distribution of viscous stresses defines the emission from the source. The standard model for the accretion disk is implied; the inner boundary of the disk is at the ISCO or can be explicitely set. The boundary conditions in the disk are the zero stress at the inner boundary and the zero accretion rate at the outer boundary. The conditions are suitable during the outbursts in X-ray binary transients with black holes. In a binary system, the accretion disk is radially confined. In Freddi, the outer radius of the disk can be set explicitely or calculated as the position of the tidal truncation radius.

[ascl:1211.002] FreeEOS: Equation of State for stellar interiors calculations

FreeEOS is a Fortran library for rapidly calculating the equation of state using an efficient free-energy minimization technique that is suitable for physical conditions in stellar interiors. Converged FreeEOS solutions can be reliably determined for the first time for physical conditions occurring in stellar models with masses between 0.1 M and the hydrogen-burning limit near 0.07 M and hot brown-dwarf models just below that limit. However, an initial survey of results for those conditions showed EOS discontinuities (plasma phase transitions) and other problems which will need to be addressed in future work by adjusting the interaction radii characterizing the pressure ionization used for the FreeEOS calculations.

[ascl:2104.011] Freeture: Free software to capTure meteors

FreeTure monitors images from GigE all-sky cameras to detect and record falling stars and fireball. Originally, it was developed for the FRIPON (Fireball Recovery and InterPlanetary Observation Network) project, which sought to cover all of France with 100 fish eyes cameras, but can be used by any station that has a GigE camera.

[ascl:1508.004] FRELLED: FITS Realtime Explorer of Low Latency in Every Dimension

FRELLED (FITS Realtime Explorer of Low Latency in Every Dimension) creates 3D images in real time from 3D FITS files and is written in Python for the 3D graphics suite Blender. Users can interactively generate masks around regions of arbitrary geometry and use them to catalog sources, hide regions, and perform basic analysis (e.g., image statistics within the selected region, generate contour plots, query NED and the SDSS). World coordinates are supported and multi-volume rendering is possible. FRELLED is designed for viewing HI data cubes and provides a number of tasks to commonly-used MIRIAD (ascl:1106.007) tasks (e.g. mbspect); however, many of its features are suitable for any type of data set. It also includes an n-body particle viewer with the ability to display 3D vector information as well as the ability to render time series movies of multiple FITS files and setup simple turntable rotation movies for single files.

[ascl:2305.001] FRIDDA: Fisher foRecast code for combIned reDshift Drift and Alpha

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.

[ascl:2309.019] FRISBHEE: FRIedmann Solver for Black Hole Evaporation in the Early-universe

FRISBHEE (FRIedmann Solver for Black Hole Evaporation in the Early-universe solves the Friedmann - Boltzmann equations for Primordial Black Holes + SM radiation + BSM Models. Considering the collapse of density fluctuations as the PBH formation mechanism, the code handles monochromatic and extended mass and spin distributions. FRISBHEE can return the full evolution of the PBH, SM and Dark Radiation comoving energy densities, together with the evolution of the PBH mass and spin as a function of the log10 at scale factor, and can determine the relic abundance in the case of Dark Matter produced from BH evaporation for monochromatic and extended distributions.

[ascl:1406.006] FROG: Time-series analysis

FROG performs time series analysis and display. It provides a simple user interface for astronomers wanting to do time-domain astrophysics but still offers the powerful features found in packages such as PERIOD (ascl:1406.005). FROG includes a number of tools for manipulation of time series. Among other things, the user can combine individual time series, detrend series (multiple methods) and perform basic arithmetic functions. The data can also be exported directly into the TOPCAT (ascl:1101.010) application for further manipulation if needed.

[ascl:1911.010] Fruitbat: Fast radio burst redshift estimation

Fruitbat estimates the redshift of Fast Radio Bursts (FRB) from their dispersion measure. The code combines various dispersion measure (DM) and redshift relations with the YMW16 galactic dispersion measure model into a single easy to use API.

