Jul 12 – 23, 2021
Europe/Berlin timezone

Large-scale cosmic ray anisotropy measured by the GRAPES-3 experiment

Jul 15, 2021, 12:00 PM
1h 30m


Talk CRI | Cosmic Ray Indirect Discussion


Medha Chakraborty (Tata Institute of Fundamental Research)


The deflection of cosmic rays (CRs) in the interstellar magnetic field results in an almost isotropic flux as observed on Earth. However, an anisotropy has been observed at the level of $\sim 10^{−4} − 10^{−3}$. The GRAPES-3 experiment located at Ooty, India consists of an array of 400 plastic scintillator detectors. It measures the particle densities and their relative arrival times in extensive air showers produced by the CRs. This information collected is then reconstructed to obtain the energy and direction of the primary CRs. The near-equatorial location of GRAPES-3 provides an opportunity to study this anisotropy in both hemispheres of the celestial sphere in the TeV-PeV energy range. However, detector and atmospheric effects that induce a few percent change in the primary CR flux are challenges to be addressed. The techniques developed to address the systematic effects along with the results of anisotropy studies will be presented.


Anisotropy; GRAPES;

Subcategory Experimental Results
Collaboration other (fill field below)
other Collaboration GRAPES-3

Primary authors

Medha Chakraborty (Tata Institute of Fundamental Research) for the GRAPES-3 collaboration

Presentation materials