Monte Carlo simulations of soft proton flares: testing the physics with XMM-Newton

Low energy protons (<100-300 keV) in the Van Allen belt and the outer regions can enter the field of view of X-ray focusing telescopes, interact with the Wolter-I optics, and reach the focal plane. The use of special filters protects the XMM-Newton focal plane below an altitude of 70000 km, but above this limit the effect of soft protons is still present in the form of sudden flares in the count rate of the EPIC instruments, causing the loss of large amounts of observing time. We try to characterize the input proton population and the physics interaction by simulating, using the BoGEMMS framework, the proton interaction with a simplified model of the X-ray mirror module and the focal plane, and comparing the result with a real observation. The analysis of ten orbits of observations of the EPIC/pn instrument show that the detection of flares in regions far outside the radiation belt is largely influenced by the different orientation of the Earth's magnetosphere respect with XMM-Newton's orbit, confirming the solar origin of the soft proton population. The Equator-S proton spectrum at 70000 km altitude is used for the proton population entering the optics, where a combined multiple and Firsov scattering is used as physics interaction. If the thick filter is used, the soft protons in the 30-70 keV energy range are the main contributors to the simulated spectrum below 10 keV. We are able to reproduce the proton vignetting observed in real data-sets, with a 50\% decrease from the inner to the outer region, but a maximum flux of 0.01 counts cm-2 s-1 keV-1 is obtained below 10 keV, about 5 times lower than the EPIC/MOS detection and 100 times lower than the EPIC/pn one. Given the high variability of the flare intensity, we conclude that an average spectrum, based on the analysis of a full season of soft proton events is required to compare Monte Carlo simulations with real events

Entanglement entropy from non-equilibrium Monte Carlo simulations

We study the entanglement entropy in lattice field theory using a simulation algorithm based on Jarzynski's theorem. We focus on the entropic c-function for the Ising model in two and in three dimensions: after validating our algorithm against known analytical results from conformal field theory in two dimensions, we present novel results for the three-dimensional case. We show that our algorithm, which is highly parallelized on graphics processing units, allows one to precisely determine the subleading corrections to the area law, which have been investigated in many recent works. Possible generalizations of this study to other strongly coupled theories are discussed.Comment: 1+33 pages; v2: typos corrected, matches published versio

Parallel waveform extraction algorithms for the Cherenkov Telescope Array Real-Time Analysis

The Cherenkov Telescope Array (CTA) is the next generation observatory for the study of very high-energy gamma rays from about 20 GeV up to 300 TeV. Thanks to the large effective area and field of view, the CTA observatory will be characterized by an unprecedented sensitivity to transient flaring gamma-ray phenomena compared to both current ground (e.g. MAGIC, VERITAS, H.E.S.S.) and space (e.g. Fermi) gamma-ray telescopes. In order to trigger the astrophysics community for follow-up observations, or being able to quickly respond to external science alerts, a fast analysis pipeline is crucial. This will be accomplished by means of a Real-Time Analysis (RTA) pipeline, a fast and automated science alert trigger system, becoming a key system of the CTA observatory. Among the CTA design key requirements to the RTA system, the most challenging is the generation of alerts within 30 seconds from the last acquired event, while obtaining a flux sensitivity not worse than the one of the final analysis by more than a factor of 3. A dedicated software and hardware architecture for the RTA pipeline must be designed and tested. We present comparison of OpenCL solutions using different kind of devices like CPUs, Graphical Processing Unit (GPU) and Field Programmable Array (FPGA) cards for the Real-Time data reduction of the Cherenkov Telescope Array (CTA) triggered data.Comment: In Proceedings of the 34th International Cosmic Ray Conference (ICRC2015), The Hague, The Netherlands. All CTA contributions at arXiv:1508.0589

The AGILE Gamma-Ray observatory: software and pipelines

In this paper is described the approach used to develop the software system of the AGILE γ-ray Observatory, from the definition phase to construction, verification and calibration activities of the satellite, until operations for scientific observations. Flexible software architectures, effective software management workflow, new algorithms (from payload simulators to reconstruction algorithms, from detection algorithms for Real-Time Analysis systems to the follow-up of science alerts in the multi-wavelenght and multi-messenger context) and team management approach are described. The approach followed by the AGILE Team in more than twenty years of work is a key element of the success of the AGILE Observatory, and the foundation for the involvement in new high-energy telescopes and observatories. Our legacy is not only in experience and tools but also in lesson learned, that are described in this work

ASTRI Mini-Array Use Cases of the Power Management System Collector

The ASTRI Mini-Array (MA) is an INAF project to construct and operate an experiment to study gamma-ray sources emitting at very high-energy in the TeV spectral band. This document defines the Use Cases of the Power Management System Collector (PMSC)

ASTRI Mini-Array Use Cases of the Telescope Service Cabinet Control System

The ASTRI Mini-Array (MA) is an INAF project to construct and operate an experiment to study gamma-ray sources emitting at very high-energy in the TeV spectral band. This document defines the Use Cases of the Telescope Service Cabinet Control System (TSCCS)

CIWS Software Specification Document (SSD)

The Customizable Instrument Workstation Software (CIWS) is a telescope - and instrument - independent software system for raw Level 0 (L0) and Level 1 (L1) data handling. The system is aimed at providing a common and standard solution for the storage, processing, quick look and retrieval of the data generated by space-borne or ground-based telescopes and by the auxiliary data sources (e.g.: calibration facilities housekeeping) during the development, integration, verification, test and operation activities to be carried out on the telescope instrument. The present document represents the output of the Software Requirement phase and of the Architectural Design phase. The purposes of this document are the following: 1. to serve as a tool to gather the software requirements that will drive the development of the software of this subsystem 2. it could be used as a guide to select and re-use existing software, to be identified at a later stage during the architecture definition of the subsystem 3. it should be used to identify the correct interfaces with external system