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361.
The fundamental plane (FP) scaling relations and their evolution are a powerful tool for studying the global properties of
early-type galaxies and their evolutionary history. The form of the FP, as derived by surveys in the local Universe at wavelengths
ranging from the U to the K band, cannot be explained by metallicity variations alone among early-type galaxies; systematic variations in age, dark matter
content, or homology breaking are required. A large-scale study of early-type galaxies at 0.1 < z < 0.6demonstrates that the SB intercept of the FP, the rest frame (U-V) colour, and the absorption line strengths all evolve passively, thereby implying a high mean formation redshift for the stellar
content. The slope of the FP evolves with redshift, which is broadly consistent with systematic age effects occurring along
the early-type galaxy sequence. The implication that the least luminous early-type galaxies formed later than the luminous
galaxies is discussed in the context of the evolution of thecolour–magnitude relation, the Butcher–Oemler effect and hierarchical
galaxy formation models.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
362.
C. S. Crawford A. C. Fabian P. Gandhi R. J. Wilman R. M. Johnstone 《Monthly notices of the Royal Astronomical Society》2001,324(2):427-442
We present observations of a sample of optically faint, hard X-ray sources of the kind likely to be responsible for much of the hard X-ray background. We confirm that such sources are easily detected in the near-infrared, and find that they have a featureless continuum suggesting that the active nucleus is heavily obscured. The infrared colours of the majority of the targets observed are consistent with absorbed elliptical host galaxies at z =1–2. It is likely that we are observing some of the brighter members of the important new class of X-ray type II quasars. 相似文献
363.
We have undertaken a study of coronal features observed at meter-decameter wavelengths using the Clark Lake radioheliograph.
Among the coronal structures we have studied are the radio manifestations of coronal streamers on the solar disk and above
the solar limb. We have analyzed the radio data quantitatively, using ray-tracing models for comparison with the maps. Our
study provides information about the streamers' three-dimensional shapes, scales, and density profiles, for comparison with
related observations using white-light coronagraphs. 相似文献
364.
365.
366.
HUANGGuoqiang DONGShuanglin WANGFang 《中国海洋大学学报(英文版)》2005,4(1):56-60
Attractabilities of different diets and dietary selectivity of Chinese shrimp, Fenneropenaeus chinensis were studied through behavior observation and feeding experiment, respectively. The five diets used in the experiment are: Fish Flesh (FF), Shrimp Flesh (SF), Clam Foot (CF), Polychaete Worm (PW), and Formulated Diet (FD). No significant differences of attractability exist between any two different diets when every two natural diets or all five diets are provided simultaneously. On the other hand, significant differences of attractability exist between FD and every single natural diet when they are provided simultaneously. Results of behavioral observation indicate that natural diets are more attractive than FD. In feeding experiment, Chinese shrimp has distinct selectivity on different diets. It positively selects CF and PW, negatively selects FF and SF, and excludes FD absolutely. The results of the present studies indicate that the dietary selectivity of shrimp was based not only on the attractabilities of the diets, but also on the responses such as growth and food conversion. 相似文献
367.
The self-consistent dynamic pole tide in global oceans 总被引:1,自引:0,他引:1
S. R. Dickman 《Geophysical Journal International》1985,81(1):157-174
368.
369.
A.W.R. Bevan R. Hutchison A.J. Easton G.P. Durant C.M. Farrow 《Meteoritics & planetary science》1985,20(3):491-501
High Possil and Strathmore are the first (1804) and last (1917) meteorite falls, respectively, of the three recorded in Scotland. Olivine compositions and total Fe contents in High Possil (Fa25.2; 21.35 wt %) and Strathmore (Fa25.3; 20.6 wt %) confirm their classification as L-group chondrites (Mason, 1963), and the presence of abundant plagioclase feldspar shows that both chondrites belong to petrologic type 6. Both chondrites display thermal and mechanical alteration attributable to moderate shock-loading appropriate to facies c (High Possil) and c-d (Strathmore) (Dodd and Jarosewich, 1979). Incipient shock-melting of metal and troilite in both chondrites is the first described from Lc chondrites, and differences in the responses of metallic and silicate minerals to shock-loading are discussed. 相似文献
370.
In the present paper we have studied the resonance problem arising for critical mass values following Birkhoff's method of normalisation. It has been shown that for both the critical values the motion will remain unstable whether the critical terms are left in the Hamiltonian or carried to the coordinates in the process of normalisation. 相似文献