GrailQuest & HERMES: Hunting for Gravitational Wave Electromagnetic Counterparts and Probing Space-Time Quantum Foam

Within Quantum Gravity theories, different models for space-time quantisation predict an energy dependent speed for photons. Although the predicted discrepancies are minuscule, GRB, occurring at cosmological distances, could be used to detect this signature of space-time granularity with a new concept of modular observatory of huge overall collecting area consisting in a fleet of small satellites in low orbits, with sub-microsecond time resolution and wide energy band (keV-MeV). The enormous number of collected photons will allow to effectively search these energy dependent delays. Moreover, GrailQuest will allow to perform temporal triangulation of high signal-to-noise impulsive events with arc-second positional accuracies: an extraordinary sensitive X-ray/Gamma all-sky monitor crucial for hunting the elusive electromagnetic counterparts of GW. A pathfinder of GrailQuest is already under development through the HERMES project: a fleet of six 3U cube-sats to be launched by 2021/22

A comparison of trapped particle models in low earth orbit

Space radiation is well-known to pose serious issues to solid-state high-energy sensors. Therefore, radiation models play a key role in the preventive assessment of the radiation damage, duty cycles, performance and lifetimes of detectors. In the context of HERMES-SP mission we present our investigation of AE8/AP8 and AE9/AP9 specifications of near-Earth trapped radiation environment. We consider different circular Low-Earth orbits. Trapped particles fluxes are obtained, from which maps of the radiation regions are computed, estimating duty cycles at different flux thresholds. Outcomes are also compared with published results on in-situ measurements. This study is done on behalf of the HERMES-SP collaboration

A software toolkit to simulate activation background for high energy detectors onboard satellites

A software toolkit for the simulation of activation background for high energy detectors onboard satellites is presented on behalf of the HERMES-SP1 collaboration. The framework employs direct Monte Carlo and analytical calculations allowing computations two orders of magnitude faster and more precise than a direct Monte Carlo simulation. The framework was developed in a way that the model of the satellite can be replaced easily. Therefore the framework can be used for different satellite missions. As an example, the proton induced activation background of the HERMES CubeSat is quantified

Investigation of neutron scattering in the Multi-Blade detector with Geant4 simulations

The European Spallation Source (ESS) is the world's next generation spallation-based neutron source. The research conducted at ESS will yield in the discovery and development of new materials including the fields of manufacturing, pharmaceuticals, aerospace, engines, plastics, energy, telecommunications, transportation, information technology and biotechnology. The spallation source will deliver an unprecedented neutron flux. In particular, the reflectometers selected for construction, ESTIA and FREIA, have to fulfill challenging requirements. Local incident peak rate can reach 10(5) Hz/mm(2). For new science to be addressed, the spatial resolution is aimed to be less than 1 mm with a desired scattering of 10(-4) (peak-to-tail ratio). The latter requirement is approximately two orders of magnitude better than the current state-of-the-art detectors. The main aim of this work is to quantify the cumulative contribution of various detector components to the scattering of neutrons and to prove that the respective effect is within the requirements set for the Multi-Blade detector by the ESS reflectometers. To this end, different sets of geometry and beam parameters are investigated, with primary focus on the cathode coating and the detector window thickness

VizieR Online Data Catalog: GLADE v2.3 catalog (Dalya+, 2018)

We are introducing a value-added full-sky galaxy catalog with high completeness for identifying gravitational wave (GW) sources in order to support future electromagnetic (EM) follow-up projects of the LIGO/Virgo Collaboration. The catalog has been constructed (combined and matched) from four existing galaxy catalogs: GWGC, 2MPZ, 2MASS XSC and HyperLEDA. Additionally, we have extended GLADE with the SDSS-DR12 quasar catalog. GLADE contains 3,262,883 objects, which is two orders of magnitude greater than the number of galaxies in the GWGC catalog alone (53,312). Naturally, GLADE could be used in a broad range of various astrophysical projects besides EM follow-up efforts

VizieR Online Data Catalog: GLADE v2.3 catalog (Dalya+, 2018)

We are introducing a value-added full-sky galaxy catalog with high completeness for identifying gravitational wave (GW) sources in order to support future electromagnetic (EM) follow-up projects of the LIGO/Virgo Collaboration. The catalog has been constructed (combined and matched) from four existing galaxy catalogs: GWGC, 2MPZ, 2MASS XSC and HyperLEDA. Additionally, we have extended GLADE with the SDSS-DR12 quasar catalog. GLADE contains 3,262,883 objects, which is two orders of magnitude greater than the number of galaxies in the GWGC catalog alone (53,312). Naturally, GLADE could be used in a broad range of various astrophysical projects besides EM follow-up efforts

From transition crisis to the global crisis: twenty years of capitalism and labour in the Central and Eastern EU new member states

This paper analyses the developments in wages, employment and income distribution in the Central and Eastern European new member states twenty years after transition to capitalism, divided into three periods: 1) the transition crisis; 2) post-transition growth; and 3) the crisis episode of 2008-9. Total employment has at best stagnated or slightly decreased. Modest wage increases have fallen behind productivity increases. Furthermore, the global crisis has led to employment losses in all countries, and real wages have already started to decrease in several countries

A summary on an investigation of GAGG:Ce afterglow emission in the context of future space applications within the HERMES nanosatellite mission

GAGG:Ce (Cerium-doped Gadolinium Aluminium Gallium Garnet) is a promising new scintillator crystal. A wide array of interesting features | such as high light output, fast decay times, almost non-existent intrinsic background and robustness | make GAGG:Ce an interesting candidate as a component of new space-based gamma-ray detectors. As a consequence of its novelty, literature on GAGG:Ce is still lacking on points crucial to its applicability in space missions. In particular, GAGG:Ce is characterized by unusually high and long-lasting delayed luminescence. This afterglow emission can be stimulated by the interactions between the scintillator and the particles of the near-Earth radiation environment. By contributing to the noise, it will impact the detector performance to some degree. In this manuscript we summarize the results of an irradiation campaign of GAGG:Ce crystals with protons, conducted in the framework of the HERMES-TP/SP (High Energy Rapid Modular Ensemble of Satellites - Technological and Scienti c Path nder) mission. A GAGG:Ce sample was irradiated with 70 MeV protons, at doses equivalent to those expected in equatorial and sun-synchronous Low- Earth orbits over orbital periods spanning 6 months to 10 years, time lapses representative of satellite lifetimes. We introduce a new model of GAGG:Ce afterglow emission able to fully capture our observations. Results are applied to the HERMES-TP/SP scenario, aiming at an upper-bound estimate of the detector performance degradation due to the afterglow emission expected from the interaction between the scintillator and the near- Earth radiation environment