|
|
Principal Component Analysis of GRBs
We have carried out a principal component analysis for gamma-ray bursts in the BATSE 3B catalog. This shows that only two out of the three basic quantities of duration, peak flux, and fluence are independent. The principal component analysis provides a potentially useful tool for estimating the number of physically important variables responsible for the GRB phenomenon.
|
|
|
Difference between the short and long GRBs
We show evidences for a power-law dependence between the fluence and the duration of GRBs, with a statistically significant different index for the long and short groups. Our results provide new evidence suggesting an intrinsic difference between the long and short bursts, which probably reflects a difference in the physical character of the energy release process.
|
|
|
Different satellites - different GRB redshifts
The measured redshifts of GRBs, which were first detected by the Swift satellite, seem to be bigger on average than the redshifts of GRBs detected by other satellites. We analyzed the redshift distribution of GRBs triggered and observed by different satellites (Swift, HETE2, BeppoSax, Ulyssses). After considering the possible biases significant difference was found at the p = 95.70% level in the redshift distributions of GRBs measured by HETE and the Swift.
|
