HECATEv2: An all-sky galaxy catalogue for multimessenger astrophysics

Abstract

We present HECATEv2, the second release of the Heraklion Extragalactic Catalogue (HECATE), an all-sky, value-added galaxy catalogue comprising 204733 galaxies from the HyperLEDA database with recession velocity <14000 km/s (D~200 Mpc). This release focuses on qualitative upgrades of the provided information while maintaining the same parent galaxy sample as HECATEv1. Improvements include a new cosmology-based distance framework, expanded and homogenised optical and mid-infrared photometry from SDSS-DR17/NSA, PS1-DR2, and AllWISE, and new quality-control flags for stellar contamination, incorrect photometry, and coordinate inconsistencies. We also extend the galaxy-size coverage and derive stellar population parameters for a substantially larger fraction of the sample. Star-formation rates (SFR) and stellar masses (Mstar) are now available for >70% of galaxies using updated mid-IR/optical calibrations that account for stellar population age and dust attenuation, while gas-phase metallicities are derived for ~90%. Activity classifications are provided for >50% of galaxies based on spectroscopic and/or photometric diagnostics, and supermassive black hole masses for ~86%. In terms of L$_{B}$,L$_{Ks}$,SFR, and Mstar, HECATEv2 is among the most complete local-Universe catalogues with spectroscopic redshifts. We also provide spatial completeness maps as a function of distance and luminosity, highlighting variations across the sky. Compared to other catalogues (e.g. GLADE+, NED-LVS), HECATEv2 offers broader (optical, near- and far-IR photometry, metallicity, activity classifications) or comparable (mid-IR photometry, SFR, Mstar) coverage, making it a robust reference for studies of SMBH-host galaxy connections, gravitational-wave and high-energy transient hosts, population analyses, and rare galaxy subpopulations.

Figures (18)

• Figure 1: A few examples of galaxies identified as having wrong photometric matches by our analysis desrcibed in Sect.\ref{['subsec:wrong_phot_wrong_coord']}. The top and bottom rows display galaxy images obtained from SDSS and the PS1-DR2 surveys, respectively, in the g band. The cyan ellipse represents the D$_{25}$ size of each galaxy, and the magenta open circle marks the incorrect photometric match. The orange x symbol represents the HECATEv2's galaxy center (RA,DEC).
• Figure 2: Comparison between the SDSS/NSA (cModelMag or PETRO_MAG) and the rescaled PS1-DR2 Kron magnitudes as a function of the reference standard SDSS magnitudes, for the common bands (i.e. g,r,i,z) between the two optical surveys. The dashed dark gray line depicts the line of equality while the black dashed lines show the 16% and 84% percentiles. The two photometries are highly consistent, with a scatter of $\sim 0.25$ mag around the equality line.
• Figure 3: Comparison between the forced photometry magnitudes and the rescaled magnitudes derived from our hybrid photometric scheme (W$_{\rm hyb}$), as a function of the reference standard WF magnitudes. The dashed dark gray line indicates the line of equality while the black dashed lines show the 16% and 84% percentiles. The two photometries are in strong agreement with a scatter less than $\sim 0.5$ mag around the equality line.
• Figure 4: The ratio of the R1 radius (as provided by HECATE) to the SMA_SB25_G radius (from the SGA-2020 catalogue) is shown as a function of R1. Blue diamonds represent the median ratio in 9 equally spaced R1 bins, while the blue solid lines indicate the 16th and 84th percentiles. The black dashed line denotes the one-to-one relation. Overall, the two size measurements are in good agreement, with a small systematic offset (less than $\approx$20%) likely due to the higher signal-to-noise of the deeper optical imaging used in SGA-2020.
• Figure 5: Top panel: Comparison between the rescaled $\mathrm{SFR}$ (left panel) and $\mathrm{{M}_{\star}}$ (right panel) estimates from S18 with respect to the reference K23 estimates. The y-axis shows the logarithmic ratio of the values (i.e. $\textrm{log}_{10}(\frac{SFR_{S18}}{SFR_{K23}})$ and $\textrm{log}_{10}(\frac{M_{\star S18}}{M_{\star K23}})$ ), with the black dashed horizontal line at zero indicating equality between the two methods. The black dashed lines indicate the 16% and 84% percentiles of the distributions. As shown the homogenised $\mathrm{SFR}$ and $\mathrm{{M}_{\star}}$ estimates are in a good agreement. Bottom panel: Comparison between the original $\mathrm{SFR}$ (left panel) and $\mathrm{{M}_{\star}}$ (right panel) estimates from L19 with respect to the reference K23 estimates. The difference in the lower $\mathrm{SFR}$ and $\mathrm{{M}_{\star}}$ regimes are primarly driven by aperture effects.