GRB jet structure and the jet break

Lamb, Gavin P.; Канн, Д. А.; Fernandez, J.; Mandel, Ilya; Levan, A. J.; Tanvir, N. R.

doi:10.1093/mnras/stab2071

Cited by 33 publications

(18 citation statements)

References 105 publications

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“…To test how the inhomogeneity of these jet surfaces affect the afterglow lightcurves for various observers, we generate afterglows at a fixed emission frequency for observers at various inclinations and rotations with respect to the outflow. The afterglows are calculated using the method described in Lamb & Kobayashi (2017); Lamb et al (2018Lamb et al ( , 2021. The lightcurves for each 𝜙 element at a polar angle 𝜃 = [0.0, 0.3, 0.7, 1.0, 1.5, 2.0, 3.0, 4.0, 5.0, & 6.0] × 𝜃 𝑐 for the two simulation models are shown in Figure 2.…”

Section: Methodsmentioning

confidence: 99%

“…More detailed studies of the GRB population indicate that the typical inclination for an observed GRB is 0.57 of the jet's effective opening angle, 𝜃 𝑐 in our notation,(Ryan et al 2015). This suggests that the jet opening angle for GRBs are typically smaller by a factor ∼ 0.64 than the simple estimates(Lamb et al 2021).MNRAS 000, 1-9 (2021) 6 G. P.Lamb et al…”

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confidence: 87%

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Inhomogeneous Jets from Neutron Star Mergers: One Jet to Rule them all

Lamb¹,

Nativi²,

Rosswog³

et al. 2022

Preprint

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The broad, ∼ 4 order of magnitude range in energy, inferred via afterglow observations, for the short Gamma-Ray Burst (GRB) population is difficult to reconcile with the narrow energy distribution expected from neutron star merger progenitors. Using the resultant profiles from 3D hydrodynamic simulations of relativistic jets interacting with neutron star merger wind ejecta, we show how the inhomogeneity of energy and velocity can alter the observed afterglow lightcurve. From a single jet we find that the peak afterglow flux depends sensitively on the observer's line-of-sight: at an inclination within the GRB emitting region we find peak flux variability on the order < 0.5 dex through rotational orientation, and < 1.3 dex for polar inclination. The inferred jet kinetic energy for a fixed parameter afterglow covers ∼ 1/3 of the observed short GRB population. We find a physically motivated, analytic jet structure function via our simulations and include an approximation for the varying collimation due to the merger ejecta mass. We show that by considering the observed range of merger ejecta masses, a short GRB jet population with a single intrinsic energy is capable of explaining the observed broad diversity in short GRB kinetic energies.

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Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 87%

Inhomogeneous Jets from Neutron Star Mergers: One Jet to Rule them all

Lamb¹,

Nativi²,

Rosswog³

et al. 2022

Preprint

Self Cite

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“…Continuous deceleration leads to the point that the entire surface of the jet is observable and the jet begins to spread sideways, producing a break in the light curve across the entire afterglow spectrum [27,28]. The sharpness of this break and the change in the afterglow decay rate depend on how long the jet remains collimated and on the jet radial density profile and energy distribution [29,30]. The time of the jet break is related to the jet opening angle, the bulk Lorentz factor and the density of the circumburst medium (CBM).…”

Section: Imentioning

confidence: 99%

“…The detected achromatic breaks are observed in a few cases. The absence of jet-break signatures in most GRB afterglows has been interpreted as due to the over-simplified assumption homogenous jets with sharp edges, whereas more complex models now include structured jets that produce several chromatic jet-breaks, or much smoother breaks, or jets that can keep their structure for longer than previously thought making difficult to detect breaks without a wide temporal coverage [30].…”