[ascl:1506.006] fsclean: Faraday Synthesis CLEAN imager

Fsclean produces 3D Faraday spectra using the Faraday synthesis method, transforming directly from multi-frequency visibility data to the Faraday depth-sky plane space. Deconvolution is accomplished using the CLEAN algorithm, and the package includes Clark and Högbom style CLEAN algorithms. Fsclean reads in MeasurementSet visibility data and produces HDF5 formatted images; it handles images and data of arbitrary size, using scratch HDF5 files as buffers for data that is not being immediately processed, and is limited only by available disk space.

[ascl:1710.012] FSFE: Fake Spectra Flux Extractor

The fake spectra flux extractor generates simulated quasar absorption spectra from a particle or adaptive mesh-based hydrodynamic simulation. It is implemented as a python module. It can produce both hydrogen and metal line spectra, if the simulation includes metals. The cloudy table for metal ionization fractions is included. Unlike earlier spectral generation codes, it produces absorption from each particle close to the sight-line individually, rather than first producing an average density in each spectral pixel, thus substantially preserving more of the small-scale velocity structure of the gas. The code supports both Gadget (ascl:0003.001) and AREPO (ascl:1909.010).

[ascl:1010.043] FSPS: Flexible Stellar Population Synthesis

FSPS is a flexible SPS package that allows the user to compute simple stellar populations (SSPs) for a range of IMFs and metallicities, and for a variety of assumptions regarding the morphology of the horizontal branch, the blue straggler population, the post--AGB phase, and the location in the HR diagram of the TP-AGB phase. From these SSPs the user may then generate composite stellar populations (CSPs) for a variety of star formation histories (SFHs) and dust attenuation prescriptions. Outputs include the "observed" spectra and magnitudes of the SSPs and CSPs at arbitrary redshift. In addition to these fortran routines, several IDL routines are provided that allow easy manipulation of the output. FSPS was designed with the intention that the user would make full use of the provided fortran routines. However, the full FSPS package is quite large, and requires some time for the user to become familiar with all of the options and syntax. Some users may only need SSPs for a range of metallicities and IMFs. For such users, standard SSP sets for several IMFs, evolutionary tracks, and spectral libraries are available here.

[ascl:1711.003] FTbg: Background removal using Fourier Transform

FTbg performs Fourier transforms on FITS images and separates low- and high-spatial frequency components by a user-specified cut. Both components are then inverse Fourier transformed back to image domain. FTbg can remove large-scale background/foreground emission in many astrophysical applications. FTbg has been designed to identify and remove Galactic background emission in Herschel/Hi-GAL continuum images, but it is applicable to any other (e.g., Planck) images when background/foreground emission is a concern.

[ascl:9912.002] FTOOLS: A general package of software to manipulate FITS files

FTOOLS, a highly modular collection of utilities for processing and analyzing data in the FITS (Flexible Image Transport System) format, has been developed in support of the HEASARC (High Energy Astrophysics Research Archive Center) at NASA's Goddard Space Flight Center. The FTOOLS package contains many utility programs which perform modular tasks on any FITS image or table, as well as higher-level analysis programs designed specifically for data from current and past high energy astrophysics missions. The utility programs for FITS tables are especially rich and powerful, and provide functions for presentation of file contents, extraction of specific rows or columns, appending or merging tables, binning values in a column or selecting subsets of rows based on a boolean expression. Individual FTOOLS programs can easily be chained together in scripts to achieve more complex operations such as the generation and displaying of spectra or light curves. FTOOLS development began in 1991 and has produced the main set of data analysis software for the current ASCA and RXTE space missions and for other archival sets of X-ray and gamma-ray data. The FTOOLS software package is supported on most UNIX platforms and on Windows machines. The user interface is controlled by standard parameter files that are very similar to those used by IRAF. The package is self documenting through a stand alone help task called fhelp. Software is written in ANSI C and FORTRAN to provide portability across most computer systems. The data format dependencies between hardware platforms are isolated through the FITSIO library package.

[ascl:2112.025] FTP: Fast Template Periodogram

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.

[ascl:2004.011] FUNDPAR: Deriving FUNDamental PARameters from equivalent widths

FUNDPAR determines fundamental parameters of solar-type stars, by using as input the Equivalent Widths of Fe I,II lines. The code uses solar-scaled ATLAS9 model atmospheres with NEWODF opacities, together with the 2009 version of the MOOG (ascl:1202.009) program. Parameter files control different details, such as the mixing-length parameter, the overshooting, and the damping of the lines. FUNDPAR also derives the uncertainties of the parameters.

