Partículas elementales de las profundidades de nuestro universo

Blazar acelerando los rayos cósmicos

Comenzando un viaje a través del universo: el descubrimiento de fábricas de neutrinos extragalácticos. Crédito: © Benjamin Modificar

Investigadores revelan por primera vez el origen de los neutrinos, partículas elementales que llegan a nuestro planeta desde las profundidades del Universo.

Altamente energéticos y difíciles de detectar, los neutrinos viajan miles de millones de años luz antes de llegar a la Tierra. Aunque se sabe que estas partículas elementales provienen de las profundidades de nuestro Universo, su origen preciso sigue siendo un misterio. Un equipo de investigación internacional, dirigido por la Universidad de Würzburg y la Universidad de Ginebra (UNIGE), está arrojando luz sobre un aspecto de este enigma: se cree que los neutrinos nacen en blazars, núcleos galácticos alimentados por agujeros negros supermasivos. Estos resultados fueron publicados el 14 de julio en la revista Cartas de revistas astrofísicas.

La atmósfera de nuestro planeta está continuamente bombardeada por rayos cósmicos. Estos consisten en partículas cargadas eléctricamente de energías extremadamente altas, hasta 1020 electronvoltios. Como referencia, eso es un millón de veces más que la energía alcanzada en el acelerador de partículas más poderoso del mundo,[{” attribute=””>CERN’s Large Hadron Collider near Geneva. The incredibly energetic particles come from deep outer space and have traveled billions of light years. Where do they originate, what shoots them through the Universe with such tremendous force? These questions have remained among the greatest challenges of astrophysics for over a century.

Cosmic rays’ birthplaces produce neutrinos. These neutral particles are very difficult to detect. They have almost no mass and barely interact with matter. They race through the Universe and can travel right through galaxies, planets, and the human body almost without a trace. “Astrophysical neutrinos are produced exclusively in processes involving cosmic ray acceleration,” explains astrophysics Professor Sara Buson from Julius-Maximilians-Universität (JMU) Würzburg in Bavaria, Germany. This is precisely what makes these neutrinos unique messengers paving the way to pinpoint cosmic ray sources.

A step forward in a controversial debate

Despite the vast amount of data that astrophysicists have collected, the association of high-energy neutrinos with the astrophysical sources that originate them has remained an unsolved problem for years. Sara Buson has always considered it a major challenge. It was in 2017 that the researcher and collaborators first brought a blazar (TXS 0506+056) into the discussion as a potential neutrino source in the journal Science. Blazars are active galactic nuclei powered by supermassive black holes that emit much more radiation than their entire galaxy. A scientific debate was sparked by the publication about whether there truly is a connection between blazars and high-energy neutrinos.

Following this first encouraging step, in June 2021 Prof. Buson’s group began an ambitious multi-messenger research project with the support of the European Research Council. This involves analyzing various signals (“messengers,” e.g. neutrinos) from the Universe. The main goal is to shed light on the origin of astrophysical neutrinos and possibly establish blazars as the first source of extragalactic high-energy neutrinos with high certainty.

The project is now showing its first success: In the journal Astrophysical Journal Letters, Sara Buson, along with her group, the former postdoctoral researcher Raniere de Menezes (JMU) and Andrea Tramacere from the University of Geneva, reports that blazars can be confidently associated with astrophysical neutrinos at an unprecedented degree of certainty.

Revealing the role of blazars

Andrea Tramacere is one of the experts in numerical modeling of acceleration processes and radiation mechanisms acting in relativistic jets — outflows of accelerated matter, approaching the speed of light — in particular blazar jets. “The accretion process and the rotation of the DOI: 10.3847/2041-8213/ac7d5b

Leave a Reply

Your email address will not be published.