Small-scale structure of the disc velocity distribution. A maximum entropy statistical approach - Part II

Among metallicity, colour, and other star properties, the eccentricity of the star’s orbit behaves as a very good sampling parameter to find a more detailed structure for the disc velocity distribution, allowing distinctions between different eccentricity layers. For subsam- ples with eccentricities...

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Detalles Bibliográficos
Autor: Cubarsí Morera, Rafael|||0000-0001-7748-1322
Tipo de recurso: informe técnico
Fecha de publicación:2009
País:España
Institución:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/6700
Acceso en línea:https://hdl.handle.net/2117/6700
Access Level:acceso abierto
Palabra clave:Astronomy and astrophysics
Probabilities
Stochastic processes
Mathematical statistics
Astronomia
Astrofísica
Probabilitats
Processos estocàstics
Estadística matemàtica
85 ASTRONOMY AND ASTROPHYSICS
60 PROBABILITY THEORY AND STOCHASTIC PROCESSES
62 STATISTICS
Àrees temàtiques de la UPC::Matemàtiques i estadística::Estadística matemàtica::Mètodes estadístics
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oai_identifier_str oai:upcommons.upc.edu:2117/6700
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spelling Small-scale structure of the disc velocity distribution. A maximum entropy statistical approach - Part IICubarsí Morera, Rafael|||0000-0001-7748-1322Astronomy and astrophysicsProbabilitiesStochastic processesMathematical statisticsAstronomiaAstrofísicaProbabilitatsProcessos estocàsticsEstadística matemàtica85 ASTRONOMY AND ASTROPHYSICS60 PROBABILITY THEORY AND STOCHASTIC PROCESSES62 STATISTICSÀrees temàtiques de la UPC::Matemàtiques i estadística::Estadística matemàtica::Mètodes estadísticsAmong metallicity, colour, and other star properties, the eccentricity of the star’s orbit behaves as a very good sampling parameter to find a more detailed structure for the disc velocity distribution, allowing distinctions between different eccentricity layers. For subsam- ples with eccentricities e < 0.15, star velocities are approximately symmetrically distributed around the LSR in the radial direction, with a dearth of stars at the LSR. For e = 0.15, the core distribution of the thin disc is supported by two major stellar groups with opposite radial velocities. Several simulations confirm that such a double-peaked distribution comes from the lognormal distribution of the velocity amplitudes. For maximum eccentricity 0.3 and maximum distance to the Galactic plane 0.5 kpc a representative thin disc sample is obtained. An explanation of the apparent vertex deviation of the disc from the swinging of those major kinematic groups around the LSR is possible, which predicts a continuously changing orientation of the disc’s pseudo ellipsoid.20092009-12-0120102010-03-18reporthttp://purl.org/coar/resource_type/c_93fcAOhttp://purl.org/coar/version/c_b1a7d7d4d402bcceinfo:eu-repo/semantics/reportapplication/pdfhttps://hdl.handle.net/2117/6700reponame:UPCommons. Portal del coneixement obert de la UPCinstname:Universitat Politècnica de Catalunya (UPC)Inglésengopen accesshttp://purl.org/coar/access_right/c_abf2Attribution-NonCommercial-NoDerivs 3.0 Spainhttp://creativecommons.org/licenses/by-nc-nd/3.0/es/info:eu-repo/semantics/openAccessoai:upcommons.upc.edu:2117/67002026-05-27T15:37:01Z
dc.title.none.fl_str_mv Small-scale structure of the disc velocity distribution. A maximum entropy statistical approach - Part II
title Small-scale structure of the disc velocity distribution. A maximum entropy statistical approach - Part II
spellingShingle Small-scale structure of the disc velocity distribution. A maximum entropy statistical approach - Part II
Cubarsí Morera, Rafael|||0000-0001-7748-1322
Astronomy and astrophysics
Probabilities
Stochastic processes
Mathematical statistics
Astronomia
Astrofísica
Probabilitats
Processos estocàstics
Estadística matemàtica
85 ASTRONOMY AND ASTROPHYSICS
60 PROBABILITY THEORY AND STOCHASTIC PROCESSES
62 STATISTICS
