The Effect Of Zonal Tides On The DynamicalEllipticity Of The EarthAnd Its Influence On The Nutation

In this paper, the expressions of variations of the dynamical ellipticity and the principal moments of inertia due to the deformations produced by the zonal part of the tidal potential are obtained. Starting from these expressions, we have studied from equations related to Hamiltonian theory, their effects on the nutation and finally we have evaluated numerically such influences, with a level of truncation at 0.1 μas. Thus we have shown that some coefficients are quite large with respect to the usual accuracy of up-to-date observations. This revised version was published online in July 2006 with corrections to the Cover Date.     

The Availability of Phosphorus in The Bacterial Model of The Interstellar Grains

It is shown that phosphorus availability is in close balance with the phosphorus requirement of the bacterial grain model. This correspondence, which would be fortuitous if the interstellar grains were of inorganic origin, points to the correctness of the biological model. This revised version was published online in July 2006 with corrections to the Cover Date.     

The lunar exosphere: The sputtering contribution

We have extended our Monte Carlo model of exospheres [Wurz, P., Lammer, H., 2003. Icarus 164 (1), 1-13] by treating the ion-induced sputtering process from a known surface in a self-consistent way. The comparison of the calculated exospheric densities with experimental data, which are mostly upper limits, shows that all of our calculated densities are within the measurement limits. The total calculated exospheric density at the lunar surface of about 1×¹⁰⁷ m⁻³ as result of solar wind sputtering we find is much less than the experimental total exospheric density of about ¹⁰¹² m⁻³. We conclude that sputtering contributes only a small fraction of the total exosphere, at least close to the surface. Because of the considerably larger scale height of atoms released via sputtering into the exosphere, sputtered atoms start to dominate the exosphere at altitudes exceeding a few 1000 km, with the exception of some light and abundant species released thermally, e.g. H₂, He, CH₄, and OH. Furthermore, for more refractory species such as calcium, our model indicates that sputtering may well be the dominant mechanism responsible for the lunar atmospheric inventory, but observational data does not yet allow firm conclusions to be drawn.     

The Large-Scale Structures Of The Quiet-Sun Photosphere

The area density distribution of bright photospheric points on the quiet solar surface is not uniform. The distributions show some considerable pecularities. This article is a study of their characteristics during the four last solar activity minima in Bartels longitudes. The bright-photospheric-point distributions on the equatorial and polar solar surface exhibit a type of sectoral-hemispherical asymmetry. The density distributions vary a lot, but have the tendency to alternate with a period of 22 years. The phase origin of density concentrations is the first structural pecularity of the photospheric point distributions. The simultaneous appearance of bright regions on the equatorial and polar solar surface in spatial antiphase lock and, at the same time, the half-phase shift (11 years) between polar and equatorial cycles suggests a synchronous distribution process. This time synchronization is the second important pecularity of density concentrations. Therefore, the solar activity organization in minima occurs according to strict synchronization, like being under the control of a very precise clock.     

Primordial Angular Gradients In The Temperature Of The CMBR And The Density Fluctuations

A non-conventional approach is developed and used to find the primordial angular gradient, anisotropy, of the temperature of the Cosmic Microwave Background Radiation (CMBR), as well as the density fluctuations in an adiabatic expanding universe. The obtained results is a consequence of considering the magnitude of the angular gradient of the temperature of the CMBR as a constant function with respect to the proper time of the spatially perturbed FRW expanding universe. This revised version was published online in July 2006 with corrections to the Cover Date.     

On The Origin of The High-Perihelion Scattered Disk: The Role of The Kozai Mechanism And Mean Motion Resonances

