In November 2019 about 300 scientists and guests from all over the world celebrated the 20th anniversary of the Pierre Auger Observatory with a ceremony and a scientific symposium at the site of the Observatory in Argentina. The Pierre Auger Observatory has been built to study ultra-high energy cosmic rays, particles of the highest energies ever observed.
The participants of the celebration lined up in front of the main building of the observatory for a group picture (photo: Miguel Martin).
Ultra-High Energy Cosmic-Rays
Cosmic-rays are charged particles constantly bombarding the Earth and are one of the cosmic messengers that help us understand our Universe. At the highest energies, they are not much deflected by the Galactic and extragalactic magnetic fields, opening up the possibility of a new window in astronomy, the observation of the near-by Universe with charged-particles. The goal of the Pierre Auger Observatory is to study the nature and origin of those ultra-high energy cosmic rays, whose energy exceeds more than 100,000 times the energy that can be achieved in man-made accelerators.
The Pierre Auger Observatory
The Pierre Auger Observatory was conceived by Jim Cronin, Alan Watson and other scientists in 1991 to address the mysteries of the origin and nature of the highest-energy cosmic rays. It was clear to them that only a very large detector would reach the exposure to collect enough events to answer the questions raised by a century of earlier experiments. The Observatory design employs a „hybrid“ detector system consisting of a 3000 km2 array of 1660 particle detectors overlooked by 27 optical telescopes. These complementary detector techniques record both the particles and the faint fluorescence light resulting from the gigantic particle cascade initiated in the atmosphere by these mysterious cosmic rays. Soon after the foundation in 1999, construction of the Observatory started and was completed in 2008.
20th Anniversary
f.l.t.r.: Roberto Rivarola (Member of Board of Directors of CONICET), Fernando Ferroni (Chair of Finance Board), Ingo Allekotte (Bariloche, Project Manager Pierre Auger Observatory), Jorge Vergara Martínez (Mayor of Malargüe), Paula Nahirñak (Sub-secretary of State in Secretariat for Science and Technology), Osvaldo Calzetta (President CNEA), Ralph Engel (KIT, Spokesperson Pierre Auger Observatory), Alberto Etchegoyen (CNEA, Site Spokesperson), Julio Cobos (National Senator for the Province of Mendoza), Laura Montero (Vice-governor of the Province of Mendoza), Ernesto Maqueda (CNEA), Alan Watson (former Spokesperson Pierre Auger Observatory) (photo: Miguel Martin)
Scientists of the 90 participating institutes and groups, as well as representatives of all 17 member states of the international collaboration met in Malargüe, Argentina in mid-November to celebrate the 20th anniversary of the experiment as well as the scientific results achieved so far. A scientific symposium opened the festivities and highlighted the state of research. On the second day, the participants visited the detectors of the Observatory in the Argentine Pampa. Many of the scientists and guests participated also in the parade for the anniversary of the city of Malargüe. The meeting continued with a ceremonial act at the campus of the Observatory. Venerable members of the collaboration as well as representatives of funding agencies and local politicians addressed the audience and congratulated the collaboration not only on the scientific successes, but also on the social relevance and impact of the project in the province of Mendoza. One highlight of the ceremony was the conferral of the status “Honorable Senator” to the Pierre Auger Observatory by the Senate of Argentina. After unveiling a sculpture by Juan Pezzani symbolizing the role of the Pierre Auger Observatory in Argentina, the meeting concluded with a dinner banquet with typical Argentine barbecue and wine.
A Bright Future
Spurred by the science results obtained so far, the Observatory is currently undergoing an upgrade („AugerPrime“), mostly aimed at improving the sensitivity of the observatory to the particle type and mass of ultra-high energy cosmic rays. This is done by installing new electronics, and additional and complementary detectors, allowing for a better separation of the type of the incoming particle on an event-by-event basis. The added observables are critical to select the subset of particle cascades that were produced most likely by lighter primary cosmic rays, which in turn may hold the key to identifying and studying the cosmic accelerators outside our own galaxy. More generally, the data collected with AugerPrime will also be used to explore fundamental particle physics at energies beyond those accessible at terrestrial accelerators, and perhaps yield the observation of new physics phenomena.
— CANCELLED/POSTPONED, please check the website of the event for further information —
The second EPS (European Physical Society) Conference on Gravitation is held at King’s College (London, UK) from April 7th to April 9th, 2020. The aim of the conference is to discuss experimental aspects of Gravity, including General Relativity tests, measurements of the G constant, Geodesy, and Gravitational Waves.
The conference is organized in days focused around key topics introduced by invited speakers and followed by contributed talks. There will also be a poster session, together with four Young Scientist Awards to the best poster contributions by skilled young researchers .
Early registration ends 1st March, 2020 and abstract submission ends 2nd February, 2020.
