RCSEDv2: homogenization of multi-wavelength photometric data

TL;DR

RCSEDv2 provides a large, homogenized multi-wavelength photometric catalog of 4 million galaxies, enabling detailed spectral energy distribution analysis and scientific studies of galaxy properties.

Contribution

It introduces a comprehensive methodology for homogenizing multi-survey photometric data, including extinction correction, system conversion, aperture correction, and k-correction, for a large galaxy sample.

Findings

Homogenized photometric data for 4 million galaxies.

Enabled construction of calibrated galaxy spectral energy distributions.

Facilitated scientific analysis of galaxy properties.

Abstract

RCSEDv2 (https://rcsed2.voxastro.org/), the second Reference Catalog of Spectral Energy Distributions of galaxies includes the largest homogeneously processed photometric dataset for 4 million galaxies assembled from several wide-field surveys. Here we describe the methodology of the photometric data homogenization. We first correct all photometric measurements for the foreground Galactic extinction, then convert them into the photometric system we adopted as a standard (GALEX + SDSS + UKIDSS + WISE). We computed aperture corrections into several pre-defined apertures by using published galaxy sizes / light profiles and image quality for each of the surveys. We accounted for k-corrections using our own analytic approximations. Such a homogeneous photometric catalog allows us to build fully calibrated SEDs for the galaxies in our sample (defined by the availability of their spectra) and enables direct scientific analysis of this unique extragalactic dataset.