We explore the influence of non-axisymmetric modes on the dynamics of the collapsed core of rotating, magnetized high-mass stars in three-dimensional simulations of a rapidly rotating star with an initial mass of $M_{ZAMS}$ = 35 solar masses endowed with four different pre-collapse configurations of the magnetic field, ranging from moderate to very strong field strength and including the field predicted by the stellar evolution model. The model with the weakest magnetic field achieves shock revival due to neutrino heating in a gain layer characterized by a large-scale, hydrodynamic m = 1 spiral mode. Later on, the growing magnetic field of the proto-neutron star launches weak outflows into the early ejecta. Their orientation follows the evolution of the rotational axis of the proto-neutron star, which starts to tilt from the original orientation due to the asymmetric accretion flows impinging on its surface. The models with stronger magnetization generate mildly relativistic, magnetically driven polar outflows propagating over a distance of $10^4$ km within a few 100 ms. These jets are stabilized against disruptive non-axisymmetric instabilities by their fast propagation and by the shear of their toroidal magnetic field. Within the simulation times of around 1 s, the explosions reach moderate energies and the growth of the proto-neutron star masses ceases at values substantially below the threshold for black hole formation, which, in combination with the high rotational energies, might suggest a possible later proto-magnetar activity.
We investigate the explosion of stars with zero-age main-sequence masses between 20 and 35 solar masses and varying degrees of rotation and magnetic fields including ones commonly considered progenitors of gamma-ray bursts (GRBs). The simulations, combining special relativistic magnetohydrodynamics, a general relativistic approximate gravitational potential, and two-moment neutrino transport, demonstrate the viability of different scenarios for the post-bounce evolution. Having formed a highly massive proto-neutron star (PNS), several models launch successful explosions, either by the standard…
The final collapse of the cores of massive stars can lead to a wide variety of outcomes in terms of electromagnetic and kinetic energies, nucleosynthesis, and remnants. The connection of this wide spectrum of explosion and remnant types to the properties of the progenitors remains an open issue. Rotation and magnetic fields in Wolf-Rayet stars of subsolar metallicity may explain extreme events such as superluminous supernovae and gamma-ray bursts powered by proto-magnetars or collapsars. Continuing numerical studies of magnetorotational core collapse including detailed neutrino physics, we foc…
Gravitational waves from magnetorotational core-collapse supernovae using 3D GRMHD simulations: effect of rotation and magnetic fields
Max-Planck-Institut für Astrophysik（马克斯·普朗克天体物理研究所）；University of Amsterdam（阿姆斯特丹大学）；University of Hamburg（汉堡大学）；University of Tennessee（田纳西大学）；GRAPPA, University of Amsterdam（阿姆斯特丹大学引力、暗物质和粒子物理中心）；IoP, University of Amsterdam（阿姆斯特丹大学物理系）；University of British Columbia（不列颠哥伦比亚大学）；National Center for Supercomputing applications, University of Illinois（伊利诺伊大学国家超级计算应用中心）；University of Illinois（伊利诺伊大学）
Phenomenologically, two classes of GRBs (long/soft vs. short/hard) are identified based on their gamma-ray properties. The boundary between the two classes is vague. Multi-wavelength observations lead to identification of two types of GRB progenitor: one related to massive stars (Type II), and another related to compact stars (Type I). Evidence suggests that the majority of long GRBs belong to Type II, while at least the majority of nearby short GRBs belong to Type I. Nonetheless, counter examples do exist. Both long-duration Type I and short-duration Type II GRBs have been observed. In this t…
The long gamma ray bursts (GRBs) may arise from the core collapse of massive stars. However, the long GRB rate does not follow the star formation rate (SFR) at high redshifts. In this Letter, we focus on the binary merger model and consider the high spin helium stars after the merger as the progenitor of long GRBs. With this scenario, we estimate the GRB rate by the population synthesis method with the metallicity evolution. Low metallicity binaries are easier to become long GRB progenitors than those for solar metallicity due to the weak wind mass loss and the difference in the stellar evolut…
