# Combined VERITAS and NuSTAR observations of the gamma-ray binary HESS J0632+057

## TL;DR

This study presents simultaneous NuSTAR and VERITAS observations of the gamma-ray binary HESS J0632+057, providing insights into its non-thermal emission mechanisms and constraining pulsar wind properties.

## Contribution

First simultaneous hard X-ray and VHE gamma-ray observations of HESS J0632+057, used to test the pulsar scenario and constrain pulsar wind parameters.

## Key findings

- Spectral energy distributions support the pulsar wind collision model.
- Constraints on pulsar spin-down luminosity and wind magnetization.
- Insights into the non-thermal emission processes in gamma-ray binaries.

## Abstract

HESS J0632+057 is a gamma-ray binary composed of a compact object and a Be star, with an orbital period of about 315 days. The actual nature of its non-thermal emission, spanning from radio to very-high-energy (VHE, >100 GeV) gamma-rays, is currently unknown. In this contribution we will present the results of a set of simultaneous observations performed by the NuSTAR X-ray telescope and the VERITAS observatory. The combination of hard X-rays (3-30 keV) and VHE gamma-rays (0.1-5 TeV) provide valuable information for the understanding of the radiative processes occurring in the system. The spectral energy distributions (SED) derived from the observations are used to probe the pulsar scenario, in which the system is powered by a rapidly rotating neutron star. The non-thermal emission is produced by the particles accelerated at the shock formed by the collision of the pulsar and stellar winds. As a results of the model fitting, we constrain the relation between the pulsar spin-down luminosity and the magnetization of the pulsar wind.