Ejwst Catalogue Achieves Complete Access to All Active Galactic Nuclei Observations

Active galactic nuclei (AGN) are now being scrutinised like never before, thanks to the James Webb Space Telescope’s powerful capabilities. Virginia Lenk, from the Zentrum für Astronomie der Universität Heidelberg, alongside Alvaro Labiano of Telespazio UK S.L. for ESA, and Chiara Circosta from the European Space Agency (ESA), and et al., have compiled the first extensive catalogue of these observations , the eJWST active galactic nucleus observation catalogue , containing details of 3,242 individual AGN observed by JWST. This resource systematically filters and organises data from the European Archive of the James Webb (eJWST), cross-matching observations with existing catalogues to provide a readily accessible and invaluable tool for astronomers studying these energetic phenomena with unprecedented detail.

This groundbreaking work, utilising the European Archive of the JWST (eJWST), systematically filters and organises observations to provide the astronomical community with readily accessible data products related to AGNs. The research team achieved this by leveraging keywords specified by principal investigators in their JWST proposals, alongside manual review of approved programmes and cross-matching with existing AGN catalogues such as the Million Quasar catalogue, the SDSS MaNGA AGN catalogue, and the CDFS catalogue. This meticulous approach ensures a robust and reliable resource for AGN research.

The study unveils detailed information for each AGN, including its name, coordinates, and redshift, alongside specifics of the JWST observations, instrument used, aperture settings, and applied filters. Crucially, the catalogue provides direct links for data downloads, streamlining the research process for astronomers worldwide. JWST, launched in December 2021, is a collaborative effort between NASA, ESA, and CSA, delivering unprecedented sensitivity and wavelength coverage from 0.6 to 28 microns. Equipped with instruments like the Near Infrared Camera (NIRCam), Near Infrared Spectrograph (NIRSpec), and Mid-Infrared Instrument (MIRI), the telescope generates approximately 28.6 Gb of data daily, processed through a multi-stage calibration pipeline to Calibration Level 3 science-ready products.
Experiments show that the eJWST archive, part of ESA’s science archives, is designed for efficient access to JWST data, integrating seamlessly with data from other ESA missions. The team’s methodology involved careful consideration of the JWST data pipeline, which includes stages from initial calibration (Level 1) to fully processed mosaics and spectra (Level 3), ensuring the catalogue reflects the most up-to-date data processing standards. By systematically compiling observations identified through keywords like “Quasars” and “Seyfert galaxies”, as detailed in Table 1 from approved Cycle 4 proposals, the researchers established a valuable resource for studying AGN phenomena with unprecedented detail. The research establishes a critical foundation for future investigations into galaxy evolution, as AGNs significantly influence the properties of their host galaxies.

This work opens new avenues for exploring distant and faint AGNs, previously undetectable due to limitations in resolution or obscuration by dust, and promises to advance our understanding of these powerful cosmic engines. The catalogue’s accessibility through eJWST, MAST, and CADC, all utilising the common archive observation model (CAOM), ensures broad community access and facilitates collaborative research efforts. The research team harnessed the European Archive of the JWST (eJWST) to systematically filter and organise observations, facilitating access to all JWST data products pertaining to AGNs. This work began with a detailed review of approved JWST programmes, identifying observations flagged with specific keywords designated by principal investigators in their proposals. To ensure completeness, the study cross-matched these identified observations with existing AGN catalogues, including the Million Quasar catalogue, the SDSS MaNGA AGN catalogue, and the CDFS catalogue.

Researchers employed this multi-faceted approach to capture a broad spectrum of AGN observations, mitigating potential biases inherent in relying solely on proposal keywords. The team then accessed data processed through the JWST Data Management System (DMS), which calibrates data to three levels: Level 1 applies basic corrections, Level 2 performs pixel flat-fielding and world-coordinate derivation, and Level 3 assembles science-ready mosaics and spectra. Experiments also incorporated observations at Calibration Level -1, representing planned but not yet executed observations listed within the archives. The DMS utilises frequently updated software pipelines, currently at version 1.17.0, to accommodate evolving instrument behaviour and calibration refinements.

This innovative methodology enabled the creation of a detailed catalogue containing target names, coordinates, redshifts, and specifics of each JWST observation, including the instrument used, aperture settings, and applied filters. The resulting catalogue provides direct links to data downloads from the eJWST, MAST, and CADC archives, all utilising the common archive observation model (CAOM) for data consistency. The team meticulously cross-matched observations with existing AGN catalogues, including the Million Quasar catalogue, the SDSS MaNGA AGN catalogue, and the CDFS catalogue, ensuring a robust and complete dataset. Experiments revealed detailed information for each AGN, encompassing its name, coordinates, and redshift, alongside specifics of the JWST observations such as the instrument used, aperture settings, and applied filters.

Data shows that the JWST transmits approximately 28.6 Gb of data to Earth twice daily, which is then processed through three calibration levels before being archived. Calibration Level 1 applies initial corrections, while Level 2 incorporates pixel flat-fielding and world-coordinate information. The final Calibration Level 3 assembles science-ready mosaics, data cubes, and spectra, enabling detailed analysis of AGN phenomena. Results demonstrate the power of JWST’s four scientific instruments, the Near Infrared Camera (NIRCam), Near Infrared Spectrograph (NIRSpec), Mid-Infrared Instrument (MIRI), and Fine Guidance Sensor/Near InfraRed Imager and Slitless Spectrograph (FGS/NIRISS), in probing AGN characteristics.

Measurements confirm that the telescope operates across a wavelength range of 0.6 to 28 microns, providing extraordinary sensitivity for studying these distant objects. The catalogue provides direct links for data downloads, offering the scientific community a valuable resource for AGN research and facilitating further investigation into galaxy evolution. Tests prove the efficacy of the eJWST archive, which is designed for efficient access to all JWST science data products and is searchable in combination with data from other ESA missions. The research team identified a range of AGN descriptions within approved JWST programmes, including quasars, Seyfert galaxies, blazars, and radio galaxies, highlighting the breadth of AGN types targeted by JWST observations. This work represents one of the first extensive collections of its kind, systematically gathering data from the European JWST archive (eJWST) using keywords from principal investigator proposals and cross-matching with existing AGN catalogues like the Million Quasar catalogue and the SDSS MaNGA AGN catalogue. The catalogue details target information, including name, coordinates, and redshift, alongside specifics of each JWST observation, such as instrument used, aperture, and filter selection, and importantly, provides direct links to download the associated data. The significance of this catalogue lies in its facilitation of future research on AGNs, offering a readily accessible resource for astronomers studying these energetic phenomena.

By consolidating observations from JWST’s powerful instruments, NIRCam, NIRSpec, MIRI, and FGS/NIRISS, the catalogue streamlines access to high-resolution imaging, spectroscopy, and photometric data, enabling detailed investigations into AGN physics and evolution. The authors acknowledge a limitation in relying on keywords provided by investigators, potentially leading to incomplete coverage, and the ongoing evolution of the JWST data pipeline requiring periodic updates to the catalogue. Future work could focus on incorporating data from additional catalogues and expanding the catalogue to include derived parameters, further enhancing its utility for the astronomical community.