Two R-Process Components in Ultra-Metal-Poor Stars: The Neutron-Capture Element Distribution of CS 22892-052 |
| |
Authors: | Bo Zhang Ji Li Yue-Xiang Wang Yan-Xia Zhang Jun-Hong Liu Qiu-He Peng |
| |
Institution: | (1) Department of Physics, Hebei Normal University, Shijiazhuang, 050016, P.R. China;(2) Chinese Academy of Sciences –, Peking University Joint Beijing Astrophysical Center, Beijing, 100871, P.R. China;(3) Beijing Astronomical Observatory, Beijing, 100012, P.R. China;(4) Department of Physics, Shijiazhuang Teacher's College, Shijiazhuang, 050054, P.R. China;(5) Department of Astronomy, Nanjing University, Nanjing, 210093, P.R. China |
| |
Abstract: | The abundance patterns of neutron-capture elements in very metal-poor halo stars play a crucial role in guiding and constraining
theoretical models of nucleosynthesis. Many studies have suggested that the abundance patterns of the heavier (Z≥ 56) stable neutron-capture elements in very metal-poor halo stars are consistent with the solar system r-process abundance distribution, but this concordance breaks down for the lighter neutron-capture elements in the range of
40<Z<56. Some studies argue that there are two separate r-processes respectively responsible for the productions of the heavier and lighter neutron-capture elements. The new observed
data of the lighter n-capture elements in the 40<Z<56 domain (Nb, Ru, Rh, Pd, Ag and Cd) in CS 22892-052 makes it available to examine whether or not there are two different
r-processes. Based upon these observed abundances of n-capture elements in ultra metal-poor star CS22892-052, we present a phenomenological model to identify the characters of
the different nucleosynthesis processes in very metal-poor stars. The results show that the model predictions can well match
the observations in CS 22892-052, which truly means that there are different r-processes for the lighter and heavier neutron-capture elements, and the stellarr-process patterns are similar to the solar system r-process abundance distribution.
This revised version was published online in July 2006 with corrections to the Cover Date. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|