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双语推荐：星系

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使用了目前最大的棒旋星系样本之一,着重于研究旋涡星系中央的比恒星形成率(sSFR)和棒结构的关系。我们用1g sSFR=-11 a~(-1)作为星系宁静态和活跃态的分界,统计对比了棒旋星系和非棒旋星系中央的sSFR,发现相对于非棒旋星系,棒旋星系处于中央宁静态的比重更大,而在中央活跃态其恒星形成活动更剧烈。为消除星系样本恒星质量差异对星系中央sSFR统计结果的影响,获得控制样本,使棒旋星系和非棒旋星系具有相同的恒星质量分布。随后发现这两类星系在中央宁静态中的统计差异消失,而在中央活跃态棒旋星系的恒星形成活动依旧相对剧烈,尤其体现在长棒星系中。这说明棒结构对旋涡星系中央的恒星形成起到促进作用,且作用效果与棒的长短相关。
We investigate the effects of bars in spiral galaxies on galaxy central specific Star Formation Rate (sSFR) using a sample of over 9000 spiral galaxies drawn from Sloan Digital Sky Survey, with morphological classifications assigned by visual inspection. Our sample includes three types: none-barred galaxies and galaxies hosting long or short bars, respectively. By identifying star-forming and quiescent population, we find barred spiral galaxies tend to be central quiescent. However, the star-forming barred spiral galaxies tend to have stronger central star forming activities than the unbarred spiral galaxies. In order to find the connection between central sSFR and the presence of a bar within the spiral galaxy, we construct control samples where barred and unbarred ones are closely matched by stellar mass. We then find the same proportion of central quiescent galaxies for barred and unbarred ones. Furthermore, the star-forming barred ones still have stronger central star for

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收集了89个Seyfert星系样本,利用反响映射法和恒星弥散速度法计算了Seyfert星系的黑洞质量,分别研究了Seyfert 1和Seyfert 2星系的黑洞质量与吸积率、热光度和红移之间的相关性,结果发现Seyfert 1星系的黑洞质量与吸积率、热光度和红移之间具有强相关性,Seyfert 2星系的黑洞质量与吸积率之间具有弱的负相关性,与热光度和红移之间具有弱相关性.两类Seyfert星系的区别除了源于吸积盘倾角不同外,还可能与星系的环境、演化和星系核的活动有关.
In this paper, we collected 89 samples of Seyfert galaxies, calculated the black hole mass of Seyfert galaxies using the reverberation mapping method and the central velocity disper-sion respectively,and studied the correlation between the black hole mass of Seyfert 1 and Sey-fert 2 galaxies,accretion rate,bolometric luminosity and the redshift.There are strong correla-tions between black hole mass of Seyfert 1 and accretion rate,between the black hole mass of Seyfert 1 and the bolometric luminosity,and between the black hole mass of Seyfert 1 and the redshift,while there are weak negative correlation between the black hole mass of Seyfert 2 and the accretion rate,weak correlation between the black hole mass of Seyfert 2 and the bolometric luminosity,and between the black hole mass of Seyfert 2 and the redshift.The differences be-tween the two kinds of Seyfert galaxies not only be due to the different aspect angles,may also be due to the environment,the evolution of galaxies and activi

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面向类（face-on）旋涡星系盘的有效厚度或标高不能通过表面亮度测光的方式测量，为了获得面向类旋涡星系盘的厚度参数,将基于三维星系盘引力势Poisson方程在等角对数螺旋型物质密度扰动情形下的解,运用一种解析法对面向类旋涡星系盘的标高进行测算，为了去除星系核球的光污染而获得旋臂最内点位置（ro）的重要参数,使用了在星系观测图像中扣除双成份（盘＋核球）测光模型的图像处理方法，通过对旋涡星系相关结构参数的拟合测量,各得到了一个普通旋涡星系（S）与棒旋星系（SB）的有效厚度与相关参数,并给出了它们的球盘比（rb/rd）和星系盘的标长与厚度之比（rd/H），采用这种在观测图像中扣除双成份测光模型的方法,将更容易看清旋臂结构的最内端,因而这里获得的禁区半径ro的数值往往比从原星系图像上直接测量的数值要小,获得的星系盘有效厚度将更薄。
It is uneasy to obtain the disk thickness of face-on spiral galaxies by mea-suring the galactic light distributions. Here we obtain the spiral galactic disk thickness based on an asymptotic expression of Poisson’s equation for a logarithmic perturbation of matter density in spiral galaxies. For measuring the key parameter of the innermost position of the spiral arm (forbidden radius r0) freed from the contamination by the light of bulge, an improved image processing method is used in this study by subtract-ing a decomposition brightness model from the galactic observed image. On the basis of measuring some fundamental parameters of spiral structures, we obtain the disk thickness and some other parameters of two (types S and SB) face-on spiral galaxies, and their ratio parameters (rb/rd and rd/H ) are also derived. By using this improved subtracted-method, it is easy to measure the forbidden radius r0, which is smaller than that obtained from unsubtracted-method.

