Ir al contenido (pulsa Retorno)

Universitat Politècnica de Catalunya

    • Català
    • Castellano
    • English
    • LoginRegisterLog in (no UPC users)
  • mailContact Us
  • world English 
    • Català
    • Castellano
    • English
  • userLogin   
      LoginRegisterLog in (no UPC users)

UPCommons. Global access to UPC knowledge

57.066 UPC E-Prints
You are here:
View Item 
  •   DSpace Home
  • E-prints
  • Grups de recerca
  • gAGE - grup d'Astronomia i GEomàtica
  • Articles de revista
  • View Item
  •   DSpace Home
  • E-prints
  • Grups de recerca
  • gAGE - grup d'Astronomia i GEomàtica
  • Articles de revista
  • View Item
JavaScript is disabled for your browser. Some features of this site may not work without it.

Eccentricity samples: implications on the potential and the velocity distribution

Thumbnail
View/Open
SAJ170221004C.pdf (373,6Kb)
Share:
 
 
10.2298/SAJ170221004C
 
  View Usage Statistics
Cita com:
hdl:2117/114123

Show full item record
Cubarsí Morera, RafaelMés informacióMés informació
Stojanovic, Milan
Ninkovic, Slobodan
Document typeArticle
Defense date2017
Rights accessOpen Access
All rights reserved. This work is protected by the corresponding intellectual and industrial property rights. Without prejudice to any existing legal exemptions, reproduction, distribution, public communication or transformation of this work are prohibited without permission of the copyright holder
Abstract
Planar and vertical epicycle frequencies and local angular velocity are related to the derivatives up to the second order of the local potential and can be used to test the shape of the potential from stellar disc samples. These samples show a more complex velocity distribution than halo stars and should provide a more realistic test. We assume an axisymmetric potential allowing a mixture of independent ellipsoidal velocity distributions, of separable or Staeckel form in cylindrical or spherical coordinates. We prove that values of local constants are not consistent with a potential separable in addition in cylindrical coordinates and with a spherically symmetric potential. The simplest potential that fits the local constants is used to show that the harmonical and non-harmonical terms of the potential are equally important. The same analysis is used to estimate the local constants. Two families of nested subsamples selected for decreasing planar and vertical eccentricities are used to borne out the relation between the mean squared planar and vertical eccentricities and the velocity dispersions of the subsamples. According to the first-order epicycle model, the radial and vertical velocity components provide accurate information on the planar and vertical epicycle frequencies. However, it is impossible to account for the asymmetric drift which introduces a systematic bias in estimation of the third constant. Under a more general model, when the asymmetric drift is taken into account, the rotation velocity dispersions together with their asymmetric drift provide the correct fit for the local angular velocity. The consistency of the results shows that this new method based on the distribution of eccentricities is worth using for kinematic stellar samples.
CitationCubarsi, R., Stojanovic, M., Ninkovic, S. Eccentricity samples: implications on the potential and the velocity distribution. "Serbian Astronomical Journal", 2017, vol. 194, p. 33-50. 
URIhttp://hdl.handle.net/2117/114123
DOI10.2298/SAJ170221004C
ISSN1450-698X
Publisher versionhttp://www.doiserbia.nb.rs/img/doi/1450-698X/2017/1450-698X1700004C.pdf
Collections
  • gAGE - grup d'Astronomia i GEomàtica - Articles de revista [73]
  • Departament de Matemàtiques - Articles de revista [2.895]
Share:
 
  View Usage Statistics

Show full item record

FilesDescriptionSizeFormatView
SAJ170221004C.pdf373,6KbPDFView/Open

Browse

This CollectionBy Issue DateAuthorsOther contributionsTitlesSubjectsThis repositoryCommunities & CollectionsBy Issue DateAuthorsOther contributionsTitlesSubjects

© UPC Obrir en finestra nova . Servei de Biblioteques, Publicacions i Arxius

info.biblioteques@upc.edu

  • About This Repository
  • Contact Us
  • Send Feedback
  • Inici de la pàgina