A principle of corresponding states for two-component, self-gravitating fluids
R. Caimmi
备注：
72 pages, 8 tables, and 18 figures; some typos corrected; tables 1, 2, 3, 5, 7, better formatted; principle of corresponding states defined in section 2
Macrogases are defined as two-component, large-scale celestial objects where the subsystems interact only via gravitation. The macrogas equation of state is formulated and compared to the van der Waals equation of state for ordinary gases. By analogy, it is assumed that real macroisothermal curves in macrogases occur as real isothermal curves in ordinary gases, where a phase transition takes place along a horisontal line in the macrovolume-macropressure (Mv-Mp) plane. A simple guidance case and two density profiles which satisfactorily fit to observations or simulations, are studied in detail. For sufficiently steep density profiles, a critical macroisothermal curve exists as shown by ordinary gases, where the critical point coincides with the horisontal inflexion point. By analogy with ordinary gases, the first quadrant of the (Mv-Mp) plane may be divided into three parts, namely (i) the G region, where only gas exists; (ii) the S region, where only stars exist; (iii) the GS region, where both gas and stars exist. An application is made to a subsample of elliptical galaxies investigated within the SAURON project. Different models characterized by equal subsystem mass ratio and different scaled truncation radii, are considered and the related position of sample objects on the (Mv-Mp) plane is determined. Tipically, fast rotators are found to lie within the S region, while slow rotators are close (from both sides) to the boundary between the S and the GS region. The net effect of the uncertainty affecting observed quantities, on the position of sample objects on the (Mv-Mp) plane, is also investigated. Finally, a principle of corresponding states is formulated for macrogases with assigned density profiles and scaled truncation radii.
The imprints of the instantaneous appearance of a conformal Killing vector field on the evolution of self-gravitating fluid spheres
Instituto Universitario de Física Fundamental y Matemáticas, Universidad de Salamanca（萨拉曼卡大学基础物理与数学大学研究所）；Escuela de Física, Facultad de Ciencias, Universidad Central de Venezuela（委内瑞拉中央大学理学院物理系）；Departamento de Matemática Aplicada and Instituto Universitario de Física Fundamental y Matemáticas, Universidad de Salamanca（萨拉曼卡大学应用数学系及基础物理与数学大学研究所）
