电子的自旋S=\sqrt{1/2 * (1/2+1)}\hbar;
假设电子是一个实体的球状，半径为r，它的转动惯量为I=2/5 m_e r^2;
其中电子质量m_e＝9.1E-28g,
自旋转动角动量则为L=I w,
假设电子在个半径处角速度都相等，并且角速度w假设满足在r处线速度为光速c（角速度不能再大了），这对应着电子的最小半径，则w=v/r=c/r
由S=L，得
\sqrt{3/4}\hbar = 2/5 m_e r^2 c/r
解得r_min=8.3E-11cm
可是这个半径比测出来的上限10^-16cm要大得多啊，也比经典半径10^-13cm大。怎么回事呢？
会不会电子自身也存在一个“驻波”，就像电子在原子核外稳定存在要形成驻波样（这也是出现能级分离的原因）。
星期三, 十二月 27, 2006
星期一, 十二月 25, 2006
星期日, 十二月 24, 2006
EPR对能做的三件事
就是两个相干的电子，被分到远处，一人拿一个，想到了三个应用：
一、攻城。假设这两人是古代的将军，分别站在城的东北角和西南角，然后上下测量一下各自手中的电子，如果将军A测到的是上，就攻对应的一个门，而将军B测到的是下，并知道A要攻那个门，于是可以达到协同作战的目的，并且不需要通信，也不需要预先商量，因此不怕泄密，而且连他们自己预先都不知道。（这算不算信息的超光速传输？）
二、 密码传送。反正密码也不非当事人指定不可，只要能加密和解密东西就可以了。比如A和B各拿两个电子，测一下上下，于是得到了一个两位的二进制数，就用它做密码，然后A把加密的密文传给B。好处是密码是临时产生的，连当事人都不能预先知道，不会泄密；密钥不需要中间传输过程，不会被窃听（这是一般加密方法所难应付的）。
三、划拳（或者叫投标）。 生活中有一种事情，就是AB两人要把自己的心事告诉对方，但有怕对方会根据自己说的改变本来应该说的，于是采用一种办法：将内容写在纸上，然后同时交给对方看。更具体的一个例子就是：AB两人（仅此二人）对一个东西竞标，显然是出的越少越好，但又要大于对方，最好的办法就是把标价写在纸上。 但如果两人相距很远呢？你说我们通过视频，也许是个办法；不过用EPR对却可以做得更好。两人首先要拥有两套EPR对，分别用于传出和接受，传出是利用“隐形传态”技术，将自己想传的内容作用在己方电子上，然后对方的电子就处于自己想表达的态上，但是现在对方并不能测量，因为他不知道是该测上下，还是左右方向。等这边传好，那边也传好之后，告诉对方是测哪个方向（这个方向即可以是统一的，也可以是对每个电子都不同的）。然后根据所得的方向信息测量结果。这样做的好处是不需要第三方，即不用节外生枝。（因为投标都是 有一个组织方，他们收取标书，这一方又需要监督，不然会产生信任问题，于是问题复杂。其实监督方也是需要监督的，于是监督机制只不过是现实中把腐败在往小的方向压缩，但逻辑上是不能解决信任问题的）注意这里还可能产生作弊现象：如果B先得到方向，（这点时间差是要允许的）利用很短的时间看到了A要说的，发现自己不能中标了，于是就把自己的方向乱给，这样B也能测出东西，但是是随机的数，于是就可能比B所出的标要大了。对付这种作弊需要额外增加一些东西传输作为验证，就是增加几位，这几位是有确定意义的，比如说要求后三位全为零，这样，如果是随机方向，测到的就只有1／8的可能全为零。如果增加校验的位数，发现作弊的可能性越大。另外还要注意的是在传出数据之后己方应该摧毁传输装置或者用什么方法保证确实已经传了而不能之后再有什么动作。
一、攻城。假设这两人是古代的将军，分别站在城的东北角和西南角，然后上下测量一下各自手中的电子，如果将军A测到的是上，就攻对应的一个门，而将军B测到的是下，并知道A要攻那个门，于是可以达到协同作战的目的，并且不需要通信，也不需要预先商量，因此不怕泄密，而且连他们自己预先都不知道。（这算不算信息的超光速传输？）
二、 密码传送。反正密码也不非当事人指定不可，只要能加密和解密东西就可以了。比如A和B各拿两个电子，测一下上下，于是得到了一个两位的二进制数，就用它做密码，然后A把加密的密文传给B。好处是密码是临时产生的，连当事人都不能预先知道，不会泄密；密钥不需要中间传输过程，不会被窃听（这是一般加密方法所难应付的）。
三、划拳（或者叫投标）。 生活中有一种事情，就是AB两人要把自己的心事告诉对方，但有怕对方会根据自己说的改变本来应该说的，于是采用一种办法：将内容写在纸上，然后同时交给对方看。更具体的一个例子就是：AB两人（仅此二人）对一个东西竞标，显然是出的越少越好，但又要大于对方，最好的办法就是把标价写在纸上。 但如果两人相距很远呢？你说我们通过视频，也许是个办法；不过用EPR对却可以做得更好。两人首先要拥有两套EPR对，分别用于传出和接受，传出是利用“隐形传态”技术，将自己想传的内容作用在己方电子上，然后对方的电子就处于自己想表达的态上，但是现在对方并不能测量，因为他不知道是该测上下，还是左右方向。等这边传好，那边也传好之后，告诉对方是测哪个方向（这个方向即可以是统一的，也可以是对每个电子都不同的）。然后根据所得的方向信息测量结果。