Progenitors of long GRBs, and core-collapse supernovae in general, may have two separate mechanisms driving the outflows: quasi-isotropic neutrino-driven supernova explosions followed by a highly collimated relativistic outflow driven by the GRB central engine, a black hole or a magnetar. We consider the dynamics of the second GRB-driven explosion propagating through expanding envelope generated by the passage of the primary supernova shock. Beyond the central core, in the region of steep density gradient created by the SN shock breakout, the accelerating secondary quasi-spherical GRB shock be…
The characteristics of the Gamma-Ray Bursts (GRBs) environment may reflect the differences in GRB progenitors: long GRBs are expected to be found in high-density star-forming regions of the GRB host galaxies, while short ones may be associated with an older stellar population that may have had the time to travel far from stellar forming regions in potentially lower density regions. The latter is related to the hypothesis that short GRBs are associated to the merging of compact objects (BH-NS or NS-NS). We used the Swift XRT GRB afterglow archive to compare the intrinsic neutral hydrogen column…
The physical origin of fast radio bursts (FRBs) is unknown. Young magnetars born from gamma-ray bursts (GRBs) have been suggested to be a possible central engine of FRBs. We test such a hypothesis by systematically searching for GRB-FRB spatial associations from 110 FRBs and 1440 GRBs. We find that one FRB event, FRB 171209, discovered by the Parkes telescope is spatially coincident with a historical long-duration GRB 110715A at $z=0.82$. The afterglow of GRB 110715A is consistent with being powered by a millisecond magnetar. The extragalactic dispersion measure of FRB 171209 is in excess of t…
During the last 15 years, a standard paradigm has emerged to explain both the progenitor nature and the observed radiations of gamma-ray bursts. In this work we show three GRBs for which the standard paradigm could be tested with high statistics due to their exceptional spectral and temporal coverage. While GRB 1110205 represents a very good example of the standard scenario, GRB 090102 and GRB 111209A do not fit into the standard paradigm.
GRBs are the most energetic electromagnetic events in the Universe. Those whose typical duration is longer than a few seconds are known as long GRBs and shorter than a few seconds are short GRBs. It is widely accepted that these events are associated with the collapse of a very massive star and the neutron star (NS) binary merger, respectively. A fast-spinning, strongly magnetized NS could be expected before a black hole (BH) in both scenarios. We allude to the thermal neutrinos' particular properties propagating inside the fireball for differentiating both scenarios in this work. We first der…
The study of short-duration gamma-ray bursts (GRBs) has undergone a revolution in recent years thanks to the discovery of the first afterglows and host galaxies in May 2005. In this review we summarize our current knowledge of the galactic and sub-galactic environments of short GRBs, and the implications for the progenitor population. The most crucial results are: (i) some short GRBs occur in elliptical galaxies; (ii) the majority of short GRBs occur in star forming galaxies; (iii) the star forming hosts of short GRBs are distinct from the host galaxies of long GRBs in terms of star formation …
GRB 121027A is un-usual with its extremely long-lasting, energetic X-ray flares. The total energy release in X-ray flares is about one order of magnitude higher than prompt gamma-rays, making it special from most long GRBs. We show that while the prompt gamma-ray emission satisfies the empirical E_{iso}-E_{p} relation of typical long GRBs, the X-ray flares, whose spectra can be fit with a cutoff-power-law model with well-constrained E_p, significantly deviate from such a relation. Nonetheless, a time-resolved spectral analysis of X-ray flares suggest that the X-ray emission is consistent with …
GRB 230204B: GIT Discovery of a Fast Fading Afterglow Associated with an Energetic GRB from a Massive-Star Progenitor
Indian Institute of Technology Bombay（印度理工学院孟买分校）；Center for Astrophysics | Harvard & Smithsonian（哈佛-史密森天体物理中心）；University of Johannesburg（约翰内斯堡大学）；National Radio Astronomy Observatory（美国国家射电天文台）
GRB 230204B 是由高能 GRB 产生的致密星前身，其快速衰减的后光子和高能喷流特征表明其喷流在风型介质中扩展。
