Delayed outflows from black hole accretion tori following neutron star binary coalescence

Fernández, Rodrigo; Metzger, Brian D.

doi:10.1093/mnras/stt1312

Cited by 366 publications

(497 citation statements)

References 105 publications

(125 reference statements)

Supporting

Mentioning

458

Contrasting

Unclassified

Order By: Relevance

“…More work is clearly needed to distinguish the magnetar hypothesis from other proposed sites of the light r-process elements, such as binary neutron star mergers (Fernández & Metzger 2013;Wanajo et al 2014;Perego et al 2014;Just et al 2015;Goriely et al 2015;Martin et al 2015;Wu et al 2016). …”

Section: As Sources Of Light R-process Nuclei In Metal-poor Starsmentioning

confidence: 99%

“…Such abundances variations are again difficult to explain from standard PNS winds, which, other than due to usually modest variations in the PNS mass, should produce broadly similar yields for each supernova. This has motivated considering alternative sources for the light r-process nuclei in the environments of neutron star mergers, such as accretion disk winds (Fernández & Metzger 2013;Perego et al 2014;Just et al 2015;Martin et al 2015;Wu et al 2016) or components of the dynamical ejecta with higher electron fractions (Wanajo et al 2014;Goriely et al 2015). This paper focuses on another variation on the canonical picture of neutrino-driven wind that occurs if the PNS is formed rapidly-rotating, with an ultra-strong magnetic field B ∼ > 10 14 −10 15 G, similar to those of Galactic magnetars (a so-called "millisecond proto-magnetar"; Thompson 2003).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Neutrino-heated winds from millisecond protomagnetars as sources of the weak r-process

Vlasov

Metzger

Lippuner

et al. 2017

Monthly Notices of the Royal Astronomical Society

Self Cite

View full text Add to dashboard Cite

We explore heavy element nucleosynthesis in neutrino-driven winds from rapidly-rotating, strongly magnetized proto-neutron stars ("millisecond proto-magnetars") for which the magnetic dipole is aligned with the rotation axis, and the field is assumed to be a static force-free configuration. We process the proto-magnetar wind trajectories calculated by Vlasov et al. (2014) through the r-process nuclear reaction network SkyNet using contemporary models for the evolution of the wind electron fraction during the proto-neutron star cooling phase. Although we do not find a successful second or third peak r-process for any rotation period P, we show that proto-magnetars with P ∼ 1 − 5 ms produce heavy element abundance distributions that extend to higher nuclear mass number than from otherwise equivalent spherical winds (with the mass fractions of some elements enhanced by factors of ∼ > 100 − 1000). The heaviest elements are synthesized by outflows emerging along flux tubes which graze the closed zone and pass near the equatorial plane outside the light cylinder. Due to dependence of the nucleosynthesis pattern on the magnetic field strength and rotation rate of the proto-neutron star, natural variations in these quantities between core collapse events could contribute to the observed diversity of the abundances of weak r-process nuclei in metal-poor stars. Further diversity, including possibly even a successful third-peak r-process, could be achieved for misaligned rotators with non-zero magnetic inclination with respect to the rotation axis. If proto-magnetars are central engines for GRBs, their relativistic jets should contain a high mass fraction of heavy nuclei of characteristic mass numberĀ ≈ 100, providing a possible source for ultra-high energy cosmic rays comprised of heavy nuclei with an energy spectrum that extends beyond the nominal GZK cut-off for protons or iron nuclei.

show abstract

Section: As Sources Of Light R-process Nuclei In Metal-poor Starsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Neutrino-heated winds from millisecond protomagnetars as sources of the weak r-process

Vlasov

Metzger

Lippuner

et al. 2017

Monthly Notices of the Royal Astronomical Society

Self Cite

View full text Add to dashboard Cite

show abstract

“…Simulations of binary NS mergers find the dynamical ejection of ∼0.01 M e of material (Rosswog et al 1999;Hotokezaka et al 2013a;Kyutoku et al 2015;Radice et al 2016), while a comparable or greater amount of mass may be lost in outflows from the remnant accretion disk Fernández & Metzger 2013;Just et al 2015). In the case of a long-lived NS remnant, the disk wind ejecta mass can approach the total disk mass of ≈0.1 M e (Metzger & Fernández 2014).…”