这样做的好处是不需要第三方，即不用节外生枝。（因为投标都是 有一个组织方，他们收取标书，这一方又需要监督，不然会产生信任问题，于是问题复杂。其实监督方也是需要监督的，于是监督机制只不过是现实中把腐败在往小的方向压缩，但逻辑上是不能解决信任问题的）注意这里还可能产生作弊现象：如果B先得到方向，（这点时间差是要允许的）利用很短的时间看到了A要说的，发现自己不能中标了，于是就把自己的方向乱给，这样B也能测出东西，但是是随机的数，于是就可能比B所出的标要大了。对付这种作弊需要额外增加一些东西传输作为验证，就是增加几位，这几位是有确定意义的，比如说要求后三位全为零，这样，如果是随机方向，测到的就只有1／8的可能全为零。如果增加校验的位数，发现作弊的可能性越大。另外还要注意的是在传出数据之后己方应该摧毁传输装置或者用什么方法保证确实已经传了而不能之后再有什么动作。
星期二, 十二月 19, 2006
冬天树林里晒太阳比广场上暖和
因为树林可以档风啊。
建立一个理想模型：树林都成针状垂直于地面，太阳直射，这样从树林里向太阳方向看，“光深”为零，而向四周看，如果树林足够大的话，“光深”为无穷，既然光进不来，风也进不来了，因此这里比广场暖和。呵呵
建立一个理想模型：树林都成针状垂直于地面，太阳直射，这样从树林里向太阳方向看，“光深”为零，而向四周看，如果树林足够大的话，“光深”为无穷，既然光进不来，风也进不来了，因此这里比广场暖和。呵呵
星期日, 十二月 17, 2006
星期三, 十一月 22, 2006
Zanjani2003 电和磁场中里德堡原子的实验研究
博士论文
通过实验研究在静电场和磁场下的高里德堡态原子。
HIGH RESOLUTION MICROWAVE SPECTROSCOPY OF ULTRA COLD RYDBERG ATOMS AS A PROBE OF ELECTRIC AND MAGNETIC FIELDS
by
Parisa Bohlouli Zanjani
A thesis presented to the University of Waterloo in fulfillment of the thesis requirement for the degree of Master of Science in Physics
Waterloo, Ontario, 2003
Parisa Bohlouli Zanjani, 2003
通过实验研究在静电场和磁场下的高里德堡态原子。
HIGH RESOLUTION MICROWAVE SPECTROSCOPY OF ULTRA COLD RYDBERG ATOMS AS A PROBE OF ELECTRIC AND MAGNETIC FIELDS
by
Parisa Bohlouli Zanjani
A thesis presented to the University of Waterloo in fulfillment of the thesis requirement for the degree of Master of Science in Physics
Waterloo, Ontario, 2003
Parisa Bohlouli Zanjani, 2003
Lai2001 强磁场中的物质
综述强磁场中的物质，包括原子，分子，凝聚态等。也是以天文为背景的。
Matter in strong magnetic fields
Dong Lai
REVIEWS OF MODERN PHYSICS, VOLUME 73：629, JULY 2001
Matter in strong magnetic fields
Dong Lai
REVIEWS OF MODERN PHYSICS, VOLUME 73：629, JULY 2001
Turbiner2006 强磁场下的单电子分子 4
基于对单中子星1E1207.4 − 5209的谱的观测，指出在强磁场中的单电子系统中，氢原子不是能量最低的，因此氢分子离子等是可能稳定存在的。
One-electron molecular systems in a strong magnetic field
Alexander V. Turbiner∗,1, Juan Carlos López Vieyra
Physics Reports 424 (2006) 309 – 396
One-electron molecular systems in a strong magnetic field
Alexander V. Turbiner∗,1, Juan Carlos López Vieyra
Physics Reports 424 (2006) 309 – 396
Harding2006 中子星强磁场物理 4
综述了中子星表面强磁场的影响以及观测应用。天文背景浓。
Physics of strongly magnetized neutron stars
Alice K Harding and Dong Lai
