CMB & LSS Virtual Research Community Marcos López-Caniego Enrique Martínez Isabel Campos Jesús Marco Instituto de Física de Cantabria (CSIC-UC) EGI Community Forum Garching March

In the last decade the computation infrastructures available to astronomers across Europe have grown exponentially and most european countries nowadays have modern facilities to support the needs of their researchers. In many cases one could even say that the amount of resources is growing faster that the ability of the scientists to use them. The reason for this are simple:  the use of HPC, GRID, Cloud, etc. is not always straightforward and the learning curves can vary significantly depending on the complexity of the workflows.  Once people get used to one of these infrastructures, in general HPC, it is common that they don’t want to dedicate the time and effort to port their applications to another, the GRID, for example, even if it is more suitable for the kind of analysis that they do.  Part of this problem could be solved with more training activities as well as more efficient middleware to manage the workflows. Under the umbrella of the EGEE project many research groups in Europe got involved in GRID related activities to take advantage of the vast amount of resources that had been deployed.

This was the case of the Observational Cosmology and Instrumentation group at IFCA. We ported several applications to the GRID and used it for various analysis related to ESA’s Planck mission analysis. In our case, the success was directly related to the fact that in our Institute we had the support from the people in the Advanced Computing and e-Science group that were, and still are, deeply involved in GRID technology and run and maintain part of the GRID-CSIC, the largest GRID infrastructure in Spain. Things have evolved since the times of EGEE and now we have EGI coordinating the GRID activities at the European level and the NGI’s coordinating and supporting the GRID activities at the national level. But even though the infrastructures are run by the national organizations, the research groups are every day more and more international. In addition, research groups in astronomy don’t use computing infrastructures in the same way. In fact, some groups only use HPC, other only use GRID, etc. Moreover, the applications and their requirements can be totally different from one field of astronomy to another. Therefore it is difficult to run and support a VRC for the whole A&A when the use cases and problematic are very different from one sub- community to another, even within astronomy.

For this reason we would like to propose the creation of a VRC that could agglutinate research communities working in the fields of Cosmic Microwave Background and Large Scale Structure of the Universe across Europe. At IFCA we have the necessary infrastructure, manpower and expertise to support the creation of this CMB/LSS VRC. We are part of Spanish e-Science Network, are involved in the activities of the National Grid Initiative and, as it was mentioned above, run and maintain a part of the GRID-CSIC cluster, with roughly 1400 cores, 3TB RAM and 14 TB of storage at IFCA. And these numbers will increase soon as part of a planned and continuous growth of the infrastructure. From the scientific point of view we are part of the Planck and QUIJOTE collaborations working on CMB science and part of the J-Pass Survey devoted to LSS structure studies, among others. We are also involved in state of the art cosmological LSS simulations in collaboration with colleagues in Madrid, Potsdam and Sussex.

CPU hoursRAMStorageCPU hoursRAMStorage Component Separation SZ Cluster detection PS detection T and P PS Detection Bayesian Non Gaussianity Large Scale Structure simulations Total GB50 TB GB48TB Last 12 monthsNext 6 months Summary of the typical amount of resources used by the members of our group for CMB/LSS studies CMB LSS

Trying to respond to the questions posed by Claudio: 1 – This VRC aggregates observational and theoretical cosmologists involved in CMB and Large Scale Structure studies. At this stage we have not quantified the amount of potential users, but this is a very active field that involves complex and extensive computing analysis and, therefore, we suspect that the number of people willing to participate could be large. Regarding the amount of resources brought into the VRC, above we already listed the GRID-CSIC resources available at IFCA, part of which could be shared for members of the VRC. If we consider the whole GRID-CSIC infrastructure in Spain, we have access to as much as four times the amount of resources available at IFCA, not to mention other HPC infrastructures such as Altamira and the Barcelona Supercomputing Center. 2 – At this stage we can not list the services needed by our VRC that EGI already offers or that our VRC could contribute. 3 – Current status for setting up the new VRC: we are at a very early stage, identifying research groups across Europe that could be interested in joining the VRC. We only had informal contacts with people in Spain and Germany, but based on the feedback obtained in the EGI meeting in Amsterdam and the feedback from this meeting we plan to start contacting the people that have shown an interest in creating this VRC, in particular our colleagues in Potsdam. At this stage we have not established any direct contact with EGI, only through Claudio.