arXiv subjects

Katharina Egg

Publications and source records attributed to Katharina Egg.

3 recordsLinked to original sources

arXiv2026

Joint X-ray and gamma-ray analysis at the photon level: Application to MSH 15-52

Joint analysis of multi-wavelength (MWL) data at the level of photon events is challenging, but it provides a statistically preferable method of fitting the data, in contrast to fitting derived flux points. Data from X-ray and gamma-ray instruments are well-suited for a joint description, due to their common physical origin (same particle population and non-thermal processes) and incidentally also due to the high similarity of their formats. Such a description is especially desirable for objects such as pulsar wind nebulae (PWNe), diffuse sources that originate from outflows of particles that have been accelerated by pulsars. Photon emission is generated by particle interactions with the surrounding magnetic and radiation fields. The rich MWL emission from PWNe renders MWL studies essential to obtain a comprehensive picture of their physical properties. We demonstrate a joint MWL analysis of 3D X-ray and gamma-ray data at the photon event level by importing eROSITA X-ray data into the Gammapy software framework. We present our pipeline for converting eROSITA 3D (two spatial and one spectral dimension) event data into a Gammapy-readable format. We validated the approach through comparison with standard X-ray data products and analysis. Furthermore a 3D eROSITA data analysis as well as a joint fit with 3D H.E.S.S. data and Fermi 4FGL catalogue flux points was performed. We show through the analysis of data from the PWN MSH\,15-52 that 1D fits of Gammapy-extracted eROSITA spectra agree with the results of the native X-ray tool PyXspec. We demonstrate that 3D analyses on X-ray data can be conducted, with both background subtraction and background modelling. Furthermore, we show that joint analyses at event level between 3D X-ray and gamma-ray data can be conducted in Gammapy. This opens up exciting new possibilities for joint analyses of PWNe and other objects.

astro-ph.HE↗

arXiv2026

Towards a joint X-ray and gamma-ray analysis of Pulsar Wind Nebulae with Gammapy

For detailed studies of Pulsar Wind Nebulae (PWNe), objects that show photon emission across the entire electromagnetic spectrum, multiwavelength analyses are crucial. The comparison of especially X-ray and gamma-ray emission and their angular sizes can help us to constrain the properties of PWNe, such as their particle transport mechanism or their potential for the acceleration of hadronic particles. In this vein, we are working towards a joint analysis of eROSITA X-ray data and H.E.S.S. gamma-ray data. To enable this, eROSITA data is adapted into the framework of Gammapy, a Python package for gamma-ray analysis through a multi-step process of adapting the formats of not only the photon event list, but also all X-ray response functions, into open data formats compatible with Gammapy. This is accomplished using newly developed Python converter functions. In this contribution we present the first eROSITA maps of the PWN MSH 15-52 in Gammapy, compared to the associated H.E.S.S. emission.

astro-ph.HE↗

arXiv2025

Joint eROSITA and H.E.S.S. analysis of MSH 15-52 using Gammapy

Pulsar wind nebulae (PWNe) are prominent sources in the very-high energy (VHE) gamma-ray sky, constituting the most numerous identified source class in the H.E.S.S. Galactic Plane Survey (HGPS). They are comprised of energetic particles originating from the pulsar and expanding into the surrounding medium. As such, PWNe are of very high scientific interest as PeVatron candidates, objects that could potentially accelerate particles up to PeV energies. Additionally other aspects of their acceleration mechanism are being actively investigated, such as the open question of whether they accelerate not only leptonic but also hadronic particles, and the details of their morphology and particle transport mechanism. As PWNe emit photons over a broad range of the electromagnetic spectrum, multiwavelength (MWL) studies are crucial for the investigation and study of their emission. In this vein we present a joint eROSITA X-ray and H.E.S.S. gamma-ray study of the PWN MSH 15-52. We showcase our custom code for integrating the EDR and DR1 eROSITA data into the Gammapy framework, a python package optimised for the analysis of gamma-ray data. We present the first 3D (spatial and spectral) fit to eROSITA data by using Gammapy. We furthermore combine these data with the public H.E.S.S. gamma-ray observations of MSH 15-52, resulting in a joint physical fit of the underlying particle population, and a subsequent discussion of the physical implications of our results. Finally we give an outlook towards future efforts in MWL studies of PWNe and the broader context of MWL data analysis with Gammapy.

astro-ph.HE↗