Rep. Prog. Phys. 69 (2006) 2631–2708
Physics of strongly magnetized neutron stars
Alice K Harding and Dong Lai
Rep. Prog. Phys. 69 (2006) 2631–2708
Lieb 1992 中子星表面的重原子
考虑强磁场，原子序数，将计算分为5个区，分别近似计算。
Heavy atoms in the strong magnetic field of a Neutron Star
Lieb et al
PRL， 1992， 69， 749
Heavy atoms in the strong magnetic field of a Neutron Star
Lieb et al
PRL， 1992， 69， 749
Kravchenko1996 强磁场下氢原子的精确解
计算均匀磁场下的氢原子
Highly Accurate Solution for a Hydrogen Atom in a Uniform Magnetic Field
Yu. P. Kravchenko,1,2 M. A. Liberman,1,2 and B. Johansson1
The highly accurate series solution for a hydrogen atom in a uniform magnetic field of arbitrary strength is obtained. It is derived in the form of a power series in two variables, the radius and the sine of the cone angle, with explicit recurrent relations for the coefficients of the power series. As an illustration, a brief list of energy values with accuracy 10212 hartree for the magnetic field
0 < B < 4000 and pictures of selected anticrossings in the chaotic region of the spectrum are presented.
VOLUME 77, NUMBER 4 PHYS I CAL RE V I EW LETTERS 22 JULY 1996
Highly Accurate Solution for a Hydrogen Atom in a Uniform Magnetic Field
Yu. P. Kravchenko,1,2 M. A. Liberman,1,2 and B. Johansson1
The highly accurate series solution for a hydrogen atom in a uniform magnetic field of arbitrary strength is obtained. It is derived in the form of a power series in two variables, the radius and the sine of the cone angle, with explicit recurrent relations for the coefficients of the power series. As an illustration, a brief list of energy values with accuracy 10212 hartree for the magnetic field
0 < B < 4000 and pictures of selected anticrossings in the chaotic region of the spectrum are presented.
VOLUME 77, NUMBER 4 PHYS I CAL RE V I EW LETTERS 22 JULY 1996
Heyl1998 强磁场中少电子原子分子的计算
计算了氢原子，氦原子和氢分子离子的波函数等。
PHYSICAL REVIEW A VOLUME 58, NUMBER 5 NOVEMBER 1998
Hydrogen and helium atoms and molecules in an intense magnetic field
Jeremy S. Heyl* and Lars Hernquist
We calculate the atomic structure of hydrogen and helium atoms and molecules in an intense magnetic field analytically and numerically with a judiciously chosen basis.
