A further study of $t_{\mathrm{burst}}$ of GRBs: rest frame properties, external plateau contributions and multiple parameter analysis

Abstract

[Zhang 2014] propose to redefine the true GRB central engine activity duration, $t_{\mathrm{burst}}$, by considering the contributions from the prompt $\gamma$-ray emission, X-ray flare and internal plateau features. With a comprehensive study on a large sample of Swift GRBs, it is shown that the $t_{\mathrm{burst}}$ distribution in the observer frame consists of a bimodal feature, suggesting the existence of a new population of ultra-long GRBs. In this work, we make a series of further studies on $t_{\mathrm{burst}}$: we update the Swift GRB sample up to June 2016; we investigate the properties of $t_{\mathrm{burst}}$ distribution in the rest frame; we redefine $t_{\mathrm{burst}}$ by involving external plateau contributions; we make a multiple parameter analysis to investigate whether the bursts within the ultra-long population being statistically different in sense of other features besides the duration distribution. We find that for all situations, the distribution of $t_{\mathrm{burst}}$ requires two normal distributions in logarithmic space to provide a good fit, both in observer frame and rest frame. Considering the observational gap effect would not completely erase the bimodal distribution feature. However the bursts within the ultra-long population may have no statistically different in sense of other features besides the duration term. We thus suggest that if the ultra-long population of GRBs indeed exists, their central engine mechanism and radiation mechanism should be similar to the normal population, but they have longer central engine activity timescale.

arXiv commentAccepted for publication in ApJ

References in corpus (31)

• Collapsars - Gamma-Ray Bursts and Explosions in "Failed Supernovae"
• Methods and results of an automatic analysis of a complete sample of Swift-XRT observations of GRBs
• The Supernova -- Gamma-Ray Burst Connection
• Gamma-Ray Bursts as the Death Throes of Massive Binary Stars
• Are Gamma-Ray Bursts in Star Forming Regions?
• Physical processes shaping GRB X-ray afterglow lightcurves: theoretical implications from the Swift XRT observations
• The Physics of Gamma-Ray Bursts and Relativistic Jets
• Evidence for a Canonical GRB Afterglow Light Curve in the Swift/XRT Data
• Bright X-ray Flares in Gamma-Ray Burst Afterglows
• Refreshed Shocks and Afterglow Longevity in GRB
• Swift observations of GRB 070110: an extraordinary X-ray afterglow powered by the central engine
• A very luminous magnetar-powered supernova associated with an ultra-long gamma-ray burst
• A new population of ultra-long duration gamma-ray bursts
• A Comprehensive Analysis of the Swift/XRT Data: II. Diverse Physical Origins of the Shallow Decay Segment
• Impulsive and Varying Injection in GRB Afterglows
• A Complete Reference of the Analytical Synchrotron External Shock Models of Gamma-Ray Bursts
• Mass Fall-back and Accretion in the Central Engine of Gamma-Ray Bursts
• Collapsar Jets, Bubbles and Fe Lines
• Steepening of Afterglow Decay for Jets Interacting with Stratified Media
• Properties of Gamma-Ray Burst Progenitor Stars
• How Long does a Burst Burst?
• Giant X-ray Bump in GRB 121027A: Evidence for Fall-back Disk Accretion
• Blue Supergiant Model for Ultra-Long Gamma-Ray Burst with Superluminous-Supernova-Like Bump
• GRB 091024A and the nature of ultra-long gamma-ray bursts
• The ultra-long GRB 111209A - II. Prompt to afterglow and afterglow properties
• On the average Gamma-Ray Burst X-ray flaring activity
• A Comparative Study of Long and Short GRBs. I. Overlapping Properties
• Are Ultra-long Gamma-Ray Bursts different?
• Are Ultra-Long Gamma-Ray Bursts Caused by Blue Supergiant Collapsars, Newborn Magnetars, or White Dwarf Tidal Disruption Events?
• Black hole central engine for ultra-long gamma-ray burst 111209A and its associated supernova 2011kl
• Relation between the intrinsic and observed central engine activity time: implications for ultra-long GRBs

Cited by in corpus (7)

• The Optical/NIR afterglow of GRB 111209A: Complex yet not Unprecedented
• The shallow decay segment of GRB X-ray afterglow revisited
• Characteristics of Two-episode Emission Patterns in {\em Fermi} Long Gamma-Ray Bursts
• Outflows from black hole hyperaccretion systems: short and long-short gamma-ray bursts and "quasi-supernovae"
• The Prompt Emission of Gamma-Ray Bursts from the Wind of Newborn Millisecond Magnetars: A Case Study of GRB 160804A
• External Shock in a Multi-Bursting Gamma-ray Burst: Energy Injection Phase induced by the Later Launched Ejecta
• Comparative Statistical Analysis of Prompt and Afterglow X-Ray Flares in Gamma-Ray Bursts: Insights into Extended Central Engine Activity