arXiv subjects

Eloise Moore

Publications and source records attributed to Eloise Moore.

4 recordsLinked to original sources

arXiv2026

PIC simulations of nonrelativistic high-Mach-number oblique shocks propagating in a turbulent medium

Collisionless shocks are common in astrophysical systems and stand as sites of particle acceleration. While particles at perpendicular shocks may not return to the upstream region, at oblique shocks a fraction of energetic electrons manage to escape the shock and travel upstream. An extended region known as the electron foreshock is formed, where these reflected particles drive various instabilities that may promote electron acceleration. Here we present the first 2D3V particle-in-cell (PIC) simulations of electron-ion non-relativistic oblique shocks that explore the interaction of the foreshock with pre-existing compressive turbulence with relative amplitude of 15% based on interstellar medium estimates. We find that pre-existing turbulence influences the emergence and behavior of the whistler-wave instability, as it enhances the amplitudes of the magnetic-field fluctuations and leads to larger nonlinear structures. This impacts the dynamics of the reflected electrons, resulting in a shorter and hotter electron foreshock. At the end of our simulations, with pre-existing upstream turbulence we observe non-thermal electrons that are more numerous, reach higher energies, and carry a larger portion of the total energy.

physics.plasm-ph↗

arXiv2024

Management of a Multi-User Robotic Observatory

The Zadko Observatory located approximately 70 kilometres north of Perth in the Yeal nature reserve within the Shire of Gingin, Western Australia, initially housed the 1.0 metre f/4 fast-slew Zadko Telescope which was commissioned in June 2008. Since the Zadko telescope has been in operation it has proven its worth by detecting numerous Gamma Ray Burst afterglows, two of these being the most distant 'optical transients' imaged by an Australian telescope. The Zadko telescope also contributed to the discovery of colliding neutron stars in 2017 capturing the imagination of the public. Another important use for the Zadko Telescope is the tracking and mapping of Space Debris which consist of all man-made objects, including their fragments or parts, other than active space vehicles larger than 10 microns and orbiting the Earth in outer space. The Zadko telescope forms part of the ARC Centre of Excellence for Gravitational Wave Discovery (OzGrav). With a view to supporting ongoing scientific instrument upgrades and observatory maintenance it has proven critical to attract additional funding and seek out collaboration with international partners. In this article, we will focus on the administrative and technical details of the Observatory, focusing on the sustainability of the Observatory and its ongoing potential for future growth into an internationally recognized Space Surveillance Hub. We will review the evolution of the Observatory, from its early, single instrument state, to its current multi-telescope and multi-instrument capabilities. We will finish by outlining the future of the Observatory and surrounds.

astro-ph.IM↗

arXiv2024

The impact of the site quality of the Zadko Observatory on its scientific results

We present the site quality of the Zadko Observatory, focusing on the brightness of the sky and the effects of the weather on the efficiency of the Observatory. We discuss these effects and their consequences for the scientific goals of the Observatory. Without surprise, the overall sky quality had decreased during the last decade. However, this decrease is mostly due to the weather pattern at the Observatory rather than the light pollution. We put an emphasis on how important the preservation of the sky darkness is for small observatories, in order to stabilize the global degradation of the site quality, as this directly impacts the scientific return of the observations.

astro-ph.IM↗

arXiv2023

Constraints on the ultra-high energy cosmic ray output of gamma-ray bursts

Ultra-high energy cosmic rays are the most extreme energetic particles detected on Earth, however, their acceleration sites are still mysterious. We explore the contribution of low-luminosity gamma-ray bursts to the ultra-high energy cosmic ray flux, since they form the bulk of the nearby population. We analyse a representative sample of these bursts detected by BeppoSAX, INTEGRAL and Swift between 1998-2016, and found that in order to reconcile our theoretical flux with the observed flux, these bursts should accelerate at most $10^{-13}$ M$_\odot$ of ultra-high energy cosmic rays.

astro-ph.HE↗