PHYSICAL REVIEW A VOLUME 58, NUMBER 5 NOVEMBER 1998
Hydrogen and helium atoms and molecules in an intense magnetic field
Jeremy S. Heyl* and Lars Hernquist
We calculate the atomic structure of hydrogen and helium atoms and molecules in an intense magnetic field analytically and numerically with a judiciously chosen basis.
Kravchenko1996 任意磁场下氢原子的精确解
主要是给出了氢原子的各能级随磁场的变化。
氢原子的哈密顿量：
Exact solution for a hydrogen atom in a magnetic field of arbitrary strength
Yu. P. Kravchenko and M. A. Liberman
An exact solution describing the quantum states of a hydrogen atom in a homogeneous magnetic field of arbitrary strength is obtained in the form of a power series in the radial variable with coefficients being polynomials in the sine of the polar angle. Energy levels and wave functions for the ground state and for several excited states are calculated exactly for the magnetic field varying in the range 0< B/(m^2e^3c/h^3) < 4000.
氢原子的哈密顿量：
Exact solution for a hydrogen atom in a magnetic field of arbitrary strength
Yu. P. Kravchenko and M. A. Liberman
An exact solution describing the quantum states of a hydrogen atom in a homogeneous magnetic field of arbitrary strength is obtained in the form of a power series in the radial variable with coefficients being polynomials in the sine of the polar angle. Energy levels and wave functions for the ground state and for several excited states are calculated exactly for the magnetic field varying in the range 0< B/(m^2e^3c/h^3) < 4000.
Braun2002 强磁场中原子的能级计算
二维密度泛函计算强磁场中的原子能级。包括He，C，N和He的一些激发态。
与multi-Landau-channel Hartree-Fock calculations方法做了比较。
说明进一步的计算还没有做，也很困难。
Density-functional calculations in a two-dimensional finite-element basis for atoms in very strong magnetic fields: Energy values
Author M. Braun
PHYSICAL REVIEW A, VOLUME 65, 033415
与multi-Landau-channel Hartree-Fock calculations方法做了比较。
说明进一步的计算还没有做，也很困难。
Density-functional calculations in a two-dimensional finite-element basis for atoms in very strong magnetic fields: Energy values
Author M. Braun
PHYSICAL REVIEW A, VOLUME 65, 033415
Kondratyev2001 强磁场对原子核质量的影响
在磁场达到10^16G以上之后，会影响到原子核的质量。（属于 原子核的内容）
THE ASTROPHYSICAL JOURNAL, 546:1137È1148, 2001 January 10
MAGNETIC FIELD EFFECT ON MASSES OF ATOMIC NUCLEI
V. N. KONDRATYEV,1 TOSHIKI MARUYAMA, AND SATOSHI CHIBA
Advanced Science Research Center, Japan Atomic Energy Research Institute, 2-4 Shirane, Tokai-mura, Naka-gun, Ibaraki 319-1195 Japan
THE ASTROPHYSICAL JOURNAL, 546:1137È1148, 2001 January 10
MAGNETIC FIELD EFFECT ON MASSES OF ATOMIC NUCLEI
V. N. KONDRATYEV,1 TOSHIKI MARUYAMA, AND SATOSHI CHIBA
Advanced Science Research Center, Japan Atomic Energy Research Institute, 2-4 Shirane, Tokai-mura, Naka-gun, Ibaraki 319-1195 Japan
星期二, 十一月 21, 2006
Potekhin1997 强磁场下氢原子的电离
不采用绝热近似（绝热近似是什么？忘了）计算了氢原子的电离。是以朗道能级为基础的。
Astron. Astrophys. 317, 618 629 (1997)
Ionization of the hydrogen atom in strong magnetic elds
Beyond the adiabatic approximation
A.Y. Potekhin1;2;3, G.G. Pavlov4;1, and J.Ventura2;3
Astron. Astrophys. 317, 618 629 (1997)
Ionization of the hydrogen atom in strong magnetic elds
Beyond the adiabatic approximation
A.Y. Potekhin1;2;3, G.G. Pavlov4;1, and J.Ventura2;3
Miller1991 强磁场中原子的计算
用Hartree－Fock方法计算了多个原子的能级和振子强度。自认为此方法可以扩展，计算更高序数的原子。
| Title: | Atoms in very strong magnetic fields | |
| Authors: | Miller, M. C.; Neuhauser, D. | |
