M31 pixel lensing: Observations at the Loiano telescope

TL;DR

This paper presents pixel lensing observations of M31 using the Loiano telescope, developing an automatic detection pipeline, estimating expected signals via simulations, and identifying two microlensing candidates consistent with self-lensing.

Contribution

It introduces a fully automated pipeline for microlensing detection in M31 and evaluates its efficiency through Monte Carlo simulations, providing initial candidate events.

Findings

Detected 2 microlensing candidates

Results are compatible with M31 self-lensing expectations

Insufficient data to confirm dark matter halo content

Abstract

We discuss pixel lensing observations towards M31 carried out at the Loiano telescope. We have established a fully automatic pipeline for the detection and the characterization of microlensing events. We have evaluated the efficiency of the pipeline. We have estimated the expected signal by means of a Monte Carlo simulation. As a result we select 2 microlensing candidates. This is compatible with the expected M31 self-lensing signal. The small statistics of events at disposal does not still allow us, however, to draw definite conclusions on the content of compact halo objects.