Gamma-ray burst taxonomy: looking for the third class on the spectral peak energy-duration plane in the rest frame
arXiv:2504.20263 · doi:10.1051/0004-6361/202452673
Abstract
Two classes of Gamma-ray bursts (GRBs), corresponding to the short/hard and the long/soft events, with a putative intermediate class, are typically considered in the observer frame. However, when considering GRB characteristics in the cosmological rest frame, the boundary between the classes becomes blurred. The goal of this research is to check for the evidences of a third "intermediate" class of GRBs and investigate how the transformation from the observer to the rest frame affects the hardness-duration-based classification. We applied fits with skewed and non-skewed (symmetric) Gaussian and Student distributions to the sample of 409 GRBs with reliably measured redshifts to cluster the bursts on the hardness (Ep) - duration (T90) plane. We found that, based on AIC/BIC criteria, the statistically preferred number of clusters on the GRB rest-frame hardnesses-duration plane does not exceed two. We also assess the robustness of the clustering technique. We did not find any solid evidence of an intermediate GRB class on the rest-frame hardness-duration plane.
22 pages, 4 figures, 15 tables, A&A accepted
References in corpus (28)
- The Supernova -- Gamma-Ray Burst Connection
- Statistical applications of the multivariate skew-normal distribution
- Distributions generated by perturbation of symmetry with emphasis on a multivariate skew distribution
- Discerning the physical origins of cosmological Gamma-ray bursts based on multiple observational criteria: the cases of z=6.7 GRB 080913, z=8.3 GRB 090423, and some short/hard GRBs
- A Kilonova Following a Long-Duration Gamma-Ray Burst at 350 Mpc
- A nearby long gamma-ray burst from a merger of compact objects
- A long-duration gamma-ray burst with a peculiar origin
- JWST detection of heavy neutron capture elements in a compact object merger
- The optically unbiased GRB host (TOUGH) survey. I. Survey design and catalogs
- The First Swift BAT Gamma-Ray Burst Catalog
- The Ep,i - Eiso correlation: type I gamma-ray bursts and the new classification method
- The Konus-Wind catalog of gamma-ray bursts with known redshifts. I. Bursts detected in the triggered mode
- Uncovering the Intrinsic Variability of Gamma-ray Bursts
- The Afterglow and Early-Type Host Galaxy of the Short GRB 150101B at z=0.1343
- The Konus-Wind catalog of gamma-ray bursts with known redshifts. II. Waiting mode bursts simultaneously detected by Swift/BAT
- An Unambiguous Separation of Gamma-Ray Bursts into Two Classes from Prompt Emission Alone
- Statistical Study of Observed and Intrinsic Durations among BATSE and Swift/BAT GRBs
- Classification of Gamma-Ray Burst durations using robust model-comparison techniques
- GRB minimum variability timescale with Insight-HXMT and Swift: implications for progenitor models, dissipation physics and GRB classifications
- Searching for differences in Swift's intermediate GRBs
- A long optical plateau in the afterglow of the Extended Emission short GRB 150424A: Evidence for energy injection by a magnetar?
- Evidence for two distinct populations of kilonova-associated Gamma Ray Bursts
- Late-Time VLA Reobservations Rule Out ULIRG-Like Host Galaxies For Most Pre-Swift Long-Duration Gamma-Ray Bursts
- A Comparative Study of Long and Short GRBs. II. A Multi-wavelength Method to distinguish Type II (massive star) and Type I (compact star) GRBs
- Two Dimensional Classification of the Swift/BAT GRBs
- Multivariate analysis of BATSE gamma-ray burst properties using skewed distributions
- Investigating signatures of cosmological time dilation in duration measures of prompt gamma-ray burst light curves
- On the temporal variability classes found in long gamma-ray bursts with known redshift