| Affiliation: | AA(Illinois, University, Urbana), AB(California Institute of Technology, Pasadena) | |
| Publication: | Royal Astronomical Society, Monthly Notices (ISSN 0035-8711), vol. 253, Nov. 1, 1991, p. 107-122. (MNRAS Homepage) | |
| Publication Date: | 11/1991 |
星期一, 十一月 20, 2006
Pavlov2005 强磁场中的一价氦原子
计算了强磁场中的一价氦原子的能级。
这篇文章至少说明结合天文背景的原子能谱计算还有大量可以做的工作。
The Astrophysical Journal, 635:L61–L64, 2005 December 10
ONCE-IONIZED HELIUM IN SUPERSTRONG MAGNETIC FIELDS
George G. Pavlov1 and Victor G. Bezchastnov2,3
Received 2005 April 15; accepted 2005 November 1; published 2005 November 30
ABSTRACT
It is generally believed that magnetic fields of some neutron stars, the so-called magnetars, are enormously strong,
up to 1014–1015 G. Recent investigations have shown that the atmospheres of magnetars are possibly composed of
helium. We calculate the structure and bound-bound radiative transitions of the He ion in superstrong fields,
including the effects caused by the coupling of the ion’s internal degrees of freedom to its center-of-mass motion.
We show that He in superstrong magnetic fields can produce spectral lines with energies of up to ≈3 keV, and it
may be responsible for absorption features detected recently in the soft X-ray spectra of several radio-quiet isolated
neutron stars. Quantization of the ion’s motion across a magnetic field results in a fine structure of spectral lines,
with a typical spacing of tens of electron volts in magnetar-scale fields. It also gives rise to ion cyclotron transitions,
whose energies and oscillator strengths depend on the state of the bound ion. The bound-ion cyclotron lines of He
can be observed in the UV-optical range at G, and they get into the soft X-ray B 1013 range at B 1014 G.
Subject headings: atomic processes—line: formation—stars: individual (1E 1207.45209)—
stars: magnetic fields—stars: neutron—X-rays: stars
这篇文章至少说明结合天文背景的原子能谱计算还有大量可以做的工作。
The Astrophysical Journal, 635:L61–L64, 2005 December 10
ONCE-IONIZED HELIUM IN SUPERSTRONG MAGNETIC FIELDS
George G. Pavlov1 and Victor G. Bezchastnov2,3
Received 2005 April 15; accepted 2005 November 1; published 2005 November 30
ABSTRACT
It is generally believed that magnetic fields of some neutron stars, the so-called magnetars, are enormously strong,
up to 1014–1015 G. Recent investigations have shown that the atmospheres of magnetars are possibly composed of
helium. We calculate the structure and bound-bound radiative transitions of the He ion in superstrong fields,
including the effects caused by the coupling of the ion’s internal degrees of freedom to its center-of-mass motion.
We show that He in superstrong magnetic fields can produce spectral lines with energies of up to ≈3 keV, and it
may be responsible for absorption features detected recently in the soft X-ray spectra of several radio-quiet isolated
neutron stars. Quantization of the ion’s motion across a magnetic field results in a fine structure of spectral lines,
with a typical spacing of tens of electron volts in magnetar-scale fields. It also gives rise to ion cyclotron transitions,
whose energies and oscillator strengths depend on the state of the bound ion. The bound-ion cyclotron lines of He
can be observed in the UV-optical range at G, and they get into the soft X-ray B 1013 range at B 1014 G.