The properties of a massive star prior to its final explosion are imprinted in the circumstellar medium (CSM) created by its wind and termination shock. We perform a detailed, comprehensive calculation of the time-variable and angle-dependent transmission spectra of an average-luminosity Gamma-Ray Burst (GRB) which explodes in the CSM structure produced by the collapse of a 20 Msun, rapidly rotating, Z=0.001 progenitor star. We study both the case in which metals are initially in the gaseous phase, as well as the situation in which they are heavily depleted into dust. We find that high-velocit…
While there is mounting evidence that long Gamma-Ray Bursts (GRBs) are associated with the collapse of massive stars, the detailed structure of their pre-supernova stage is still debatable. Particularly uncertain is the degree of mixing among shells of different composition, and hence the role of magnetic torques and convection in transporting angular momentum. Here we show that early-time afterglow observations with the Swift satellite place constraints on the allowed GRB pre-supernova models. In particular, they argue against pre-supernova models in which different elemental shells are unmix…
We assess the variance of the post-collapse evolution remnants of compact, massive, low-metallicity stars, under small changes in the degrees of rotation and magnetic field of selected pre-supernova cores. These stellar models are commonly considered progenitors of long gamma-ray bursts. The fate of the proto-neutron star (PNS) formed after collapse, whose mass may continuously grow due to accretion, critically depends on the poloidal magnetic field strength at bounce. Should the poloidal magnetic field be sufficiently weak, the PNS collapses to a black hole (BH) within a few seconds. Models o…
[Abridged] The study of short-duration gamma-ray bursts (GRBs) experienced a complete revolution in recent years thanks to the discovery of the first afterglows and host galaxies in May 2005. These observations demonstrated that short GRBs are cosmological in origin, reside in both star forming and elliptical galaxies, are not associated with supernovae, and span a wide isotropic-equivalent energy range of ~10^48-10^52 erg. However, a fundamental question remains unanswered: What are the progenitors of short GRBs? The most popular theoretical model invokes the coalescence of compact object bin…
Gamma-ray bursts (GRB) are the most intense electromagnetic (EM) sources in the Universe. Long GRB (LGRB) correspond to those events with a typical prompt emission of more than a few seconds. It is generally assumed that they are originated after an implosion of a very massive star within a central compact object engine that can be either a black hole (BH) or a rapidly-spinning highly-magnetized neutron star (NS). Nevertheless, one of the most challenging aspects of defining a unique model is that the progenitor remains initially hidden for direct EM observation. In this work, we investigate t…
The dissipation process of GRB prompt emission is still unknown. Study of temporal variability may provide a unique way to discriminate the imprint of the inner engine activity from geometry and propagation related effects. We define the minimum variability timescale (MVT) as the shortest duration of individual pulses that shape a light curve for a sample of GRBs and test correlations with peak luminosity, Lorentz factor, and jet opening angle. We compare these correlations with predictions from recent numerical simulations for a relativistic structured -- possibly wobbling -- jet and assess t…
After the detection of GRB 170817A, the first unambiguous off-axis gamma-ray burst (GRB), several studies tried to understand the structure of GRB jets. The initial jet structure (directly produced by the central engine) can be partially preserved, or can be completely modified by the interaction with the environment. In this study, we perform three-dimensional, special relativistic hydrodynamics simulations of long GRB jets evolving through a massive progenitor star. Different jet scenarios were considered: Top-hat, Gaussian jets dominated by pressure or by kinetic energy, as well as a model …
GRB 130925A is a peculiar event characterized by an extremely long gamma-ray duration ($\approx$7 ks), as well as dramatic flaring in the X-rays for $\approx$20 ks. After this period, its X-ray afterglow shows an atypical soft spectrum with photon index $Γ$$\sim$4, as observed by Swift and Chandra, until $\approx 10^7$ s, when XMM-Newton observations uncover a harder spectral shape with $Γ$$\sim$2.5, commonly observed in GRB afterglows. We find that two distinct emission components are needed to explain the X-ray observations: a thermal component, which dominates the X-ray emission for several…
