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Repository Products

VAPOLA is the first publicly accessible repository dedicated to AGN and black hole targets observed with ALMA in VLBI mode. It provides science-ready, full-polarization, multi-epoch, and multi-band high-level data products, including:

• calibrated interferometric visibilities;
• full-Stokes I, Q, U, and V images in FITS and CASA formats;
• diagnostic and quality-control plots;
• linear- and circular-polarization maps;
• spectral-index maps;
• Faraday-rotation products, where supported by the frequency coverage;
• tabulated polarimetric parameters; and
• time-domain diagnostics and light curves for variable sources such as Sagittarius A*.

Images are produced for individual spectral windows and, where appropriate, by combining the available spectral windows. The calibrated visibilities support additional imaging, spectral, polarimetric, and time-domain analyses beyond the distributed high-level products.

The repository is hosted at the Italian Centre for Astronomical Archives (IA2) and is updated as new datasets become available. Its standardized, largely automated pipeline starts from fully calibrated ALMA QA2 datasets, ensuring internal consistency while minimizing manual intervention.

VAPOLA supports EHT scientific activities through standardized data products while making these datasets available for broader scientific use by the astronomical community. The pipeline and archive are described in VAPOLA I.

Permissions and downloads

Data Access

All raw ALMA datasets processed by VAPOLA become publicly accessible through the ALMA Science Archive after the applicable proprietary period expires. Access to the high-level products distributed by VAPOLA depends on their release status:

To log in or create an account, open the user menu in the upper-right corner. Existing users can enter their username and password and select Login. New users can select Register and provide a username, email address, and password. New accounts initially have public access; any approved PI or EHT permissions are assigned separately and appear automatically after login.

The repository tree is organized by observing mode, source, year, frequency band, observing date, and product type. Some folders remain visible but are marked in red with a crossed name when the current user does not have permission to open or download them.

Products can be downloaded directly from the tree or through Download by Selection:

1. Select the observing mode and one or more product types.
2. Select the required sources, years, frequency bands, and observing dates.
3. Review the global and per-source selections.
4. Download a compressed tar archive or generate a download script.