Subject headings: atomic processes—line: formation—stars: individual (1E 1207.45209)—
stars: magnetic fields—stars: neutron—X-rays: stars
Bhattacharyya2006 中子星表面原子谱线的形状
中子星表面的原子谱线不仅要受到磁场的影响，还会受到因旋转导致的多普勒效应，还有狭义和广义相对论效应。对于弱磁场的种子星，磁场的影响甚至 可以忽略。
The Astrophysical Journal, 644:1085–1089, 2006 June 20
THE SHAPES OF ATOMIC LINES FROM THE SURFACES
OF WEAKLY MAGNETIC ROTATING NEUTRON STARS AND THEIR IMPLICATIONS
Sudip Bhattacharyya,1 M. Coleman Miller,1, 2 and Frederick K. Lamb3, 4
Received 2004 December 6; accepted 2006 March 3
ABSTRACT
Motivated by the report by Cottam et al. of iron resonance scattering lines in the spectra of thermonuclear bursts
from EXO 0748676, we have investigated the information about neutron star structure and the geometry of the
emission region that can be obtained by analyzing the profiles of atomic lines formed at the surface of the star. We
have calculated the detailed profiles of such lines, taking into account the star’s spin and the full effects of special and
general relativity, including light bending and frame dragging. We discuss the line shapes produced by rotational
Doppler broadening and magnetic splitting of atomic lines for the spin rates and magnetic fields expected in neutron
stars in low-mass X-ray binary systems.We show that narrow lines are possible even for rapidly spinning stars if the
emission region or the line of sight are close to the spin axis. For most neutron stars in low-mass systems, magnetic
splitting is too small to obscure the effects of special and general relativity.We show that the ratio of the star’s mass to
its equatorial radius can be determined to within 5% using atomic line profiles, even if the lines are broad and skewed.
This is the precision required to constrain strongly the equation of state of neutron star matter.We show further that if
the radius and latitude of emission are known to 5%–10% accuracy, then frame dragging has a potentially detectable
effect on the profiles of atomic lines formed at the stellar surface.
Subject headinggs: equation of state — line: profiles — relativity — stars: neutron — stars: rotation —
X-rays: stars
The Astrophysical Journal, 644:1085–1089, 2006 June 20
THE SHAPES OF ATOMIC LINES FROM THE SURFACES
OF WEAKLY MAGNETIC ROTATING NEUTRON STARS AND THEIR IMPLICATIONS
Sudip Bhattacharyya,1 M. Coleman Miller,1, 2 and Frederick K. Lamb3, 4
Received 2004 December 6; accepted 2006 March 3
ABSTRACT
Motivated by the report by Cottam et al. of iron resonance scattering lines in the spectra of thermonuclear bursts
from EXO 0748676, we have investigated the information about neutron star structure and the geometry of the
emission region that can be obtained by analyzing the profiles of atomic lines formed at the surface of the star. We
have calculated the detailed profiles of such lines, taking into account the star’s spin and the full effects of special and
general relativity, including light bending and frame dragging. We discuss the line shapes produced by rotational
Doppler broadening and magnetic splitting of atomic lines for the spin rates and magnetic fields expected in neutron
stars in low-mass X-ray binary systems.We show that narrow lines are possible even for rapidly spinning stars if the
emission region or the line of sight are close to the spin axis. For most neutron stars in low-mass systems, magnetic
splitting is too small to obscure the effects of special and general relativity.We show that the ratio of the star’s mass to
its equatorial radius can be determined to within 5% using atomic line profiles, even if the lines are broad and skewed.
This is the precision required to constrain strongly the equation of state of neutron star matter.We show further that if
the radius and latitude of emission are known to 5%–10% accuracy, then frame dragging has a potentially detectable
effect on the profiles of atomic lines formed at the stellar surface.
