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51.
本文利用我们所参与的1993年的国际联测光学资料,对NGC4151的BLR进行了后续Reverberation Mapping分析,其中包括a)Monte-Carlo数值模拟检验谱线光变对连续谱光变响应的最可靠的延时时标,b)用正则线性化反演方法解出BLR的转移函数。我们分析并具体解释了对NGC4151的BLR尺度的最新测量结果用1988年的测量结果存在极其显著差别的原因。 相似文献
52.
V.?T.?DoroshenkoEmail author S.?G.?Sergeev Yu.?S.?Efimov S.?A.?Klimanov S.?V.?Nazarov 《Astrophysics》2008,51(1):29-36
We report observations of 24 stars in the fields of the three Seyfert galaxies MCG +08-23-067, Mrk 817, and Mrk 290. The observations
were made with a CCD array photometer in the BVRcIc bands. The V magnitudes of the observed stars ranged from 13.5 and 17.2.
For stars of approximate magnitude 15, the typical photometric errors are 0.010, 0.011, 0.008 and 0.011 magnitude in the BVRI
bands, respectively. The BVRI magnitudes of all these stars were not known previously. In the field of the galaxy Mrk 290
a star has been found that probably has a periodic brightness variation with P=1.518 days and the mean value V=14.80 and which
may belong to the class of “spotted” stars. 14′x14′ charts are supplied for identifying the stars. These results can be used
for differential photometry of active galactic nuclei in the BVRI bands.
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Translated from Astrofizika, Vol. 51, No. 1, pp. 41–50 (February 2008). 相似文献
53.
The jets observed to emanate from many compact accreting objects may arise from the twisting of a magnetic field threading
a differentially rotating accretion disk which acts to magnetically extract angular momentum and energy from the disk. Two
main regimes have been discussed, hydromagnetic jets, which have a significant mass flux and have energy and angular momentum
carried by both matter and electromagnetic field and, Poynting jets, where the mass flux is small and energy and angular momentum
are carried predominantly by the electromagnetic field. Here, we describe recent theoretical work on the formation of relativistic
Poynting jets from magnetized accretion disks. Further, we describe new relativistic, fully electromagnetic, particle-in-cell
(PIC) simulations of the formation of jets from accretion disks. Analog Z-pinch experiments may help to understand the origin
of astrophysical jets. 相似文献
54.
Marcella Contini 《Astrophysics and Space Science》1995,233(1-2):261-266
AGN spectra are investigated by comparing model calculations with observations. Line intensity ratios show that the emitting gas is heated by shocks. Therefore, composite models which consistently account for both shocks, accompanying the radial motion of the gaseous clouds, and a photoionizing radiation flux are used. Liners are ambiguous objects between AGN and Starburst galaxies, therefore, power-law or black body radiations are considered in the models, depending on the characteristics of the line spectra. The SUMA code is used.The results show that shocks definitively play an important role, even if a photoionizing flux is generally present. Particularly, the heterogeneous nature of the objects, which are classified as Liners, is confirmed. 相似文献