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991.
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994.
Through petroleum exploration of 20 years, a new petroleum production area has been constructed in Hailar Basin. Their petroleum geological characteristics and hydrocarbon distribution has been known in detail. The Hailar Basin is a basin group consisted of many scattered sub-basins with similar structural developed history. Each sub-basin has unique hydrocarbon distributing rules, including (1) oil/gas reservoir distribution is controlled by the oil/gas sag, and the oil/gas bearing in big sag is rich; (2) underwater fan and turbidity fan are the most favorable reservoirs; structure zone controlled by main fault is favorable zone of forming composite oil/gas accumulation; (3) lower fault-block in higher rise and higher fault-block in lower rise are favorable to oil/gas accumulation; (4) deep fault and granite body are closely related to oil/gas reservoir, its distributing area is favorable area of oil and mantle source non-hydrocarbon gas formation;(5) higher geothermal area is favorable oil/gas bearing area. 相似文献
995.
Stefan Gottlöber Ewa L. okas Anatoly Klypin Yehuda Hoffman 《Monthly notices of the Royal Astronomical Society》2003,344(3):715-724
Presented here are high spatial and spectral resolution Chandra X-ray observations of the famous interacting galaxy pair, the Mice, a system similar to, though less evolved than, the well-known Antennae galaxies. Previously unpublished ROSAT High Resolution Imager data of the system are also presented.
Starburst-driven galactic winds outflowing along the minor axis of both galaxies (but particularly the northern one) are observed, and spectral and spatial properties, and energetics are presented. That such a phenomenon can occur in such a rapidly evolving and turbulent system is surprising, and this is the first time that the very beginning – the onset, of starburst-driven hot gaseous outflow in a full-blown disc–disc merger has been seen.
Point-source emission is seen at the galaxy nuclei, and within the interaction-induced tidal tails. Further point-source emission is associated with the galactic bar in the southern system. A comparison of the source X-ray luminosity function and of the diffuse emission properties is made with the Antennae and other galaxies, and evidence of a more rapid evolution of the source population than the diffuse component is found. No evidence for variability is found between the Chandra and previous observations. 相似文献
Starburst-driven galactic winds outflowing along the minor axis of both galaxies (but particularly the northern one) are observed, and spectral and spatial properties, and energetics are presented. That such a phenomenon can occur in such a rapidly evolving and turbulent system is surprising, and this is the first time that the very beginning – the onset, of starburst-driven hot gaseous outflow in a full-blown disc–disc merger has been seen.
Point-source emission is seen at the galaxy nuclei, and within the interaction-induced tidal tails. Further point-source emission is associated with the galactic bar in the southern system. A comparison of the source X-ray luminosity function and of the diffuse emission properties is made with the Antennae and other galaxies, and evidence of a more rapid evolution of the source population than the diffuse component is found. No evidence for variability is found between the Chandra and previous observations. 相似文献
996.
Using a numerically accurate radiation-gas dynamical method we investigate the winds scenario for aspherical planetary nebulae
(PNe). Our model includes the interaction of two winds: as low high mass-loss rate wind (a `super wind'); and a fast wind;
low mass-loss rate wind. Our model also includes the evolution of the UV spectrum of the PNe centeral star. As stated in the
section3 of Paper I (Ganbari and Khesali, 2001), we consider a three dimensional density distribution ρ(r,θφ for the super wind, in this way we enter the effects of cooling and heating mechanisms in our model. Taking into account
the above assumptions, we introduce the code (DIS3D) and numerically we study the dynamical and ionization properties of the
planetary nebula NGC3132. We show that it is possible by simulations to reproduce the shape of PNe in three dimensions, and
calculating the physical quantities throughout the entire nebula.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
997.
Photoelectric Vilnius seven-color photometry is presented and analyzed for a sample of 24 red giant branch and clump stars
in the open cluster NGC 7789. For each star we have determined photometric spectral type, absolute magnitude, interstellar
reddening, effective temperature, metallicity, and surface gravity. From averages over the stars in the sample we find the
mean reddening to the cluster E
Y−V
= 0.21± 0.02 (s.d.), or E
B−V
= 0.25, and the apparent distance modulus (m−M)
V
= 12.21± 0.10 (s.d.), which yield a distance of 1840 pc. The mean overall metallicity is found to be [Fe/H] = −0.18± 0.09
(s.d.). The clump stars, on average, appear to be slightly more metal-rich than the other red giants, which is most probably
caused by evolutionary changes of carbon and nitrogen molecular bands falling in the photometric passbands. A difference in
mass between the two groups of stars has also been detected, which suggests that the clump stars might have undergone extra
mass loss before reaching their core He-burning phase of evolution. 相似文献
998.