Subject headinggs: equation of state — line: profiles — relativity — stars: neutron — stars: rotation —
X-rays: stars
Sanwal2002 孤立中子星1E 1207.4－5209的X射线谱
1E 1207.4－5209是超新星遗迹PKS 1209－51/52中的一颗孤立中子星，文章给了Chandra对它X射线的谱的观测。在0.7和1.4keV上有明显的吸收。一个可能的解释是一价氦原子在强磁场中的跃迁。
The Astrophysical Journal, 574:L61–L64, 2002 July 20
DISCOVERY OF ABSORPTION FEATURES IN THE X-RAY SPECTRUM OF AN ISOLATED NEUTRON STAR
D. Sanwal,1 G. G. Pavlov,1 V. E. Zavlin,2 and M. A. Teter1
Received 2002 April 19; accepted 2002 June 17; published 2002 June 24
ABSTRACT
We observed 1E 1207.45209, a neutron star in the center of the supernova remnant PKS 120951/52, with
the ACIS detector aboard the Chandra X-Ray Observatory and detected two absorption features in the source
spectrum. The features are centered near 0.7 and 1.4 keV; their equivalent widths are about 0.1 keV. We discuss
various possible interpretations of the absorption features and exclude some of them. A likely interpretation is
that the features are associated with atomic transitions of once-ionized helium in the neutron star atmosphere
with a strong magnetic field. The first clear detection of absorption features in the spectrum of an isolated neutron
star provides an opportunity to measure the mass-to-radius ratio and to constrain the equation of state of the
superdense matter.
Subject headings: pulsars: individual (1E 1207.45209)—stars: neutron—
supernovae: individual (PKS 120951/52)—X-rays: stars
The Astrophysical Journal, 574:L61–L64, 2002 July 20
DISCOVERY OF ABSORPTION FEATURES IN THE X-RAY SPECTRUM OF AN ISOLATED NEUTRON STAR
D. Sanwal,1 G. G. Pavlov,1 V. E. Zavlin,2 and M. A. Teter1
Received 2002 April 19; accepted 2002 June 17; published 2002 June 24
ABSTRACT
We observed 1E 1207.45209, a neutron star in the center of the supernova remnant PKS 120951/52, with
the ACIS detector aboard the Chandra X-Ray Observatory and detected two absorption features in the source
spectrum. The features are centered near 0.7 and 1.4 keV; their equivalent widths are about 0.1 keV. We discuss
various possible interpretations of the absorption features and exclude some of them. A likely interpretation is
that the features are associated with atomic transitions of once-ionized helium in the neutron star atmosphere
with a strong magnetic field. The first clear detection of absorption features in the spectrum of an isolated neutron
star provides an opportunity to measure the mass-to-radius ratio and to constrain the equation of state of the
superdense matter.
Subject headings: pulsars: individual (1E 1207.45209)—stars: neutron—
supernovae: individual (PKS 120951/52)—X-rays: stars
Cottam2006 中子星中引力红移后的谱
文章对X射线双星EXO 0748-676的X射线暴做了观测，辨认出了一些铁线，发现引力红移值在0.35.
Comments: Published in Nature (Nov 7, 2002)
Journal-ref: Nature 420 (2002) 51-54
Gravitationally redshifted absorption lines in the X-ray burst spectra of a neutron star
Authors: J. Cottam (1), F. Paerels (2), M. Mendez (3) ((1) NASA/GSFC, (2) Columbia, (3) SNON)Comments: Published in Nature (Nov 7, 2002)
Journal-ref: Nature 420 (2002) 51-54
The fundamental properties of neutron stars provide a direct test of the equation of state of cold nuclear matter, a relationship between pressure and density that is determined by the physics of the strong interactions between the particles that constitute the star. The most straightforward method of determining these properties is by measuring the gravitational redshift of spectral lines produced in the neutron star photosphere. The equation of state implies a mass-radius relation, while a measurement of the gravitational redshift at the surface of a neutron star provides a direct constraint on the mass-to-radius ratio. Here we report the discovery of signficant absorption lines in the spectra of 28 bursts of the low-mass X-ray binary EXO 0748-676. We identify the most signficant features with the Fe XXVI and XXV n=2-3 and O VIII n=1-2 transitions, all with a redshift of z=0.35, identical within small uncertainties for the respective transitions. For an astrophysically plausible range of masses (M ~ 1.3-2.0 M_solar), this value is completely consistent with models of neutron stars composed of normal nuclear matter, while it excludes some models in which the neutron stars are made of more exotic matter.
