# The Use of Weighting in Periodicity Searches in All-Sky Monitor Data: Applications to the GLAST LAT

## TL;DR

This paper investigates how different weighting schemes in power spectrum analysis affect the detection of periodic signals in all-sky monitor data, with a focus on simulated gamma-ray observations from the GLAST LAT.

## Contribution

It introduces a modified weighting scheme based on the Cochran semi-weighted mean that improves periodicity detection regardless of source brightness.

## Key findings

- Modified weighting improves sensitivity in simulated gamma-ray data.
- Simple weighting can reduce detection sensitivity depending on source brightness.
- Cochran semi-weighted mean enhances power spectrum analysis.

## Abstract

The light curves produced by all-sky monitors, such as the Rossi X-ray Timing Explorer All-Sky Monitor and the Swift Burst Alert Telescope (BAT), generally have non-uniform error bars. In searching for periodic modulation in this type of data using power spectra it can be important to use appropriate weighting of data points to achieve the best sensitivity. It was recently demonstrated that for Swift BAT data a simple weighting scheme can actually sometimes reduce the sensitivity of the power spectrum depending on source brightness. Instead, a modified weighting scheme, based on the Cochran semi-weighted mean, gives improved results independent of source brightness. We investigate the benefits of weighting power spectra in period searches using simulated GLAST LAT observations of gamma-ray binaries.