银盘恒星的年龄-金属丰度关系研究

该文回顾了恒星的AMR(年龄-金属丰度关系)研究的历史,评述了研究的现状;介绍和比较了确定恒星年龄和金属丰度的有关方法;分析和讨论了最近有关AMR研究的4个大样本工作,分别利用每两样本之间的共同样本星,详细比较了它们分别给出的恒星年龄、金属丰度和AMR;结果表明样本的选择效应以及确定恒星年龄和金属丰度的方法或采用参数的不同都会影响AMR.通过比较选取了恒星年龄比较一致且金属丰度精度相对较高的2个样本,分别包括4 007和1 042颗恒星,用纯运动学标准确定了各自的星族成分,分别讨论了薄盘和厚盘恒星的AMR,结果显示厚盘恒星的存在明显的AMR,而薄盘恒星的A:MR不如厚盘那么明显,也提出了进一步研究AMR需要开展的几项工作.     

Mass-height relation for antimatter meteors

A formula to compute the mass-height relation for the case of possible antimatter meteor entrance is derived.It is governed by the annihilation cross section for the atom-antiatom interactions which experimentally is unknown,and by various mechanisms which are possibly reducing its value. For the special case of thermal energies,the annihilation cross-section _an may be connected with the elastic cross-section_el by the relation % MathType!MTEF!2!1!+-% feaafeart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeq4Wdm3aaS% baaSqaaiaabggacaqGUbaabeaakiabg2da9iabeo8aZnaaBaaaleaa% caqGLbGaaeiBaaqabaGccqGHpis1caWGMbWaaSbaaSqaaiaadMgaae% qaaaaa!4227!\[\sigma _{{\rm{an}}} = \sigma _{{\rm{el}}} \prod f_i \],where the factors % MathType!MTEF!2!1!+-% feaafeart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamOzamaaBa% aaleaacaWGPbaabeaaaaa!37F1!\[f_i \]are all less or equal to unity. Among them, the most significant is the barrier factor % MathType!MTEF!2!1!+-% feaafeart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamOzamaaBa% aaleaacaWGIbaabeaaaaa!37EA!\[f_b \] _b described by many scientists, which may possibly reduce the annihilation cross-section down to lower than 10^–11 times than that of a simple elastic collision. The above formula could also be found useful, for some applications, which are currently in progress.     

Velocity-height relation for antimatter meteors

A general velocity-height relation for both antimatter and ordinary matter meteor is derived. This relation can be expressed as % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaSaaaeaacq% aHfpqDdaWgaaWcbaGaamOEaaqabaaakeaacqaHfpqDdaWgaaWcbaGa% eyOhIukabeaaaaGccqGH9aqpcaqGLbGaaeiEaiaabchacaqGGaWaam% WaaeaacqGHsisldaWcaaqaaiaadkeaaeaacaWGHbaaaiaabwgacaqG% 4bGaaeiCaiaabIcacaqGTaGaamyyaiaadQhacaGGPaaacaGLBbGaay% zxaaGaeyOeI0YaaSaaaeaacaWGdbaabaGaamOqaiabew8a1naaBaaa% leaacqGHEisPaeqaaaaakmaacmaabaGaaGymaiabgkHiTiaabwgaca% qG4bGaaeiCamaadmaabaGaeyOeI0YaaSaaaeaacaWGcbaabaGaamyy% aaaacaqGLbGaaeiEaiaabchacaqGOaGaaeylaiaadggacaWG6bGaai% ykaaGaay5waiaaw2faaaGaay5Eaiaaw2haaiaacYcaaaa!64FD!\[\frac{{\upsilon _z }}{{\upsilon _\infty }} = {\text{exp }}\left[ { - \frac{B}{a}{\text{exp( - }}az)} \right] - \frac{C}{{B\upsilon _\infty }}\left\{ {1 - {\text{exp}}\left[ { - \frac{B}{a}{\text{exp( - }}az)} \right]} \right\},\]where _z is the velocity of the meteoroid at height z, its velocity before entrance into the Earth's atmosphere, is the scale-height, and C parameter proportional to the atom-antiatom annihilation cross- section, which is experimentally unknown. The parameter B (B = DA₀/m) is the well known parameter for koinomatter (ordinary matter) meteors, D is the drag factor, ₀ is the air density at sea level, A is the cross sectional area of the meteoroid and m its mass.When the annihilation cross-section is zero — in the case of ordinary meteors — the parameter C is also zero and the above derived equation becomes % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaSaaaeaacq% aHfpqDdaWgaaWcbaGaamOEaaqabaaakeaacqaHfpqDdaWgaaWcbaGa% eyOhIukabeaaaaGccqGH9aqpcaqGLbGaaeiEaiaabchacaqGGaWaam% WaaeaacqGHsisldaWcaaqaaiaadkeaaeaacaWGHbaaaiaabwgacaqG% 4bGaaeiCaiaabIcacaqGTaGaamyyaiaadQhacaGGPaaacaGLBbGaay% zxaaGaaiilaaaa!4CF5!\[\frac{{\upsilon _z }}{{\upsilon _\infty }} = {\text{exp }}\left[ { - \frac{B}{a}{\text{exp( - }}az)} \right],\]which is the well known velocity-height relation for koinomatter meteors.In the case in which the Universe contains antimatter in compact solid structure, the velocity-height relation can be found useful.Work performed mainly at the Nuclear Physics Laboratory of the National University of Athens, Greece.     

