Public release of selected data products from DESC's DC2

On behalf of the LSST Dark Energy Science Collaboration we are happy to announce the world-wide public release v1 of a limited set of data products from the Second Data Challenge (DC2), carried out by us recently. DC2 is a simulated sky survey, covering 300 square degrees in six optical passbands following the first five years of a reference LSST observing cadence. Details about the data can be found in the DESC paper “The LSST DESC DC2 Simulated Sky Survey” (, to appear in ApJS) and the data release v1 itself is described in the “DESC DC2 Data Release Note” ( We have created a data portal ( for easy access; the documentation there includes example Python Jupyter Notebooks to demonstrate data access and simple analysis. If you use the data in your work, please cite the DC2 paper and the data release note.

In addition, we have also added the extragalactic catalog, cosmoDC2, to the data portal. This data set had been released earlier but now the web portal allows for faster download. CosmoDC2 is the underlying extragalactic catalog for the DC2 image simulations and is described in Korytov et al (LSST DESC) 2019 ApJS 245 26. If you use the data in your work, please cite this paper.

Katrin Heitmann, LSST DESC Computing & Simulations Coordinator, on behalf of the entire DESC DC2 team