Reference Catalog of galaxy SEDs
Search galaxies database. Query can be anything: object name such as NGC 60, coordinates: 236.5644 -0.1738 or J154615.45-001025.4, boolean expression: gauss_f6565_h_alpha_flx / gauss_f6565_h_alpha_flx_err > 10 AND corrmag_u < 17.0, cone search: cone('12:13:53.7 -01:13:53', '0.2arcmin').
Show query language
Tools and services

Simple yet precise online service which allows one to determine k-corrections of a galaxy in any popular photometric bandpass, given its redshift and one or more colors. For bulk computation we provide easy-to-use Python and IDL code.

A catalog of 800,299 UV-to-NIR galaxy spectral energy distributions and optical spectra compiled from GALEX, SDSS and UKIDSS data, with additional value added properties such as gas phase metallicities and non-parametric emission lines measurements. Query it using search field above.

A universal relation of optical and near-UV colours and luminosities of non-active galaxies which is connected to their star formation histories — the first scientific result obtained with RCSED.

Articles and publications

By mining the RCSED database, astronomers have added 195 rare compact elliptical galaxies to only 25 known before. Most of the newly discovered objects were in galaxy clusters, but 11 were free fliers ejected by gravitational slingshot effect from their birth places, the team reported in Science.

Galaxies exhibit a bimodal distribution in the optical color-magnitude space with a narrow "red sequence" populated by mostly early-type galaxies and a broad "blue cloud" containing star-forming objects. Researchers from Harvard and Paris Observatory added the near ultraviolet (NUV-r) color to it and discovered a tight relation in the 3D color-color-magnitude space smoothly continuing from the "blue cloud" to the "red sequence". Followed by the majority of galaxies, it can be used as a powerful classification tool, as well as a new distance estimator for intermediate redshifts that requires a minimal set of observables.

Here we propose a step-by-step guide to reproduce a compact elliptical galaxy search which resulted in a Science magazine publication. This guide exploits Virtual Observatory desktop applications such as TOPCAT, VOSpec and Aladin, and uses the RCSED catalog data.

About the catalog

RCSED (stands for the Reference Catalog of galaxy Spectral Energy Distributions) is a catalog of galaxies produced as join between GALEX, SDSS, and UKIDSS catalogs, and processed with state-of-the-art spectral analysis methods which were not available earlier. It therefore covers approximately 25% of the sky and contains k-corrected ultraviolet-to-near-infrared photometry of some 1 million galaxies, as well as properties of their stellar population, stellar and gas phase metallicity, morphological classification (from Galaxy Zoo), emission line parameters (measured by gaussian fitting and non-parametrically) and bulge + disk light profile decomposition (from Simard et al.) The multitude of data access methods compatible with the Virtual Observatory (in particular, table and spectral access services) and easy-to-use website with simple query language make RCSED a new generation catalog.

As one of the richest data collections on galaxies RCSED enables wide range of studies in extragalactic astrophysics (see examples in the Articles section). If you find RCSED useful for your research, please acknowledge it.

Start by trying one of the example queries next to the search field above and exploring individual webpages of found galaxies, or following a tutorial (we aim to add more soon). Please note that if you do not find your favorite galaxy in the RCSED database, it means that it is not included in the SDSS spectral sample of galaxies, or possibly marked there as an active galactic nucleus. If you believe that this is a mistake, please report it here.