— CANCELLED/POSTPONED, please check the website of the event for further information —
The first Pollica Summer Workshop on Dark Matter aims to bring together the world’s leading experts, both from theory and experiment, working on a broad range of ideas, existing and proposed experiments. This workshop, which will take place in the beautiful setting of the medieval town of Pollica in the Cilento region in Italy is an opportunity to galvanize theoretical efforts in a period where new experiments come online and the particle physics community must think broadly about new frontiers ahead. This is an exciting time to connect fundamental physics to the upcoming experimental landscape. The workshop is scheduled for the dates of 15-26 June 2020 and will be hosted in the 14th century Castello Dei Principi Capano.
The deadline for applications is January 31st 2020.
Gamma-ray bursts can be triggered by the explosion of a dying, super massive star, collapsing into a black hole. From the vicinity of the black hole, powerful jets shoot in opposite directions into space, accelerating electrically charged particles, which in turn interact with magnetic fields and radiation to produce gamma rays. Credit: DESY, Science Communication Lab
Gamma-ray bursts (GRBs) are sudden, short bursts of gamma radiation happening about once a day somewhere in the visible universe. According to current knowledge, they originate from colliding neutron stars or from supernova explosions of giant suns collapsing into a black hole. Since their discovery in the 1960s astronomers have been studying GRBs with satellites, as Earth’s atmosphere very effectively absorbs gamma rays. Astronomers have developed specialised telescopes that can observe a faint blue glow called Cherenkov light that cosmic gamma rays induce in the atmosphere, but these instruments are only sensitive to gamma rays with very high energies. Unfortunately, the brightness of GRBs falls steeply with increasing energy. Cherenkov telescopes have identified many sources of cosmic gamma rays at very high energies, but no GRBs to date. Satellites, on the other hand, have much too small detectors to be sensitive to the low brightness of gamma-ray bursts at very high-energies. So, it was effectively unknown, if these explosions emit gamma rays also in the very high-energy regime.
Cherenkov telescopes detect the bluish Cherenkov light generated by faster-than-light particles in Earth’s atmosphere, produced by cosmic gamma rays. Credit: DESY, Science Communication Lab
Between summer 2018 and January 2019, two international teams of astronomers, detected gamma rays from two GRB events for the first time from the ground. On 20 July 2018, faint afterglow emission of GRB 180720B in the gamma-ray regime was observed with the High-Energy Stereoscopic System (H.E.S.S.) in Namibia. On 14 January 2019, bright early emission from GRB 190114C was detected by the Major Atmospheric Gamma Imaging Cherenkov (MAGIC) telescopes on La Palma, and immediately announced to the astronomical community.
MAGIC registered gamma-rays with energies between 200 and 1000 giga-electron volts (GeV). The rapid discovery, only 60 seconds after the alarm was received, allowed to quickly alert the entire observational astronomy community. As a result, more than twenty different telescopes had a deeper look at the target. This allowed to pinpoint the details of the physical mechanism responsible for the highest energy emission, as described in a paper led by the MAGIC collaboration. Follow-up observations placed GRB 190114C at a distance of more than four billion light years.
GRB 180720B, at a distance of six billion light years even further away, could still be detected in gamma rays at energies between 100 and 440 GeV after the initial blast. The H.E.S.S. detection came quite unexpected, as gamma-ray bursts are fading fast, leaving behind an afterglow which can be seen for hours to days across many wavelengths from radio to X-rays, but had never been detected in very high-energy gamma rays before. This success is also due to an improved follow-up strategy in which observations at later times after the actual star collapse are conducted.
The detection of gamma-ray bursts at very high energies provides important new insights into the gigantic explosions. To explain how the observed very high-energy gamma rays are generated is challenging and will require more detailed theoretical modelling and measurements of more GRBs in very-high-energy gamma rays. These two groundbreaking observations have established GRBs as sources for terrestrial gamma-ray telescopes and has the potential to significantly advance our understanding of these violent phenomena. The scientists estimate that up to ten such events per year can be observed with the planned Cherenkov Telescope Array (CTA), the next generation gamma-ray observatory. The CTA will consist of more than 100 individual telescopes of three types that will be built at two locations in the northern and southern hemispheres. CTA observations are expected to start in 2023.
The full press release from DESY is available here.
In light of the present COVID-19 worldwide crisis and after carefully considering all options, it has been decided that Neutrino 2020 will be held as an online-only conference. It is assumed that it will take place on or close to the originally planned dates and it is expect that there will be a process for online poster presentation. More details on the conference format will be announced on the conference website.
The XIX International Conference on Neutrino Physics and Astrophysics will be held June 21 to 27, 2020, in Chicago, Illinois. Its primary focus is to review the current status of neutrino physics, the impact of neutrino physics on astronomy and cosmology, and the vision for the future development of these fields. The conference consists of invited plenary talks and contributed poster sessions.
The KM3NeT Collaboration is organizing a Town Hall Meeting to promote its multi-messenger programs. The workshop will take place from 17-19 December 2019 at the Aix-Marseille Université in Marseille, France. During this workshop, they would like to review the most up-to-date neutrino production models and present KM3NeT performances and multi-messenger programs.
