# Microlensing events in the Galactic bulge

## TL;DR

This study reports the first detection of microlensing events at zero latitude in the Galactic bulge using VVV survey data, analyzing their distribution and timescales to understand the Galactic structure.

## Contribution

First detection of microlensing events at zero latitude in the Galactic bulge with detailed spatial and timescale analysis using VVV data.

## Key findings

- Homogeneous spatial distribution of events with a smooth increase toward the Galactic center.
- Detected a slight asymmetry with more events at negative longitudes.
- Average timescale of 17.4 days for all events, 20.7 days for Red Clump sources.

## Abstract

For the first time we detected microlensing events at zero latitude in the Galactic bulge using the VISTA Variables in the Via Lactea Survey (VVV) data. We have discovered a total sample of N = 630 events within an area covering 20.7 sq. deg. Using the near-IR color magnitude diagram we selected N = 291 red clump sources, allowing us to analyse the longitude dependence of microlensing across the central region of the Galactic plane. We thoroughly accounted for the photometric and sampling efficiency. The spatial distribution is homogeneous, with the number of events smoothly increasing toward the Galactic center. We find a slight asymmetry, with a larger number of events toward negative longitudes than positive longitudes, that is possibly related with the inclination of the bar along the line of sight. We also examined the timescale distribution which shows a mean on 17.4 +- 1.0 days for the whole sample, and 20.7 +- 1.0 for the Red Clump subsample.