A. Alonso-Herrero S. D. Ryder J. H. Knapen † 《Monthly notices of the Royal Astronomical Society》2001,322(4):757-769
We present high-resolution near-infrared imaging obtained using adaptive optics and HST /NICMOS, and ground-based spectroscopy of the hotspot galaxy NGC 2903. Our near-infrared resolution imaging enables us to resolve the infrared hotspots into individual young stellar clusters or groups of these. The spatial distribution of the stellar clusters is not coincident with that of the bright H ii regions, as revealed by the HST /NICMOS Pa α image. Overall, the circumnuclear star formation in NGC 2903 shows a ring-like morphology with an approximate diameter of 625 pc.
The star formation properties of the stellar clusters and H ii regions have been studied using the photometric and spectroscopic information in conjunction with evolutionary synthesis models. The population of bright stellar clusters shows a very narrow range of ages, 4–7×106 yr after the peak of star formation, or absolute ages 6.5–9.5×106 yr (for the assumed short-duration Gaussian bursts), and luminosities similar to the clusters found in the Antennae interacting galaxy. This population of young stellar clusters accounts for some 7–12 per cent of the total stellar mass in the central 625 pc of NGC 2903. The H ii regions in the ring of star formation have luminosities close to that of the supergiant H ii region 30 Doradus, they are younger than the stellar clusters, and they will probably evolve into bright infrared stellar clusters similar to those observed today. We find that the star formation efficiency in the central regions of NGC 2903 is higher than in normal galaxies, approaching the lower end of infrared luminous galaxies. 相似文献
The star formation properties of the stellar clusters and H ii regions have been studied using the photometric and spectroscopic information in conjunction with evolutionary synthesis models. The population of bright stellar clusters shows a very narrow range of ages, 4–7×10
999.
1000.
R.J. Beswick A. Pedlar C.G. Mundell J.F. Gallimore 《Monthly notices of the Royal Astronomical Society》2001,325(1):151-158
We present neutral hydrogen absorption observations of the luminous infrared merger NGC 6240 using MERLIN with a resolution of 0.2 arcsec. Broad absorption (a few hundred km s−1 ) has been found against two compact radio sources within the central kpc providing dynamical information about the neutral gas components in front of these sources. A narrow absorption component is also detected superimposed upon this broad absorption and additionally against some of the extended L -band continuum. From these results we deduce that the broad component is a result of absorption by a highly disturbed disc-like structure of neutral gas aligned along the position angle of the two compact radio sources, similar to the model previously proposed by Tacconi et al. at the end of the last century based on spectral CO emission data. The narrow component is likely to arise from absorption by less disturbed neutral gas at much larger scales within the system.
Continuum observations presented here at 1.4 and 5 GHz support the view that NGC 6240 contains a double nucleus resulting from a galactic merger event and show these as two compact radio sources separated by 1.52 arcsec. We have also applied luminosity and morphological considerations to the continuum results to determine the most feasible source of radio emission for this luminous merger galaxy. We conclude that the most likely source of the radio flux found in NGC 6240 is a combination of starburst emission from radio luminous supernova remnants, similar to those found in Arp 220, and emission from a weak AGN probably triggered by a merger event. 相似文献
Continuum observations presented here at 1.4 and 5 GHz support the view that NGC 6240 contains a double nucleus resulting from a galactic merger event and show these as two compact radio sources separated by 1.52 arcsec. We have also applied luminosity and morphological considerations to the continuum results to determine the most feasible source of radio emission for this luminous merger galaxy. We conclude that the most likely source of the radio flux found in NGC 6240 is a combination of starburst emission from radio luminous supernova remnants, similar to those found in Arp 220, and emission from a weak AGN probably triggered by a merger event. 相似文献