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931.
Hajduk, et al (1992) have drawn attention to a possible source of error in our earlier analysis of visual and radar observations of shower meteors from which we calculated the ozone concentration at meteor heights. We have considered their main criticism that the features of our data which we used to calculate the ozone concentration may have been due to the constraint that our meteors had to be observed by both methods. We have shown that observations collected from radar-only systems show very similar characteristics and that these can be analysed without recourse to visual data to produce very similar results to those from our original analysis.
Presented at theInternational Conference on Meteoroids 23 – 31 August 1994 in Bratislava.Submitted to Earth, Moon and Planets 相似文献
932.
We present the results of a spectral study of Galaxy No. 47 of the list [1]. We determine the equivalent widths of the lines for the compact part of the galaxy and the relative intensities for both the compact part and the halo. We estimate the mass of the galaxy from the inclination of the H line. We obtain the electron density and the mass of the gas component of the compact part of the galaxy.Translated fromAstrofizika, Vol. 38, No. 2, 1995. 相似文献
933.
A. M. Mickaelian 《Astrophysics》1995,38(4):349-351
Optical identification of infrared sources from the IRAS Point Source Catalogue (PSC) is made by means of low-dispersion spectra of the First Byurakan Survey (FBS) and Palomar Observatory Sky Survey (POSS) red and blue images. The purpose of this work is to examine the composition of the PSC sample of fainter sources at high galactic latitudes and to reveal QSOs, infrared galaxies, red stars (C and M), planetary nebulae, for their further investigation at the optical range. 100 of 108 unknown IRAS sources in the region with 3h50m 7h40m and + 69° + 73° are optically identified. Optical coordinates, V magnitudes, color indices, and preliminary classes are determined. According to preliminary classification 3 objects turned out to be QSOs, 36 are galaxies with very interesting morphology, 5 are faint planetary nebulae, 9 are carbon stars, and 47 are late M-type stars.Published in Astrofizika, Vol. 38, No. 4, pp. 625–629, October–December, 1995. 相似文献
934.
"While 'closed-door' immigration policies are adopted by most countries, 'exceptionalist' legislation is often made to permit entry of special immigrant groups. An example is the British Nationality (Hong Kong) Act 1990, which was passed in the run-up to the change in sovereignty of Hong Kong in 1997. Britain's increasingly restrictive immigration policies prior to 1990 [have] resulted in the majority of Hong Kong citizens having British nationality (as British Dependent Territories citizens) but without the right of abode in the U.K. The 1990 Act conferred full British citizenship status on 50,000 heads of households in Hong Kong." The authors conclude that "in a world of marked global inequalities, immigration pressure will become even more extreme and is likely to produce an increasing number of cases of exceptionalist immigration legislation in countries with both ?open' and 'closed'-door policies.' 相似文献
935.
Planar deformation features in quartz grains from the resurge deposit of the Lockne structure,Sweden
Abstract— Microscopic planar deformation features (PDFs) in quartz grains are diagnostic of shock meta-morphism during hypervelocity impact cratering. Measurements of the poles of sets of PDFs and the optic axis of 25 quartz grains were carried out for a sample of the Loftarsten deposit from the Lockne area, Sweden. The most abundant PDFs observed in the sample from the Lockne area correspond to those found at known impact craters (i.e., ω (1013} and π (1012). This study confirms the previous suggestion that the Lockne structure is an impact crater. The Loftarsten is, therefore, interpreted as the final stage of resurge deposition after a marine impact at Lockne in the Middle Ordovician. 相似文献
936.
In this paper we present multicolor images of the Beta Pictoris disk, obtained with a new Coronograph, built at STScI, for ESO's New Technology Telescope. These B, V, and R observations probe the Beta Pictoris circumstellar disk in to a distance of 35 AU (2) from the central star. We derive surface brightness profiles for the disk and discuss the results in the context of two-component disk models (e.g. Backmanet al. 1992), which are based on fits to available optical and infrared data for Beta Pictoris's disk. These models generally imply that the disk is composed of 1) an outer disk extending from 100–1000 AU, with a midplane particle density decreasing as n(r) r–3, 2) a transition region extending from 10–100 AU with lower density and either smaller grains or a less steep spatial gradient than the outer component, 3) an innermost clear zone with even lower density. 相似文献
937.
Elia M. Leibowitz 《Astrophysics and Space Science》1995,228(1-2):367-372
TAUVEX - Tel Aviv University UV Explorer is a space telescope that is currently being built in Israel, to be flown on board the Russian international sattelite SRG - Spectrum Roentgen Gamma, in late 1995 or early 1996. TAUVEX is an imager in the near UV spectral window. Its major goal is to make a survey of about 10% of the UV sky, in the range = 1350 - 3500Å. A successful operation of TAUVEX will partially fill an important gap in our recognition of the sky, namely the distribution and the nature of the celestial UV sources, which are still mostly unknown. TAUVEX will also operate as a fast multicolor photometer in its UV range of operation. TAUVEX is aligned in parallel to the common optical axix of all the other instruments on board SRG, most of which are telescopes and monitors for high energy radiation. SRG will be thus able to perform for the first time in history simultaneous astronomical observations in one and the same celestial body, that cover together 7 order of magnitude of the recorded radiation. The observations of TAUVEX can be greatly enhanced by ground base observations. 相似文献
938.
Interpretation of X-ray eclipses in SS 433 binary system in the framework of wind-wind collision model yields high value of mass ratioq =m
x
/m
v
> 1 which implies high mass of relativistic objectm
x
> 8M
. 相似文献
939.
A method to fit flat rotation curves is presented, wherein the galactic density for a disk model is expressed in terms of a Dirichlet polynomial. This procedure allows us to obtain the total galactic mass and to predict the circular velocity at large galactocentric distances.Application of the method to the Galaxy, M31 and four Sc galaxies shows that a significant galactic mass is located beyond the optical radius although it is considerably smaller than the integral mass values obtained from current models with a massive corona included. Observed rotation curves and convergent total mass are obtained, thus the total mass for the Milky Way Galaxy is 5.69×1011
M
. 相似文献
940.
Interaction of an ejecting pulsar in a binary with a matter surrounding it is considered. Around the pulsar a cavern is formed, and its shape calculated. Non-stationary regime of floating caverns filled with binary radioemission is discussed. This regime can lead to a special radio-burster. It is noticed that in binaries with rather large separation between components a pulsed radioemission from a pulsar can be observable. In this case, the pulsar will be a fine probe for exploration of physical characteristics of a stellar wind from a normal expansion. 相似文献