ICRC2015

The On-Site Analysis of the Cherenkov Telescope Array

1 Aug 2015, 15:30

1h

Mississippi Foyer (World Forum)

Board: 76

Poster contribution GA-EX Poster 2 GA

Speaker

Fabian Schüssler (CEA)

Description

The Cherenkov Telescope Array (CTA) observatory will be one of the largest ground-based very-high-energy gamma-ray observatories. The on-site analysis will perform a first CTA scientific analysis of data acquired from the array of telescopes, in both northern and southern sites. The On-Site Analysis has two pipelines: the Level-A pipeline (also known as Real-Time Analysis, RTA) and the level-B one. The RTA performs a data quality monitoring and must be able of issuing automated alerts on variable and transient astrophysical sources within 30 seconds from the last acquired Cherenkov event that contributes to the alert, with a sensitivity not worst than the final one by more than a factor of 3. The Level-B Analysis has a better sensitivity (not be worse by a factor of 2) and should start within 10 hours from the acquisition of the data: for this reason this analysis could be performed at the end of an observation or next morning. The latency (in particular for the RTA) and the sensitivity requirements are challenging because of the large data rate, a few GByte/s. The remote connection to the CTA candidate site with a rather limited network bandwidth makes the issue of the exported data size extremely critical and prevents any kind of processing in real-time of the data outside the site of the telescopes. For these reasons the analysis will be performed on-site with infrastructures co-located with the telescopes, with limited electrical power availability and with a reduced possibility of human intervention. This means that the on-site hardware infrastructure should have low-power consumption. A substantial effort toward the optimization of high-throughput computing service is envisioned to provide hardware and software solutions with high-throughput, low-power consumption and at low-cost. This contribution provides a summary of the design of the on-site analysis and reports some prototyping activities.