Àrees temàtiques de la UPC::Matemàtiques i estadística::Estadística matemàtica::Mètodes estadístics
title_short Small-scale structure of the disc velocity distribution. A maximum entropy statistical approach - Part II
title_full Small-scale structure of the disc velocity distribution. A maximum entropy statistical approach - Part II
title_fullStr Small-scale structure of the disc velocity distribution. A maximum entropy statistical approach - Part II
title_full_unstemmed Small-scale structure of the disc velocity distribution. A maximum entropy statistical approach - Part II
title_sort Small-scale structure of the disc velocity distribution. A maximum entropy statistical approach - Part II
dc.creator.none.fl_str_mv Cubarsí Morera, Rafael|||0000-0001-7748-1322
author Cubarsí Morera, Rafael|||0000-0001-7748-1322
author_facet Cubarsí Morera, Rafael|||0000-0001-7748-1322
author_role author
dc.subject.none.fl_str_mv Astronomy and astrophysics
Probabilities
Stochastic processes
Mathematical statistics
Astronomia
Astrofísica
Probabilitats
Processos estocàstics
Estadística matemàtica
85 ASTRONOMY AND ASTROPHYSICS
60 PROBABILITY THEORY AND STOCHASTIC PROCESSES
62 STATISTICS
Àrees temàtiques de la UPC::Matemàtiques i estadística::Estadística matemàtica::Mètodes estadístics
topic Astronomy and astrophysics
Probabilities
Stochastic processes
Mathematical statistics
Astronomia
Astrofísica
Probabilitats
Processos estocàstics
Estadística matemàtica
85 ASTRONOMY AND ASTROPHYSICS
60 PROBABILITY THEORY AND STOCHASTIC PROCESSES
62 STATISTICS
Àrees temàtiques de la UPC::Matemàtiques i estadística::Estadística matemàtica::Mètodes estadístics
description Among metallicity, colour, and other star properties, the eccentricity of the star’s orbit behaves as a very good sampling parameter to find a more detailed structure for the disc velocity distribution, allowing distinctions between different eccentricity layers. For subsam- ples with eccentricities e < 0.15, star velocities are approximately symmetrically distributed around the LSR in the radial direction, with a dearth of stars at the LSR. For e = 0.15, the core distribution of the thin disc is supported by two major stellar groups with opposite radial velocities. Several simulations confirm that such a double-peaked distribution comes from the lognormal distribution of the velocity amplitudes. For maximum eccentricity 0.3 and maximum distance to the Galactic plane 0.5 kpc a representative thin disc sample is obtained. An explanation of the apparent vertex deviation of the disc from the swinging of those major kinematic groups around the LSR is possible, which predicts a continuously changing orientation of the disc’s pseudo ellipsoid.
publishDate 2009
dc.date.none.fl_str_mv 2009
2009-12-01
2010
2010-03-18
dc.type.none.fl_str_mv report
http://purl.org/coar/resource_type/c_93fc
AO
http://purl.org/coar/version/c_b1a7d7d4d402bcce
dc.type.openaire.fl_str_mv info:eu-repo/semantics/report
format report
dc.identifier.none.fl_str_mv https://hdl.handle.net/2117/6700
url https://hdl.handle.net/2117/6700
dc.language.none.fl_str_mv Inglés
eng
language_invalid_str_mv Inglés
language eng
dc.rights.none.fl_str_mv open access
http://purl.org/coar/access_right/c_abf2
Attribution-NonCommercial-NoDerivs 3.0 Spain
http://creativecommons.org/licenses/by-nc-nd/3.0/es/
dc.rights.openaire.fl_str_mv info:eu-repo/semantics/openAccess
rights_invalid_str_mv open access
http://purl.org/coar/access_right/c_abf2
Attribution-NonCommercial-NoDerivs 3.0 Spain
http://creativecommons.org/licenses/by-nc-nd/3.0/es/
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.source.none.fl_str_mv reponame:UPCommons. Portal del coneixement obert de la UPC
instname:Universitat Politècnica de Catalunya (UPC)
instname_str Universitat Politècnica de Catalunya (UPC)
reponame_str UPCommons. Portal del coneixement obert de la UPC
collection UPCommons. Portal del coneixement obert de la UPC
repository.name.fl_str_mv
repository.mail.fl_str_mv
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score 15,301603

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