Mass-luminosity relation for massive stars

A catalog of massive (⩾10 M _⊙) stars in binary and multiple systems with well-known masses and luminosities has been compiled. The catalog is analyzed using a theoretical mass-luminosity relation. This relation allows both normal main-sequence stars and stars with peculiarities: with clear manifestations of mass transfer, mass accretion, and axial rotation, to be identified. Least-squares fitting of the observational data in the range of stellar masses 10M _⊙ ⩽ M ≲ 50 M _⊙ yields the relation L ∼ M ^2.76. An erratum to this article is available at .     

The redshift-magnitude relation for galaxies

An analysis of the redshift-magnitude data for the 98 clusters of the list of Sandage and Hardy (1973) is repeated taking into account both the effect of richness and Bautz-Morgan classification on the absolute magnitude of the brightest members. We find that while the relationship between M and B-M class—whatever it is—does not change the value ofq ₀ theM-r relation is so dependent on the model of the Universe that we cannot use all the clusters in the analysis unless we establish that relation in an independent way. The analysis of richness 1 and 2 clusters support an open model of the Universe (q ₀<0.5) while the uncertainties in the attribution of richness to the three most distant clusters do not permit to discard the steady state.     

Luminosity-HI velocity width relation for spirals

Multicolour and multiaperture photometry of 22 late-type Virgo cluster galaxies in a newV (5500 Å),r (6738 Å),IV (10500 Å) system confirm the previously known correlations between the luminosity and H₁ velocity width, and show them to be strongly wavelength dependent with the slope of the relation reaching a maximum value of ～ ? 10 at 10500 Å and remaining constant at longer wavelengths. The scatter in the luminosity-H₁ width relation is nearly the same, whether we use (V)^c _?0.5, (r)^c _?0.5, (IV)^c _-0.5, or (H)^c _-0.5 magnitudes. The error in the determination of the corrected magnitudes is much less than the scatter in the luminosity-H₁ width relations as evidenced by the fact that the residuals of individual galaxies inV, r, IV, andH are correlated with one another. An attempt to use a ‘kinematic magnitude’ instead of an isophotal magnitude shows the slope of the luminosity-H₁ width relations to be reduced substantially. Observations in theV, r, andIV system for fifteen field galaxies and three galaxies in the Cancer and Zw 74-23 clusters have been obtained and combined with the H₁ velocity width to derive their differences in distance modulus, between the galaxy and the Virgo cluster, through the luminosity-H₁ width relations of the Virgo cluster galaxies. The three independent differences in the distance modulus of each galaxy agree with one another indicating that the relations usingV, r andIV magnitudes have the same zero point in absolute magnitude, independent of the wavelength of observations. The distance modulus difference from the Virgo cluster to the three galaxies U 4334, U 8942 and U 8944, which are outside the Local Supercluster, are +1·50, +3·45 and +2·81 mag respectively and are in agreement with those of +1·75, +3·23 and +2·46 mag derived for the same galaxies by Aaronsonet al. (1980) throughH magnitudes. The scatter in the velocity distance relation of the field galaxies compares well with the mean error derived in the luminosity-H_I width relations and hence is intrinsic.     

A recurrence relation for inclination functions

When the terms of the series expansion for the gravitational potential of the Earth are expressed in terms of the orbital elements of an arbitrary Earth satellite, the orbital inclination,i, appears in each, term as the argument of a function of inclination only. For the special case when the field is axi-symmetric, studied in an earlier paper, a recurrence relation was given for a normalized inclination function,A ^k l(i), with two parameters. The present paper gives a recurrence relation for a general normalized function,K ^k lm(i), with three parameters.     

On the period-luminosity-colour relation for galactic Cepheids

A period-luminosity-colour relation is derived from the data of 29 galactic Cepheids with known distances collected from the literature, and is then compared with the simpler period-luminosity relation. The insignificant reduction in the dispersion seems to argue against the introduction of the colour term. It is, however, demonstrated that this evidence may be fictitious and due to the use of Cepheids, whose membership in a star aggregate is still doubtful. The exclusion of these stars leads to a PLC relation which shows a significantly smaller dispersion than that given by the corresponding PL relation.     

