10 research outputs found
A Study on anisotropy of cosmic ray distribution with a small array of water-cherenkov detectors
The study of the anisotropy of the arrival directions is an essential tool to
investigate the origin and propagation of cosmic rays primaries. A simple way
of recording many cosmic rays is to record coincidences between a number of
detectors. We have monitored multi-TeV cosmic rays by a small array of water
cherenkov detectors in Tehran(35 43 N, 51 20 E, 1200m a.s.l). More than
1.1*10^6 extensive air shower events were recorded. In addition to the Compton-
Getting effect due to the motion of the earth in the Galaxy, an anisotropy has
been observed which is due to a unidirectional anisotropy of cosmic ray flow
along the Galactic arms.Comment: 16 pages 9 figs and one tabl
Observation of EGRET Gamma-Ray Sources by an Extensive Air Shower Experiment
Ultra-high-energy (E100 Tev) Extensive Air Showers (EASs) have been
monitored for a period of five years (1997 - 2003), using a small array of
scintillator detectors in Tehran, Iran. The data have been analyzed to take in
to account of the dependence of source counts with respect to the zenith angle.
During a calendar year different sources come in the field of view of the
detector at varying zenith angles. Because of varying thickness of the
overlaying atmosphere, the shower count rate is extremely dependent on zenith
angle which have been carefully analyzed over time. High energy gamma-ray
sources from EGRET third catalogue where observed and the data were analyzed
using an excess method. A number of upper limits for a number of EGRET sources
were obtained, including 6 AGNs or probably AGNs and 4 unidentified sources.Comment: 14 pages, 8 figures, Astronomy and Astrophysics, accepte
New Simple Method for Analysis of Extensive Air Showers
Cosmic rays have valuable information about universe surroundings us. Finding
energy, mass and arrival direction of primary cosmic ray particle are the most
important aspects of extensive air shower studies. In order to determine these
parameters, arrival direction and core position of extensive air showers should
be determined at first. In this article, a new method has been introduced that
utilizes arrival time information of secondary particles of extensive air
showers for finding their core location and correcting plane wave front
approximation so that calculate the arrival direction of extensive air showers.
This method does not need number sensitive detectors-detectors which are
sensitive to the number of crossing particles- and consequently there is no
need for lateral distribution models. This model has been developed by analysis
of simulated events generated by CORSIKA package.Comment: published, and superseded by arXiv:1103.066