Temperature-averaged and total free-free Gaunt factors for κ and Maxwellian distributions of electrons
Autor(a) principal: | |
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Data de Publicação: | 2015 |
Outros Autores: | |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/10174/20579 https://doi.org/10.1051/0004-6361/201526104 |
Resumo: | Aims. Optically thin plasmas may deviate from thermal equilibrium and thus, electrons (and ions) are no longer described by the Maxwellian distribution. Instead they can be described by κ-distributions. The free-free spectrum and radiative losses depend on the temperature-averaged (over the electrons distribution) and total Gaunt factors, respectively. Thus, there is a need to calculate and make available these factors to be used by any software that deals with plasma emission. Methods. We recalculated the free-free Gaunt factor for a wide range of energies and frequencies using hypergeometric functions of complex arguments and the Clenshaw recurrence formula technique combined with approximations whenever the difference between the initial and final electron energies is smaller than 10−10 in units of z2Ry. We used double and quadruple precisions. The temperature- averaged and total Gaunt factors calculations make use of the Gauss-Laguerre integration with 128 nodes. Results. The temperature-averaged and total Gaunt factors depend on the κ parameter, which shows increasing deviations (with respect to the results obtained with the use of the Maxwellian distribution) with decreasing κ. Tables of these Gaunt factors are provided. |
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Temperature-averaged and total free-free Gaunt factors for κ and Maxwellian distributions of electronsatomic processesradiation mechanismsbremsthralungISMAims. Optically thin plasmas may deviate from thermal equilibrium and thus, electrons (and ions) are no longer described by the Maxwellian distribution. Instead they can be described by κ-distributions. The free-free spectrum and radiative losses depend on the temperature-averaged (over the electrons distribution) and total Gaunt factors, respectively. Thus, there is a need to calculate and make available these factors to be used by any software that deals with plasma emission. Methods. We recalculated the free-free Gaunt factor for a wide range of energies and frequencies using hypergeometric functions of complex arguments and the Clenshaw recurrence formula technique combined with approximations whenever the difference between the initial and final electron energies is smaller than 10−10 in units of z2Ry. We used double and quadruple precisions. The temperature- averaged and total Gaunt factors calculations make use of the Gauss-Laguerre integration with 128 nodes. Results. The temperature-averaged and total Gaunt factors depend on the κ parameter, which shows increasing deviations (with respect to the results obtained with the use of the Maxwellian distribution) with decreasing κ. Tables of these Gaunt factors are provided.Astronomy & Astrophysics2017-02-02T11:45:04Z2017-02-022015-08-17T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articlehttp://hdl.handle.net/10174/20579http://hdl.handle.net/10174/20579https://doi.org/10.1051/0004-6361/201526104enghttp://www.aanda.org/articles/aa/abs/2015/08/aa26104-15/aa26104-15.htmlmavillez@uevora.ptnd343de Avillez, MiguelBreitschwerdt, Dieterinfo:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2024-01-03T19:10:33Zoai:dspace.uevora.pt:10174/20579Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-20T01:12:00.766069Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
Temperature-averaged and total free-free Gaunt factors for κ and Maxwellian distributions of electrons |
title |
Temperature-averaged and total free-free Gaunt factors for κ and Maxwellian distributions of electrons |
spellingShingle |
Temperature-averaged and total free-free Gaunt factors for κ and Maxwellian distributions of electrons de Avillez, Miguel atomic processes radiation mechanisms bremsthralung ISM |
title_short |
Temperature-averaged and total free-free Gaunt factors for κ and Maxwellian distributions of electrons |
title_full |
Temperature-averaged and total free-free Gaunt factors for κ and Maxwellian distributions of electrons |
title_fullStr |
Temperature-averaged and total free-free Gaunt factors for κ and Maxwellian distributions of electrons |
title_full_unstemmed |
Temperature-averaged and total free-free Gaunt factors for κ and Maxwellian distributions of electrons |
title_sort |
Temperature-averaged and total free-free Gaunt factors for κ and Maxwellian distributions of electrons |
author |
de Avillez, Miguel |
author_facet |
de Avillez, Miguel Breitschwerdt, Dieter |
author_role |
author |
author2 |
Breitschwerdt, Dieter |
author2_role |
author |
dc.contributor.author.fl_str_mv |
de Avillez, Miguel Breitschwerdt, Dieter |
dc.subject.por.fl_str_mv |
atomic processes radiation mechanisms bremsthralung ISM |
topic |
atomic processes radiation mechanisms bremsthralung ISM |
description |
Aims. Optically thin plasmas may deviate from thermal equilibrium and thus, electrons (and ions) are no longer described by the Maxwellian distribution. Instead they can be described by κ-distributions. The free-free spectrum and radiative losses depend on the temperature-averaged (over the electrons distribution) and total Gaunt factors, respectively. Thus, there is a need to calculate and make available these factors to be used by any software that deals with plasma emission. Methods. We recalculated the free-free Gaunt factor for a wide range of energies and frequencies using hypergeometric functions of complex arguments and the Clenshaw recurrence formula technique combined with approximations whenever the difference between the initial and final electron energies is smaller than 10−10 in units of z2Ry. We used double and quadruple precisions. The temperature- averaged and total Gaunt factors calculations make use of the Gauss-Laguerre integration with 128 nodes. Results. The temperature-averaged and total Gaunt factors depend on the κ parameter, which shows increasing deviations (with respect to the results obtained with the use of the Maxwellian distribution) with decreasing κ. Tables of these Gaunt factors are provided. |
publishDate |
2015 |
dc.date.none.fl_str_mv |
2015-08-17T00:00:00Z 2017-02-02T11:45:04Z 2017-02-02 |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/10174/20579 http://hdl.handle.net/10174/20579 https://doi.org/10.1051/0004-6361/201526104 |
url |
http://hdl.handle.net/10174/20579 https://doi.org/10.1051/0004-6361/201526104 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
http://www.aanda.org/articles/aa/abs/2015/08/aa26104-15/aa26104-15.html mavillez@uevora.pt nd 343 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.publisher.none.fl_str_mv |
Astronomy & Astrophysics |
publisher.none.fl_str_mv |
Astronomy & Astrophysics |
dc.source.none.fl_str_mv |
reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
instname_str |
Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
instacron_str |
RCAAP |
institution |
RCAAP |
reponame_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
collection |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
repository.name.fl_str_mv |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
repository.mail.fl_str_mv |
|
_version_ |
1799136601692962816 |