The Heraklion Extragalactic Catalogue (HECATE v2.0): A value-added galaxy catalogue and its applications

The Heraklion Extragalactic CATalogue is a reference catalog which contains all known nearby galaxies in the local Universe (D ≲ 200Mpc). By incorporating and homogenizing data from HyperLEDA, NED, and infrared/optical surveys, the catalog provides a broad array of information such as positions, sizes, distances, morphological classifications, Star Formation Rate (SFR), stellar mass (M⋆), metallicity, and activity classifications. In the updated version (v2.0) of the catalogue, we increase the completeness of SFR, and M⋆ from ∼ 46% and ∼ 65% up to ∼ 76% and ∼ 90%, respectively, based on a combination of new calibrations and standard mid-infrared diagnostics. In addition, we calculate the gas-phase metallicity of the galaxies, either using the standard emission line-based spectroscopic relation or the stellar mass-metallicity scaling relation. As a result, the completeness of the Metallicity is increased from ∼ 30% up to ∼ 90%. Finally, by applying a new galactic activity classifier based on mid-IR/optical colors and machine learning, we increase the activity classification in the catalog from ∼ 30% to ∼ 60%. This catalog can have several astrophysical applications such as the identification of the hosts of gravitational-wave (GW) events, demographics of different source populations, and the connection between the X-ray luminosity of galaxies with their stellar population parameters using large statistical samples.'