ALTO is the name of our own project that we started back in 2015. We are developing and operating prototype particle detectors in Växjö. These are designed for Very High Energy (VHE) gamma-ray astronomy observations to de done at high altitudes. At the same time we perform Monte Carlo simulations to optimize the layout of the full observatory, to be located in the Southern hemisphere at an altitude greater than 4800 meters, as for instance in Argentina near San Antonio De Los Cobres.
For our ALTO activities, we have a separate webpage and blog:
Here below you can find a picture of our detectors in Växjö. The picture was taken in January 2019. For the moment we have two large water Cherenkov detectors and several scintillator detectors and we continuously take data. The signals we see in the detectors are generated by the passage of relativistic particles in water and in oil. These relativistic particles are created in the atmosphere by interactions of cosmic rays with the atoms composing the atmosphere.