Neutron-Capture Elements in the Double-Enhanced Star HE 1305-0007: a New s- and r-Process Paradigm
CUI Wen-Yuan 1,2,3, CUI Dong-Nuan1, DU Yun-Shuang1, ZHANG Bo 1,2
1Department of Physics, Hebei Normal University, Shijiazhuang 0500162National Astronomical Observatories, Chinese Academy of Sciences, Beijing 1000123Graduate School of the Chinese Academy of Sciences, Beijing 100049
Neutron-Capture Elements in the Double-Enhanced Star HE 1305-0007: a New s- and r-Process Paradigm
CUI Wen-Yuan 1,2,3;CUI Dong-Nuan1;DU Yun-Shuang1;ZHANG Bo 1,2
1Department of Physics, Hebei Normal University, Shijiazhuang 0500162National Astronomical Observatories, Chinese Academy of Sciences, Beijing 1000123Graduate School of the Chinese Academy of Sciences, Beijing 100049
摘要The star HE 1305-0007 is a metal-poor double-enhanced star with metallicity [Fe/H] =-2.0, which is just at the upper limit of the metallicity for the observed double-enhanced stars. Using a parametric model, we find that almost all s-elements were made in a single neutron exposure. This star should be a member of a post-common-envelope binary. After the s-process material has experienced only one neutron exposure in the nucleosynthesis region and is dredged-up to its envelope, the AGB evolution is terminated by the onset of common-envelope evolution. Based on the high radial-velocity of HE 1305-0007, we speculate that the star could be a runaway star from a binary system, in which the AIC event has occurred and produced the r-process elements.
Abstract：The star HE 1305-0007 is a metal-poor double-enhanced star with metallicity [Fe/H] =-2.0, which is just at the upper limit of the metallicity for the observed double-enhanced stars. Using a parametric model, we find that almost all s-elements were made in a single neutron exposure. This star should be a member of a post-common-envelope binary. After the s-process material has experienced only one neutron exposure in the nucleosynthesis region and is dredged-up to its envelope, the AGB evolution is terminated by the onset of common-envelope evolution. Based on the high radial-velocity of HE 1305-0007, we speculate that the star could be a runaway star from a binary system, in which the AIC event has occurred and produced the r-process elements.
CUI Wen-Yuan;;CUI Dong-Nuan;DU Yun-Shuang;ZHANG Bo;. Neutron-Capture Elements in the Double-Enhanced Star HE 1305-0007: a New s- and r-Process Paradigm[J]. 中国物理快报, 2007, 24(5): 1417-1420.
CUI Wen-Yuan, , CUI Dong-Nuan, DU Yun-Shuang, ZHANG Bo,. Neutron-Capture Elements in the Double-Enhanced Star HE 1305-0007: a New s- and r-Process Paradigm. Chin. Phys. Lett., 2007, 24(5): 1417-1420.
[1] Hill V et al 2000 Astron. Astrophys. 353 557 [2] Cohen J G et al 2003 Astrophys. J. 588 1082 [3] Qian Y Z and Wasserburg G J 2003 Astrophys. J. 588 1099 [4] Zijlstra A A 2004 Mon. Not. R. Astron. Soc. 348 L23 [5] Zhang B, Ma K and Zhou G D 2006 Astrophys. J. 642 1075 [6] Barbuy B et al 2005 Astron. Astrophys. 429 1031 [7] Wanajo S et al 2005 Astrophys. J. 636 842 [8] Gallino R et al 1998 Astrophys. J. 497 388 [9] Gallino R et al 2003 Nucl. Phys. A 718 181 [10] Straniero O et al 1995 Astrophys. J. 440 L85 [11] Straniero O, Gallino R and Cristallo S 2006 Nucl. Phys. A 777 311 [12] Cohen J G et al 2005 Astrophys. J. 633 L109 [13] Goswami A et al 2006 Mon. Not. R. Astron. Soc. 372 343 [14] Busso M et al 2001 Astrophys. J. 557 802 [15] Aoki W et al 2001 Astrophys. J. 561 346 [16] Arlandini C et al 1999 Astrophys. J. 525 886 [17] Cui W Y et al 2007 Astrophys. J. 657 1037 [18] Ma K, Cui W Y and Zhang B 2007 Mon. Not. R. Astron.Soc. 375 1418 [19] Iben I Jr 1977 Astrophys. J. 217 788 [20] Groenewegen M A T and de Jong T 1993 Astron.Astrophys. 267 410 [21] Karakas A I, Lattanzio J C and Pols O R 2002 Publ. Astron.Soc. Australia 19 515 [22] Cui W Y and Zhang B 2006 Mon. Not. R. Astron. Soc. 368 305 [23] Herwig F 2000 Astron. Astrophys. 360 952 [24] Herwig F 2004 Astrophys. J. 605 425 [25] Fujimoto M Y, Ikeda Y and Iben I Jr 2000 Astrophys.J. 529 L25 [26] Iwamoto N et al 2003 Nucl. Phys. A 718 193 [27] Travaglio C et al 2004 Astrophys. J. 601 864
2007, Vol. 24 
