Observations of Steady Flux of PeV--Energy Extensive Air Showers from Cygnus X-3 during 1984--1986
Abstract
Data taken with a 24-detector extensive-air-shower (EAS) array, operating at Ooty since June, 1984, have been used to search for excess of EASs of energy greater than 250 TeV from the direction of binary X-ray source Cyg X-3. The data show a time-averaged excess in the number of showers from this direction, over the background determined from other regions of the sky having the same declination. The excess is most prominent among older showers having a flatter lateral distribution. A part of this excess shows up significantly in the phase region, 0.6-0.8 in the 4.8-hr periodicity analysis. These observations correspond to an integral flux of (7.16 + or - 3.15) x 10 to the -13th/sq cm sec at energies greater than 250 TeV and of (1.04 + or - 0.44) x 10 to the -13th/sq cm sec at energies greater than 2.5 PeV. The observations confirm, for the first time, results reported by the Kiel group (Samorski and Stamm, 1983) of a directional excess from the direction of Cyg X-3, without requiring the 4.8-hr periodicity analysis as was necessary in many of the other experiments reporting positive signals. This emphasizes the advantage of good angular resolution for such studies.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- July 1988
- DOI:
- 10.1086/185215
- Bibcode:
- 1988ApJ...330L.107T
- Keywords:
-
- Cosmic Ray Showers;
- Gamma Rays;
- Neutron Stars;
- Particle Flux Density;
- X Ray Binaries;
- Angular Resolution;
- Electron Emission;
- Electron Energy;
- Histograms;
- Light Curve;
- Relativistic Particles;
- Space Radiation;
- GAMMA RAYS: GENERAL;
- X-RAYS: SOURCES