MAGIC observations of variable very-high-energy gamma-ray emission from PKS1510-089 during May 2015 outburst

TL;DR

This paper reports the first detection of day-scale variability in VHE gamma-ray emission from PKS1510-089 during a 2015 outburst, providing new insights into the source's high-energy behavior.

Contribution

It presents MAGIC observations of VHE gamma-ray variability in PKS1510-089, a first for this source, along with spectral analysis and external Compton modeling.

Findings

Detection of VHE gamma-ray flux variability on days scale

Spectral properties of the VHE emission during outburst

Modeling of emission with external Compton scenario

Abstract

PKS1510-089 is a flat spectrum radio quasar located at a redshift of 0.36. It is one of only a few such sources detected in very-high-energy (VHE, >100 GeV) gamma rays. Though PKS1510-089 is highly variable at GeV energies, until recently no variability has been observed in the VHE band. In 2015 May PKS1510-089 showed a high state in optical and in the GeV range. A VHE gamma-ray flare was detected with MAGIC at that time, showing the first instance of VHE gamma-ray flux variability on the time scale of days in this source. We will present the MAGIC results from this observation, discuss their temporal and spectral properties in the multi-wavelength context and present modelling of such emission in the external Compton scenario.