# Primary gamma ray selection in a hybrid timing/imaging Cherenkov array

## TL;DR

This paper investigates hybrid reconstruction techniques for a Cherenkov array at TAIGA, combining timing and imaging methods to improve gamma-ray event selection and background suppression for high-energy gamma-ray astronomy.

## Contribution

It introduces an optimal hybrid gamma event selection method combining imaging and timing data, enhancing background suppression in Cherenkov arrays.

## Key findings

- Background suppression of about 100 times at distances up to 450 m for energies >50 TeV.
- Identified optimal imaging and shower parameters for hybrid gamma-ray selection.
- Demonstrated cost-effective potential for large-area gamma-ray observatories.

## Abstract

This work is a methodical study on hybrid reconstruction techniques for hybrid imaging/timing Cherenkov observations. This type of hybrid array is to be realized at the gamma-observatory TAIGA intended for very high energy gamma-ray astronomy (>30 TeV). It aims at combining the cost-effective timing-array technique with imaging telescopes. Hybrid operation of both of these techniques can lead to a relatively cheap way of development of a large area array. The joint approach of gamma event selection was investigated on both types of simulated data: the image parameters from the telescopes, and the shower parameters reconstructed from the timing array. The optimal set of imaging parameters and shower parameters to be combined is revealed. The cosmic ray background suppression factor depending on distance and energy is calculated. The optimal selection technique leads to cosmic ray background suppression of about 2 orders of magnitude on distances up to 450 m for energies greater than 50 TeV.