SExtractor (Source-Extractor) is a program that builds a catalog of objects from an astronomical image. It is particularly oriented towards the reduction of large scale galaxy-survey data, but it also performs well on moderately crowded star fields. Its main features are:

  • Support for multi-extension FITS (MEF)

  • Speed: up to about 50 Mpixel/s or 10,000 sources/s with a 3 GHz processor

  • Ability to work with very large images (up to 2Gx2G pixels on 64 bit machines) thanks to buffered image access

  • Real-time filtering of images to improve detectability

  • Robust deblending of overlapping extended objects

  • Flexible catalog output of desired parameters only

  • Pixel-to-pixel photometry in dual-image mode

  • Fast and accurate Point-Spread-Function and galaxy model fitting.

  • Handling of weight maps and flag maps.

  • Optimum handling of images with variable SNR.

  • Built-in catalog cross-identification.

  • Special mode for photographic scans.

  • XML VOTable-compliant catalog output.

  • XSLT filter sheet provided for convenient access to metadata from a regular web browser.