GRB 201104A: A "Repetitive" Short Gamma-Ray Burst?

Abstract

Gamma-ray bursts (GRBs) are divided into short gamma-ray bursts (SGRBs) and long gamma-ray bursts (LGRBs) based on the bimodal distribution of their durations. LGRBs and SGRBs are typically characterized by different statistical characteristics. Nevertheless, there are some samples that challenge such a framework, such as GRB 060614, a long-duration burst with short-burst characteristics. Furthermore, GRBs are generally considered to be an event with no periodic or repetitive behavior, since the progenitors usually undergo destructive events, such as massive explosions or binary compact star mergers. In this work, we investigated Fermi data for possible quasiperiodic oscillations and repetitive behaviors of GRBs using timing analysis methods and report a special event GRB 201104A, which is a long-duration burst with the characteristics of an SGRB, and it exhibits a "repetitive" behavior. We propose that such a situation may arise from lensed SGRBs and attempt to verify it by Bayesian inference. In addition, we extend the spectral analysis to Bayesian inference. In spite of the existence of at least two distinct time periods with a nearly identical spectrum, there is no strong evidence that they result from a lensing GRB. Taking the gravitational-lensing scenario out of consideration, a long burst would resemble a short burst in its repetitive behavior, which presents a challenge for the current classification scheme.

15 pages, 6 figures, 2 tables; Accepted for publication in ApJ

References in corpus (21)

• Array Programming with NumPy
• An Ordinary Short Gamma-Ray Burst with Extraordinary Implications: Fermi-GBM Detection of GRB 170817A
• The Physics of Gamma-Ray Bursts and Relativistic Jets
• Long gamma-ray bursts and core-collapse supernovae have different environments
• The optically unbiased GRB host (TOUGH) survey. I. Survey design and catalogs
• A Comprehensive Analysis of Fermi Gamma-ray Burst Data: II. $E_{\mathrm{p}}$-Evolution Patterns and Implications for the Observed Spectrum-Luminosity Relations
• Discovery and confirmation of the shortest gamma ray burst from a collapsar
• The Ep,i - Eiso correlation: type I gamma-ray bursts and the new classification method
• A Peculiarly Short-duration Gamma-Ray Burst from Massive Star Core Collapse
• The peculiar short-duration GRB 200826A and its supernova
• Are LGRBs biased tracers of star formation? Clues from the host galaxies of the $Swift$/BAT6 complete sample of bright LGRBs III: Stellar masses, star formation rates and metallicities at $z>1$
• Comparing the spectral lag of short and long gamma-ray bursts and its relation with the luminosity
• On the Spectral Lags of the Short Gamma-Ray Bursts
• Evidence for an intermediate-mass black hole from a gravitationally lensed gamma-ray burst
• A deep survey of short GRB host galaxies over $z\sim 0-2$: implications for offsets, redshifts, and environments
• A Comparative Study of Long and Short GRBs. I. Overlapping Properties
• A Comprehensive Power Spectral Density Analysis of Astronomical Time Series. II. The Swift/BAT Long Gamma-Ray Bursts
• GRB 200716C: Evidence for a Short Burst Being Lensed
• Discovery of the optical afterglow and host galaxy of short GRB181123B at $z=1.754$: Implications for Delay Time Distributions
• A Search for Millilensing Gamma-Ray Bursts in the Observations of Fermi GBM
• Hardness Test of GRB 950830 as a Gravitationally Lensed Echo

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