[ascl:1112.002] Funtools: FITS Users Need Tools

Funtools is a "minimal buy-in" FITS library and utility package developed at the the High Energy Astrophysics Division of SAO. The Funtools library provides simplified access to a wide array of file types: standard astronomical FITS images and binary tables, raw arrays and binary event lists, and even tables of ASCII column data. A sophisticated region filtering library (compatible with ds9) filters images and tables using boolean operations between geometric shapes, support world coordinates, etc. Funtools also supports advanced capabilities such as optimized data searching using index files.

Because Funtools consists of a library and a set of user programs, it is most appropriately built from source. Funtools has been ported to Solaris, Linux, LinuxPPC, SGI, Alpha OSF1, Mac OSX (darwin) and Windows 98/NT/2000/XP. Once the source code tar file is retrieved, Funtools can be built and installed easily using standard commands.

[ascl:1205.005] Fv: Interactive FITS file editor

Fv is an easy-to-use graphical program for viewing and editing any FITS format image or table. The Fv software is small, completely self-contained and runs on Windows PCs, most Unix platforms and Mac OS-X. Fv also provides a portal into the Hera data analysis service from the HEASARC.

[ascl:1010.015] Fyris Alpha: Computational Fluid Dynamics Code

Fyris Alpha is a high resolution, shock capturing, multi-phase, up-wind Godunov method hydrodynamics code that includes a variable equation of state and optional microphysics such as cooling, gravity and multiple tracer variables. The code has been designed and developed for use primarily in astrophysical applications, such as galactic and interstellar bubbles, hypersonic shocks, and a range of jet phenomena. Fyris Alpha boasts both higher performance and more detailed microphysics than its predecessors, with the aim of producing output that is closer to the observational domain, such as emission line fluxes, and eventually, detailed spectral synthesis. Fyris Alpha is approximately 75,000 lines of C code; it encapsulates the split sweep semi-lagrangian remap PPM method used by ppmlr (in turn developed from VH1, Blondin et al. 1998) but with an improved Riemann solver, which is derived from the exact solver of Gottlieb and Groth (1988), a significantly faster solution than previous solvers. It has a number of optimisations that have improved the speed so that additional calculations neeed for multi-phase simulations become practical.

[ascl:2202.001] GA Galaxy: Interacting galaxies model fitter

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.

[ascl:1801.011] GABE: Grid And Bubble Evolver

GABE (Grid And Bubble Evolver) evolves scalar fields (as well as other purposes) on an expanding background for non-canonical and non-linear classical field theory. GABE is based on the Runge-Kutta method.

[ascl:0003.001] GADGET-2: A Code for Cosmological Simulations of Structure Formation

The cosmological simulation code GADGET-2, a new massively parallel TreeSPH code, is capable of following a collisionless fluid with the N-body method, and an ideal gas by means of smoothed particle hydrodynamics (SPH). The implementation of SPH manifestly conserves energy and entropy in regions free of dissipation, while allowing for fully adaptive smoothing lengths. Gravitational forces are computed with a hierarchical multipole expansion, which can optionally be applied in the form of a TreePM algorithm, where only short-range forces are computed with the `tree'-method while long-range forces are determined with Fourier techniques. Time integration is based on a quasi-symplectic scheme where long-range and short-range forces can be integrated with different timesteps. Individual and adaptive short-range timesteps may also be employed. The domain decomposition used in the parallelisation algorithm is based on a space-filling curve, resulting in high flexibility and tree force errors that do not depend on the way the domains are cut. The code is efficient in terms of memory consumption and required communication bandwidth. It has been used to compute the first cosmological N-body simulation with more than 10^10 dark matter particles, reaching a homogeneous spatial dynamic range of 10^5 per dimension in a 3D box. It has also been used to carry out very large cosmological SPH simulations that account for radiative cooling and star formation, reaching total particle numbers of more than 250 million. GADGET-2 is publicly released to the research community.

