scholarly journals Constraining models of the pulsar wind nebula in SNR G0.9+0.1 via simulation of its detection properties using the Cherenkov Telescope Array

2020 ◽  
Vol 499 (3) ◽  
pp. 3494-3509
Author(s):  
M Fiori ◽  
L Zampieri ◽  
A Burtovoi ◽  
P Caraveo ◽  
L Tibaldo
Keyword(s):  
Systematic Errors ◽  
High Energy ◽  
Emission Region ◽  
Telescope Array ◽  
Instrument Response Function ◽  
Cherenkov Telescope ◽  
Cutoff Energy ◽  
Spectral Models ◽  
Pulsar Wind ◽  
The Impact

ABSTRACT SNR G0.9+0.1 is a well-known source in the direction of the Galactic Centre composed by a Supernova Remnant (SNR) and a Pulsar Wind Nebula (PWN) in the core. We investigate the potential of the future Cherenkov Telescope Array (CTA), simulating observations of SNR G0.9 + 0.1. We studied the spatial and spectral properties of this source and estimated the systematic errors of these measurements. The source will be resolved if the very high-energy emission region is bigger than ∼0.65′. It will also be possible to distinguish between different spectral models and calculate the cutoff energy. The systematic errors are dominated by the Instrument Response Function instrumental uncertainties, especially at low energies. We computed the evolution of a young PWN inside an SNR using a one-zone time-dependent leptonic model. We applied the model to the simulated CTA data and found that it will be possible to accurately measure the cutoff energy of the γ-ray spectrum. Fitting of the multiwavelength spectrum will allow us to constrain also the magnetization of the PWN. Conversely, a pure power-law spectrum would rule out this model. Finally, we checked the impact of the spectral shape and the energy density of the Inter-Stellar Radiation Fields on the estimate of the parameters of the PWN, finding that they are not significantly affected.

scholarly journals Prospects for γ-ray observations of narrow-line Seyfert 1 galaxies with the Cherenkov Telescope Array – II. γ–γ absorption in the broad-line region radiation fields

2020 ◽  
Vol 494 (1) ◽  
pp. 411-424 ◽  
Author(s):  
P Romano ◽  
M Böttcher ◽  
L Foschini ◽  
C Boisson ◽  
S Vercellone ◽  
...  
Keyword(s):  
High Energy ◽  
Emission Region ◽  
Broad Line ◽  
Narrow Line ◽  
Telescope Array ◽  
Cherenkov Telescope ◽  
Broad Line Region ◽  
Radiation Fields ◽  
Line Region ◽  
Γ Ray

ABSTRACT Gamma-ray emitting narrow-line Seyfert 1 (γ-NLS1) galaxies possibly harbour relatively low-mass black holes (106–108 M⊙) accreting close to the Eddington limit, and share many characteristics with their sibling sources, flat-spectrum radio quasars. Although they have been detected in the MeV–GeV band with Fermi–LAT, they have never been seen in the very high energy band with current imaging atmospheric Cherenkov telescopes (IACTs). Thus, they are key targets for the next-generation IACT, the Cherenkov Telescope Array (CTA). In a previous work we selected, by means of extensive simulations, the best candidates for a prospective CTA detection (SBS 0846+513, PMN J0948+0022, and PKS 1502+036) taking into account the effects of both the intrinsic absorption (approximated with a cut-off at 30 GeV), and the extragalactic background light on the propagation of γ-rays. In this work, we simulate the spectra of these three sources by adopting more realistic broad-line region (BLR) absorption models. In particular, we consider the detailed treatment of γ–γ absorption in the radiation fields of the BLR as a function of the location of the γ-ray emission region with parameters inferred from observational constraints. We find that, due to the energy range extent and its sensitivity, CTA is particularly well suited to locate the γ-ray emitting region in γ-NLS1. In particular CTA will be able not only to distinguish whether the γ-ray emitting region is located inside or outside the BLR, but also where inside the BLR it may be.

scholarly journals Probing the absorption of gamma-rays by IR radiation from the dusty torus in FSRQs with the Cherenkov telescope array

2020 ◽  
Vol 495 (3) ◽  
pp. 3463-3473 ◽  
Author(s):  
Giorgio Galanti ◽  
Marco Landoni ◽  
Fabrizio Tavecchio ◽  
Stefano Covino
Keyword(s):  
Gamma Ray ◽  
High Energy ◽  
Emission Region ◽  
Emission Model ◽  
Ir Radiation ◽  
Telescope Array ◽  
Cherenkov Telescope ◽  
Line Region ◽  
Uv Photons ◽  
Dusty Torus