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不少河外星系的周边发现有不同形态的恒星潮汐流,它们大多源自主星系潮汐力场对伴星系的作用,少数来自球状星团,而对它们进行探测有着重要的天体物理意义。对几个代表性河外星系的潮汐流、星系团环境中的星流结构、潮汐流探测的统计性质和球状星团潮汐尾的探测现状及若干相关问题作了简要介绍。
Many stellar tidal streams around external galaxies have been found since 1998. Most of such streams that can be observationally detected are formed from striped matter of nearby dwarf satellites, and a few ones from old globular clusters, which are usually with relatively small sizes and can also be called as tidal tails of clusters. A lot of observational and theoretical studies on the tidal streams have been done during recent more than 10 years, including tidal streams of individual field galaxies and in environment of galaxy clusters, statistics of tidal streams, tidal tails of globular clusters etc. Andromeda galaxy (M31) is the best one which can be studied in detail so as to detect its halo substructure such as tidal streams. In the early 20th century, a great southern stellar stream in M31 was found, which is 100 kpc further away along the line of sight than M31 and some 30 kpc in front of the galaxy. Then, the complex structure of the M31 stellar halo was also detected, which

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冷核是指在一部分X射线星系团中出现的低温高亮的核状结构。冷核星系团在X射线表面亮度轮廓、温度轮廓、中心冷却时间、质量沉积率、熵轮廓等多个方面具有与非冷核星系团截然不同的观测特征。星系团冷核的发现距今已有40年,人们对冷核的认识经历了由冷流模型到稳定冷核模型的转变。但是直到今天,冷核的产生机制和维持条件仍未完全弄清。研究冷核对于理解活动星系核产能机制、星系际元素增丰过程、星系团的形成与演化、大尺度结构形成等众多领域具有非常重要的意义。
Cool cores are common structures in the center of X-ray luminous galaxy clusters. Present observations indicate that the fraction of cool-core clusters is about 50%or even larger. The dense intra-cluster medium in cool cores emits very strong X-ray radiation through bremsstrahlung, thus forms a sharply peaked X-ray surface brightness distribution, while the temperature is lower than the virial temperature. The energy loss is so fast that the cooling time of a cool core can be shorter than the age of the cluster. These phenomenons always indicate the existence of a cool core. However, so far a clear definition of a cool-core cluster is not established. Parameters such as the surface brightness concentration, the central cooling time, and the mass deposition rates all work for the low redshift clusters, but their reliabilities in high redshifts are not verified. As the gas is cooling, the mass deposition rates are not as large as predicted by the classical cooling flow theory. There is s

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通过利用CANDELS-EGS（Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey-Extended Groth Strip）场中HST WFC3（Hubble Space Telescope Wide Field Camera 3）F160W高分辨率的观测图像,研究了9个光谱红极亮红外星系的形态结构特征，发现这些星系的形态表现出多样性（从椭圆到多个亮核或弥散的结构）,如：双核,气体桥,双不对称体,不规则或椭圆结构，为了定量地研究这些极亮红外星系的形态,测量了它们在静止光学波段的形态参数（基尼系数G和矩指数M20），与近邻极亮红外星系相比,高红移极亮红外星系的G偏小而M20偏大,表明这些星系的星族分布聚集度小且不对称性大，基于对样本中极亮红外星系2维面亮度轮廓的拟合,得到这些星系的有效半径分布在2.4 kpc到5.8 kpc之间,其平均值是（3.9±1.1）kpc，相比较于近邻相似质量的恒星形成星系来说,高红移极亮红外星系的平均大小要小1到2倍.在类似红移和红外光度条件下,得出的这些结果也与其它文献中给出的结论相一致。
Using high-resolution HST WFC3 (Hubble Space Telescope Wide Field Camera 3) F160W imaging from the CANDELS-EGS (Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey-Extended Groth Strip) field, we present the mor-phology analysis of 9 ultraluminous infrared galaxies (ULIRGs) at z ≈ 2. We find a wide range of morphological diversities for these ULIRGs, from spheroid to multiple bright nuclei or diffuse structures, e.g., double nuclei, bridges, dual asymmetries, irreg-ular, or elliptical structures. In quantitative, these sources show a lower Gini coe?cient (G) and a higher moment (M20) in the rest-frame optical morphology, compared to the lower redshift counterparts, indicating less concentrated and symmetric spatial distri-bution of the stellar mass of ULIRGs at z≈2. Moreover, we derive accurate effective radii of these ULIRGs through 2-D profile fitting, which range from 2.4 to 5.8 kpc, with a mean value of (3.9 ± 1.1) kpc. We find that the sizes of these ULIRGs

