Visualizing Astronomical Dendrograms

You can use Glue to visualize dendrograms created by the astrodendro package.

Enabling the viewer

The dendrogram viewer will be automatically available if the astrodendro package is installed. To install it, simply use:

pip install astrodendro

Building a dendrogram

The details of constructing dendrograms for astronomical images is beyond the scope of this document – see http://dendrograms.org/ for more information. The following snippet builds a dendrogram from the W5 image used in the tutorial:

from astropy.io import fits
from astrodendro import Dendrogram

data = fits.getdata('W5.fits')
dg = Dendrogram.compute(data, min_value=500, min_npix=50)
dg.save_to('w5_dendro.fits')

Next, load this file into Glue, choosing “Denrdogram” as a file type. You can now visualize the W5 dendrogram alongside its image:

../_images/dendro.png

Linking to Catalog Properties

If you have used astrodendro to compute a catalog of structure properties, you can visualize that in Glue as well. The best way to do this is to save the catalog as a table, load it into Glue, and merge it with the dendrogram dataset. This will supplement the dendrogram with the additional catalog-derived properties.