European Cosmic Ray Symposium Research Articles

26th Extended European Cosmic Ray Symposium

PrefaceParticle astrophysics that is also called astroparticle physics combines efforts and interests of two communities, particle physicists and astrophysicists, and presents the broadest field of research that covers experiments involving man-made machines as well as experiments that are running for billions of years by Nature itself. These involve all types of known and yet unknown particles and emissions in the broadest energy range possible, from nano-eV to 1021 eV, far exceeding the capabilities of the terrestrial and extraterrestrial laboratories. Last decade was rich on discoveries and breakthrough results in many areas of traditional astroparticle physics, and gave birth to two brand new branches of astronomy: gravitational and neutrino. The hopes are that this rapid and exciting progress will continue in years to come and the key factors to ensure its sustainability are the face to face meetings and exchange of enriching ideas between the communities with different backgrounds.The 26th Extended European Cosmic Ray Symposium (E+CRS) took place at Altai State University (Barnaul-Belokurikha, Russia, 610 July 2018), and was organized by Altai State University in partnership with the Skobeltsyn Institute of Nuclear Physics of the Lomonosov Moscow State University and Novosibirsk State University.Since the first symposia, which started 50 years ago with two parts held in 1968 in Lodz, Poland (high energy, extensive air showers and astrophysical aspects) and in Bern (solar and heliospheric phenomena), the ECRS became one of the major conferences in the field of astroparticle physics with the emphasis on meeting the demands of young scientists and European collaborations.Based on the decision of the International Advisory Committee (IAC), adopted during the 25th ECRS (Turin, Italy, 2016), the 26th European Cosmic Ray Symposium was scheduled to be held in 2018 in conjunction with the 35th Russian Cosmic Ray Conference at Altai State University (Barnaul, Russia). Conducting a joint conference in the geographical center of Eurasia was aimed at the expansion of the geography of participants, including young scientists from different countries. In addition, the IAC decided to modify the format of the symposium (following the COSPAR International Assembly model) in order to expand the representation of key global research programs in the areas of the symposium. A change in the name and the abbreviation of the symposium into the 26th Extended European Cosmic Ray Symposium (E+CRS) reflects these goals.List of confference photographs are available in this pdf.

Heliospheric Energetic Particles and Galactic Cosmic Ray Modulation

The paper presents an overview of the SH ‘Solar and Heliospheric cosmic rays’ session of the 24th European Cosmic Ray Symposium (ECRS), Kiel, Germany, 2014. It covers the topics of Solar Energetic Particle (SEP) origin, acceleration and transport at the Sun and in the interplanetary medium, also from the aspect of multi-spacecraft observations, as well as the Galactic Cosmic Ray (GCR) short- and long-term variations and the Jovian electron variations in the heliosphere. Relevant instruments and methods presented are also covered by this review. The paper is written from a personal perspective, emphasizing those results that the author found most interesting.

Ultra-High Energy Cosmic Rays: A Recap of the Discussions at the European Cosmic Ray Symposium 2014

This contribution summarizes the talks, posters, and discussions of the ECRS 2014, held in Kiel, Germany - related to the research field of ultra-high energy cosmic rays (UHECR). Here, the definition of UHECR is cosmic rays with an energy above approximately 0.1 EeV, i.e. 1017 eV, and the corresponding sessions were named HECR-II. Recent experimental results, like the identified heavy knee in the cosmic ray energy spectrum or the hotspot in the arrival direction of cosmic rays with highest energy, will be shown and discussed in relation to the need and requirements of future experimental efforts.

Supernova remnants and pulsar wind nebulae with Imaging Atmospheric Cherenkov Telescopes (IACTs)

The observation of very-high-energy (VHE, E > 100 GeV) gamma rays is an excellent tool to study the most energetic and violent environments in the Galaxy. This energy range is only accessible with ground-based instruments such as Imaging Atmospheric Cherenkov Telescopes (IACTs) that reconstruct the energy and direction of the primary gamma ray by observing the Cherenkov light from the induced extended air showers in Earths atmosphere. The main goals of Galactic VHE gamma-ray science are the identification of individual sources of cosmic rays (CRs), such as supernova remnants (SNRs), and the study of other extreme astrophysical objects at the highest energies, such as gamma-ray binaries and pulsar wind nebulae (PWNe).One of the main challenges is the discrimination between leptonic and hadronic gamma-ray production channels. To that end, the gamma-ray signal from each individual source needs to be brought into context with the multi-wavelength environment of the astrophysical object in question, particularly with observations tracing the density of the surrounding interstellar medium, or synchrotron radiation from relativistic electrons.In this review presented at the European Cosmic Ray Symposium 2014 (ECRS2014), the most recent developments in the field of Galactic VHE gamma-ray science are highlighted, with particular emphasis on SNRs and PWNe.

Future instrumentation in cosmic ray research

This paper is based on a rapporteur talk given at the 24th European Cosmic Ray Symposium (Kiel, Germany, September 1 - 5, 2014). The object of the talk and paper is a summary based on oral talks and posters presented in the frame of the session “Future instrumentation in cosmic ray research (INS)”.

Energetic particles in the heliosphere and GCR modulation: Reviewing of SH-posters

This rapporteur paper addresses the SH poster session titled "Energetic particles in the heliosphere (solar and anomalous CRs, GCR modulation)" of the 23rd European Cosmic Ray Symposium (ECRS) and the 32nd Russian Cosmic Ray Conference (RCRC). The 65 posters presented are tentatively divided into five sections: Instruments and Methods; Solar Energetic Particles; Short Term Variations; Long Term Variations; Heliosphere.

Mechanisms and sites of ultra high energy cosmic ray origin

We shortly discuss several astrophysical scenarios leading to cosmic ray acceleration up to extremely high energies reaching the scale of 10 20 eV. The processes suggested in the literature include acceleration at relativistic jet terminal shocks and shear boundary layers, shocks in large scale accretion flows onto supergalactic cosmic structures, particle reflections from ultra-relativistic shocks postulated to exist in sources of gamma ray bursts, the processes involving the neutron star rotating magnetospheres and dormant quasars. Some of these objects can explain cosmic rays with highest energies if one tunes the model parameters to limits enabling the highest acceleration efficiency. We also note that some of the considered processes allow for acceleration efficiency in the Hillas diagram, β, to be much larger than unity. The present paper is based on a review talk presented during the European Cosmic Ray Symposium in Lodz, 2000.

The energyspectrum and the high-resolution Fly's Eye

This paper summarizes a highlight talkpresented at the 17th European Cosmic RaySymposium in Lodz. The current status ofthe cosmic ray energy spectrum and thehigh-resolution Fly's Eye experiment arereviewed. Differences between reportedmeasurements suggest that the possibleexistence of a cut-off remains unresolved.

The HEGRA experiment status and recent results

The following report summarizes part of the presentations given at the 15th European Cosmic Ray Symposium 1996. It contains the status and recent results from the HEGRA imaging atmospheric Cherenkov telescopes (IACT) concerning Mrk 501 and GRS 1915+105 and recent results from the HEGRA arrays concerning the search for gamma-radiation from galactic and extragalactic sources and energy spectrum and composition of primary cosmic rays.