Section: Magnetar Modelmentioning

confidence: 99%

Radio Constraints on Long-Lived Magnetar Remnants in Short Gamma-Ray Bursts

Fong

Metzger

Berger

et al. 2016

ApJ

View full text Add to dashboard Cite

The merger of a neutron star (NS) binary may result in the formation of a rapidly spinning magnetar. The magnetar can potentially survive for seconds or longer as a supramassive NS before collapsing to a black hole if, indeed, it collapses at all. During this process, a fraction of the magnetar's rotational energy of ∼10 53 erg is transferred via magnetic spin-down to the surrounding ejecta. The resulting interaction between the ejecta and the surrounding circumburst medium powers a year-long or greater synchrotron radio transient. We present a search for radio emission with the Very Large Array following nine short-duration gamma-ray bursts (GRBs) at rest-frame times of ≈1.3-7.6 yr after the bursts, focusing on those events that exhibit early-time excess X-ray emission that may signify the presence of magnetars. We place upper limits of 18-32 μJy on the 6.0 GHz radio emission, corresponding to spectral luminosities of (0.05-8.3)×10 39 erg s −1 . Comparing these limits to the predicted radio emission from a long-lived remnant and incorporating measurements of the circumburst densities from broadband modeling of short GRB afterglows, we rule out a stable magnetar with an energy of 10 53 erg for half of the events in our sample. A supramassive remnant that injects a lower rotational energy of 10 52 erg is ruled out for a single event, GRB 050724A. This study represents the deepest and most extensive search for long-term radio emission following short GRBs to date, and thus the most stringent limits placed on the physical properties of magnetars associated with short GRBs from radio observations.

show abstract

“…There has been no sign of nucleosynthetic events making the nuclei exclusively with A 130. Contribution from, e.g., the subsequent BH accretiontorus wind (Surman et al 2008;Wanajo & Janka 2012;Fernández & Metzger 2013) might cure this problem.…”

Section: Introductionmentioning

confidence: 99%

PRODUCTION OF ALL THE r -PROCESS NUCLIDES IN THE DYNAMICAL EJECTA OF NEUTRON STAR MERGERS

Wanajo

Sekiguchi

Nishimura

et al. 2014

ApJ

633

852

View full text Add to dashboard Cite

Recent studies suggest that binary neutron star (NS-NS) mergers robustly produce the heavy rprocess nuclei above the atomic mass number A ∼ 130 because of their ejecta consisting of almost pure neutrons (electron fraction of Y e < 0.1). However, little production of the lighter r-process nuclei (A ≈ 90-120) conflicts with the spectroscopic results of r-process-enhanced Galactic halo stars. We present, for the first time, the result of nucleosynthesis calculations based on the fully generalrelativistic simulation of a NS-NS merger with approximate neutrino transport. It is found that the bulk of the dynamical ejecta are appreciably shock-heated and neutrino-processed, resulting in a wide range of Y e (≈ 0.09-0.45). The mass-averaged abundance distribution of calculated nucleosynthesis yields is in reasonable agreement with the full-mass range (A ≈ 90-240) of the solar r-process curve. This implies, if our model is representative of such events, that the dynamical ejecta of NS-NS mergers can be the origin of the Galactic r-process nuclei. Our result also shows that the radioactive heating after ∼ 1 day from the merging, giving rise to r-process-powered transient emission, is dominated by the β-decays of several species close to stability with precisely measured half-lives. This implies that the total radioactive heating rate for such an event can be well constrained within about a factor of two if the ejected material has a solar-like r-process pattern.

show abstract

Delayed outflows from black hole accretion tori following neutron star binary coalescence

Cited by 366 publications

References 105 publications

Neutrino-heated winds from millisecond protomagnetars as sources of the weak r-process

Neutrino-heated winds from millisecond protomagnetars as sources of the weak r-process

Radio Constraints on Long-Lived Magnetar Remnants in Short Gamma-Ray Bursts

PRODUCTION OF ALL THE r -PROCESS NUCLIDES IN THE DYNAMICAL EJECTA OF NEUTRON STAR MERGERS

Contact Info

Product

Resources

About