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dc.contributor.authorFerrão, Sabrina Tigikpt_BR
dc.contributor.authorZiebell, Luiz Fernandopt_BR
dc.contributor.authorYoon, Peter H.pt_BR
dc.date.accessioned2018-02-28T02:27:57Zpt_BR
dc.date.issued2017pt_BR
dc.identifier.issn0004-637Xpt_BR
dc.identifier.urihttp://hdl.handle.net/10183/173037pt_BR
dc.description.abstractThe ubiquity of high-energy tails in the charged particle velocity distribution functions (VDFs) observed in space plasmas suggests the existence of an underlying process responsible for taking a fraction of the charged particle population out of thermal equilibrium and redistributing it to suprathermal velocity and energy ranges. The present Letter focuses on a new and fundamental physical explanation for the origin of suprathermal electron velocity distribution function (EVDF) in a collisional plasma. This process involves a newly discovered electrostatic bremsstrahlung (EB) emission that is effective in a plasma in which binary collisions are present. The steady-state EVDF dictated by such a process corresponds to a Maxwellian core plus a quasi-inverse power-law tail, which is a feature commonly observed in many space plasma environments. In order to demonstrate this, the system of selfconsistent particle- and wave-kinetic equations are numerically solved with an initially Maxwellian EVDF and Langmuir wave spectral intensity, which is a state that does not reflect the presence of EB process, and hence not in force balance. The EB term subsequently drives the system to a new force-balanced steady state. After a long integration period it is demonstrated that the initial Langmuir fluctuation spectrum is modified, which in turn distorts the initial Maxwellian EVDF into a VDF that resembles the said core-suprathermal VDF. Such a mechanism may thus be operative at the coronal source region, which is characterized by high collisionality.en
dc.format.mimetypeapplication/pdf
dc.language.isoengpt_BR
dc.relation.ispartofThe astrophysical journal. Bristol. Vol. 849, no. 2 ( 2017), L30, 5 p.pt_BR
dc.rightsOpen Accessen
dc.subjectSolar winden
dc.subjectVento solarpt_BR
dc.subjectProcessos de colisao em plasmaspt_BR
dc.subjectSun: coronaen
dc.subjectSun: particle emissionen
dc.subjectOndas de Langmuir em plasmaspt_BR
dc.titleGeneration of suprathermal electrons by collective processes in collisional plasmapt_BR
dc.typeArtigo de periódicopt_BR
dc.identifier.nrb001055818pt_BR
dc.type.originEstrangeiropt_BR


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