Burwitz2002 孤立中子星RX J1856.5-3754的热谱观测
由Chamdra和XMM－Newton观测。此文是反面的，认为辐射可以用两个黑体成分拟合，而不是强磁场中的原子谱。
The thermal radiation of the isolated neutron star RX J1856.5-3754 observed with Chandra and XMM-Newton
Authors: V. Burwitz, F. Haberl, R. Neuhaeuser, P. Predehl, J. Truemper, V.E. Zavlin (Max-Planck-Institut fuer extraterrestrische Physik (MPE Garching))Comments: 6 pages, (including 3 figures) accepted for publication in Astronomy and Astrophysics (A&A)
Journal-ref: Astron.Astrophys. 399 (2003) 1109-1114
We present results of the analysis of data collected in 57-ks XMM-Newton and 505-ks Chandra observations of the nearby ~= 120 pc isolated neutron star RX J1856.5-3754. We confirm most of the statements made by Burwitz et al. (2001) who discussed the original 55-ks Chandra data. Detailed spectral analysis of the combined X-ray and optical data rules out the currently available nonmagnetic light and heavy element neutron star atmosphere (LTE) models with hydrogen, helium, iron and solar compositions. We find that strongly magnetized atmosphere models also are unable to represent the data. The X-ray and optical data show no spectral features and are best fitted with a two-component blackbody model with kT_{bb,X}^{\infty} ~= 63.5 eV and R_{bb,X}^{\infty} ~= 4.4(d/120 pc) km for the hot X-ray emitting region, and kT_{bb,opt}^{\infty}<33>17(d/120 pc) km for the rest of the neutron star surface responsible for the optical flux. The large number of counts collected with XMM-Newton allows us to reduce the upper limit on periodic variation in the X-ray range down to 1.3% (at a 2\sigma confidence level) in the 10^{-3}-50 Hz frequency range. In an attempt to explain this small variability, we discuss an one-component model with kT_{bb}^{\infty} ~= 63 eV and R_{bb}^{\infty} ~= 12.3(d/120 pc) km. This model requires a low radiative efficiency in the X-ray domain, which may be expected if the neutron star has a condensed matter surface.
星期五, 十一月 10, 2006
星期五, 十月 27, 2006
星期四, 十月 05, 2006
Verma2006 FeIX的精细结构 2
计算给出了FeIX的80多个能级. 扩展了NIST的数据.
The Astrophysical Journal Supplement Series, 164:297-305, 2006 May
New Relativistic Atomic Data for Fe IX
Nupur Verma , Alok K. S. Jha , and Man MohanThe Astrophysical Journal Supplement Series, 164:297-305, 2006 May
星期四, 九月 28, 2006
Medin2006 用密度泛函理论(DFT)计算强磁场中的物质ii 3
主要内容:
这一篇主要就是讲关于非原子分子的更复杂的物质在强磁场中. (Lai Dong有一篇RMP上强磁场中物质的文章, 2001.) 在他们文章中, 与第i篇所不同只不过是原子的个数不同而已, 就是H_N中的N比较大而已.
精彩摘抄:
文章信息:
astro-ph/0607166
Density-Functional-Theory Calculations of Matter in Strong Magnetic Fields: II. Infinite Chains and Condensed Matter
Authors: Zach Medin, Dong Lai (Cornell)
这一篇主要就是讲关于非原子分子的更复杂的物质在强磁场中. (Lai Dong有一篇RMP上强磁场中物质的文章, 2001.) 在他们文章中, 与第i篇所不同只不过是原子的个数不同而已, 就是H_N中的N比较大而已.
精彩摘抄:
文章信息:
astro-ph/0607166
Density-Functional-Theory Calculations of Matter in Strong Magnetic Fields: II. Infinite Chains and Condensed Matter
Authors: Zach Medin, Dong Lai (Cornell)
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