GNU Astronomy Utilities

7.4.1 Detection and catalog production

Most existing common tools in low-level astronomical data-analysis (for example, SExtractor208) merge the two processes of detection and measurement (catalog production) in one program. However, in light of Gnuastro’s modularized approach (modeled on the Unix system) detection is separated from measurements and catalog production. This modularity is therefore new to many experienced astronomers and deserves a short review here. Further discussion on the benefits of this methodology can be seen in Akhlaghi 2016.

As discussed in the introduction of MakeCatalog, detection (identifying which pixels to do measurements on) can be done with different programs. Their outputs (a labeled dataset) can be directly fed into MakeCatalog to do the measurements and write the result as a catalog/table. Beyond that, Gnuastro’s modular approach has many benefits that will become clear as you get more experienced in astronomical data analysis and want to be more creative in using your valuable data for the exciting scientific project you are working on. In short the reasons for this modularity can be classified as below: