On the dynamic efficiency of internal shocks in magnetized relativistic outflows

Abstract

We study the dynamic efficiency of conversion of kinetic-to-thermal/magnetic energy of internal shocks in relativistic magnetized outflows. We model internal shocks as being caused by collisions of shells of plasma with the same energy flux and a non-zero relative velocity. The contact surface, where the interaction between the shells takes place, can break up either into two oppositely moving shocks (in the frame where the contact surface is at rest), or into a reverse shock and a forward rarefaction. We find that for moderately magnetized shocks (magnetization $\sigma \simeq 0.1$), the dynamic efficiency in a single two-shell interaction can be as large as 40%. Thus, the dynamic efficiency of moderately magnetized shocks is larger than in the corresponding unmagnetized two-shell interaction. If the slower shell propagates with a sufficiently large velocity, the efficiency is only weakly dependent on its Lorentz factor. Consequently, the dynamic efficiency of shell interactions in the magnetized flow of blazars and gamma-ray bursts is effectively the same. These results are quantitatively rather independent on the equation of state of the plasma. The radiative efficiency of the process is expected to be a fraction $f_r<1$ of the estimated dynamic one, the exact value of $f_r$ depending on the particularities of the emission processes which radiate away the thermal or magnetic energy of the shocked states.

Accepted for publication in MNRAS. 8 pages, 6 figures. The definitive version is available at http://www.blackwell-synergy.com

References in corpus (12)

• Gamma-Ray Bursts: Progress, Problems & Prospects
• Very high efficiency photospheric emission in long duration gamma-ray bursts
• Spectral and timing properties of a dissipative GRB photosphere
• Deceleration of arbitrarily magnetized GRB ejecta: the complete evolution
• Angular Energy Distribution of Collapsar-Jets
• A powerful hydrodynamic booster for relativistic jets
• Collimated Jet or Expanding Outflow: Possible Origins of GRBs and X-Ray Flashes
• A multidimensional grid-adaptive relativistic magnetofluid code
• Internal shocks in relativistic outflows: collisions of magnetized shells
• Gamma-ray burst internal shocks with magnetization
• Observational Effects of Anomalous Boundary Layers in Relativistic Jets
• On invisible plasma content in radio-loud AGNs: The case of TeV blazar Markarian 421

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