Astrophysics Source Code Library

Making codes discoverable since 1999

Searching for codes credited to 'Christiaens, Valentin'

Tip! Refine or expand your search. Authors are sometimes listed as 'Smith, J. K.' instead of 'Smith, John' so it is useful to search for last names only. Note this is currently a simple phrase search.

[ascl:1603.003] VIP: Vortex Image Processing pipeline for high-contrast direct imaging of exoplanets

VIP (Vortex Image Processing pipeline) provides pre- and post-processing algorithms for high-contrast direct imaging of exoplanets. Written in Python, VIP provides a very flexible framework for data exploration and image processing and supports high-contrast imaging observational techniques, including angular, reference-star and multi-spectral differential imaging. Several post-processing algorithms for PSF subtraction based on principal component analysis are available as well as the LLSG (Local Low-rank plus Sparse plus Gaussian-noise decomposition) algorithm for angular differential imaging. VIP also implements the negative fake companion technique coupled with MCMC sampling for rigorous estimation of the flux and position of potential companions.

[ascl:2301.028] special: SPEctral Characterization of directly ImAged Low-mass companions

special (SPEctral Characterization of directly ImAged Low-mass companions) characterizes low-mass (M, L, T) dwarfs down to giant planets at optical/IR wavelengths. It can also be used more generally to characterize any type of object with a measured spectrum, provided a relevant input model grid, regardless of the observational method used to obtain the spectrum (direct imaging or not) and regardless of the format of the spectra (multi-band photometry, low-resolution or medium-resolution spectrum, or a combination thereof). It analyzes measured spectra, calculating the spectral correlation between channels of an IFS datacube and empirical spectral indices for MLT-dwarfs. It fits input spectra to either photo-/atmospheric model grids or a blackbody model, including additional parameters such as (extra) black body component(s), extinction and total-to-selective extinction ratio, and can use emcee (ascl:1303.002), nestle (ascl:2103.022), or UltraNest (ascl:1611.001) samplers infer posterior distributions on spectral model parameters in a Bayesian framework, among other tasks.

[ascl:2311.002] VCAL-SPHERE: Hybrid pipeline for reduction of VLT/SPHERE data

VCAL-SPHERE, for VIP-based Calibration of VLT/SPHERE data, is a versatile pipeline for high-contrast imaging of exoplanets and circumstellar disks. The pipeline covers all steps of data reduction, including raw calibration, pre-processing and post-processing (i.e., modeling and subtraction of the stellar halo), for the IFS, IRDIS-DBI and IRDIS-CI modes (and combinations thereof) of the VLT instrument SPHERE. The three main steps of the reduction correspond to different modules, where the first follows the recommended EsoRex (ascl:1504.003) workflow and associated recipes with occasional inclusion of VIP (ascl:1603.003) routines (e.g., for PCA-based sky subtraction), while the other two stages fully rely on the VIP toolbox. Although the default parameters of the pipeline should yield a good reduction in most cases, these can be tuned using JSON parameter files for each stage of the pipeline for optimal reduction of specific datasets.

[ascl:2403.007] MINDS: Hybrid pipeline for the reduction of JWST/MIRI-MRS data

The MINDS hybrid pipeline is based on the JWST pipeline and routines from the VIP package (ascl:1603.003) for the reduction of JWST MIRI-MRS data. The pipeline compensates for some of the known weaknesses of the official JWST pipeline to improve the quality of spectrum extracted from MIRI-MRS data. This is done by leveraging the capabilities of VIP, another large data reduction package used in the field of high-contrast imaging.

The front end of the pipeline is a highly automated Jupyter notebook. Parameters are typically set in one cell at the beginning of the notebook, and the rest of the notebook can be run without any further modification. The Jupyter notebook format provides flexibility, enhanced visibility of intermediate and final results, more straightforward troubleshooting, and the possibility to easily incorporate additional codes by the user to further analyze or exploit their results.