72 research outputs found
Multiwavelength analysis of the TeV-radio galaxy 3C 84/NGC 1275
No full textThe radio galaxy 3C 84 is a well-studied source of radio emission and was detected as NGC1275 also in the MeV/TeV regime by gamma-ray detectors like MAGIC and Fermi-LAT.
It is still unclear where and how the gamma-ray emission is produced.
In this thesis, I will confine possible emission sites and exclude the region near the black hole as the origin of the gamma-ray production.
For this aim, I investigate the optical depth of the broad-line region using data published by MAGIC and Fermi-LAT.
Furthermore, a cross-correlation study is performed to find a possible correlation between the light curves of the two radio components in 3C84 detected by the VLBA and the gamma-ray light curve measured by Fermi-LAT.
A significant correlation between the core component and the gamma-ray emission is found, which is in line with the results I derive from analyzing the optical depth of the broad-line region.
For the first time, I perform a long-term analysis of NGC1275 for four years of MAGIC data, which reveals a short flare at the beginning of 2017 and a very low state of activity since then.
To perform this long-term analysis, the software framework autoMAGIC was developed in the course of this thesis.
autoMAGIC enables fully automatic and reproducible analyses of long-term data and can be used for the automatic processing of MAGIC data in the future.Der aktive galaktische Kern 3C84, bekannt als Quelle von Radiostrahlung, wurde in den letzten Jahren auch von Gammastrahlungsdetektoren wie MAGIC und Fermi-LAT detektiert.
Um die Entstehung der Gammastrahlung zu verstehen, grenze ich die Region ein, in der diese Strahlung entstehen kann, indem ich die Absorbtion der Gammastrahlung in der Broad-Line-Region berechne.
Aufgrund dieser Studie kann die direkte Umgebung des schwarzen Lochs als Entstehungsregion ausgeschlossen werden.
Außerdem führe ich eine Korrelationsanalyse der Lichtkurven der zwei bekannten radio-hellen Regionen mit der Lichtkurve im MeV/TeV-Bereich durch.
Diese Analyse findet eine signifikante Korrelation zwischen der Kernkomponente der Quelle und der Fermi-LAT Lichtkurve.
Im Rahmen dieser Arbeit wurde außerdem die erste Langzeitstudie der von MAGIC gemessenen hochenergetischen Gammastrahlung von NGC1275 durchgeführt.
Die Ergebinisse dieser Analyse zeigen ein kurzes Aufleuchten der Quelle Anfang 2017 und danach lediglich einen sehr schwachen Fluss.
Um diese Langzeitanalyse durchzuführen, wurde autoMAGIC entwickelt, ein Programm zur automatischen und reproduzierbaren Analyse der von MAGIC gemessenen Daten.
autoMAGIC kann über diese Arbeit hinaus für alle Standardanalysen genutzt werden und wird maßgeblich dazu beitragen die Daten der MAGIC Kollaboration für die kommenden Jahrzehnte zu archivieren
Author Correction: The NLR gene family: from discovery to present day
No full textAuthor Correction: The NLR gene family: from discovery to present da
Excluding possible sites of high-energy emission in 3C 84
No full textThe FR-I galaxy 3C 84, that is identified with the misaligned blazar NGC 1275, is well known as one of the very few radio galaxies emitting gamma-rays in the TeV range. Yet, the gamma-ray emission region cannot be pinpointed and the responsible mechanisms are still unclear. We calculate the optical absorption depth of high-energy photons in the broad-line region of 3C 84 depending on their energy and distance to the central black hole. Based on these calculations, a lower limit on the distance of the emission region from the central black hole can be derived. These lower limits are estimated for two broad-line region geometries (shell and ring) and two states of the source, the low state in 2016 October–December and a flare state in 2017 January. For the shell geometry, we can place the emission region outside the Ly α radius. For the ring geometry and the low flux activity, the minimal distance between the black hole, and the gamma-ray emission region is close to the Ly α radius. In the case of the flaring state (ring geometry), the results are not conclusive. Our results exclude the region near the central black hole as the origin of the gamma-rays detected by Fermi–LAT and Major Atmospheric Gamma-Ray Imaging Cherenkov. With these findings, we can constrain the theoretical models of acceleration mechanisms and compare the possible emission region to the source’s morphology resolved by radio images from the Very Long Baseline Array
Survey report 1999/2000 summer season Voyage 4 to 6 Australian Antarctic Division Author - Mark Anderson / UTAS
No full textProgress Code: completedStatement: The values provided in spatial coverage are estimates only.
