Coherent radiation from energetic electron streams via collisionless bremsstrahlung in strong plasma turbulence

Weatherall, James C.; Benford, Gregory

doi:10.1086/170455

Cited by 36 publications

(36 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…ERB detections may in fact involve observational selection of extreme physical conditions. An individual emitter might be a charge clump in the relativistic flow of a magnetosphere (Weatherall & Benford 1991;Weatherall 1998;Hankins et al 2003;Asseo & Porzio 2006). Clumps may be produced from a two-stream instability or a bunching instability associated with coherent synchrotron radiation (Goldreich & Keeley 1971;Buschauer & Benford 1978;Schmekel et al 2005;Schmekel & Lovelace 2006;Schmekel 2005).…”

Section: Maximal Shot Pulse Amplitudesmentioning

confidence: 99%

Supergiant pulses from extragalactic neutron stars

Cordes

Wasserman

2016

Mon. Not. R. Astron. Soc.

316

275

View full text Add to dashboard Cite

We consider radio bursts that originate from extragalactic neutron stars (NSs) by addressing three questions about source distances. What are the physical limitations on coherent radiation at GHz frequencies? Do they permit detection at cosmological distances? How many bursts per NS are needed to produce the inferred burst rate ∼ 10 3 -10 4 sky −1 day −1 ? The burst rate is comparable to the NS formation rate in a Hubble volume, requiring only one per NS if they are bright enough. However, radiation physics causes us to favor a closer population. More bursts per NS are then required but repeats in 10 to 100 yr could still be negligible. Bursts are modeled as sub-ns, coherent shot pulses superposed incoherently to produce msduration ∼ 1 Jy amplitudes; each shot-pulse can be much weaker than the burst amplitude, placing less restrictive requirements on the emission process. Nonetheless, single shot pulses are similar to the extreme, unresolved (< 0.4 ns) MJy shot pulse seen from the Crab pulsar, which is consistent with coherent curvature radiation emitted near the light cylinder by an almost neutral clump with net charge ∼ ±10 21 e and total energy 10 23 ergs. Bursts from Gpc distances require incoherent superposition of ∼ 10 12 d 2 Gpc shot pulses or a total energy 10 35 d 2 Gpc erg. The energy reservoir near the light cylinder limits the detection distance to few × 100 Mpc for a fluence ∼ 1 Jy ms unless conditions are more extreme than for the Crab pulsar. Similarly, extreme single pulses from ordinary pulsars and magnetars could be detectable from throughout the Local Group and perhaps farther. Contributions to dispersion measures from galaxy clusters will be significant for some of the bursts. We discuss tests for the signatures of bursts associated with extragalactic NSs.

show abstract

Section: Maximal Shot Pulse Amplitudesmentioning

confidence: 99%

Supergiant pulses from extragalactic neutron stars

Cordes

Wasserman

2016

Mon. Not. R. Astron. Soc.

316

275

View full text Add to dashboard Cite

show abstract

“…If, on the contrary, the jet presents density fluctuations that are correlated, then the radiation can be coherent, and therefore strongly enhanced. This correlation in the density fluctuations is the result of turbulence generated by the coupling between the background plasma and the beam: electrons from the beam perturb the plasma, producing the twostream instability, then cavitons form, and beam-electron bunching is also generated (Weatherall & Benford 1991). Turbulence development should not significantly affect the cold nature of the beam as long as the turbulence-associated electron velocities do not themselves become relativistic in the flow frame.…”

Section: The Coherent Emission Mechanismmentioning

confidence: 99%

A model for the repeating FRB 121102 in the AGN scenario

Vieyro

Romero

Bosch‐Ramon

et al. 2017

A&A

View full text Add to dashboard Cite

Context. Fast radio bursts, or FRBs, are transient sources of unknown origin. Recent radio and optical observations have provided strong evidence for an extragalactic origin of the phenomenon and the precise localization of the repeating FRB 121102. Observations using the Karl G. Jansky Very Large Array (VLA) and very-long-baseline interferometry (VLBI) have revealed the existence of a continuum non-thermal radio source consistent with the location of the bursts in a dwarf galaxy. All these new data rule out several models that were previously proposed, and impose stringent constraints to new models. Aims. We aim to model FRB 121102 in light of the new observational results in the active galactic nucleus (AGN) scenario. Methods. We propose a model for repeating FRBs in which a non-steady relativistic e ± -beam, accelerated by an impulsive magnetohydrodynamic (MHD)-driven mechanism, interacts with a cloud at the centre of a star-forming dwarf galaxy. The interaction generates regions of high electrostatic field called cavitons in the plasma cloud. Turbulence is also produced in the beam. These processes, plus particle isotropization, the interaction scale, and light retardation effects, provide the necessary ingredients for short-lived, bright coherent radiation bursts. Results. The mechanism studied in this work explains the general properties of FRB 121102, and may also be applied to other repetitive FRBs. Conclusions. Coherent emission from electrons and positrons accelerated in cavitons provides a plausible explanation of FRBs.

show abstract

“…Weatherall and Hobbs [10] showed that electrostatic bunching was an effective means of generating plasma harmonics. Subsequently, Weatherall and Benford (WB) [11] reported a spectrum showing strong emission at the plasma line and its harmonics with a power spectrum below a cut-off at ω ∼ ω c , …”

Section: Plasma and Harmonic Emission From Relativistic Electrons Permentioning

confidence: 99%

“…Figure 3. (a) Beam radiation power spectrum from WB model [11], and (b) single particle radiation from a laser-accelerated electron perturbed by a soliton field (2), for a 0 = 30, n e /n c = 100, both having power decays p ∼ 5/3. …”

Section: Plasma and Harmonic Emission From Relativistic Electrons Permentioning

confidence: 99%

Plasma effects in harmonic emission in relativistic laser interactions with overdense plasma targets examined from single particle radiation models

Ondarza-Rovira

Boyd

2012

J. Phys.: Conf. Ser.

View full text Add to dashboard Cite

Multiple attosecond pulse generation in relativistically laser-driven overdense plasmas X Lavocat-Dubuis, F Vidal, J-P Matte et al.High-order harmonic generation using plasma mirrors F Quéré, C Thaury, H George et al. Abstract. Intense femtosecond laser pulses incident on supercritical plasmas can generate reflected high-order harmonics of the fundamental frequency that extend over the xuv spectral region, characterized by a power decay Pm ∼ m −p , where m is the harmonic number. It has been shown in earlier reports that plasma effects can modify the emission spectrum producing decay indexes p significantly weaker than the universal value 8/3 predicted by the similarity theory, these being within the range 4/3 ≤ p ≤ 8/3. In this paper we employ two single particle radiation models to demonstrate that plasma density effects substantially modify the emission radiated by a relativistic electron accelerated by the electric field of the laser pulse, and show that the harmonic power decay is commonly characterized by the indexes 4/3 and 5/3, with remarkable similitudes to those particle-in-cell results recently reported in ultrarelativistic laser-plasma interactions.

show abstract

Coherent radiation from energetic electron streams via collisionless bremsstrahlung in strong plasma turbulence

Cited by 36 publications

References 0 publications

Supergiant pulses from extragalactic neutron stars

Supergiant pulses from extragalactic neutron stars

A model for the repeating FRB 121102 in the AGN scenario

Plasma effects in harmonic emission in relativistic laser interactions with overdense plasma targets examined from single particle radiation models

Contact Info

Product

Resources

About