FACT - Monitoring Blazars at Very High Energies

TL;DR

The FACT telescope demonstrates the feasibility of silicon-based photosensors for monitoring TeV blazar variability, providing rapid flare alerts and valuable data over three years of observations.

Contribution

This paper presents the first three years of blazar monitoring using silicon-based photosensors, showcasing rapid alert capabilities and continuous variability studies.

Findings

Successful detection of blazar flares within the first three years.

Implementation of real-time quick look analysis for immediate flare alerts.

Validation of silicon-based photosensors in Cherenkov Astronomy.

Abstract

The First G-APD Cherenkov Telescope (FACT) was built on the Canary Island of La Palma in October 2011 as a proof of principle for silicon based photosensors in Cherenkov Astronomy. The scientific goal of the project is to study the variability of active galatic nuclei (AGN) at TeV energies. Observing a small sample of TeV blazars whenever possible, an unbiased data sample is collected. This allows to study the variability of the selected objects on timescales from hours to years. Results from the first three years of monitoring will be presented. To provide quick flare alerts to the community and trigger multi-wavelength observations, a quick look analysis has been installed on-site providing results publicly online within the same night. In summer 2014, several flare alerts were issued. Results of the quick look analysis are summarized.