The Formation and Merger of Compact Objects in the Central Engine of Active Galactic Nuclei and Quasars: Gamma‐Ray Burst and Gravitational Radiation

Cheng, K. S.; Wang, Jianmin

doi:10.1086/307572

Cited by 49 publications

(40 citation statements)

References 63 publications

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“…It has also been argued that GRBs might be associated with some types of quasars, such as radio‐quiet quasars (Scharted, Andernach & Greiner 1997) and metal‐rich quasars (Cheng et al 1997; Cheng & Wang 1999). There are two classes of quasars, i.e.…”

Section: Introductionmentioning

confidence: 99%

A possible energy mechanism for cosmological -ray bursts

Cheng

2001

Monthly Notices of the Royal Astronomical Society

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We suggest that an extreme Kerr black hole with a mass ∼106 M⊙, a dimensionless angular momentum and a marginally stable orbital radius located in a normal galaxy may produce a γ‐ray burst (GRB) by capturing and disrupting a star. During the capture period, a transient accretion disc is formed and a strong transient magnetic field ∼ lasting for may be produced at the inner boundary of the accretion disc. A large amount of rotational energy of the black hole is extracted and released in an ultrarelativistic jet with a bulk Lorentz factor Γ larger than 103 via the Blandford–Znajek process. The relativistic jet energy can be converted into γ‐radiation via an internal shock mechanism. The GRB duration should be the same as the lifetime of the strong transient magnetic field. The maximum number of sub‐bursts is estimated to be because the disc material is likely to break into pieces with a size about the thickness of the disc h at the cusp The shortest risetime of the burst estimated from this model is ∼ The model GRB density rate is also estimated.

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Section: Introductionmentioning

confidence: 99%

A possible energy mechanism for cosmological -ray bursts

Cheng

2001

Monthly Notices of the Royal Astronomical Society

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“…An active galactic nucleus (AGN) origin is another possibility, whereby a main-sequence (MS) or white-dwarf (WD) is tidally disrupted near a super-massive black hole. In such scenarios, however, the variability timescale still requires the energy source to be stellar-mass objects (Carter 1992;Cheng & Wang 1999).…”

Section: Proposed Grb Progenitor Scenariosmentioning

confidence: 99%

Toward an Understanding of the Progenitors of Gamma‐Ray Bursts

Bloom¹

2003

PUBL ASTRON SOC PAC

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The various possibilities for the origin ("progenitors") of gamma-ray bursts (GRBs) manifest in differing observable properties. Through deep spectroscopic and high-resolution imaging observations of some GRB hosts, I demonstrate that well-localized long-duration GRBs are connected with otherwise normal star-forming galaxies at moderate redshifts of order unity. Using high-mass binary stellar population synthesis models, I quantify the expected spatial extent around galaxies of coalescing neutron stars, one of the leading contenders for GRB progenitors. I then test this scenario by examining the offset distribution of GRBs about their apparent hosts making extensive use of ground-based optical data from Keck and Palomar and space-based imaging from the Hubble Space Telescope. The offset distribution appears to be inconsistent with the coalescing neutron star binary hypothesis (and, similarly, blackhole-neutron star coalescences); instead, the distribution is statistically consistent with a population of progenitors that closely traces the ultraviolet light of galaxies. This is naturally explained by bursts which originate from the collapse of massive stars ("collapsars"). This claim is further supported by the unambiguous detections of intermediate-time (approximately three weeks after the bursts) emission "bumps" which appear substantially more red than the afterglows themselves. I claim that these bumps could originate from supernovae that occur at approximately the same time as the associated GRB; if true, GRB 980326 and GRB 011121 provide strong observational evidence connecting cosmological GRBs to high-redshift supernovae and implicate massive stars as the progenitors of at least some long-duration GRBs. Regardless of the true physical origin of these bumps, it appears that all viable alternative models of these bumps (such as dust scattering of the afterglow light) require a substantial amount of circumburst matter that is distributed as a wind-stratified medium; this too, implicates massive stars. Also suggested herein are some future observations which could further solidify or refute the supernova claim. In addition to the observational and modeling work, I also constructed the Jacobs Camera (JCAM), a dual-beam optical camera for the Palomar 200-inch Telescope designed to follow-up rapid GRB localizations. viii

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“…It can be understood why metal rich Quasars could be the host galaxies of GRBs in the following reasons (Cheng & Wang 1999). The production rate of compact objects, i.e.…”

Section: (Iii)accretion Onto Massive Black Holesmentioning

confidence: 99%

Gamma-Ray Bursts: Afterglows and Central Engines

Cheng

Liu

2001

Chin. J. Astron. Astrophys.

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Gamma-ray bursts (GRBs) are most intense transient gamma-ray events in the sky when they are on together with the strong evidences (i.e. the isotropic and inhomogeneous distribution of GRBs detected by BASTE) that they are located at cosmological distances, which make them the most energetic events ever known. For example, the observed radiation energies of some GRBs are equivalent to convert more than one solar mass energy into radiation completely. This is thousand times stronger than that of supernova explosion. Unconventional energy mechanisms and extremely high conversion efficiency for these mysterious events are required. The discovery of host galaxies and association with supernovae in the cosmological distances by the recently launched satellite of BeppoSAX and ground based radio and optical telescopes in GRB afterglow provides further support to the cosmological origin of GRBs and put strong constraints on central engines of GRBs. It is the aim of this article to review the possible central engines, energy mechanisms, dynamical and spectral evolution of GRBs, especially focusing on the afterglows in multi-wavebands.

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The Formation and Merger of Compact Objects in the Central Engine of Active Galactic Nuclei and Quasars: Gamma‐Ray Burst and Gravitational Radiation

Cited by 49 publications

References 63 publications

A possible energy mechanism for cosmological -ray bursts

A possible energy mechanism for cosmological -ray bursts

Toward an Understanding of the Progenitors of Gamma‐Ray Bursts

Gamma-Ray Bursts: Afterglows and Central Engines

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