Variability of the giant X-ray bump in GRB 121027A and its possible origin

Hou, Shu-Jin; Liu, Tong; Gu, Wei‐Min; Lin, Da-Bin; Li, Yaping; Men, Yunpeng; Wu, Xue-Feng; Lei, Wei‐Hua; Lu, Junhui

doi:10.1093/mnras/stu682

Cited by 20 publications

(14 citation statements)

References 44 publications

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“…Pruet et al (2004a) adopted a steady-state wind model to simulate the outflow and found that the electron fractions depend on the viscosity and accretion rate of the disk. Most recently, the detailed properties of the jet or outflow ejected by the system of accretion disk and black hole have been improved by many works (Hou et al 2014;Liu et al 2010;Reynoso et al 2006, etc. ), which can explain the shapes of observed profiles for a wide variety of GRBs.…”

Section: Discussionmentioning

confidence: 99%

Elemental abundances associated with gamma-ray bursts: nucleosynthesis in outflows

Tao

2015

A&A

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Aims. Outflows from accretion disks have been suggested to be suitable sites for producing heavy elements. The objective of this work is to investigate nucleosynthesis in the outflows launched from the inner accretion disks of collapsars that are associated with gamma-ray bursts (GRBs). Methods. By using a collapsar model of advection-dominated accretion and an adiabatic expanding outflow model, we simulated chemical yields inside the outflows associated with GRBs. As a result of the extremely high temperature (above 10 10 K), the dominated species existing in the inner region of the disk are proton, neutron, 2 H, and 4 He, which are photodisintegrated from heavy nuclei. Assuming that an explosive nucleosynthesis could operate in outflows from collapsar accretions associated with GRBs, heavier species including the iron-group will be synthesized significantly. Although various outflow models have been investigated carefully in the past, the uncertainties in predicting the outflow birthplace (ejected-radius r j ) in the accretion disk are still quite large. Unlike recent researches on this topic that located the production of heavy elements in GRBs in the outer parts of the disk, in this study we focus our attention mainly on the outflows triggered from the inner region of collapsar accretion. Results. We find 56 Ni can be abundantly produced in all the outflow cases considered here from the inner collapsar disk. The highest 56 Ni's mass fraction in the outflows reaches 0.463, which can imply that the 56 Ni-rich outflows will lead to an observable violent explosion of a GRB event. The mass fractions of 57 Ni, 59 Cu (decays to 59 Ni), and 60 Zn (decays to 60 Ni) could be 10 −2 , and the abundance of 58 Ni reaches 10 −3 . Our simulations support that the effective production of heavy elements can occur in the outflows from the inner regions of the collapsar accretion disks. Our results also show that the amount of heavy species produced in outflows depends on the eject-radius r j of the accretion disk where the outflows take place; outflows launched at larger radii can be helpful to increase the quantities of heavy nuclei by means of the lower disk temperature, which agrees with the conclusions of recent studies. Furthermore, a recently published article reported that some nuclei, such as 28 Si, 32 S, 36 Ar, 40 Ca, 44 Ti, 48 Cr, 54 Fe, and 55−56 Co, experience a dip and then rise in their mass fraction while evolving in the outflow, and this characteristic behavior has occurred in many more outflow cases, and this is reported for the first time in the literature. This characteristic phenomenon also occurs in our nucleosynthetic simulations.

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Section: Discussionmentioning

confidence: 99%

Elemental abundances associated with gamma-ray bursts: nucleosynthesis in outflows

Tao

2015

A&A

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“…These types of massive stars (M ≥ 100 M ), which are thought to form in the early Universe at low metallicity (Z ∼ 10 −4 Z ), have also been proposed as progenitor of the so-called ultra-long GRBs (Salvaterra et al 2013;Ma et al 2015), i.e. GRB 111209A (Gendre et al 2013), GRB 121027A (Hou et al 2014), and GRB 130925A (Evans et al 2014).…”

Section: Pop III or Enriched Pop Ii Progenitormentioning

confidence: 99%

The high-redshift gamma-ray burst GRB 140515A

Melandri

Bernardini

D’Avanzo

et al. 2015

A&A

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High-redshift gamma-ray bursts (GRBs) offer several advantages when studying the distant Universe, providing unique information about the structure and properties of the galaxies in which they exploded. Spectroscopic identification with large ground-based telescopes has improved our knowledge of this kind of distant events. We present the multi-wavelength analysis of the high-z Swift GRB GRB 140515A (z = 6.327). The best estimate of the neutral hydrogen fraction of the intergalactic medium towards the burst is x HI ≤ 0.002. The spectral absorption lines detected for this event are the weakest lines ever observed in GRB afterglows, suggesting that GRB 140515A exploded in a very low-density environment. Its circum-burst medium is characterised by an average extinction (A V ∼ 0.1) that seems to be typical of z ≥ 6 events. The observed multi-band light curves are explained either with a very hard injected spectrum (p = 1.7) or with a multi-component emission (p = 2.1). In the second case a long-lasting central engine activity is needed in order to explain the late time X-ray emission. The possible origin of GRB 140515A in a Pop III (or in a Pop II star with a local environment enriched by Pop III) massive star is unlikely.

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“…Observations with the Swift and Fermi satellites show that following the steep decline, many GRBs exhibit flares (e.g., Burrows et al 2005;Zhang et al 2006;Chincarini et al 2007;Falcone et al 2007;Yi et al 2016, giant bumps (e.g., Wu, Hou & Lei 2013;Hou et al 2014) or plateaus (e.g., Troja et al 2007;Liang, Zhang & Zhang 2007;Corsi & Mészáros 2009;Rowlinson et al 2013) in their X-ray light curves. These phenomena are closely related to the late-time activities of the GRB central engines (e.g., Bernardini et al 2011;Liu, Gu & Zhang 2017;Liu 2018Liu , 2019.…”

Section: Conclusion and Discussionmentioning

confidence: 99%

Neutrinos and gravitational waves from magnetized neutrino-dominated accretion discs with magnetic coupling

Song

Liu

Wei

2020

Monthly Notices of the Royal Astronomical Society

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Gamma-ray bursts (GRBs) might be powered by a black hole (BH) hyperaccretion systems via the Blandford-Znajek (BZ) mechanism or neutrino annihilation from neutrino-dominated accretion flows (NDAFs). Magnetic coupling (MC) between the inner disc and BH can transfer angular momentum and energy from the fast-rotating BH to the disc. The neutrino luminosity and neutrino annihilation luminosity are both efficiently enhanced by the MC process. In this paper, we study the structure, luminosity, MeV neutrinos, and gravitational waves (GWs) of magnetized NDAFs (MNDAFs) under the assumption that both the BZ and MC mechanisms are present. The results indict that the BZ mechanism will compete with the neutrino annihilation luminosity to trigger jets under the different partitions of the two magnetic mechanisms. The typical neutrino luminosity and annihilation luminosity of MNDAFs are definitely higher than those of NDAFs. The typical peak energy of neutrino spectra of MNDAFs is higher than that of NDAFs, but similar to those of core-collapse supernovae. Moreover, if the MC process is dominant, then the GWs originating from the anisotropic neutrino emission will be stronger particularly for discs with high accretion rates.

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Variability of the giant X-ray bump in GRB 121027A and its possible origin

Cited by 20 publications

References 44 publications

Elemental abundances associated with gamma-ray bursts: nucleosynthesis in outflows

Elemental abundances associated with gamma-ray bursts: nucleosynthesis in outflows

The high-redshift gamma-ray burst GRB 140515A

Neutrinos and gravitational waves from magnetized neutrino-dominated accretion discs with magnetic coupling

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