Glossary

event

The detection of a particle by a VHE instrument, including measurements (reconstructions) of its arrival time, direction-of-origin on the sky, and energy.

event-list

A table of information about detected particles (events), with one row per detection, and columns describing their parameters. This may include other relevant instrument-dependent event parameters such as particle class or background probability.

IACT

Short for “Imaging Atmospheric Cherenkov Telescope”

IRF

Short for “Instrument Response Function”. The set of IRFs allows to transform the measurements in detector units/coordinates to astrophysical quantities with physical units/coordinates

observation

From a conceptual standpoint, an observation is the act of recording data with a telescope, including relevant data processing. For VODF Level-1, it is also the minimal set of data that a user can fetch to perform a science analysis.

reconstruction

For VHE data, reconstruction is the act of estimating physical parameters of the detected particle (photon, neutrino, cosmic ray) from lower-level instrumental parameters. For example, for an IACT, one might reconstruct a gamma ray photon’s energy from the Cherenkov light intensity and geometric parameters of the detected air-shower.

PR

Short for “Pull Request”

SOI

Short for “Stable Observation Interval”. It is a time interval during which the IRFs are considered as stable, within systematics.

VHE

Very-High-Energy, i.e. pertaining to particles roughly in the energy range of a few GeV to hundreds of TeV.

WCD

Short for “Water Cherenkov Detector”