The free escape continuum of diffuse ions upstream of the Earth's quasi-parallel bow shock


Autoria(s): Trattner, K. J.; Allegrini, F.; Dayeh, M. A.; Funsten, H. O.; Fuselier, S. A.; Heirtzler, D.; Janzen, P.; Kucharek, H.; McComas, D. J.; Möbius, E.; Moore, T. E.; Petrinec, S. M.; Reisenfeld, D. B.; Schwadron, N. A.; Wurz, Peter
Data(s)

01/07/2013

Resumo

The Earth's bow shock is very efficient in accelerating ions out of the incident solar wind distribution to high energies (≈ 200 keV/e). Fluxes of energetic ions accelerated at the quasi-parallel bow shock, also known as diffuse ions, are best represented by exponential spectra in energy/charge, which require additional assumptions to be incorporated into these model spectra. One of these assumptions is a so-called "free escape boundary" along the interplanetary magnetic field into the upstream direction. Locations along the IBEX orbit are ideally suited for in situ measurements to investigate the existence of an upstream free escape boundary for bow shock accelerated ions. In this study we use 2 years of ion measurements from the background monitor on the IBEX spacecraft, supported by ACE solar wind observations. The IBEX Background Monitor is sensitive to protons > 14 keV, which includes the energy of the maximum flux for diffuse ions. With increasing distance from the bow shock along the interplanetary magnetic field, the count rates for diffuse ions stay constant for ions streaming away from the bow shock, while count rates for diffuse ions streaming toward the shock gradually decrease from a maximum value to ~1/e at distances of about 10 RE to 14 RE. These observations of a gradual decrease support the transition to a free escape continuum for ions of energy >14 keV at distances from 10 RE to 14 RE from the bow shock.

Formato

application/pdf

Identificador

http://boris.unibe.ch/44358/1/jgra50447.pdf

Trattner, K. J.; Allegrini, F.; Dayeh, M. A.; Funsten, H. O.; Fuselier, S. A.; Heirtzler, D.; Janzen, P.; Kucharek, H.; McComas, D. J.; Möbius, E.; Moore, T. E.; Petrinec, S. M.; Reisenfeld, D. B.; Schwadron, N. A.; Wurz, Peter (2013). The free escape continuum of diffuse ions upstream of the Earth's quasi-parallel bow shock. Journal of Geophysical Research: Space Physics, 118(7), pp. 4425-4434. AGU Publications 10.1002/jgra.50447 <http://dx.doi.org/10.1002/jgra.50447>

doi:10.7892/boris.44358

info:doi:10.1002/jgra.50447

urn:issn:2169-9380

Idioma(s)

eng

Publicador

AGU Publications

Relação

http://boris.unibe.ch/44358/

Direitos

info:eu-repo/semantics/openAccess

Fonte

Trattner, K. J.; Allegrini, F.; Dayeh, M. A.; Funsten, H. O.; Fuselier, S. A.; Heirtzler, D.; Janzen, P.; Kucharek, H.; McComas, D. J.; Möbius, E.; Moore, T. E.; Petrinec, S. M.; Reisenfeld, D. B.; Schwadron, N. A.; Wurz, Peter (2013). The free escape continuum of diffuse ions upstream of the Earth's quasi-parallel bow shock. Journal of Geophysical Research: Space Physics, 118(7), pp. 4425-4434. AGU Publications 10.1002/jgra.50447 <http://dx.doi.org/10.1002/jgra.50447>

Palavras-Chave #520 Astronomy #620 Engineering #530 Physics
Tipo

info:eu-repo/semantics/article

info:eu-repo/semantics/publishedVersion

PeerReviewed