a Python implementation of proper image subtraction (Zackay, Ofek & Gal-Yam 2016, ApJ, 830, 27). Original written by Paul Vreeswijk with vital input from Barak Zackay and Eran Ofek.
This branch has been adapted by Kerry Paterson for integration into pipeline for MeerLICHT and the Catalina Sky Survey (CSS) telescope on Mt Lemmon for use in the Search After Gravitational waves Using Arizona Observatories (SAGUARO).
This module accepts a new and a reference fits image, runs SExtractor on them, finds their WCS solution using Astrometry.net, uses PSFex to infer the position-dependent PSFs of the images and SWarp to map the reference image to the new image and performs optimal image subtraction following Zackay et al. (2016) to produce the subtracted image (D), the significance image (S), the corrected significance image (Scorr), and PSF photometry image (Fpsf - alpha in the paper) and associated error image (Fpsferr). The inferred PSFs are also used to extract optimal photometry (following Horne 1986, PASP, 98, 609) of all sources detected by SExtractor. The configuration files of SExtractor, PSFex and SWarp are located in the Config directory.
ZOGY can now be installed using pip install. Either run "pip install git+https://github.com/KerryPaterson/ZOGY.git" or download or clone the repo, then run "pip install ." within the ZOGY folder. ZOGY also makes use of the following external programs which need to be installed separately:
- Astrometry.net (in particular "solve-field" and index files): http://astrometry.net
- SExtractor: http://www.astromatic.net/software/sextractor
- SWarp: http://www.astromatic.net/software/swarp
- PSFex: http://www.astromatic.net/software/psfex
- ds9
This project is licensed under the terms of the MIT license.