We study the transfer process from the scattered disk (SD) to the high-perihelion scattered disk (HPSD) (defined as the population with perihelion distances q > 40 AU and semimajor axes a>50 AU) by means of two different models. One model (Model 1) assumes that SD objects (SDOs) were formed closer to the Sun and driven outwards by resonant coupling with the accreting Neptune during the stage of outward migration (Gomes 2003b, Earth, Moon, Planets 92, 29–42.). The other model (Model 2) considers the observed population of SDOs plus clones that try to compensate for observational discovery bias (Fernández et al. 2004, Icarus , in press). We find that the Kozai mechanism (coupling between the argument of perihelion, eccentricity, and inclination), associated with a mean motion resonance (MMR), is the main responsible for raising both the perihelion distance and the inclination of SDOs. The highest perihelion distance for a body of our samples was found to be q = 69.2 AU. This shows that bodies can be temporarily detached from the planetary region by dynamical interactions with the planets. This phenomenon is temporary since the same coupling of Kozai with a MMR will at some point bring the bodies back to states of lower-q values. However, the dynamical time scale in high-q states may be very long, up to several Gyr. For Model 1, about 10% of the bodies driven away by Neptune get trapped into the HPSD when the resonant coupling Kozai-MMR is disrupted by Neptune’s migration. Therefore, Model 1 also supplies a fossil HPSD, whose bodies remain in non-resonant orbits and thus stable for the age of the solar system, in addition to the HPSD formed by temporary captures of SDOs after the giant planets reached their current orbits. We find that about 12 – 15% of the surviving bodies of our samples are incorporated into the HPSD after about 4 – 5 Gyr, and that a large fraction of the captures occur for up to the 1:8 MMR (a ⋍ 120 AU), although we record captures up to the 1:24 MMR (a ≃ 260 AU). Because of the Kozai mechanism, HPSD objects have on average inclinations about 25°–50°, which are higher than those of the classical Edgeworth–Kuiper (EK) belt or the SD. Our results suggest that Sedna belongs to a dynamically distinct population from the HPSD, possibly being a member of the inner core of the Oort cloud. As regards to 2000 CR₁₀₅ , it is marginally within the region occupied by HPSD objects in the parametric planes (q,a) and (a,i), so it is not ruled out that it might be a member of the HPSD, though it might as well belong to the inner core.     

度盘对径改正的几何原理

立足于实测，用平面几何的方法讨论子午环度盘对径改正的几何原理与测量设备，测量数据之间的关系     

The ``Great Debate': The case for AGNs

We summarize the evidence from multiwavelength observations that the dominant power source in the majority of ultraluminous infrared galaxies (ULIGs) may be an active galactic nucleus (AGN). In the broader context of the debate, we also show that –- 1. ULIGs are indeed a key stage in the transformation of merging gas-rich disks into ellipticals,2. ULIGs are plausibly the precursors of quasi-stellar objects (QSOs), and 3. ULIGs do appear to be local templates of the high luminosity tail of major gas-rich mergers at z 1–4.     

The Optical Layout Of The HEGRA Cherenkov Telescopes

The raytracing technique was used to derive a suitable design for the HEGRA system of Cherenkov telescopes, which is at present commissioned at La Palma. The reflectors with a diameter of 3.9 m consist of 30 spherical mirrors with focal lengths in the range of 4.88 – 4.94 m. It is shown that 93% of the photons from the Cherenkov light emitted by an extended air shower are contained in the camera pixels, 0.25° in diameter, for the full field of view of = ± 2.5°. The optical performance of the HEGRA design is compared to other layouts.     

计算平均中子辐照量的新公式

根据13C辐射燃烧的低质量AGB(Asymptotic Giant Branch)星s-过程核合成模型,考察了氦壳层核合成区域中子辐照量分布(以下简称DNE)的特点.结果表明,该模型的DNE同以前的对流核合成模型一样仍然非常接近指数分布,但是每个脉冲的中子辐照量△r和平均中子辐照量To之间的关系却不再是To=-△T/lnr,而近似为To=-△r/ln{q[1.0020 0.6602(r-q) 4.6125(r-q)2-10.8962(r-q)3 13.9138(r-q)4]}(r为重叠因子, q为13C壳层占氦壳层的质量比例).该式从DNE角度将辐射s-过程恒星模型和经典模型统一起来.     

The complexH-function

The properties of theH -function for the complex albedo of single scattering are studied. It is shown that basically all the formulae derived for the real albedo of single scattering can be transferred into the complex-plane without alteration.An iterational procedure to find the numerical values of the complexH - function is set up. Some examples of the numerical results are given in the figures.     

The GRIS

The GRIS is a prism cross-dispersed spectrometer utilizing a NICMOS 3 detector array for moderate and high dispersion spectroscopy in the near infrared spectral region. The spectrometer is cryogenically cooled with liquid nitrogen and operates on the 2.3 m Steward Observatory Telescope. Initial use proves it to be an excellent tool for near infrared astrophysics.     

The magnetoheliograph

A method is described, which makes it possible to obtain a magnetic photograph directly in one image without the use of photographic subtraction.Presently Guest Investigator at the Mount Wilson and Palomar Observatories.     

The Boulder

The external morphologies of Boulder 1, Station 2, and of the four samples taken from it by the Apollo 17 crew, are briefly described. The boulder is a polymict breccia, containing the following principal materials as clasts: gray competent breccias (GCBx), black competent breccias (BCBx), anorthositic breccias (AnBx), pigeonite basalt (PB), coarse norite (CN). All are enclosed in a matrix of light-colored friable breccia (LFBx).     

