New evidence for a linear colour–magnitude relation and a single Schechter function for red galaxies in a nearby cluster of galaxies down to M*+ 8     

S. Andreon  J.-C. Cuillandre  E. Puddu  Y. Mellier 《Monthly notices of the Royal Astronomical Society》2006,372(1):60-68

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Opening angles, Lorentz factors and confinement of X-ray binary jets     

J. C. A. Miller-Jones  R. P. Fender  E. Nakar 《Monthly notices of the Royal Astronomical Society》2006,367(4):1432-1440

We present a collation of the available data on the opening angles of jets in X-ray binaries, which in most cases are small (≲10°). Under the assumption of no confinement, we calculate the Lorentz factors required to produce such small opening angles via the transverse relativistic Doppler effect. The derived Lorentz factors, which are in most cases lower limits, are found to be large, with a mean >10, comparable to those estimated for active galactic nuclei (AGN) and much higher than the commonly assumed values for X-ray binaries of 2–5. Jet power constraints do not, in most cases, rule out such high Lorentz factors. The upper limits on the opening angles show no evidence for smaller Lorentz factors in the steady jets of Cygnus X-1 and GRS 1915+105. In those sources in which deceleration has been observed (notably  XTE J1550−564  and Cygnus X-3), some confinement of the jets must be occurring, and we briefly discuss possible confinement mechanisms. It is however possible that all the jets could be confined, in which case the requirement for high bulk Lorentz factors can be relaxed.  相似文献   

Photoevaporation of protoplanetary discs – I. Hydrodynamic models     

R. D. Alexander  C. J. Clarke  J. E. Pringle 《Monthly notices of the Royal Astronomical Society》2006,369(1):216-228

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胶东“玲珑-焦家式”金矿资源潜力与找矿   总被引：1，自引：1，他引：0  

李士先  王建收 《山东国土资源》2006,22(12):36-41

“玲珑焦家式”金矿的成岩成矿,从新太古代至中生代存在着继承性的成因关系,成矿具有长期性、多源性特点,但中生代燕山早期岩浆活动是主导成矿因素。区域化探成果显示胶东金矿直接矿源岩———郭家岭花岗岩金的丰度比原始矿源岩———早前寒武纪变质沉积岩系及侵入岩系金的丰度低1/2。郭家岭花岗岩面积在2 km2以上岩体定量估计金亏损总量与胶东金矿总量预测的资源量相当,从一个侧面展现了胶东金矿资源的潜力。望儿山金矿的找矿实践展示,焦家式金矿在1 000 m以下尚有巨大潜力,整个胶东金矿产区在3 000 m以上的资源潜力应在5000 t以上。  相似文献   

我国个人所得税制度完善的法律思考     

刘升 《广东海洋大学学报》2006,26(2):44-46

个人所得税是与每个人联系都很紧密的税种,它的完善与否,直接体现了我国法制建设的完善程度及居民素质的高低。但现行税制由于内外原因,存在各种缺陷。因此有必要在理论中找到对策,并在实践中寻求答案逐步完善个人所得税制度。  相似文献   

Colour variability of asteroids in the Sloan Digital Sky Survey Moving Object Catalog     

Gy. M. Szabó  &#;. Ivezi&#; †  M. Juri&#;  R. Lupton  L. L. Kiss 《Monthly notices of the Royal Astronomical Society》2004,348(3):987-998

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应用ATA的对数周期馈源方案于FAST的可能性探讨     

吴盛殷  熊继衮  吕善伟  张江林  徐祥  南仁东  金乘进 《天文学进展》2004,22(2):179-187

介绍应用于美国凤凰计划的Allen望远镜阵(ATA)的对数周期馈源(LPA)概况，初步给出此种馈源的基本参数及性能，仿真估算了其驻波比和方向图，并结合正在进行中的我国500m孔径球面射电望远镜(FAST)计划，探讨了应用这种宽带馈源的可能性及其限制。  相似文献   

Erratum: Towards cosmological concordance on galactic scales     

Frank C. van den Bosch  H. J. Mo  Xiaohu Yang 《Monthly notices of the Royal Astronomical Society》2004,348(2):736-736

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Galaxy spectral parametrization in the 2dF Galaxy Redshift Survey as a diagnostic of star formation history     

Darren S. Madgwick  Rachel Somerville  Ofer Lahav  Richard Ellis 《Monthly notices of the Royal Astronomical Society》2003,343(3):871-879

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WR 7a: a V Sagittae or a qWR star?     

A. S. Oliveira  J. E. Steiner  D. Cieslinski 《Monthly notices of the Royal Astronomical Society》2003,346(3):963-967

The star WR 7a, also known as SPH 2, has a spectrum that resembles that of V Sagittae stars although no O  vi emission has been reported. The Temporal Variance Spectrum – TVS – analysis of our data shows weak but strongly variable emission of O  vi lines which is below the noise level in the intensity spectrum.
Contrary to what is seen in V Sagittae stars, optical photometric monitoring shows very little, if any, flickering. We found evidence of periodic variability. The most likely photometric period is   P _phot= 0.227(±14) d  , while radial velocities suggest a period of   P _spec= 0.204(±13) d  . One-day aliases of these periods can not be ruled out. We call attention to similarities with HD 45166 and DI Cru (= WR 46), where multiple periods are present. They may be associated to the binary motion or to non-radial oscillations.
In contrast to a previous conclusion by Pereira et al., we show that WR 7a contains hydrogen. The spectrum of the primary star seems to be detectable as the N  v 4604 Å  absorption line is visible. If so, it means that the wind is optically thin in the continuum and that it is likely to be a helium main sequence star.
Given the similarity to HD 45166, we suggests that WR 7a may be a qWR – quasi Wolf–Rayet – star. Its classification is WN4h/CE in the Smith, Shara & Moffat three-dimensional classification system.  相似文献