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Spectral data cubes: 144 RA pixels pixels x 144 Decl. pixels x 1024 frequency channels x 2 polarizations (Example spectral line data cube)
Spectral weights: 144 RA pixels pixels x 144 Decl. pixels x 1024 frequency channels x 2 polarizations (Example spectral line weights - also a cube)
Continuum maps: 144 RA pixels pixels x 144 Decl. pixels x 2 polarizations (Example continuum FITS image)
Continuum weights: 144 RA pixels pixels x 144 Decl. pixels x 2 polarizations (Example continuum weights)
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Archive Access to ALFALFA Data Products
The modalities Modalities for the discovery and filtering of ALFALFA data sets in the Archive.
- Any primary project that has an associated ALFALFA "product" (a set of cubes, catalog entry, or spectrum) should show the ALFALFA results as a related product in the project view.
- This should be displayed in a similar manner to any Images or other SRDP related products, but clearly show that it is an ALFALFA product.
- In the observation view ALFALFA data cube sets are displayed and filtered with the other EBs stored in the archive.
- A column showing that they belong to the ALFALFA collection should be optionally displayed
- The user should be able to suppress display of members of the ALFALFA (or any other) collection.
- No reprocessing capabilities (e.g. optimized imaging) should be provided for data cubes from the ALFALFA collection (the project is COMPLETED).
- A dedicated "ALFALFA" view of the archive, that enables searches on the ALFALFA specific meta-data columns.
- A cone search of the RA and Dec fields (as described in the above catalog description) should be supported.
- Searching on ranges of heliocentric redshift (in the above table) should be supported.
- The ALFALFA view should also provide links to the ALFALFA project, and publications explaining the processing and data products (ALFALFA publications).
End user manipulation
The expectation is that a user would search for a position on the sky, or via a galaxy name (NED resolver, etc.). For instance, if one searches on the position 12h20m00s, +09d00m00s, four data cubes, each with three additional ancillary products, would be returned (16 totals hits, total volume would be ~ 1.6 GB).
At the most basic level, using AstroPy, we would expect an end user to download a set of ALFALFA files and manipulate them with some simple Python or a Jupyter notebook (Example demo: ReadTheDocs).
This is out of the archive scope, but is useful so that we all know what the data look like.
Stakeholders
Brian Kent, NRAO, Project Sponsor and Technical Expert
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