文章基本信息

标题：Stellar systems following the R 1/ m luminosity law
其他标题：III. Photometric, intrinsic, and dynamical properties for all Sérsic indices
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作者：Maarten Baes ; Luca Ciotti
期刊名称：Astronomy & Astrophysics
印刷版ISSN：0004-6361
电子版ISSN：1432-0746
出版年度：2019
卷号：626
DOI：10.1051/0004-6361/201935320
语种：English
出版社：EDP Sciences
摘要：The Sérsic orR1/mmodel has become the de facto standard model to describe the surface brightness profiles of early-type galaxies and the bulges of spiral galaxies. The photometric, intrinsic, and dynamical properties of this model have been investigated, but mainly for fairly large Sérsic indicesm. For small values ofm, appropriate for low-mass and dwarf ellipticals, a detailed investigation of these properties is still lacking. In this study, we used a combination of numerical and analytical techniques to investigate the Sérsic model over the entire range of Sérsic parameters, focussing on the smallmregime, where a number of interesting and surprising properties are found. For all valuesm < 1, the model is characterised by a finite central luminosity density, and form< 1/2, even a central depression in the luminosity density profile. This behaviour translates to the dynamical properties: we show that all Sérsic models withm⩾ 1/2 can be supported by an isotropic velocity dispersion tensor, and that these isotropic models are stable to both radial and non-radial perturbations. The models withm< 1/2, on the other hand, cannot be supported by an isotropic velocity dispersion tensor.
关键词：engalaxies: photometrygalaxies: structuregalaxies: kinematics and dynamicsmethods: analytical