We explore the possibility that radio loud gamma-ray bursts (GRBs) result from the collapse of massive stars in interacting binary systems, while radio quiet GRBs are produced by the collapse of single massive stars. A binary collapsar system can have the necessary angular momentum and energy budget to explain the longer prompt gamma-ray durations and higher isotropic energies seen in the the radio loud sub-sample of long GRBs. Additionally binary systems can lead to rich and extended circumstellar environments that allow for the presence of the long-lived radio afterglows seen in the radio lo…
The origin of gamma-ray bursts (GRBs) is still a fascinating field of research nowadays. While we have been collecting more and more observationally constrained properties of GRB-physics, new theoretical results on the progenitor evolution (be it stellar or compact object) have also emerged. I review some of the most promising progenitor theories for forming a short-duration GRB. A special emphasis is put on the hypothetical case of forming a short-duration GRB through the double black hole merger scenario -- in which case we may expect to observe a gravitational wave emission too. The chemica…
Recently, the first association between an ultra-long gamma-ray burst (GRB) and a supernova is reported, i.e., GRB 111209A/SN 2011kl, which enables us to investigate the physics of central engines or even progenitors for ultra-long GRBs. In this paper, we inspect the broad-band data of GRB 111209A/SN 2011kl. The late-time X-ray lightcurve exhibits a GRB 121027A-like fall-back bump, suggesting a black hole central engine. We thus propose a collapsar model with fall-back accretion for GRB 111209A/SN 2011kl. The required model parameters, such as the total mass and radius of the progenitor star, …
It is notoriously difficult to localize short $γ$-ray bursts (sGRBs) and their hosts to measure their redshifts. These measurements, however, are critical to constrain the nature of sGRB progenitors, their redshift distribution and the $r$-process element enrichment history of the universe. Here, we present spectroscopy of the host galaxy of GRB111117A and measure its redshift to be $z = 2.211$. This makes GRB111117A the most distant high-confidence short duration GRB detected to date. Our spectroscopic redshift supersedes a lower, previously estimated photometric redshift value for this burst…
Long Gamma-Ray Bursts (GRBs) are produced by ultra-relativistic jets launched from core collapse of massive stars. Most massive stars form in binaries and/or in star clusters, which means that there may be a significant external photon field (EPF) around the GRB progenitor. We calculate the inverse-Compton scattering of EPF by the hot electrons in the GRB jet. Three possible cases of EPFs are considered: the progenitor is (I) in a massive binary system, (II) surrounded by a Wolf-Rayet-star wind, and (III) in a dense star cluster. Typical luminosities of 10^46 - 10^50 erg/s in the 1 - 100 GeV b…
We analyse the distribution of matter around the progenitor star of gamma-ray burst GRB 021004 as well as the properties of its host galaxy with high-resolution echelle as well as near-infrared spectroscopy. Observations were taken by the 8.2m Very Large Telescope with the Ultraviolet and Visual Echelle spectrograph (UVES) and the Infrared Spectrometer And Array Camera (ISAAC) between 10 and 14 hours after the onset of the event. We report the first detection of emission lines from a GRB host galaxy in the near-infrared, detecting H-alpha and the [O III] doublet. These allow an independent mea…
Kilonova and progenitor properties of merger-driven gamma-ray bursts
Goethe Universität Frankfurt（法兰克福歌德大学）；INAF – Osservatorio di Astrofisica e Scienza dello Spazio（意大利国家天体物理研究所天体物理学与空间科学天文台）；INFN – Sezione di Bologna（意大利国家核物理研究所博洛尼部分部）；Nikhef（荷兰国家粒子物理研究所）；Institute for Gravitational and Subatomic Physics (GRASP), Utrecht University（乌得勒支大学引力与亚原子物理研究所）；University of Ferrara（费拉拉大学）；INFN, Sezione di Ferrara（意大利国家核物理研究所费拉拉分部）；INAF – Osservatorio Astronomico d’Abruzzo（意大利国家天体物理研究所阿布鲁佐天文台）；Universita‘ di Napoli Federico II（那不勒斯费德里科二世大学）；INAF – Osservatorio Astronomico di Capodimonte（意大利国家天体物理研究所卡波迪蒙特天文台）
