Gamma-Ray Bursts Exhibit Isotropic Distribution with Dipolar Structure

Recent research has examined the distribution of gamma-ray bursts (GRBs) from the updated FERMI/GBM catalogue, focusing on their statistical isotropy. The study, titled "Dipolar Fluence distribution of statistically isotropic FERMI Gamma-Ray Bursts," investigates whether these astrophysical events exhibit any preferred direction in their angular distribution. The authors employed a model-independent approach to analyze the data, comparing it with a variety of statistically isotropic cosmic objects to determine the significance of their findings.

The results indicate that the angular distribution of FERMI GRBs is statistically isotropic across the celestial sphere. However, the analysis of the directional distribution of GRB fluence revealed a dipolar structure, suggesting a preference for certain latitudes near the galactic plane. Notably, this directional preference does not correlate with the Milky Way, implying that the origin of these bursts may be extragalactic.

Furthermore, the study found that the dipole direction aligns closely with the cosmic microwave background dipole when analyzing BATSE Channel 4 fluence data, which includes GRBs with energies exceeding 300 keV. This alignment may provide insights into the broader cosmic structure and the behavior of high-energy astrophysical phenomena.

The findings of this research contribute to our understanding of the nature and origin of gamma-ray bursts, which are among the most energetic events in the universe. By confirming the isotropic nature of these bursts while also identifying a dipolar structure, the study opens avenues for further exploration into the mechanisms driving these powerful explosions and their implications for cosmic evolution.

For more details, the full paper can be accessed at arXiv:2409.01480.