The sun and exoplanets: The solitude of man

Solar pulsations with a period of P ₀ = 9600.606(12) were discovered in 1974. A more recent discovery is that planetary distances in the solar system are subject to spatial resonance with the parameter L ₀ ?? cP ₀ ?? 9600 ls and that the P ₀ pulsation itself has cosmological significance (coherent cosmic oscillation, or the pace of absolute time of the universe; c is the speed of light). As of June 2011, 552 extrasolar planets have been discovered. Statistical analysis shows that the distribution of the semimajor axes of alien planets does not have L ₀ resonance. Moreover, it appears to have no resonance at all. This frustrates the 20th-century hopes for the existence of extraterrestrial civilizations and possible contact with them. They are simply not there. This explanation of the Fermi paradox, or the Great Silence, appears to rest on the triumph of the anthropic principle, which has been successfully implemented by nature within our planetary system. This leads to a vision whereby the cosmos seems to be created specially for us. The scale L ₀ indicates that the sun is a special quantum object, where L ₀ is a wave function parameter that is not subject to the rational principles of the classical world, but rather follows a peculiar, quantum logic.     

The Case For Renewed Human Exploration Of The Moon

The European Space Agency, ESA, is currently studying 3 high-energy astronomy missions that use the International Space Station (ISS). These are Lobster-ISS, an all-sky imaging X-ray monitor, the Extreme Universe Space Observatory (EUSO) which will study the highest energy cosmic rays by using the Earth's atmosphere as a giant detector and XEUS — the X-ray Evolving Universe Spectroscopy Mission, a potential successor to ESA's XMM-Newton X-ray observatory. These first 2 missions will he attached to the external platforms on the Columbus module, while XEUS will visit the ISS to attach additional X-ray mirrors to enlarge the original 4.5 m diameter mirrors to the 10 m diameter required to observed redshifted iron lines from massive black holes in the early Universe. This revised version was published online in July 2006 with corrections to the Cover Date.     

The Scalar Boundary Conditions For The Motion Of The Elastic Earth To Second Order In Ellipticity

The scalar equations of infinitesimal elastic gravitational motion for a rotating, slightly elliptical Earth are always used to study the Earth's nutation and tides theoretically, while the determination of the integration of the equations depends, to a certain extent, on the choice of a set of appropriate boundary conditions. In this paper, a continuity quantity related to the displacement is first transformed from the elliptical reference boundary to the corresponding effective spherical domain, and then converted from a vector (or tensor) form to a scalar form by generalized surface spherical harmonics expansion. All the related components, including the displacement vector field (or the stress tensor field), are then decomposed into the poloidal and toroidal field using the symmetry restrictions on the normal mode eigenfunctions. After truncation, the boundary conditions are finally derived, in a scalar ordinary differential form. The process of the derivation is second order in ellipticity and in full detail. Moreover, the other boundary conditions are also presented as second order in ellipticity at the end of this paper. This revised version was published online in July 2006 with corrections to the Cover Date.     

用自激励门限自回归分析方法模拟和预报太阳黑子数的长期变化

本文用一种新方法——自激励门限自回归分析方法对太阳黑子相对数年平均值进行拟合和预报检验,并对未来第22周逐年年均值作出预报。 目激励门限自回归分析模型的形式如下: 在对1956至1985年逐年太阳黑子相对数年均值的预报检验中,最大拟会误差为40.6,最小拟合误差为0.3,平均拟合误差为±12.5。 对1986至1997年逐年太阳黑子相对数年均值的预报见表(4)。定出第21周极小在1986年或1987年,极大在1990或1991年,极大值R_M=81.2±16.2。     

Thermal Emission From The Dust Coma Of Comet Hale-Bopp And The Composition Of The Silicate Grains

The dust coma of comet Hale-Bopp was observed in the thermal infrared over a wide range in solar heating (R = 4.9–0.9 AU) and over the full wavelength range from 3 μm to 160 μm. Unusual early activity produced an extensive coma containing small warm refractory grains; already at 4.9 AU, the 10 μm silicate emission feature was strong and the color temperature was 30% above the equilibrium blackbody temperature. Near perihelion the high color temperature, strong silicate feature, and high albedo indicated a smaller mean grain size than in other comets. The 8–13 μm spectra revealed a silicate emission feature similar in shape to that seen in P/Halley and several new and long period comets. Detailed spectral structure in the feature was consistent over time and with different instruments; the main peaks occur at 9.3, 10.0 and 11.2 μm. These peaks can be identified with olivine and pyroxene minerals, linking the comet dust to the anhydrous chondritic aggregate interplanetary dust particles. Spectra at 16–40 μm taken with the ISO SWS displayed pronounced emission peaks due to Mg-rich crystalline olivine, consistent with the 11.2 μm peak. This revised version was published online in July 2006 with corrections to the Cover Date.