TY - JOUR
T1 - Radiative striped wind model for gamma-ray bursts
AU - Bégué, D.
AU - Pe'er, A.
AU - Lyubarsky, Y.
N1 - Funding Information: DB is supported by a grant from Stiftelsen Olle Engkvist Byggmästare. AP acknowledges support by the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement no. 618499. YL is supported by the Israeli Science Foundation under the grant no. 719/2014. Funding Information: DB is supported by a grant from Stiftelsen Olle Engkvist Byggm?stare. AP acknowledges support by the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement no. 618499. YL is supported by the Israeli Science Foundation under the grant no. 719/2014. Publisher Copyright: © 2017 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society
PY - 2017/6/1
Y1 - 2017/6/1
N2 - In this paper, we revisit the striped wind model in which the wind is accelerated by magnetic reconnection. In our treatment, radiation is included as an independent component, and two scenarios are considered. In the first one, radiation cannot stream efficiently through the reconnection layer, while the second scenario assumes that radiation is homogeneous in the striped wind. We show how these two assumptions affect the dynamics. In particular, we find that the asymptotic radial evolution of the Lorentz factor is not strongly modified whether radiation can stream through the reconnection layer or not. On the other hand, we show that the width, density and temperature of the reconnection layer are strongly dependent on these assumptions. We then apply the model to the gamma-ray burst context and find that photons cannot diffuse efficiently through the reconnection layer below radius rDΔ ∼ 1010.5 cm, which is about an order of magnitude below the photospheric radius. Above rDΔ, the dynamics asymptotes to the solution of the scenario in which radiation can stream through the reconnection layer. As a result, the density of the current sheet increases sharply, providing efficient photon production by the Bremsstrahlung process that could have profound influence on the emerging spectrum. This effect might provide a solution to the soft photon problem in gamma-ray bursts.
AB - In this paper, we revisit the striped wind model in which the wind is accelerated by magnetic reconnection. In our treatment, radiation is included as an independent component, and two scenarios are considered. In the first one, radiation cannot stream efficiently through the reconnection layer, while the second scenario assumes that radiation is homogeneous in the striped wind. We show how these two assumptions affect the dynamics. In particular, we find that the asymptotic radial evolution of the Lorentz factor is not strongly modified whether radiation can stream through the reconnection layer or not. On the other hand, we show that the width, density and temperature of the reconnection layer are strongly dependent on these assumptions. We then apply the model to the gamma-ray burst context and find that photons cannot diffuse efficiently through the reconnection layer below radius rDΔ ∼ 1010.5 cm, which is about an order of magnitude below the photospheric radius. Above rDΔ, the dynamics asymptotes to the solution of the scenario in which radiation can stream through the reconnection layer. As a result, the density of the current sheet increases sharply, providing efficient photon production by the Bremsstrahlung process that could have profound influence on the emerging spectrum. This effect might provide a solution to the soft photon problem in gamma-ray bursts.
KW - Diffusion
KW - Gamma-ray burst: general
KW - Magnetic reconnection
KW - Radiative transfer
UR - http://www.scopus.com/inward/record.url?scp=85040223289&partnerID=8YFLogxK
U2 - https://doi.org/10.1093/mnras/stx237
DO - https://doi.org/10.1093/mnras/stx237
M3 - Article
SN - 0035-8711
VL - 467
SP - 2594
EP - 2611
JO - MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
JF - MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
IS - 3
ER -