Flares in Long and Short Gamma-Ray Bursts: A Common Origin in a Hyperaccreting Accretion Disk

By R. Perna, Philip Armitage, Bing Zhang. 2005

214 citations recorded by the source corpus.

Early-time X-ray observations of gamma-ray bursts (GRBs) with the Swift satellite have revealed a more complicated phenomenology than was known before. In particular, the presence of flaring activity on a wide range of timescales probably requires late-time energy production within the GRB engine. Since the flaring activity is observed in both long and short GRBs, its origin must be within what is in common for the two likely progenitors of the two classes of bursts: a hyperaccreting accretion disk around a black hole of a few solar masses. Here we show that some of the observational properties of the flares, such as the duration-timescale correlation, and the duration-peak luminosity anticorrelation displayed by most flares within a given burst, are qualitatively consistent with viscous disk evolution, provided that the disk at large radii either fragments or otherwise suffers large-amplitude variability. We discuss the physical conditions in the outer parts of the disk and conclude that gravitational instability, possibly followed by fragmentation, is the most likely candidate for this variability.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/007ccb2942478881dc63510d006ebd25a2bf9b29

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In Astronomy and Astrophysics

1. Bing Zhang
2. B. Metzger
3. E. Berger
4. Pawan Kumar
5. E. Liang
6. Binbin Zhang
7. E. Nakar
8. E. Ramirez-Ruiz

In Instrumentation

1. Bing Zhang
2. E. Liang
3. E. Berger
4. Pawan Kumar
5. L. Amati
6. Binbin Zhang
7. Stephan Rosswog
8. B. Metzger

Citations in the corpus

• The Ep,i–Eiso correlation in gamma-ray bursts: updated observational status, re-analysis and main implications (2006, background): “…the engine and/or late internal shocks (Fan & Wei 2005; Burrows et al. 2005; Wu et al. c© 2005 RAS, MNRAS 000, 1–15 The Ep,i – Eiso correlation in GRBs: update, re–analysis and main implications 11 2006; Perna et al. 2006; Proga & Zhang 2006) and thus can be considered part of the prompt emission.”
• Physical Processes Shaping Gamma-Ray Burst X-Ray Afterglow Light Curves: Theoretical Implications from the Swift X-Ray Telescope Observations (2005, background): “Perna et al. (2006) suggest that if the accretion disk is fragmented into blobs or otherwise has largeamplitude density fluctuation at large radii from the central engine, the viscous disk evolution would cause more spread for blobs farther out from the central engine.”
• Gamma-ray burst afterglows (2006, background): “The requirement that both long and short GRBs should produce X-ray flares with similar properties prompted Perna et al. (2006) to suggest that fragmentation in the accretion disk, the common ingredient in both long and short GRB models, may be the agent for episodic accretion that power the flares.”
• Making a Short Gamma-Ray Burst from a Long One: Implications for the Nature of GRB 060614 (2006, background): “Alternatively, disk fragmentation (Perna et al. 2006) or magnetic field barrier near the accretor (Proga & Zhang 2006) would induce intermittent accretion that power the flares.”
• Neutrino-dominated accretion flows as the central engine of gamma-ray bursts (2017, background): “The criterion, Q < 1, indicates that the disk is gravitationally unstable, which may cause two classes of possible behaviors (e.g., Perna et al. 2006): (1) If the local cooling of the disk is rapid, the disk may fragment into two or more parts (e.g., Nelson 2000).”
• FORMATION OF STABLE MAGNETARS FROM BINARY NEUTRON STAR MERGERS (2013, background): “…hard to explain if all the BNS mergers produce an HMNS which collapses to a BH in less than ∼ 1s; the remnant torus is also expected to be completely accreted on the same timescale (Rezzolla et al. 2011), unless magnetic or gravitational instabilities set in (Proga & Zhang 2006; Perna et al. 2006).”
• Swift Observations of GRB 070110: An Extraordinary X-Ray Afterglow Powered by the Central Engine (2007, background): “…X-ray flares therefore require that the central engine accretes episodically, either due to fragmentation or density fluctuation of the accretion disc (e.g. King et al. 2005; Perna et al. 2006; Rosswog 2006), or due to modulation of the magnetic fields near the accretor (Proga & Zhang 2006).”
• The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/Virgo GW170817. V. Rising X-Ray Emission from an Off-axis Jet (2017, background): “Short GRBs are sometimes accompanied by late-time X-ray emission (e.g., Perley et al. 2009; Margutti et al. 2011; Fong et al. 2014), which may originate from a long-lived central engine, such as an accreting black hole (e.g., Perna et al. 2006) or a millisecond magnetar (e.g., Metzger et al. 2008).”
• A Comprehensive Analysis of Swift XRT Data. II. Diverse Physical Origins of the Shallow Decay Segment (2007, background): “…University of Nevada, Las Vegas, NV 89154, USA; lew@physics.unlv.edu; zbb@physics.unlv.edu;bzhang@physics.unlv.edu 2 Department of Physics, Guangxi University, Nanning 530004, China 3 National Astronomical Observatories/Yunnan Observatory, CAS, Kunming 650011, China 2006; Perna et al. 2006).”
• Gamma-Ray Bursts in the Swift Era (2009, background): “…the flow patterns near relativistic objects accreting matter in the hypercritical regime (Di Matteo et al. 2002, Chen and Beloborodov 2007, Proga and Zhang 2006, Perna et al. 2006, Shibata et al. 2007, Kumar et al. 2008), where photons are unable to provide cooling but neutrinos do so efficiently.”
• DISCERNING THE PHYSICAL ORIGINS OF COSMOLOGICAL GAMMA-RAY BURSTS BASED ON MULTIPLE OBSERVATIONAL CRITERIA: THE CASES OF z = 6.7 GRB 080913, z = 8.2 GRB 090423, AND SOME SHORT/HARD GRBs (2009, background): “The progenitor and central engine models must then be modified to invoke a much longer accretion time scale (King et al. 2005; Perna et al. 2006; Proga & Zhang 2006), or a non-BH-torus central engine (Dai et al. 2006; Staff et al. 2007).”
• Fallback accretion in the aftermath of a compact binary merger (2006, background): “Perna et al. (2006) have suggested that such a fragmentation in the outskirts of an accretion disk could be the common mechanism behind the flaring observed in both long and short bursts.”
• The physics of gamma-ray bursts & relativistic jets (2014, background): “[748] argued that the outer part of accretion disk, for long and short GRBS, is susceptible to gravitational instability and could fragment into clumps, and the accretion of these clumps produces X-ray flares; short GRBs require some extreme conditions for this mechanism to work.”