# Gamma-rays from SS433: evidence for periodicity

## TL;DR

This study analyzes 9 years of Fermi-LAT data to detect gamma-ray emission from SS433, revealing its significance, spatial extension, and periodic modulation aligned with the jet precession, indicating emission near the source.

## Contribution

First detection of gamma-ray emission from SS433 with evidence of periodic modulation matching jet precession period.

## Key findings

- Detected SS433 gamma-ray emission at ~13σ significance.
- Found spatial extension towards the X-ray hotspot.
- Observed gamma-ray flux modulation with jet precession period.

## Abstract

In this paper we present our study of the gamma-ray emission from the microquasar SS433. Integrating over 9 years of Fermi-LAT \textsc{pass8} data, we detect SS433 with a significance of ~13$\sigma$ in the 200 to 500 MeV photon energy range, with evidence for an extension in the direction of the w1 X-ray `hotspot`. A temporal analysis reveals evidence for modulation of SS433's gamma-ray emission with the precession period of its relativistic jet. This suggests that at least some of SS433's gamma-ray emission originates close to the object rather than from the jet termination regions.