The Astrophysics Source Code Library (ASCL) is a free online registry for source codes of interest to astronomers and astrophysicists and lists codes that have been used in research that has appeared in, or been submitted to, peer-reviewed publications. The ASCL is indexed by the SAO/NASA Astrophysics Data System (ADS) and is citable by using the unique ascl ID assigned to each code. The ascl ID can be used to link to the code entry by prefacing the number with ascl.net (i.e., ascl.net/1201.001).
The GSD library reads data written in the James Clerk Maxwell Telescope GSD format. This format uses the General Single-Dish Data model and was used at the JCMT until 2005. The library provides API to open GSD files and to read their contents. The content of the data files is self-describing and the library can return the type and name of any component. The library is used by SPECX (ascl:1310.008), JCMTDR (ascl:1406.019) and COADD (ascl:1411.020). The SMURF (ascl:1310.007) package can convert GSD heterodyne data files to ACSIS format using this library.
The emission from young stellar objects (YSOs) in the mid-infrared (mid-IR) is dominated by the inner rim of their circumstellar disks. The YSOVAR project has monitored about a dozen young stellar clusters using the Spitzer Space Telescope in its warm mission phase. Individual objects typically have ~100 datapoints in one or two of the warm mission Spitzer bands; in some of the clusters there is near-simultaneous JHK data. The pYSOVAR code manages this data in a table and it calculates properties for a stack of lightcurves including simple descriptive statistics (mean, max, min, ...), timing (e.g. Lomb-Scargle periodograms), variability indixes (e.g. Stetson), and color properties (e.g. slope in the color-magnitude diagram).
Initially, this code was written specifically for the analysis of two clusters in the YSOVAR project, using the (not publically released) YSOVAR database as an input (hence the name).
As we have added more functionality, the code has become more general, so that it is now useful for other clusters in the YSOVAR dataset or for other projects that have similar data (lightcurves in one or more bands with a few hundred points for a few thousand objects). Still, the code might not work out-of-the-box for different datasets.
This code is written in python and is closely integrated with astropy tables.
HELIOS-K is an opacity calculator for exoplanetary atmospheres. It takes a line list as an input and computes the line shapes of an arbitrary number of spectral lines (~millions to billions). HELIOS-K is capable of computing 100,000 spectral lines in 1 second; it is written in CUDA and is optimized for graphics processing units (GPUs).
Isochrones, written in Python, simplifies common tasks often done with stellar model grids, such as simulating synthetic stellar populations, plotting evolution tracks or isochrones, or estimating the physical properties of a star given photometric and/or spectroscopic observations.
TAME measures the equivalent width (EWs) in high-resolution spectra. Written by IDL, TAME provides the EWs of spectral lines by profile fitting in an automatic or interactive mode and is reliable for measuring EWs in a spectrum with a spectral resolution of R ≳ 20000. It offers an interactive mode for more flexible measurement of the EW and a fully automatic mode that can simultaneously measure the EWs for a large set of lines.
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.
K2flix makes it easy to inspect the CCD pixel data obtained by NASA's Kepler space telescope. The two-wheeled extended Kepler mission, K2, is affected by new sources of systematics, including pointing jitter and foreground asteroids, that are easier to spot by eye than by algorithm. The code takes Kepler's Target Pixel Files (TPF) as input and turns them into contrast-stretched animated gifs or MPEG-4 movies. K2flix can be used both as a command-line tool or using its Python API.
UniPOPS was a suite of programs and utilities that were developed at the National Radio Astronomy Observatory (NRAO), first deployed in January 1991, and designed for reducing data from the observatory's single-dish telescopes -- the Tucson 12-m, the Green Bank 140-ft, and archived data from the Green Bank 300-ft. The primary reduction programs, 'line' (for spectral-line reduction) and 'condar' (for continuum reduction), used the People-Oriented Parsing Service (POPS) as the command line interpreter. POPS has had a 40-year history within the NRAO and elsewhere -- created in the 1970's by Jerry Hudson, subsequently adapted to single-dish analysis systems by Tom Cram, and related to the interpreter still used by AIPS. Before the start of the UniPOPS project, the 12-m and the Green Bank telescopes used what looked to the user like similar data reduction programs but were in fact very different at the code level. The "Uni" in UniPOPS signifies that this package meant to unify the previous analysis packages. Since the new system was meant to run on Sun workstations, a major upgrade from the computers previously used for data reduction, the capabilities of the software were also upgraded. For example, more memory was now available for adding new analysis routines; in comparison to its predecessors, the user-interface of UniPOPS incorporated many of the features one expected of software systems of its day, most significantly it took advantage of X-Windows. Development of UniPOPS continued within the NRAO until 2004 when the 12-m was turned over to the Arizona Radio Observatory (ARO). By then, the 140-ft had been decommissioned and the observatory had decided to use Aips++ as the analysis system for the recently-finished Green Bank Telescope. The submitted code is version 3.5 from 2004, the last supported by the NRAO. The ARO has since modified UniPOPS to run on Linux-based systems.
ROBOSPECT, written in C, automatically measures and deblends line equivalent widths for absorption and emission spectra. ROBOSPECT should not be used for stars with spectra in which there is no discernible continuum over large wavelength regions, nor for the most carbon-enhanced stars for which spectral synthesis would be favored. Although ROBOSPECT was designed for metal-poor stars, it is capable of fitting absorption and emission features in a variety of astronomical sources.