Constraining Models of the Pulsar Wind Nebula in SNR G0.9+0.1 via Simulation of its Detection Properties using the Cherenkov Telescope Array

TL;DR

This study simulates future CTA observations of SNR G0.9+0.1 to assess its spatial and spectral properties, aiming to constrain PWN models and improve understanding of its emission mechanisms.

Contribution

It demonstrates the potential of CTA to resolve the PWN, distinguish spectral models, and accurately measure the cut-off energy, advancing PWN modeling capabilities.

Findings

CTA can resolve the emission region if larger than 0.65 arcminutes.

Spectral models can be distinguished, and cut-off energy measured accurately.

PWN magnetization can be constrained through multiwavelength spectrum fitting.

Abstract

SNR G0.9+0.1 is a well known source in the direction of the Galactic Center composed by a Supernova Remnant (SNR) and a Pulsar Wind Nebula (PWN) in the core. We investigate the potential of the future Cherenkov Telescope Array (CTA), simulating observations of SNR G0.9+0.1. We studied the spatial and spectral properties of this source and estimated the systematic errors of these measurements. The source will be resolved if the VHE emission region is bigger than $\sim0.65'$. It will also be possible to distinguish between different spectral models and calculate the cut-off energy. The systematic errors are dominated by the IRF instrumental uncertainties, especially at low energies. We computed the evolution of a young PWN inside a SNR using a one-zone time-dependent leptonic model. We applied the model to the simulated CTA data and found that it will be possible to accurately measure the cut-off energy of the $\gamma$-ray spectrum. Fitting of the multiwavelength spectrum will allow us to constrain also the magnetization of the PWN. Conversely, a pure power law spectrum would rule out this model. Finally, we checked the impact of the spectral shape and the energy density of the Inter-Stellar Radiation Fields (ISRFs) on the estimate of the parameters of the PWN, finding that they are not significantly affected.