A dispersion relation for open spiral galaxies

The Lin-Shu dispersion relation is applicable in the (asymptotic) case of tight spirals (large wave numberk _R). Here we reconsider the various steps leading to the Lin-Shu dispersion relation in higher approximation, under the assumption that the wave numberk _R is not large [(k _Rr) =O(1)], and derive a new dispersion relation. This is valid for open spiral waves and bars. We prove that this dispersion relation is the appropriate limit of the nonlinear self-consistency condition in the case where the linear theory is applicable.     

The color-redshift relation for giant elliptical galaxies

The colors of giant elliptical (gE) galaxies in clusters out to redshiftz=0.2, observed by Oke and Sandage (1968), are studied for systematic color-redshift effects. To reveal any intrinsic changes, theK term is subtracted from each color, after correction for galactic reddening and the resulting (B-V) _c -K _B-V versus z relation analysed. If the Oke and SandageK terms (relevant to nuclear colors) are used, the best fitting linear relation shows negligible change withz. But if the Whitford (1970)K terms (relevant to integrated colors) are used, there is a trend to bluer colors, by 0.07 mag.atz=0.2 if higher weight is given the better observed clusters. An upper limit, of ±0.08 mag. atz=0.2, is set to possible systematic aperture effects, by the total change between nuclear and integrated B-V and U-B of nearbygE galaxies.The color-redshift trends, interpreted as evolutionary changes, are related to evolution in the magnitude-redshift relation by means of models of stellar evolution in agE galaxy. If one uses the linear fit to the color-redshift relation obtained with WhitfordK terms and neglect of any aperture effects (which is the appropriate case if Oke and Sandage used large enough apertures), and if one adopts plausible limits to the ratio between color and magnitude evolution, the effect of evolution in the magnitude-redshift relation results in a negative value ofq ₀. There are still substantial observational and theoretical uncertainties affecting this conclusion.     

A PRC relation for delta Scuti stars

The absolute radii of 78 Scuti variables in the Catalogue of the Geneva Observatory have been computed. A PRC relation among the period, radius and color has been obtained.     

The angular momentum-vs-mass relation for spectroscopic binaries

The spectroscopic binaries, considered as a single data point, fall roughly on the universal power-law of index 1.8 for angular momentum vs total mass, as defined by planets, spiral galaxies, and numerous other objects. But the individual systems in theSeventh Catalogue of the Orbital Elements of Spectroscopic Binary Systems define a curve of rather shallower slope, 1.63±0.07, over more than two orders of magnitude in mass and four in angular momentum. Various subsets (long and short periods; single and double line systems; known and unknown orbital orientations) all yield slopes from 1.48 to 1.77. These values, as well as the slightly larger one found for eclipsing systems by Sisteró and Marton, are very much what one would expect, given the form of Kepler's Third Law and the Stellar mass-radius relation.If only these well-known pieces of physics are at work, then the still-wider visual binaries should yield a slope near 5/3. Catalogues currently in press will permit easy testing of this prediction. It seems unlikely that deep clues to the origin of either binary systems or angular momentum are to be found from considerations of this nature.     

The Kukarkin-Parenago relation for dwarf novae and novae

The period-amplitude relation and the period-energy relation for dwarf novae and novae are discussed. The total outbursts energy is shown to be a more suitable characteristic of the outburst than its amplitude.Paper presented at the IAU Colloquium No. 93 on Cataclysmic Variables. Recent Multi-Frequency Observations and Theoretical Developments, held at Dr. Remeis-Sternwarte Bamberg, F.R.G., 16–19 June, 1986.     

The empirical mass-luminosity relation for low mass stars

This work is devoted to improving empirical mass-luminosity relations (MLR) and mass-metallicity-luminosity relation (MMLR) for low mass stars. For these stars, observational data in the mass-luminosity plane or the mass-metallicity-luminosity space subject to non-negligible errors in all coordinates with different dimensions. Thus a reasonable weight assigning scheme is needed for obtaining more reliable results. Such a scheme is developed, with which each data point can have its own due contribution. Previous studies have shown that there exists a plateau feature in the MLR. Taking into account the constraints from the observational luminosity function, we find by fitting the observational data using our weight assigning scheme that the plateau spans from 0.28M_⊙ to 0.50M_⊙. Three-piecewise continuous improved MLRs in K, J, H and V bands, respectively, are obtained. The visual MMLR is also improved based on our K band MLR and the available observational metallicity data.