Researchers have observed a particle accelerator with the help of special telescopes. The H.E.S.S. observatory made the first ever observations of a nova, a stellar process that involves powerful eruptions on the surface of a white dwarf. A nova creates a shock wave that tears through the surrounding medium, pulling particles with it and speeding them to extreme energies. The nova andRS Ophiuchi seem to cause particles to accelerate at speeds that correspond to ideal conditions. The journal Science has published the research.
White dwarfs are burned out old stars that have collapsed in on themselves and become extremely compact objects. When a white dwarf is in a system with a large star, it gathers material from its companion due to its gravity. A thermonuclear explosion on the surface of the white dwarf occurs when gathered material goes over a critical level. novae are known to repeat. The stars forming the system are at approximately the same distance from each other as the Earth and the Sun.
The particles were accelerated hundreds of times higher than in novae, according to the research group. As a result of the explosion, the energy was transformed into accelerated protons and heavy nuclei, which reached the maximum speeds calculated in theoretical models. According to Ruslan Konno, one of the lead authors of the study and a PhD candidate at DESY in Zeuthen, the observation that the theoretical limit for particle acceleration can actually be reached in genuine cosmic shock waves has enormous implications for astrophysics. It suggests that the acceleration process could be just as efficient in their more extreme relatives.
The researchers were able to observe and study the development of the nova in real time, for the first time, thanks to the eruption of RS Ophiuchi. This is the first time we have ever been able to measure high-energy gamma rays, and it will allow us to gain even more accurate future insights into how explosions work.
Specific telescopes were required for the measurement. The H.E.S.S. facility in Namibia has five Cherenkov telescopes that are used to investigate space rays. A new, highly sensitive state-of-the-art camera was recently installed in the largest telescope. The latest generation of cameras has been in use since late 2019, and this measurement shows just how much potential they have.
The telescopes were pointed towards the nova at a very short notice. The rapid reaction of the researchers and the wider community paved the way for extensive subsequent observations. Over the next few years, research using the CTA telescopes will show whether or not this type of nova is special. This gives rise to a number of new possibilities for gaining a better understanding and being better able to explain events linked to novae.
More information: Time-resolved hadronic particle acceleration in the recurrent Nova RS Ophiuchi, Science (2022). DOI: 10.1126/science.abn0567. www.science.org/doi/10.1126/science.abn0567 Journal information: Science Citation: Cosmic particle accelerator reaches theoretical limit (2022, March 10) retrieved 11 March 2022 from https://phys.org/news/2022-03-cosmic-particle-theoretical-limit.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
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