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观测显示星系中的大部分恒星是双星，因此星族合成研究必须考虑双星的作用。综述双星对星族合成研究的重要性。主要讨论了双星对早型星系和球状星团的能谱、谱指数、颜色、颜色-星等图、星系参数确定和恒星形成历史研究的影响。主要结论为双星有助于对星系和星团的光谱、颜色-星等图的解释，以及对星系和星团多个参数的准确确定。因此，双星是准确星族合成研究的必然要求。
Observations show that most stars are in binaries, which indicates that binaries should be taken into account in stellar popu-lation synthesis studies. This paper reviews the importance of binaries in the studies of stellar populations. The effects of binaries on the spectral energy distributions, line strength indices, colours, colour-magnitude diagrams, parameter determinations, and star forma-tion histories are discussed. The review shows that binaries are very helpful for the explanations of spectra and colour-magnitude dia-grams of galaxies and star clusters, and they also affect the determinations of many important parameters. Therefore, the inclusion of bi-naries is a natural trend for future stellar population studies.

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当前的研究表明,在小质量星系或者恒星形成率高的星系中,Ia型超新星有高的诞生率。没有经过光度经验校正,在大质量、高金属丰度、年老的、早型演化的星系中的Ia型超新星更暗;但是经过光度校正以后,亮的超新星更倾向于出现在大质量、高金属丰度、年老的、早型演化的星系中。因为高金属丰度的前身星系统是富中子的,使得在超新星爆发过程中物质更稳定地燃烧,这样产生的56Ni就很少,而56Ni提供的衰变能是Ia型超新星光度的重要来源,会导致高金属丰度环境下的Ia型超新星光变曲线下降更快而且也更暗;但是经过光度校正以后,高金属丰度环境下的Ia型超新星更亮。不同星系环境下的金属丰度不同,因而Ia型超新星56Ni产生率不同,这可能是对超新星光度与星系统计关系的最合理解释。综述了Ia型超新星的诞生率以及光度与寄主星系的统计关系。
We mainly present the dependence of SNe Ia rate and luminosity on their host galaxies. Firstly, we show that the host galaxy mass is lower or host star-formation rate is higher, SNe Ia rate will be larger. Secondly, we show that before light-curve correction, dimmer SNe Ia fluently occur in higher mass, higher star-formation rate, higher metal abundance, or older stellar galaxy system. However, after light-curve correction, brighter SNe Ia fluently occur in higher mass, higher star-formation rate, higher metal abundance, or older stellar galaxy system. Higher-metallicity pro-genitors are more neutron rich, producing more stable burning products relative to radioactive 56Ni. Since SNe Ia explosions are powered by the radioactive decay 56Ni, it is widely accepted that the intrinsic variation in SNe Ia brightness and decline rate is primarily driven by the amount of 56Ni present in SNe explosion, where more luminous and much slowly declining explosions are powered by more 56Ni, hence, und

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针对假定的目标覆盖区域,运用STK软件进行卫星仿真与覆盖分析,通过比较6星系统和15星系统,设计经济同时有效的卫星系统,对指定区域进行24h不间断地卫星覆盖侦察。
This paper assumes that the target coverage area,satellite simulation and coverage analysis using STK software, through the comparison of six star and ten star system, satellite system design economy effectively at the same time,24 hours of uninterrupted coverage of satellite reconnaissance to the designated area.

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指出了COMPASS、GPS、GLONASS和GALILEO多星系兼容共用互操作的必要性，分析了多星系兼容导航传统算法的不足，给出了一种高效实用的在用户级由七状态变量过渡到四状态变量和序贯处理四个星系间系统时差的用户位置、速度、时间滤波解算方法。
The necessity of compatibility and interoperability for COMPASS, GPS, GLONASS and GALILEO multi-satellites system is pointed out and the shortcomings of traditional algorithm for compatibility navigation of multi-satellites system are analyzed. A method of transition from seven state-variables to four state-variables and sequence processing of the difference of system time in four constellations is presented.

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