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101.
M Grande R BrowningN Waltham D ParkerS.K Dunkin B KentB Kellett C.H PerryB Swinyard A PerryJ Feraday C HoweG McBride K PhillipsJ Huovelin P MuhliP.J Hakala O VilhuJ Laukkanen N ThomasD Hughes H AlleyneM Grady R LundinS Barabash D BakerP.E Clark C.D MurrayJ Guest I CasanovaL.C d'Uston S MauriceB Foing D.J Heather V FernandesK Muinonen S.S RussellA Christou C OwenP Charles H KoskinenM Kato K SipilaS Nenonen M HolmstromN Bhandari R ElphicD Lawrence 《Planetary and Space Science》2003,51(6):427-433
The D-CIXS Compact X-ray Spectrometer will provide high quality spectroscopic mapping of the Moon, the primary science target of the ESA SMART-1 mission. D-CIXS consists of a high throughput spectrometer, which will perform spatially localised X-ray fluorescence spectroscopy. It will also carry a solar monitor, to provide the direct calibration needed to produce a global map of absolute lunar elemental abundances, the first time this has been done. Thus it will achieve ground breaking science within a resource envelope far smaller than previously thought possible for this type of instrument, by exploiting two new technologies, swept charge devices and micro-structure collimators. The new technology does not require cold running, with its associated overheads to the spacecraft. At the same time it will demonstrate a radically novel approach to building a type of instrument essential for the BepiColombo mission and potential future planetary science targets. 相似文献
102.
103.
Sediment successions in coastal cliffs around Mezen Bay, southeastern White Sea, record an unusually detailed history of former glaciations, interstadial marine and fluvial events from the Weichselian. A regional glaciation model for the Weichselian is based on new data from the Mezen Bay area and previously published data from adjacent areas. Following the Mikulinian (Eemian) interglacial a shelf‐centred glaciation in the Kara Sea is reflected in proglacial conditions at 100–90 ka. A local ice‐cap over the Timan ridge existed between 75 and 65 ka. Renewed glaciation in the Kara Sea spread southwestwards around 60 ka only, interrupted by a marine inundation, before it advanced to its maximum position at about 55–50 ka. After a prolonged ice‐free period, the Scandinavian ice‐sheet invaded the area from the west and terminated east of Mezen Bay about 17 ka. The previously published evidence of a large ice‐dammed lake in the central Arkhangelsk region, Lake Komi, finds no support in this study. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
104.
Summary ?A single-crystal X-ray investigation was performed on crystals of P21/c natural pigeonite with varying Ca and Fe* ( = Fe2+ + Mn2+) contents, in order to verify the effect of microtextural disorder on structure refinements and to constrain the crystal
chemistry of pigeonite. Antiphase domains and exsolution lamellae affect differently the refinement results. In a crystal
free of exsolution the structure obtained after refinement with all reflections is an average of that of the antiphase domains
and of their boundaries, whereas in an exsolved crystal it represents only the structure of the prevailing pigeonite lamellae.
The refinement using only h + k odd reflections seems to give the structure of the Ca-free pigeonite characteristic of the antiphase domains rather than
that of Ca-rich domain walls. The ratio of the scale factors in refinements with all reflections and with only h + k odd reflections allows the ratios of the exsolved augite and pigeonite phases to be estimated.
The crystal chemistry of the investigated samples follows the trends outlined by data on Ca-free and Fe-free synthetic samples.
In particular, it is shown that Ca and Fe* substitution for Mg induce similar changes in the average structure, i.e. both induce an expansion in the M1 polyhedron and
decrease the difference between the M2–O3 distances.
Received October 18, 2001; revised version accepted February 15, 2002 相似文献
105.
We report three new or updated techniques for probing the parameters of active galaxies based on the masses of their central
black holes MBH). First, we derived a near-IR analog of the bulge luminosity versus MBH relationship. The low scatter makes it a promising new tool to study the black hole demographics. Next, we present relations
between MBH and the10 μm and 2-10 keV nuclear luminosity. They may help to study the MBH evolution over wide redshift ranges. Finally, we measured MBH in quasars from z ∼ 3.4 to z ∼ 0.3 to search directly for MBH growth. Surprisingly, we found no evidence for growth implying that the majority of quasar host galaxies have undergone their
last major merger at z ≥ 3.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
106.
107.
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109.
The Speckle camera of the 3.5 m Telescopio Nazionale Galileo (TNG) has been used to measure apparent sizes and shapes of a number of main belt asteroids. The average size measurements are in a generally good agreement with the results of indirect IRAS-based radiometric techniques. The measured shapes are compared with predictions based on previously derived spin axis directions and lightcurve photometry of some of the observed objects. Also in this case the agreement is reasonable and the speckle observations allow us to discriminate in some cases between the two pole solutions usually found for each object. No clear evidence of binaries was found. The results show that the TNG speckle camera can be a powerful tool to resolve relatively large main belt asteroids and to calibrate the results of the IRAS survey. 相似文献
110.
C.S. Botzler J. Snigula R. Bender N. Drory G. Feulner G.J. Hill U. Hopp C. Maraston C. Mendes de Oliveira 《Astrophysics and Space Science》2003,284(2):393-396
The Munich Near-IR Cluster Survey (MUNICS) is a wide-area, medium-deep, photometric survey selected in the K' band. The project's
main scientific aims are the identification of galaxy clusters up to redshifts of unity and the selection of a large sample
of field early-type galaxies up to z < 1.5 for evolutionary studies. We created a Large Scale Structure catalog, using a new structure finding technique specialized
for photometric datasets, that we developed on the basis of a friends-of-friends algorithm. We tested the plausibility of
the resulting galaxy group and cluster catalog with the help of Color-Magnitude Diagrams (CMD), as well as a likelihood- and
Voronoi-approach.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献