# A new approach to the GeV flare of PSR B1259-63/LS2883

## TL;DR

This paper proposes a novel model where GeV gamma-ray flares in PSR B1259-63/LS2883 are caused by inverse Compton scattering of photons from an accretion disk formed by captured matter, explaining observed emissions.

## Contribution

It introduces a new accretion disk-based inverse Compton scattering model to explain the GeV flares in PSR B1259-63/LS2883, linking disk formation to flare timing.

## Key findings

- Model reproduces observed SEDs and light curves.
- Accretion disk formation is linked to disk-crossing events.
- Explains the timing and intensity of gamma-ray flares.

## Abstract

PSR B1259-63/LS2883 is a binary system composed of a pulsar and a Be star. The Be star has an equatorial circumstellar disk (CD). The {\it Fermi} satellite discovered unexpected gamma-ray flares around 30 days after the last two periastron passages. The origin of the flares remain puzzling. In this work, we explore the possibility that, the GeV flares are consequences of inverse Compton-scattering of soft photons by the pulsar wind. The soft photons are from an accretion disk around the pulsar, which is composed by the matter from CD captured by the pulsar's gravity at disk-crossing before the periastron. At the other disk-crossing after the periastron, the density of the CD is not high enough so that accretion is prevented by the pulsar wind shock. This model can reproduce the observed SEDs and light curves satisfactorily.