How Sample Completeness Affects Gamma-Ray Burst Classification

@article{Hakkila2003HowSC,
  title={How Sample Completeness Affects Gamma-Ray Burst Classification},
  author={Jon Hakkila and Timothy W. Giblin and Richard J. Roiger and David J. Haglin and William S. Paciesas and Charles A. Meegan},
  journal={The Astrophysical Journal},
  year={2003},
  volume={582},
  pages={320 - 329}
}
Unsupervised pattern-recognition algorithms support the existence of three gamma-ray burst classes: class 1 (long, large-fluence bursts of intermediate spectral hardness), class 2 (short, small-fluence, hard bursts), and class 3 (soft bursts of intermediate durations and fluences). The algorithms surprisingly assign larger membership to class 3 than to either of the other two classes. A known systematic bias has been previously used to explain the existence of class 3 in terms of class 1; this… 

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References

SHOWING 1-10 OF 36 REFERENCES

Gamma-Ray Burst Class Properties

Guided by the supervised pattern recognition algorithm C4.5 developed by Quinlan in 1986, we examine the three gamma-ray burst classes identified by Mukherjee et al. in 1998. C4.5 provides strong

Three Types of Gamma-Ray Bursts

A multivariate analysis of gamma-ray burst (GRB) bulk properties is presented to discriminate between distinct classes of GRBs. Several variables representing burst duration, fluence, and spectral

Reclassification of gamma-ray bursts

ABSTRACT We have applied two different automatic classifier algorithms to the BATSE CurrentGRB Catalog data and we obtain three different classes of GRBs. Our results confirmthe existence of a third,

Brightness-independent Measurements of Gamma-Ray Burst Durations

We demonstrate that a brightness bias exists in the third BATSE catalog duration measurements of cosmic gamma-ray bursts. This bias, caused by the fact that the outlying emission from bright bursts

Frequency of fast, narrow γ-ray bursts

Early studies of the time histories of the γ-ray burst events reported by the Vela satellites led to the suggestion that very brief, ∼ 0.1 s, bursts formed a class distinct from the longer, highly

The Hardness-Intensity Correlation in Bright Gamma-Ray Bursts

The presence of a hardness-intensity correlation (HIC) is demonstrated in a sample of 77 bright bursts observed by the Phebus and Ulysses gamma-ray burst (GRB) experiments. Using simulations, we find

Identification of two classes of gamma-ray bursts

We have studied the duration distribution of the gamma-ray bursts of the first BATSE catalog. We find a bimodality in the distribution, which separates GRBs into two classes: short events (less than

Classifying Gamma-Ray Bursts using Self-organizing Maps

Using the self-organizing map (SOM) algorithm developed by Kohonen in 1982, we investigate the three gamma-ray burst classes discovered by Mukherjee et al. in 1998 and classify the bursts in the

Correlations between various hardness ratios of gamma-ray bursts

We study correlations between various hardness ratios of gamma-ray bursts (GRBs) and investigate if there are any differences between the short- and long-duration classes of the objects in the

A Principal Component Analysis of the 3B Gamma-Ray Burst Data

We have carried out a principal component analysis for 625 gamma-ray bursts in the BATSE 3B catalog for which nonzero values exist for the nine measured variables. This shows that only two out of the