33 research outputs found
Geomagnetic field and altitude effects on the performance of future IACT arrays
The performance of IACT's arrays is sensitive to the altitude and geomagnetic
field (GF) of the observatory site. Both effects play important role in the
region of the sub-TeV gamma-ray measurements. We investigate the influence of
GF on detection rates and the energy thresholds for five possible locations of
the future CTA observatory using the Monte Carlo simulations. We conclude that
the detection rates of gamma rays and the energy thresholds of the arrays can
be fitted with linear functions of the altitude and the component of the GF
perpendicular to the shower axis core. These results can be directly
extrapolated for any possible localization of the CTA. In this paper we also
show the influence of both geophysical effects on the images of shower and
gamma/hadron separation.Comment: 4 pages, 6 figures, two-column. Contribution to ICRC 2013 proceeding
Second large-scale Monte Carlo study for the Cherenkov Telescope Array
The Cherenkov Telescope Array (CTA) represents the next generation of ground
based instruments for Very High Energy gamma-ray astronomy. It is expected to
improve on the sensitivity of current instruments by an order of magnitude and
provide energy coverage from 20 GeV to more than 200 TeV. In order to achieve
these ambitious goals Monte Carlo (MC) simulations play a crucial role, guiding
the design of CTA. Here, results of the second large-scale MC production are
reported, providing a realistic estimation of feasible array candidates for
both Northern and Sourthern Hemisphere sites performance, placing CTA
capabilities into the context of the current generation of High Energy
-ray detectors.Comment: In Proceedings of the 34th International Cosmic Ray Conference
(ICRC2015), The Hague, The Netherlands. All CTA contributions at
arXiv:1508.0589
A Site Evaluation Campaign for a Ground Based Atmospheric Cherenkov Telescope in Romania
Around the world, several scientific projects share the interest of a global
network of small Cherenkov telescopes for monitoring observations of the
brightest blazars - the DWARF network. A small, ground based, imaging
atmospheric Cherenkov telescope of last generation is intended to be installed
and operated in Romania as a component of the DWARF network. To prepare the
construction of the observatory, two support projects have been initiated.
Within the framework of these projects, we have assessed a number of possible
sites where to settle the observatory. In this paper we submit a brief report
on the general characteristics of the best four sites selected after the local
infrastructure, the nearby facilities and the social impact criteria have been
applied.Comment: 6 pages, 5 Postscript figure
Bio-inspired approach for long-range underwater navigation using model predictive control
Lots of evidence has indicated that many kinds of animals can achieve goal-oriented navigation by spatial cognition and dead reckoning. The geomagnetic field (GF) is a ubiquitous cue for navigation by these animals. Inspired by the goal-oriented navigation of animals, a novel long-distance underwater geomagnetic navigation (LDUGN) method is presented in this article, which only utilizes the declination component (D) and inclination component (I) of GF for underwater navigation without any prior knowledge of the geographical location or geomagnetic map. The D and I measured by high-precision geomagnetic sensors are compared periodically with that of the destination to determine the velocity and direction in the next step. A model predictive control (MPC) algorithm with control and state constraints is proposed to achieve the control and optimization of navigation trajectory. Because the optimal control is recalculated at each sampling instant, the MPC algorithm can overcome interferences of geomagnetic daily fluctuation, geomagnetic storms, ocean current, and geomagnetic local anomaly. The simulation results validate the feasibility and accuracy of the proposed algorithm
The influence of the geomagnetic field and of the uncertainties in the primary spectrum on the development of the muon flux in the atmosphere
In this paper we study the sensitivity of the flux of atmospheric muons to
uncertainties in the primary cosmic ray spectrum and to the treatment of the
geomagnetic field in a calculation. We use the air shower simulation program
AIRES to make the calculation for two different primary spectra and under
several approximations to the propagation of charged particles in the
geomagnetic field. The results illustrate the importance of accurate modelling
of the geomagnetic field effects. We propose a high and a low fit of the proton
and helium fluxes, and calculate the muon fluxes with these different inputs.
Comparison with measurements of the muon flux by the CAPRICE experiment shows a
slight preference for the higher primary cosmic ray flux parametrization.Comment: 24 pages, 13 figures, submitted to Phys.Rev.
Astroparticle Physics at Eastern Colombia
We present the emerging panorama of Astroparticle Physics at Eastern
Colombia, and describe several ongoing projects, most of them related to the
Latin American Giant Observatory (LAGO) Project. This research work is carried
out at the Grupo de Investigaciones en Relatividad y Gravitaci\'on of
Universidad Industrial de Santander.Comment: 19 pages, 8 figure
Estimation of the height of the first interaction in gamma-ray showers observed by Cherenkov telescopes
Very high energy gamma rays entering the atmosphere initiate Extensive Air
Showers (EAS). The Cherenkov light induced by an EAS can be observed by
ground-based telescopes to study the primary gamma rays. An important parameter
of an EAS, determining its evolution, is the height of the first interaction of
the primary particle. However, this variable cannot be directly measured by
Cherenkov telescopes. We study two simple, independent methods for the
estimation of the first interaction height. We test the methods using the Monte
Carlo simulations for the 4 Large Size Telescopes (LST) that are part of the
currently constructed Cherenkov Telescope Array (CTA) Observatory. We find that
using such an estimated parameter in the gamma/hadron separation can bring a
mild improvement (~10-20%) in the sensitivity in the energy range ~30-200 GeV.Comment: 8 pages, 6 figures, accepted for publication in Astroparticle Physic