The prompt emission of gamma-ray bursts (GRBs) is characterized by rapid variabilities, which may be a direct reflection of the unsteady central engine. We perform a series of axisymmetric 2.5-dimensional simulations to study the propagation of relativistic, hydrodynamic, intermittent jets through the envelope of a GRB progenitor star. A realistic rapidly rotating star is incorporated as the background of jet propagation, and the star is allowed to collapse due to the gravity of the central black hole. By modeling the intermittent jets with constant-luminosity pulses with equal on and off dura…
The rate of long-duration gamma ray bursts (GRBs) has been identified as a potential proxy for the star formation rate (SFR) across redshift, but the exact relationship depends on GRB progenitor models (single versus binary). The single-progenitor collapsar model accounts for the preference towards low-metallicity GRB progenitors, but is in apparent tension with some high-metallicity GRB host galaxy measurements. As a possible solution, we consider the scenario where high-metallicity GRB hosts harbour low metallicity regions in which GRB progenitors form. For this, we use the IllustrisTNG cosm…
A Tale of Two Jets: Double Relativistic Outflows from Close Binary GRB Progenitors
Institute for Frontier in Astronomy and Astrophysics, Beijing Normal University（北京师范大学前沿天文与天体物理研究院）；School of Physics and Astronomy, Beijing Normal University（北京师范大学物理与天文学院）
Keane et al. recently detected a fading radio source following FRB 150418, leading to the identification of a putative host galaxy at $z = 0.492 \pm 0.008$. Assuming that the fading source is the afterglow of FRB 150418, I model the afterglow and constrain the isotropic energy of the explosion to be a few $10^{50}$ erg, comparable to that of a short duration GRB. The outflow may have a jet opening angle of $\sim 0.22$ rad, so that the beaming-corrected energy is below $10^{49}$ erg. The results rule out most FRB progenitor models for this FRB, but may be consistent with either of the following…
It has been argued that the long gamma-ray burst (GRB) of GRB 060614 without an associated supernova (SN) has challenged the current classification and fuel model for long GRBs, and thus a tidal disruption model has been proposed to account for such an event. Since it is difficult to detect SNe for long GRBs at high redshift, the absence of an SN association cannot be regarded as the solid criterion for a new classification of long GRBs similar to GRB 060614, called GRB 060614-type bursts. Fortunately, we now know that there is an obvious periodic substructure observed in the prompt light curv…
Under the assumption that a Gamma-ray Burst (GRB) is ultimately produced by a Blandford-Znajek (BZ) jet from a highly spinning black hole BH, we put limits on the magnetic field and BH mass needed to power observed long and short GRBs. For BHs in the range of $2-10 M_{\odot}$ (for long GRBs) and $0.5-4 M_{\odot}$ (for short GRBs), we find magnetic fields in the range of $5x10^{14} \lesssim B \lesssim 10^{17}$ G are needed to power the observed GRBs. Under the simple assumption of flux conservation, we estimate the magnetic fields of the progenitor systems for both long and short GRBs, finding …
Magnetohydrodynamic (MHD) turbulence is of key importance in many high-energy astrophysical systems, where MHD instabilities can amplify local magnetic field over very short time scales. Specifically, the magnetorotational instability (MRI) and dynamo action have been suggested as a mechanism to grow magnetar-strength magnetic field ($\ge10^{15} G$) and magnetorotationally power the explosion of a rotating massive star. Such stars are progenitor candidates for type Ic-bl hypernova explosions and make up all supernovae connected to long gamma-ray bursts (GRBs). The MRI has been studied with loc…
GRB 100418A is a long burst at z=0.624 without detection of any associated supernova (SN). Its lightcurves in both the prompt and afterglow phases are similar to GRB 060614, a nearby long GRB without an associated SN. We analyze the observational data of this event and discuss the possible origins of its multi-wavelength emission. We show that its joint lightcurve at 1 keV derived from Swift BAT and XRT observations is composed of two distinguished components. The first component, whose spectrum is extremely soft (Γ= 4.32), ends with a steep decay segment, indicating the internal origin of thi…
