Reanalysis of the Isotopic Mixture of Neutron-Capture Elements in the Metal-Poor Star HD 175305
ZHANG Jiang1,2,3**, WANG Bo1,2, ZHANG Bo4, HAN Zhan-Wen1,2
1National Astronomical Observatories/Yunnan Observatory, Chinese Academy of Sciences, Kunming 650011 2Key Laboratory for the Structure and Evolution of Celestial Objects, Chinese Academy of Sciences, Kunming 650011 3School of Mathematics and Science, Shijiazhuang University of Economics, Shijiazhuang 050016 4Department of Physics, Hebei Normal University, Shijiazhuang 050016
Reanalysis of the Isotopic Mixture of Neutron-Capture Elements in the Metal-Poor Star HD 175305
ZHANG Jiang1,2,3**, WANG Bo1,2, ZHANG Bo4, HAN Zhan-Wen1,2
1National Astronomical Observatories/Yunnan Observatory, Chinese Academy of Sciences, Kunming 650011 2Key Laboratory for the Structure and Evolution of Celestial Objects, Chinese Academy of Sciences, Kunming 650011 3School of Mathematics and Science, Shijiazhuang University of Economics, Shijiazhuang 050016 4Department of Physics, Hebei Normal University, Shijiazhuang 050016
摘要The neutron-capture process is traditionally postulated to be responsible for the nucleosynthesis of heavy elements beyond Fe. Based on the least squares method and solar isotopic abundances from the classical model, we estimate the relative contributions of the s- and r-processes to the abundance of neutron-capture elements in the metal-poor star HD 175305 from the component coefficients. Applying the calculated component coefficients Cr and Cs, the model predicts the isotopic fractions of elements Nd, Sm and Eu to be f142+144=0.482, f152+154=0.525 and f151=0.450, respectively. As well as the observed abundances, the isotropic fractions are also consistent with the calculations. Finally, for the first time, we estimated the contribution percentage of the two neutron processes (the r− and s-processes) from the observed isotopic fractions of different elements in HD 175305, e.g. an r-process contribution of 67%-32%+21% from the 4604 Å line of Sm.
Abstract:The neutron-capture process is traditionally postulated to be responsible for the nucleosynthesis of heavy elements beyond Fe. Based on the least squares method and solar isotopic abundances from the classical model, we estimate the relative contributions of the s- and r-processes to the abundance of neutron-capture elements in the metal-poor star HD 175305 from the component coefficients. Applying the calculated component coefficients Cr and Cs, the model predicts the isotopic fractions of elements Nd, Sm and Eu to be f142+144=0.482, f152+154=0.525 and f151=0.450, respectively. As well as the observed abundances, the isotropic fractions are also consistent with the calculations. Finally, for the first time, we estimated the contribution percentage of the two neutron processes (the r− and s-processes) from the observed isotopic fractions of different elements in HD 175305, e.g. an r-process contribution of 67%-32%+21% from the 4604 Å line of Sm.
ZHANG Jiang;**;WANG Bo;ZHANG Bo;HAN Zhan-Wen;. Reanalysis of the Isotopic Mixture of Neutron-Capture Elements in the Metal-Poor Star HD 175305[J]. 中国物理快报, 2012, 29(1): 19701-019701.
ZHANG Jiang, **, WANG Bo, ZHANG Bo, HAN Zhan-Wen,. Reanalysis of the Isotopic Mixture of Neutron-Capture Elements in the Metal-Poor Star HD 175305. Chin. Phys. Lett., 2012, 29(1): 19701-019701.
[1] Burbidge et al 1957 Rev. Mod. Phys. 29 547
[2] Cameron A G W 1957 Astron. J. 62 9
[3] Cowan J J, Thielemann F K and Truran J W 1991 Phys. Rep. 208 267
[4] Arnould M, Goriely S and Takahashi K 2007 Phys. Rep. 450 97
[5] Busso M, Gallino R and Wasserburg G J 1999 Annu. Rev. Astron. Astrophys. 37 239
[6] Herwig F 2005 Annu. Rev. Astron. Astrophys. 43 435
[7] Izutani N, Umeda H and Tominaga N 2009 Astrophys. J. 692 1517
[8] Sneden C et al 2009 Astrophys. J. Suppl. 182 80
[9] Gallino R et al 1998 Astrophys. J. 497 388
[10] The L S, El Eid M F and Meyer B S 2007 Astrophys. J. 655 1058
[11] Magain P 1995 Astron. Astrophys. 297 686
[12] Sneden C et al 2002 Astrophys. J. 566 25
[13] Lambert D L and Allende Prieto C 2002 Mon. Not. R. Astron. Soc. 335 325
[14] Aoki W, Honda S, Beers T C and Sneden C 2003 Astrophys. J. 586 506
[15] Mashonkina L and Zhao G 2006 Astron. Astrophys. 456 313
[16] Lundqvist M, Wahlgren G M and Hill V 2007 Astron. Astrophys. 463 693
[17] Roederer I U et al 2008 Astrophys. J. 675 723
[18] Gallagher A J et al 2010 Astron. Astrophys. 523 24
[19] Smith V V and Lambert D L 1990 Ap. J. Suppl. 72 387
[20] Yong D, Lambert D L and Ivans I I 2003 Astrophys. J. 599 1357
[21] Spite M et al 2006 Astron. Astrophys. 455 291
[22] Meléndez J and Cohen J G 2007 Astrophys. J. 659 L25
[23] Hughes G L et al 2008 Mon. Not. R. Astron. Soc. 390 1710
[24] Kratz K L et al 2007 Astrophys. J. 662 39
[25] Sneden C, Cowan J J and Gallino R 2008 Annu. Rev. Astron. Astrophys. 46 241
[26] Howard W A et al 1986 Astrophys. J. 309 633
[27] Aoki W et al 2001 Astrophys. J. 561 346
[28] Zhang B, Ma K and Zhou G D 2006 Astrophys. J. 642 1075
[29] Goswami A and Aoki W 2009 Mon. Not. R. Astron. Soc. 404 253
[30] Zhang B et al 1999 Astrophys. J. 513 910
[31] Zhang J, Cui W Y and Zhang B 2010 Mon. Not. R. Astron. Soc. 402 956
[32] Li J et al 1999 Chin. Phys. Lett. 16 619
[33] Cowan J J and Sneden C 2006 Nature 440 1151
[34] Arlandini C et al 1999 Astrophys. J. 525 886
[35] Lodders K 2003 Astrophys. J. 591 1220
[36] Qian Y Z and Wasserburg G J 2007 Phys. Rep. 442 237
[37] Travaglio C et al 2004 Astrophys. J. 601 864
[38] Zhang J, Cui W Y and Zhang B 2010 Mon. Not. R. Astron. Soc. 409 1068
[39] Cui D N et al 2009 Chin. Phys. Lett. 26 039701