[ascl:2204.014] GADGET-4: Parallel cosmological N-body and SPH code

GADGET-4 (GAlaxies with Dark matter and Gas intEracT) is a parallel cosmological N-body and SPH code that simulates cosmic structure formation and calculations relevant for galaxy evolution and galactic dynamics. It is massively parallel and flexible, and can be applied to a variety of different types of simulations, offering a number of sophisticated simulation algorithms. GADGET-4 supports collisionless simulations and smoothed particle hydrodynamics on massively parallel computers.

The code can be used for plain Newtonian dynamics, or for cosmological integrations in arbitrary cosmologies, both with or without periodic boundary conditions. Stretched periodic boxes, and special cases such as simulations with two periodic dimensions and one non-periodic dimension are supported as well. The modeling of hydrodynamics is optional. The code is adaptive both in space and in time, and its Lagrangian character makes it particularly suitable for simulations of cosmic structure formation. Several post-processing options such as group- and substructure finding, or power spectrum estimation are built in and can be carried out on the fly or applied to existing snapshots. Through a built-in cosmological initial conditions generator, it is also particularly easy to carry out cosmological simulations. In addition, merger trees can be determined directly by the code.

[ascl:1108.005] Gaepsi: Gadget Visualization Toolkit

Gaepsi is a PYTHON extension for visualizing cosmology simulations produced by Gadget. Visualization is the most important facet of Gaepsi, but it also allows data analysis on GADGET simulations with its growing number of physics related subroutines and constants. Unlike mesh based scheme, SPH simulations are directly visible in the sense that a splatting process is required to produce raster images from the simulations. Gaepsi produces images of 2-dimensional line-of-sight projections of the simulation. Scalar fields and vector fields are both supported.

Besides the traditional way of slicing a simulation, Gaepsi also has built-in support of 'Survey-like' domain transformation proposed by Carlson & White. An improved implementation is used in Gaepsi. Gaepsi both implements an interactive shell for plotting and exposes its API for batch processing. When complied with OpenMP, Gaepsi automatically takes the advantage of the multi-core computers. In interactive mode, Gaepsi is capable of producing images of size up to 32000 x 32000 pixels. The user can zoom, pan and rotate the field with a command in on the finger tip. The interactive mode takes full advantages of matplotlib's rich annotating, labeling and image composition facilities. There are also built-in commands to add objects that are commonly used in cosmology simulations to the figures.

[ascl:2312.032] gaia_tools: Tools for working with Gaia and related data sets

gaia_tools contains codes for working with the ESA/Gaia data and related data sets (APOGEE, GALAH, LAMOST DR2, and RAVE). Written in Python, it includes tools to read catalogs, perform cross-matching, read RVS or XP spectra, and query the Gaia archive. gaia_tools also contains various matching recipes, such as matching APOGEE or APOGEE-RC to Gaia DR2, and RAVE to TGAS (taking into account the epoch difference).

[ascl:1403.024] GAIA: Graphical Astronomy and Image Analysis Tool

GAIA is an image and data-cube display and analysis tool for astronomy. It provides the usual facilities of image display tools, plus more astronomically useful ones such as aperture and optimal photometry, contouring, source detection, surface photometry, arbitrary region analysis, celestial coordinate readout, calibration and modification, grid overlays, blink comparison, defect patching and the ability to query on-line catalogues and image servers. It can also display slices from data-cubes, extract and visualize spectra as well as perform full 3D rendering. GAIA uses the Starlink software environment (ascl:1110.012) and is derived from the ESO SkyCat tool (ascl:1109.019).

[ascl:1707.006] Gala: Galactic astronomy and gravitational dynamics

Gala is a Python package (and Astropy affiliated package) for Galactic astronomy and gravitational dynamics. The bulk of the package centers around implementations of gravitational potentials, numerical integration, nonlinear dynamics, and astronomical velocity transformations (i.e. proper motions). Gala uses the Astropy units and coordinates subpackages extensively to provide a clean, pythonic interface to these features but does any heavy-lifting in C and Cython for speed.