Using binary evolution with Case-C mass transfer, the spins of several black holes (BHs) in X$-$ray binaries (XBs) have been predicted and confirmed (three cases) by observations. The rotational energy of these BHs is sufficient to power up long gamma$-$ray bursts and hypernovae (GRBs/HNe) and still leave a Kerr BH behind. However, strong magnetic fields and/or dynamo effects in the interior of such stars deplete their cores from angular momentum preventing the formation of collapsars. Thus, even though binaries can produce Kerr BHs, most of their rotation is acquired from the stellar mantle, …
[abridged] We investigate the afterglow properties and large-scale environments of several short-duration gamma-ray bursts (GRBs) with sub-arcsecond optical afterglow positions but no bright coincident host galaxies. The purpose of this joint study is to robustly assess the possibility of significant offsets, a hallmark of the compact object binary merger model. Five such events exist in the current sample of 20 short bursts with optical afterglows, and we find that their optical, X-ray, and gamma-ray emission are systematically fainter. These differences may be due to lower circumburst densit…
[Abridged] We present optical and NIR observations of 19 short GRB host galaxies, aimed at measuring their stellar masses and population ages. The goals of this study are to evaluate whether short GRBs track the stellar mass distribution of galaxies, to investigate the progenitor delay time distribution, and to explore any connection between long and short GRB progenitors. Using single stellar population models we infer masses of log(M/M_sun)=8.8-11.6 and population ages of tau=0.03-4.4 Gyr. We further infer maximal masses of log(M/M_sun)=9.7-11.9 by assuming stellar population ages equal to t…
In this work we present a procedure to infer the mass of progenitors and remnants of Gamma Ray Bursts (GRB), starting from the observed energy $E_{iso}^{GRB}$ emitted isotropically and considering the associated emission of Gravitational Waves (GW) $ E_{iso}^{GW}$ in the different phases. We assume that the GW energy of the progenitor $E_{PROG}^{GW}$ is emitted partially during a star collapse, and the residual energy is related to the GW energy emitted by the remnant. We take a sample of $237$ Long GRB, and use an hybrid Montecarlo procedure to explore, for each of them, a region of possible …
Neutrinos are produced in cosmic accelerators, like active galactic nuclei (AGNs), blazars, supernova (SN) remnants and gamma-ray bursts (GRBs). On their way to the Earth they experience flavor-oscillations. The interactions of the neutrinos coming from the source with other particles, e.g. intergalactic primordial neutrinos or heavy-mass right-handed neutrinos, in their way to the detector may transform the original wave packet in pointer states. This phenomenon, known as decoherence, becomes important in the reconstruction of processes at the source. In this work we study neutrino emission i…
The jet compositions, central engines, and progenitors of gamma-ray bursts (GRBs) remain open questions in GRB physics. Applying broadband observations, including GRB prompt emission and afterglow properties derived from {\em Fermi} and {\em Swift} data, as well as from Keck host-galaxy observations, we address these questions for the peculiar, bright GRB 110731A. By using the pair-opacity method, we derive $Γ_{0}>190$ during the prompt emission phase. Alternatively, we derive $Γ_{0} \approx 580$ and $Γ_{0} \approx 154$ by invoking the early-afterglow phase within the homogeneous density and w…
We show that the luminous supernovae (SNe) associated with ultra-long gamma-ray bursts (GRBs) can be related to the slow cooling from the explosions of hydrogen-free progenitors extended by pulsational pair-instability. In the accompanying paper (Marchant & Moriya 2020), we have shown that some rapidly-rotating hydrogen-free GRB progenitors that experience pulsational pair-instability can keep an extended structure caused by pulsational pair-instability until the core collapse. Such progenitors have large radii exceeding 10 Rsun and they sometimes reach beyond 1000 Rsun at the time of the core…
An electromagnetic transient powered by the radioactive decay of r-process elements, a so-called kilonova/macronova, is one of the possible observable consequences of compact binary mergers including at east one neutron star. Recent observations strongly suggest the first discovery of the electromagnetic transient, which is associated with the short GRB 130603B. We explore a possible progenitor of this event combining the numerical-relativity simulations and radiative transfer simulations of the dynamical ejecta of binary neutron star and black hole - neutron star mergers. We show that the eje…
