The Search for Very High Energy γ-rays from Misaligned AGN

The aim of this work is to study the potential for emission at very high energies (100 GeV) by misaligned active galactic nuclei (AGN) and the future prospects for observations of these objects with the next generation imaging atmospheric Cherenkov telescope, the Cherenkov Telescope Array (CTA). Initially, data collected by the H.E.S.S. array was used to study fourteen Seyfert galaxies and two other AGN with Seyfert-like properties and no new detections were reported. For each object upper limits were calculated, assuming a similar spectral shape to M87. Further work focused on modelling the GeV spectra of misaligned AGN (AGN with angles of inclination to the line of sight 5◦ ) detected in 2010 with the Fermi Space Telescope. The modelling was carried out using a multiblob model that had previously been used to model the very high energy emission of M87 and Centaurus A. This work was used to investigate the capacity of the model to reproduce the high energy spectra observed for each object, while also allowing predictions of the potential very high energy fluxes to be produced. In each case the multiblob model was able to reproduce the observed GeV spectrum. The spectral energy distributions produced were then compared to predicted sensitivity curves for a number of possible CTA configurations to determine the likelihood of detection of these misaligned AGN with the array. It was found that detection of the objects within 50 hours of observations with CTA using standard Durham analysis is unlikely, but that 3C 111 may be detectable using the Paris analysis method

High-Energy Gamma-Ray Astronomy

This volume celebrates the 30th anniversary of the first very-high energy (VHE) gamma-ray Source detection: the Crab Nebula, observed by the pioneering ground-based Cherenkov telescope Whipple, at teraelectronvolts (TeV) energies, in 1989. As we entered a new era in TeV astronomy, with the imminent start of operations of the Cherenkov Telescope Array (CTA) and new facilities such as LHAASO and the proposed Southern Wide-Field Gamma-ray Observatory (SWGO), we conceived of this volume as a broad reflection on how far we have evolved in the astrophysics topics that dominated the field of TeV astronomy for much of recent history.In the past two decades, H.E.S.S., MAGIC and VERITAS pushed the field of TeV astronomy, consolidating the field of TeV astrophysics, from few to hundreds of TeV emitters. Today, this is a mature field, covering almost every topic of modern astrophysics. TeV astrophysics is also at the center of the multi-messenger astrophysics revolution, as the extreme photon energies involved provide an effective probe in cosmic-ray acceleration, propagation and interaction, in dark matter and exotic physics searches. The improvement that CTA will carry forward and the fact that CTA will operate as the first open observatory in the field, mean that gamma-ray astronomy is about to enter a new precision and productive era.This book aims to serve as an introduction to the field and its state of the art, presenting a series of authoritative reviews on a broad range of topics in which TeV astronomy provided essential contributions, and where some of the most relevant questions for future research lie

Proceedings of the 2012 Workshop on Ambient Intelligence Infrastructures (WAmIi)

This is a technical report including the papers presented at the Workshop on Ambient Intelligence Infrastructures (WAmIi) that took place in conjunction with the International Joint Conference on Ambient Intelligence (AmI) in Pisa, Italy on November 13, 2012. The motivation for organizing the workshop was the wish to learn from past experience on Ambient Intelligence systems, and in particular, on the lessons learned on the system architecture of such systems. A significant number of European projects and other research have been performed, often with the goal of developing AmI technology to showcase AmI scenarios. We believe that for AmI to become further successfully accepted the system architecture is essential

Proceedings of the 2012 Workshop on Ambient Intelligence Infrastructures (WAmIi)

This is a technical report including the papers presented at the Workshop on Ambient Intelligence Infrastructures (WAmIi) that took place in conjunction with the International Joint Conference on Ambient Intelligence (AmI) in Pisa, Italy on November 13, 2012. The motivation for organizing the workshop was the wish to learn from past experience on Ambient Intelligence systems, and in particular, on the lessons learned on the system architecture of such systems. A significant number of European projects and other research have been performed, often with the goal of developing AmI technology to showcase AmI scenarios. We believe that for AmI to become further successfully accepted the system architecture is essential

The Automatic Telescope for Optical Monitoring

This thesis is presenting the development and commissioning phase as well as results from the first years of operation of ATOM, the Automatic Telescope for Optical Monitoring. It is now one of the worldwide first operational telescope systems that is performing observing runs in a completely automatic way whilst being able to respond to changing weather conditions without any human interaction. The basis for this system is the 75 cm telescope of Landessternwarte Heidelberg. It was upgraded and relocated to Namibia to be part of the H.E.S.S. experiment. ATOM is now monitoring potential or detected TeV emitting extragalactic sources (Active Galactic Nuclei, AGN) for H.E.S.S. in the optical spectral range to create long-term lightcurves and sent alerts in case a source is entering a flaring state. For that purpose, a complete new data reduction pipeline was developed. This pipeline is analysing the images recorded by ATOM and is producing flux calibrated lightcurves in an automatic way. All TeV-detected AGN, which are observable from Namibia, have been studied for flux and color changes (as well as some other AGN). For some sources, potential correlations between ATOM observations and measurements in the GeV energy range performed by the Fermi satellite have been investigated. Furthermore, this work is providing the framework for an increasing photometric catalog consisting of more than 200 AGN

Design concepts for the Cherenkov Telescope Array CTA: An advanced facility for ground-based high-energy gamma-ray astronomy

Ground-based gamma-ray astronomy has had a major breakthrough with the impressive results obtained using systems of imaging atmospheric Cherenkov telescopes. Ground-based gamma-ray astronomy has a huge potential in astrophysics, particle physics and cosmology. CTA is an international initiative to build the next generation instrument, with a factor of 5-10 improvement in sensitivity in the 100 GeV-10 TeV range and the extension to energies well below 100 GeV and above 100 TeV. CTA will consist of two arrays (one in the north, one in the south) for full sky coverage and will be operated as open observatory. The design of CTA is based on currently available technology. This document reports on the status and presents the major design concepts of CTA.La lista completa de autores que integran el documento puede consultarse en el archivo.Departamento de AeronáuticaFacultad de IngenieríaInstituto Argentino de RadioastronomíaFacultad de Ciencias Astronómicas y Geofísica