Section: Imentioning

confidence: 99%

A roadmap to gamma-ray bursts: new developments and applications to cosmology

Luongo¹,

Muccino²

2021

Preprint

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GRB classification and properties A. Classification: short and long GRBs B. Intermediate GRBs? C. Ultra-long GRBs and X-ray flashes D. Progenitors and open questions 1. The LGRB-supernova connection 2. SGRBs, macronovae and gravitational waves E. Observable quantities from GRBs 1. Timescales and characteristic energy as observable signature of GRBs III. Theory of GRB progenitors A. The fireball model 1. Photon-dominated scenario 2. Internal shock scenario and photospheric emission 3. Magnetized (or Poynting-flux dominated) outflows 4. Particle acceleration 5. Radiative processes IV. Reconciling cosmological indicators to GRBs A. Distance indicators B. Standard candles C. Classifying standard candles 1. Primary distance indicators 2. Secondary distance indicators V. Going ahead with standard indicators: the χ 2 analysis A. Probability distribution B. The SNe Ia measurements C. BAO measurements D. Differential age and Hubble measurements E. The R parameter F. Confidence levels and uncertainties G. Binning procedure VI. Standardizing GRBs A. GRB correlations and related issues B. Prompt emission GRB correlations 1. L iso -τ lag correlation. 2. L iso -V correlation. 3. Amati or E p -E iso correlation 4. Yonetoku or L p -E p correlation 5. Ghirlanda or E p -E γ correlation C. Prompt and afterglow emission correlations 1. Liang-Zhang or E p -E iso -t b correlation 2. Dainotti or L X -t X correlation 3. E X iso -E iso -E p correlation 4. Combo correlation 5. L-T -E correlation VII. Further issues related to constructing GRB correlations A. Evolution effects B. Instrumental selection effects C. Systematic errors D. Issues and interpretation of prompt emission GRB correlations 1. L iso -τ lag correlation. 2. L iso -V correlation. 26 3. Amati or E p -E iso correlation 26 4. Ghirlanda or E p -E γ correlation 27 5. Yonetoku or L p -E p correlation 27 E. Issues and interpretation of prompt and afterglow emission GRB correlations 27 1. Liang-Zhang or E p -E iso -t b correlation 28 2. Dainotti or L X -t X correlation 28 3. E X iso -E iso -E p correlation 28 4. Combo correlation 28 5. L-T -E correlation 29 VIII. Circularity or not circularity? 29 A. Calibration versus non-calibration 29 B. Fitting procedures with calibration 30 1. SN calibration 30 2. Model dependent calibration 30 3. Model independent calibration 30 C. The use of Bézier polynomials 32 1. Simultaneous fits 33 2. Narrow calibration 33 D. Fitting procedures without calibration 33 IX. Recent developments of cosmology with gamma-ray bursts 34 A. Numerical results using correlations 34 B. Applications of statistical analysis with GRBs 36 1. Bézier polynomials and cosmographic series 37 2. Bézier polynomials and ΛCDM and ωCDM cosmological models 38 C. The role of spatial curvature 39 X. Further application of GRBs as probes of the high-redshift Universe 41 A. Star formation rate from GRBs 41 B. High-redshift GRB rate excess 41 C. Gravitationally-lensed GRBs 41 XI. Final outlooks 42 Acknowledgments 42 References 42 8Typically dubbed time-integrated and time-resolved an...

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“…Recently, GRB jet structure has become an increasingly important ingredient in GRB afterglow modeling (e.g., Oganesyan et al 2020;Beniamini et al 2020b;Lamb et al 2021;Takahashi & Ioka 2021), especially since the historical insight provided by the multimessenger analysis of the outflow from GW170817 (Mooley et al 2018;Ghirlanda et al 2019). In the present paper, we set out to interpret flares in GRB afterglows within the same physical setup as our above-mentioned plateau model: slightly misaligned lines of sight to a structured jet.…”

Section: Introductionmentioning

confidence: 99%

Flares in gamma-ray burst X-ray afterglows as prompt emission from slightly misaligned structured jets

Duque,

Beniamini,

Daigne

et al. 2021

Preprint

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We develop a model to explain the flaring activity in gamma-ray burst X-ray afterglows within the framework of slightly misaligned observers to structured jets. We suggest that flares could be the manifestation of prompt dissipation within the core of the jet, appearing to a misaligned observer in the X-ray band because of less favorable Doppler boosting. These flares appear during the afterglow phase because of core-observer light travel delays. In this picture, the prompt emission recorded by this observer comes from material along their line of sight, in the lateral structure of the jet, outside the jet's core. We start by laying down the basic analytical framework to determine the flares characteristics as a function of those of the gamma-ray pulse an aligned observer would have seen. We show that, for typical flare observing times and luminosities, there is indeed viable parameter space to explain flares in this way. We then analytically explore this model and show that it naturally produces flares with small width, a salient property of flares. We perform fits of our model to two Swift/XRT flares representing two different types of morphology, to show that our model can capture both. The ejection time of the core jet material responsible of the flare is a critical parameter. While it always remains small compared to the observed time of the flare, confirming that our model does not require very late central engine activity, late ejection times are strongly favored, sometimes larger than the observed duration of the parent GRB's prompt emission as measured by 𝑇 90 .

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GRB jet structure and the jet break

Cited by 33 publications

References 105 publications

Inhomogeneous Jets from Neutron Star Mergers: One Jet to Rule them all

Inhomogeneous Jets from Neutron Star Mergers: One Jet to Rule them all

A roadmap to gamma-ray bursts: new developments and applications to cosmology

Flares in gamma-ray burst X-ray afterglows as prompt emission from slightly misaligned structured jets

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