局域物态方程对中子星整体性质的影响
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摘要
由于高密非对称核物质核核相互作用的复杂性,使得目前人们对高密非对称核物质的物态方程的认识还存在很大的不确定性。利用逐段修改物态方程的方法,探究了不同密度段物态方程对中子星整体性质的影响,尤其是对典型中子星(1.4 M_⊙)半径及最大质量的影响。研究进一步证实了在2倍饱和核密度附近的物态方程对典型质量中子星的半径有显著影响。还进一步分析了中子星的质量半径关系曲线特征及其斜率(dM/dR)对物态方程的依赖性,发现d M/d R主要由饱和核密度以上的中子星物质的物态方程决定。探索不同密度段物态方程对中子星整体性质的影响以及探索dM/dR对物态方程的依赖性,主要是为将来利用中子星的天文观测来反向约束致密物质的物态方程提供理论参考。
Because of the complicacy of the interaction between the nucleon-nucleon for high density matters,up to now the equation of state(EOS) of the unsymmetrical high-density nuclear matter is still uncertain. In order to investigate the imprint on the global properties by some special part of the EOS, we designedly modify part of the EOS and explore the corresponding effect on the stellar properties, especially on the radius of the typical neutron star(1.4 M⊙) and the maximum stellar mass of the neutron star sequence for a given EOS. It is further proved by our calculation that the EOS around 2 times of the saturation nuclear density has an obvious imprint on the stellar radius of a typical neutron star. In addition, we also investigate the dependence of the mass-radius curve and its slope(d M/d R) on the EOS. It is found that the slope(d M/d R) is mainly determined by the EOS above the saturation nuclear density. In fact, the investigations above will provide some useful theoretical reference.This is expected to conversely constrain the EOS of dense matter by using the future astronomic observation data of neutron star.
Because of the complicacy of the interaction between the nucleon-nucleon for high density matters,up to now the equation of state(EOS) of the unsymmetrical high-density nuclear matter is still uncertain. In order to investigate the imprint on the global properties by some special part of the EOS, we designedly modify part of the EOS and explore the corresponding effect on the stellar properties, especially on the radius of the typical neutron star(1.4 M⊙) and the maximum stellar mass of the neutron star sequence for a given EOS. It is further proved by our calculation that the EOS around 2 times of the saturation nuclear density has an obvious imprint on the stellar radius of a typical neutron star. In addition, we also investigate the dependence of the mass-radius curve and its slope(d M/d R) on the EOS. It is found that the slope(d M/d R) is mainly determined by the EOS above the saturation nuclear density. In fact, the investigations above will provide some useful theoretical reference.This is expected to conversely constrain the EOS of dense matter by using the future astronomic observation data of neutron star.
引文
[1] OPPENHEIMER J R, VOLKOFF G M. Physical Review,1939, 55:374.
[2] TOLMAN R C. Physical Review, 1939, 55:364.
[3] MORRISON I A, BAUMGARTE T W, SHAPIRO S L, et al. Astrophysical Journal, 2004, 617(2):L135.
[4] LINDBLOM L. Astrophysical Journal, 1992, 398(2):569.
[5] OZEL F, FREIRE P. Annual Review of Astronomy and Astrophysiocs, 2016, 54:401.
[6] ANTONIADIS J, WHELAN D G. Science, 2013, 340(6131):1233232.
[7] LATTIMER J M, PRAKASH M. Astrophysical Journal,2000, 550(1):426.
[8] OZEL F, PSALTIS D. Phys Rev D, 2009, 80(10):363.
[9] HAENSEL P, POTEKHIN A Y, YAKOVLEV D G. Neutron Stars 1:Equation of State and Structure[C]//Astrophysics and Space Science Library. Astrophysics and Space Science Library, 2006:363.
[10] LATTIMER J M. Annual Review of Nuclear and Particle Science, 2012, 62(1):485.
[11] XIAO Z, LI B A, CHEN L W, et al. Phys Rev Lett, 2009,102(6):062502.
[12] FENG Z Q, JIN G M. Phys Lett B, 2010, 683(2-3):140.
[13] XIE W J, ZHANG F S. Phys Lett B, 2013, 718(4-5):1510.
[14] AKMAL A, PANDHARIPANDE V R, RAVENHALL D G.Phys Rev C, 1998, 58(3):1804.
[15] WEN Dehua, LI Bao’an, PLAMEN G. Phys Rev C, 2009,80(2):801.
[16] HEBELER K, LATTIMER J M, PETHICK C J, et al. Astrophysical Journal, 2013, 773(1):773.
[2] TOLMAN R C. Physical Review, 1939, 55:364.
[3] MORRISON I A, BAUMGARTE T W, SHAPIRO S L, et al. Astrophysical Journal, 2004, 617(2):L135.
[4] LINDBLOM L. Astrophysical Journal, 1992, 398(2):569.
[5] OZEL F, FREIRE P. Annual Review of Astronomy and Astrophysiocs, 2016, 54:401.
[6] ANTONIADIS J, WHELAN D G. Science, 2013, 340(6131):1233232.
[7] LATTIMER J M, PRAKASH M. Astrophysical Journal,2000, 550(1):426.
[8] OZEL F, PSALTIS D. Phys Rev D, 2009, 80(10):363.
[9] HAENSEL P, POTEKHIN A Y, YAKOVLEV D G. Neutron Stars 1:Equation of State and Structure[C]//Astrophysics and Space Science Library. Astrophysics and Space Science Library, 2006:363.
[10] LATTIMER J M. Annual Review of Nuclear and Particle Science, 2012, 62(1):485.
[11] XIAO Z, LI B A, CHEN L W, et al. Phys Rev Lett, 2009,102(6):062502.
[12] FENG Z Q, JIN G M. Phys Lett B, 2010, 683(2-3):140.
[13] XIE W J, ZHANG F S. Phys Lett B, 2013, 718(4-5):1510.
[14] AKMAL A, PANDHARIPANDE V R, RAVENHALL D G.Phys Rev C, 1998, 58(3):1804.
[15] WEN Dehua, LI Bao’an, PLAMEN G. Phys Rev C, 2009,80(2):801.
[16] HEBELER K, LATTIMER J M, PETHICK C J, et al. Astrophysical Journal, 2013, 773(1):773.