Specviz Selections

This section explains the working theory behind the selection tool and was inspired by the the introduction of two methods to the Specviz helper:

• get_spectra()

• get_spectral_regions() (deprecated as of v4.1 in favor of get_regions())

Data loaded in are imported into Jdaviz and immediately converted into a specutils.SpectralRegion object. These are a spectral analog to the Astropy regions (which instead focuses on spatial regions and their associated WCS). These spectral regions are returned by the specviz.get_spectra() method.

The selection tool allows the user to specify a specific range on the graph. This is defined by the underlying glue library upon which Jdaviz relies on as a “glue subset.” Thus throughout the software documentation, we will refer to these user defined ranges as “subsets.” Effectively, the selection tool defines a mask that can be thought of as “definition” of which data is and is not included in the subset. Upon extraction via get_regions(), the method will return a new specutils.SpectralRegion object that applies that mask atop of the proper region (data) displayed, and realizes the subset the user defined in Jdaviz.