Nievas Rosillo, MireiaContreras González, José Luis2023-06-182023-06-182016-020927-650510.1016/j.astropartphys.2015.10.001https://hdl.handle.net/20.500.14352/24337© 2016 Elsevier Science BV. This work was supported by the Spanish MINECO under contract FPA2010-22056-C06-06 and MECD under FPU Grant A-2013-12235. The analysis was performed using the open-source tools: ROOT Data Analysis Framework [18], Python and Matplotlib [19].The so called Li&Ma formula is still the most frequently used method for estimating the significance of observations carried out by Imaging Atmospheric Cherenkov Telescopes. In this work a straightforward extension of the method for point sources that profits from the good imaging capabilities of current instruments is proposed. It is based on a likelihood ratio under the assumption of a well-known PSF and a smooth background. Its performance is tested with Monte Carlo simulations based on real observations and its sensitivity is compared to standard methods which do not incorporate PSF information. The gain of significance that can be attributed to the inclusion of the PSF is around 10% and can be boosted if a background model is assumed or a finer binning is used. (C) 2015 Elsevier B.V. All rights reserved.engjournal articlehttp://dx.doi.org/10.1016/j.astropartphys.2015.10.001http://www.sciencedirect.com/open access539.1Gamma ray astronomyLikelihood ratioSystemFísica nuclear2207 Física Atómica y Nuclear