See the report for further information.Taken from sections of the Report:<br/><br/>The main purpose of the 1999-2000 Antarctic MAGIP Field Program was to provide survey support to a number of operations being undertaken around the Davis area.<br/><br/>These include aerial photography of the penguin rookeries, Tide Gauge work, GPS control of benchmarks in the Vestfold Hills and other associated levelling projects.<br/><br/>Myself, Mark Anderson, from the Centre for Spatial Information Science, University of Tasmania, was appointed as Surveyor for the 1999/00 season. I was to work in conjunction with Technical Consultant Roger Handsworth on various projects at Davis Station.<br/><br/>PROJECT OUTLINE<br/><br/>The 1999-2000 MAGIP Field Program Surveyor's Brief outlines the work to be undertaken during the period from V4 to V6 and is included in the Appendix of this report.<br/><br/>This year the Surveyor's program consisted of the following major projects:<br/><br/>- Aerial Photography of penguin rookeries<br/><br/>- This includes the aerial photography of the penguin colonies using the Linhoff camera. These penguin colonies are located on the Islands in the Davis station area.<br/><br/>- Antarctic Tide Gauge Network<br/><br/>- To locate the already installed mount for the new tide gauge using current markers and a new camera device, and then to deploy the new tide gauge in to this mooring.<br/>- Download data from existing tide gauges in the Davis area<br/>- Level run from AUS184 to the ARGN site.<br/>- Level run from AUS184 and AUS186 to HBM1 and HBM2 along specified routes as requested in brief.<br/><br/>- Location of benchmarks in the Vestfold Hills using GPS<br/><br/>- The listing of those benchmarks already controlled in previous seasons can be found in Matt King et al's report from last season. <br/>- This year it is envisaged to survey benchmarks in the outer areas of the Vestfold Hills as a priority.<br/>- Photographs of all benchmarks showing the general area of their location is to be taken.<br/>- Confirmation of the description of benchmarks in the Vestfold Hills area.<br/><br/>- Locate all new services and buildings in the station area and remove from maps all those buildings and services that no longer exist.<br/><br/>- Repair of 'tide pole' at Deep Lake.<br/><br/>Survey specifications, details to be included in the report and other such information can be found in the 1999-2000 brief to Surveyor's included in Appendix A of this report.<br/><br/>The Related URLs include links to where the following can be downloaded: <br/>1 The survey report; <br/>2 GIS data representing features at Davis and Macquarie Island station. Data resulting from this survey has Dataset_id = 35 in the attribute table.<br/>Features surveyed are listed in the report
Ctapipe - Prototype Open Event Reconstruction Pipeline for the Cherenkov Telescope Array
No full textThe Cherenkov Telescope Array Observatory (CTAO) is the next-generation ground-based gamma-ray observatory currently under construction. It will improve over the current generation of imaging atmospheric Cherenkov telescopes (IACTs) by a factor of five to ten in sensitivity and it will be able to observe the whole sky from a combination of two sites: a northern site in La Palma, Spain, and a southern one in Paranal, Chile. CTAO will also be the first open ground-based gamma-ray observatory. Accordingly, the CTAO data processing pipeline is developed as open-source software and ctapipe will be a core package therein. The event reconstruction pipeline accepts raw data of the telescopes and processes it to produce suitable input for the higher-level science tools. Its primary tasks include reconstructing the physical properties of each recorded air shower and providing the corresponding instrument response functions. ctapipe is a python framework providing algorithms and command-line tools to facilitate raw data calibration, image extraction, image parametrization and event reconstruction. Its current main focus is the analysis of simulated data but it has also been successfully applied for the analysis of data obtained with the CTA prototype telescopes, and first science results have now been obtained by the LST-1 collaboration using ctapipe. A plugin system also allows the processing of nonCTA data. Recent updates, including event reconstruction using machine learning and a new plugin system as well as the roadmap towards a 1.0 release will be presented. © Copyright owned by the author(s) under the terms of the Creative Commons
CTAO Monte Carlo Simulations - Eventlists on DL2 data level - prod5
No full textAuthor: Cherenkov Telescope Array Observatory; Cherenkov Telescope Array Consortium Contact: [email protected] The Cherenkov Telescope Array Observatory (CTAO) will be the next-generation gamma-ray observatory and is currently under construction on the island of La Palma (Spain) and near Paranal (Chile). This repository provides access to reconstructed event information (DL2- and DL1-level, simulation parameters) from Monte Carlo simulations of the CTAO Northern Array (production 5). The Monte Carlo simulations for prod5 are described in arXiv:2108.04512 , the simulation telescopes models used in the telescope simulation program sim_telarray and the configuration used in the air-shower code CORSIKA are available from the Zenodo archive for CTA Prod5 Telescope Models . MC events are calibrated and reconstructed using the ctapipe package and stored for the following data levels: - R1-MC: simulated raw data (output from sim_telarray) - DL1 (this repository) : telescope level data including images and image parameters - DL2 (this repository) : reconstructed event parameters such as energy, direction, gamma/hadron discrimination parameters - DL3: selected events with associated instrument response functions (IRFs). Preliminary DL3-IRFs are available from [here](https://doi.org/10.5281/zenodo.5499839). For a description of the file format and data model, see CTAPipe Data Model . Data set description: - using ctapipe version 0.17 ( GitHub release page , Zenodo page ) - CTAO Northern Array on La Palma for the Alpha configuration (4 large-sized telescopes, 9 mid-sized telescopes) - Zenith angles of 20 deg, telescope pointing direction north and south - Primary particles: photons, protons - For convenience, the same data is provided in a single, large file per particle type for the whole dataset which do not contain the low-level DL1 image information and a larger number of files including this information. We explicitly note that the products provided are preliminary and do not reflect the final performance of the CTA Observatory, neither are data structure or formats finalized. We also note that these data products are different to those used for the CTAO Instrument Response Functions . In cases in which the data provided in this repository are used in a research project, we ask that the following acknowledgment is added in any resulting publication: 'This research has made use of the CTA DL1 and DL2 Event lists provided by the CTA Observatory and Consortium (version prod5-DL2-release1-DL2)' and cite this repository in the reference section of your publication. We would like to thank the computing centers that provided resources for the generation of the Prod5 simulation set, click here for a list of service providers
FACT-Tools Version v1.0.0
No full text<p>The FACT-Tools are an extension of the streams framework to analyse the data of the First G-APD Cherenkov Telescope</p>
fact-project/fact-tools: Fix license name
No full textThe FACT-Tools are an extension of the streams framework to analyse the data of the First G-APD Cherenkov Telescop
fact-project/fact-tools: Minor Improvements and fixes for Erna
No full textThe FACT-Tools are an extension of the streams framework to analyse the data of the First G-APD Cherenkov Telescop
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