[ascl:1302.011] GALA: Stellar atmospheric parameters and chemical abundances

GALA is a freely distributed Fortran code to derive the atmospheric parameters (temperature, gravity, microturbulent velocity and overall metallicity) and abundances for individual species of stellar spectra using the classical method based on the equivalent widths of metallic lines. The abundances of individual spectral lines are derived by using the WIDTH9 code developed by R. L. Kurucz. GALA is designed to obtain the best model atmosphere, by optimizing temperature, surface gravity, microturbulent velocity and metallicity, after rejecting the discrepant lines. Finally, it computes accurate internal errors for each atmospheric parameter and abundance. The code obtains chemical abundances and atmospheric parameters for large stellar samples quickly, thus making GALA an useful tool in the epoch of the multi-object spectrographs and large surveys.

[ascl:2103.018] GalacticDNSMass: Bayesian inference determination of mass distribution of Galactic double neutron stars

GalacticDNSMass performs Bayesian inference on Galactic double neutron stars (DNS) to investigate their mass distribution. Each DNS is comprised of two neutron stars (NS), a recycled NS and a non-recycled (slow) NS. It compares two hypotheses: A - recycled NS and non-recycled NS follow an identical mass distribution, and B - they are drawn from two distinct populations. Within each hypothesis it also explore three possible functional models: Gaussian, two-Gaussian (mixture model), and uniform mass distributions.

[ascl:1109.011] GalactICS: Galaxy Model Building Package

GalactICS generates N-body realizations of axisymmetric galaxy models consisting of disk, bulge and halo. Some of the code is in Fortran 77, using lines longer than 72 characters in some cases. The -e flag in the makefile allow for this for a Solaris f77 compiler. Other programs are written in C. Again, the linking between these routines works on Solaris systems, but may need to be adjusted for other architectures. We have found that linking using f77 instead of ld will often automatically load the appropriate libraries.

The graphics output by some of the programs (dbh, plotforce, diskdf, plothalo) uses the PGPLOT library. Alternatively, remove all calls to routines with names starting with "PG", as well as the -lpgplot flag in the Makefile, and the programs should still run fine.

[ascl:1108.004] Galacticus: A Semi-Analytic Model of Galaxy Formation

Galacticus is designed to solve the physics involved in the formation of galaxies within the current standard cosmological framework. It is of a type of model known as “semi-analytic” in which the numerous complex non-linear physics involved are solved using a combination of analytic approximations and empirical calibrations from more detailed, numerical solutions. Models of this type aim to begin with the initial state of the Universe (specified shortly after the Big Bang) and apply physical principles to determine the properties of galaxies in the Universe at later times, including the present day. Typical properties computed include the mass of stars and gas in each galaxy, broad structural properties (e.g. radii, rotation speeds, geometrical shape etc.), dark matter and black hole contents, and observable quantities such as luminosities, chemical composition etc.

[ascl:1303.018] Galactus: Modeling and fitting of galaxies from neutral hydrogen (HI) cubes

Galactus, written in python, is an astronomical software tool for the modeling and fitting of galaxies from neutral hydrogen (HI) cubes. Galactus uses a uniform medium to generate a cube. Galactus can perform the full-radiative transfer for the HI, so can model self-absorption in the galaxy.

[ascl:1408.011] GALAPAGOS-C: Galaxy Analysis over Large Areas

GALAPAGOS-C is a C implementation of the IDL code GALAPAGOS (ascl:1203.002). It processes a complete set of survey images through automation of source detection via SExtractor (ascl:1010.064), postage stamp cutting, object mask preparation, sky background estimation and complex two-dimensional light profile Sérsic modelling via GALFIT (ascl:1104.010). GALAPAGOS-C uses MPI-parallelization, thus allowing quick processing of large data sets. The code can fit multiple Sérsic profiles to each galaxy, each representing distinct galaxy components (e.g. bulge, disc, bar), and optionally can fit asymmetric Fourier mode distortions.