ABSTRACT Within the classical emission model, where the emission region is placed within the broad line region (BLR), flat spectrum radio quasars (FSRQs) were believed not to emit photons with energies above few tens of GeV because of the absorption with the optical-UV photons from the BLR. However, photons with observed energies up to about $300 \, \rm GeV$ have been detected for few FSRQs, whose most iconic example is PKS 1441+25 at redshift z = 0.94. The most conservative explanation for these observations is that the emission occurs at distances comparable to the size of the dusty torus. In this case, absorption of high-energy gamma-ray photons for energies above $200{-}300 \, {\rm GeV}$ is dominated by the interaction with infrared radiation emitted by the torus. We investigate if current observational data about FSRQs in flaring state can give us information about: (i) the importance of the torus absorption and (ii) the properties of the torus i.e. its temperature and its geometry. We find that present data do not arrive at energies where the torus influence is prominent and as a result it is currently hardly possible to infer torus properties from observations. However, with dedicated simulations, we demonstrate that observations with the forthcoming Cherenkov Telescope Array (CTA) will be able to constrain the torus parameters (temperature and geometry).

scholarly journals Simulation studies of the high-energy component of a future imaging Cherenkov telescope array

2008 ◽  
Author(s):  
S. Funk ◽  
J. A. Hinton ◽  
Felix A. Aharonian ◽  
Werner Hofmann ◽  
Frank Rieger
Keyword(s):  
High Energy ◽  
Simulation Studies ◽  
Energy Component ◽  
Telescope Array ◽  
Cherenkov Telescope ◽  
High Energy Component

scholarly journals The ASTRI Program

2019 ◽  
Vol 209 ◽  
pp. 01001
Author(s):  
Salvatore Scuderi
Keyword(s):  
High Energy ◽  
Telescope Array ◽  
Cherenkov Telescope ◽  
Southern Site ◽  
Complete Set ◽  
New Phase ◽  
Prototype Design ◽  
Italian National Institute ◽  
Mirror Configuration

The ASTRI (Astrofisica con Specchi a Tecnologia Replicante Italiana) program was born as a collaborative international effort led by the Italian National Institute for Astrophysics (INAF) to design and realize, within the Cherenkov Telescope Array (CTA) framework, an end-to-end prototype of the Small-Sized Telescope (SST) in a dual-mirror configuration (2M). While the activities concerning the characterization of the prototype are under completion, the program entered a new phase. With the final aim of contributing at the production of the SST telescopes for the CTAO Southern site, we started the development of nine telescopes based on the evolution of the ASTRI prototype design to work as pathfinder for the CTAO. Furthermore, together with the CHEC (Compact High Energy Camera) collaboration, the ASTRI team presented a proposal, that will be evaluated with other proposals, to deliver to CTAO the complete set of SST telescopes.

scholarly journals The Cherenkov Telescope Array production system proto-type for large-scale data processing and simulations

2021 ◽  
Vol 251 ◽  
pp. 02029
Author(s):  
Luisa Arrabito ◽  
Johan Bregeon ◽  
Patrick Maeght ◽  
Michèle Sanguillon ◽  
Andrei Tsaregorodtsev ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Data Processing ◽  
Production System ◽  
Large Scale ◽  
Current System ◽  
High Energy ◽  
Current Status ◽  
Telescope Array ◽  
Cherenkov Telescope ◽  
Very High

The Cherenkov Telescope Array (CTA) is the next-generation instrument in the very-high energy gamma ray astronomy domain. It will consist of tens of Cherenkov telescopes deployed in 2 arrays at La Palma (Spain) and Paranal (ESO, Chile) respectively. Currently under construction, CTA will start operations around 2023 for a duration of about 30 years. During operations CTA is expected to produce about 2 PB of raw data per year plus 5-20 PB of Monte Carlo data. The global data volume to be managed by the CTA archive, including all versions and copies, is of the order of 100 PB with a smooth growing profile. The associated processing needs are also very high, of the order of hundreds of millions of CPU HS06 hours per year. In order to optimize the instrument design and study its performances, during the preparatory phase (2010-2017) and the current construction phase, the CTA consortium has run massive Monte Carlo productions on the EGI grid infrastructure. In order to handle these productions and the future data processing, we have developed a production system based on the DIRAC framework. The current system is the result of several years of hardware infrastructure upgrades, software development and integration of different services like CVMFS and FTS. In this paper we present the current status of the CTA production system and its exploitation during the latest large-scale Monte Carlo campaigns.

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