The first JENAS, Joint ECFA (European Committee for Future Accelerators)-NuPECC (Nuclear Physics European Collaboration Committee)-APPEC (AstroParticle Physics European Consortium) Seminar, attracted 230 participants resulting in a full auditorium at the Laboratoire de l’Accélérateur Linéaire (LAL) in Orsay. Beyond the regular information exchange across the three European committees, the importance is recognized to reinforce their interdisciplinary links. For three days senior and junior members of the astroparticle, nuclear and particle physics communities presented their overlapping challenges. Together they have a strong aspiration to explore nature with a view to understand both the smallest and the largest structures. On the technology front they seek to make visible the invisible at these extremes, and these successes are transformed into opportunities at the human scale for amongst others health, energy and safety. Readout electronics, Silicon Photomultipliers, Big Data computing and Artificial Intelligence for analysis are only some examples of developments essential for our research. Related to the quest of unravelling new insights in fundamental physics, coverage is required from all three fields in order to address the dark matter problem, the neutrino sector and the physics with gravitational waves. In presentations on organizational matters related to education, outreach, open science and software as well as careers, synergies are clearly identifiable. At the occasion of this meeting a Diversity Charter has been launched by APPEC, ECFA and NuPECC. From a survey among the seminar participants the diversity aspects will be analyzed together with those from other conferences and events organized by the three communities.
Marek Lewitowicz (NuPECC), Jorgen D’Hondt (ECFA) and Teresa Montaruli (APPEC)
The JENAS2019 event, which was jointly organized by LAL-Orsay, IPN-Orsay, CSNSM-Orsay, IRFU-Saclay and LPNHE-Paris, allowed astroparticle, nuclear and particle physics researchers to sniffle into each other’s activities. The identified challenges can transform via joint programs into opportunities to deepen our understanding of physics. Being informed by the presentations and discussions and with a view to further explore topical synergies between the disciplines, in the closing remarks a call has been issued for novel Expressions-of-Interest. Bottom-up and community thoughts can be submitted to the chairs of the three committees/consortia for further discussion within APPEC, ECFA and NuPECC. Thoughts revolving around potential synergies in technology, physics, organization and/or applications are welcome. The letters should elaborate on the synergy topic, the objectives, the initial thoughts and the potential communities involved. These letters are not the end of the process, but potentially the start of further communications on the expressed interest. APPEC, ECFA and NuPECC will discuss and propose actions to pursue your thoughts with a view to the next JENAS event in two years.
Website: https://jenas-2019.lal.in2p3.fr
The VIth CNRS thematic School of Astroparticle Physics on “PHYSICS and ASTROPHYSICS of COSMIC RAYS” will be held from November 25th – 30th 2019 at the OHP Saint Michel l’Observatoire in France. This school follows several other schools supported / organized by the Programme National Hautes Energies (PNHE), the latter focusing on the physics of the Universe X-ray (2016), gravitational waves (2013) and gamma astronomy (2011). This one will present an observational and theoretical overview of the physics and astrophysics of cosmic rays, with hands-on training sessions on Cherenkov Telescope Array (CTA) data analysis as well as on CR propagation codes. Particular attention will be given to taking into account statistical and systematic errors in both measures and theoretical models. It will enable current and future actors in the field to understand the various transverse aspects, such as the very great importance of multi-messenger and multi-wavelength observations for understanding the key physical mechanisms in acceleration and transport. Opening up to a broader scientific community, this school aims at bringing together specialists on these topics with the aim of training the next generation of young researchers, in addition to transfer/share skills.
The Gravitational Wave Probes of Fundamental Physics (GW4FP) workshop will take place from 11-13 November at the Volkshotel in Amsterdam, The Netherlands.
As the first workshop by the European Consortium for Astroparticle Theory (EuCAPT), GW4FP aims to bring together the Gravitational Wave and Fundamental Physics communities to discuss topics in Dark Matter, exotic objects, tests of GR and early Universe physics, as well as tests of Standard Model physics in unexplored regimes.
The workshop will involve invited plenary talks covering these broad areas as well as shorter submitted talks for researchers to present their work. Since a key goal of the workshop is to foster collaboration, there will also be discussions, lightning talks and a “four corners” discussion session.
The Paris-Saclay AstroParticle Symposium 14 October – 8 November takes place at the Institut Pascal of the Paris-Saclay University. Around 30 specialists of astrophysics, cosmology and particle physics are invited to discuss and work on the themes: Dark Energy and Dark Matter. Besides the working sessions, there will be also an Open Program with specific workshops, colloquiums and general public talks.
The VIth CNRS thematic School of Astroparticle Physics on “PHYSICS and ASTROPHYSICS of COSMIC RAYS” will be held from November 25th – 30th 2019 at the OHP Saint Michel l’Observatoire in France. This school follows several other schools supported / organized by the Programme National Hautes Energies (
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