[ascl:1203.002] GALAPAGOS: Galaxy Analysis over Large Areas: Parameter Assessment by GALFITting Objects from SExtractor

GALAPAGOS, Galaxy Analysis over Large Areas: Parameter Assessment by GALFITting Objects from SExtractor (ascl:1010.064), automates source detection, two-dimensional light-profile Sersic modelling and catalogue compilation in large survey applications. Based on a single setup, GALAPAGOS can process a complete set of survey images. It detects sources in the data, estimates a local sky background, cuts postage stamp images for all sources, prepares object masks, performs Sersic fitting including neighbours and compiles all objects in a final output catalogue. For the initial source detection GALAPAGOS applies SExtractor, while GALFIT (ascl:1104.010) is incorporated for modelling Sersic profiles. It measures the background sky involved in the Sersic fitting by means of a flux growth curve. GALAPAGOS determines postage stamp sizes based on SExtractor shape parameters. In order to obtain precise model parameters GALAPAGOS incorporates a complex sorting mechanism and makes use of multiplexing capabilities. It combines SExtractor and GALFIT data in a single output table. When incorporating information from overlapping tiles, GALAPAGOS automatically removes multiple entries from identical sources.

GALAPAGOS is programmed in the Interactive Data Language, IDL. A C implementation of the software, GALAPAGOS-C (ascl:1408.011), is available, and a multi-band Galapagos version is also available.

[ascl:1710.022] galario: Gpu Accelerated Library for Analyzing Radio Interferometer Observations

The galario library exploits the computing power of modern graphic cards (GPUs) to accelerate the comparison of model predictions to radio interferometer observations. It speeds up the computation of the synthetic visibilities given a model image (or an axisymmetric brightness profile) and their comparison to the observations.

[ascl:1503.002] Galax2d: 2D isothermal Euler equations solver

Galax2d computes the 2D stationary solution of the isothermal Euler equations of gas dynamics in a rotating galaxy with a weak bar. The gravitational potential represents a weak bar and controls the flow. A damped Newton method solves the second-order upwind discretization of the equations for a steady-state solution, using a consistent linearization and a direct solver. The code can be applied as a tool for generating flow models if used on not too fine meshes, up to 256 by 256 cells for half a disk in polar coordinates.

[ascl:1104.005] GALAXEV: Evolutionary Stellar Population Synthesis Models

GALAXEV is a library of evolutionary stellar population synthesis models computed using the new isochrone synthesis code of Bruzual & Charlot (2003). This code allows one to computes the spectral evolution of stellar populations in wide ranges of ages and metallicities at a resolution of 3 Å across the whole wavelength range from 3200 Å to 9500 Å, and at lower resolution outside this range.

[ascl:1901.005] Galaxia_wrap: Galaxia wrapper for generating mock stellar surveys

Galaxia_wrap is a python wrap around the popular Galaxia tool (ascl:1101.007) for generating mock stellar surveys, such as a magnitude limited survey, using a built-in Galaxy model or directly from n-body data. It also offers n-body functionality and has been used to infer the age distribution of a specific stellar tracer population.

[ascl:1101.007] Galaxia: A Code to Generate a Synthetic Survey of the Milky Way

We present here a fast code for creating a synthetic survey of the Milky Way. Given one or more color-magnitude bounds, a survey size and geometry, the code returns a catalog of stars in accordance with a given model of the Milky Way. The model can be specified by a set of density distributions or as an N-body realization. We provide fast and efficient algorithms for sampling both types of models. As compared to earlier sampling schemes which generate stars at specified locations along a line of sight, our scheme can generate a continuous and smooth distribution of stars over any given volume. The code is quite general and flexible and can accept input in the form of a star formation rate, age metallicity relation, age velocity dispersion relation and analytic density distribution functions. Theoretical isochrones are then used to generate a catalog of stars and support is available for a wide range of photometric bands. As a concrete example we implement the Besancon Milky Way model for the disc. For the stellar halo we employ the simulated stellar halo N-body models of Bullock & Johnston (2005). In order to sample N-body models, we present a scheme that disperses the stars spawned by an N-body particle, in such a way that the phase space density of the spawned stars is consistent with that of the N-body particles. The code is ideally suited to generating synthetic data sets that mimic near future wide area surveys such as GAIA, LSST and HERMES. As an application we study the prospect of identifying structures in the stellar halo with a simulated GAIA survey.

[submitted] GalaXimView

GalaXimView (for Galaxies Simulations Viewer) is a python3+matplotlib tool designed to visualise simulations which use particles, providing notably a rotatable 3D view and corresponding projections in 2D, together with a way of navigating through snapshots of a simulation keeping the same projection.

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