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1.
Supermassive black holes (SMBHs; mass is greater than or approximately 10(5) times that of the Sun) are known to exist at the center of most galaxies with sufficient stellar mass. In the local universe, it is possible to infer their properties from the surrounding stars or gas. However, at high redshifts we require active, continuous accretion to infer the presence of the SMBHs, which often comes in the form of long-term accretion in active galactic nuclei. SMBHs can also capture and tidally disrupt stars orbiting nearby, resulting in bright flares from otherwise quiescent black holes. Here, we report on a ~200-second x-ray quasi-periodicity around a previously dormant SMBH located in the center of a galaxy at redshift z = 0.3534. This result may open the possibility of probing general relativity beyond our local universe.  相似文献   

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The rotational energy of a black hole surrounded by a torus is released through several channels. We have determined that a minor fraction of the energy is released in baryon-poor outflows from a differentially rotating open magnetic flux tube, and a major fraction of about eta/2 is released in gravitational radiation by the torus with angular velocity eta similar 0.2 to 0.5 relative to that of the black hole. We associate the energy emitted in baryon-poor outflows with gamma-ray bursts. The remaining fraction is released in torus winds, thermal emissions, and (conceivably) megaelectron-volt neutrino emissions. The emitted gravitational radiation can be detected by gravitational wave experiments and provides a method for identifying Kerr black holes in the Universe.  相似文献   

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Synchrotron emission is commonly found in relativistic jets from active galactic nuclei (AGNs) and microquasars, but so far its presence in jets from young stellar objects (YSOs) has not been proved. Here, we present evidence of polarized synchrotron emission arising from the jet of a YSO. The apparent magnetic field, with strength of ~0.2 milligauss, is parallel to the jet axis, and the polarization degree increases toward the jet edges, as expected for a confining helical magnetic field configuration. These characteristics are similar to those found in AGN jets, hinting at a common origin of all astrophysical jets.  相似文献   

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The 21-centimeter absorption line from the direction of Taurus A was used for detection of a shift in frequiency when the source passed near Sun. A possible decrease in frequency of 150 cycles per second was detected, which cannot be caused by general relativity or by the plasma around Sun.  相似文献   

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Huahui 1 is an elite transgenic male sterile restorer line of wild rice abortive-type that expresses a Bacillus thuringiensis (Bt) δ-endotoxin and provides effective and economic control oflepidopteran insects. To exploit Huahui 1 to develop a new Bt rice, the insertion site of the Bt gene was determined by thermal asymmetric interlaced PCR (TAIL-PCR). Bt was located in the promoter region ofLOC. Os10g10360, approximately 5.35 Mb from the telomere of the short arm of chromosome 10. For the first time, a Bt cytoplasmic male sterile (CMS) system was developed by introgressing Bt from Huahui 1. The recipient CMS system used consisted of Indonesia paddy rice-type II-32B (maintainer line) and II-32A (male sterile line). Marker-assisted selection was used to increase selection efficiency in the backcrossing program. In BC5F1, the Bt plant 85015-8 was selected for further analyses, as it had the highest SSR marker homozygosity. In addition, the linkage drag of the foreign Bt gene in 85015-8 was minimized to 8.01-11.46 Mb. The foreign Bt gene was then delivered from 85015-8 into II-32A. The resultant Bt II-32A and Bt II-32B lines were both resistant to lepidopteran in field trials, and agronomic traits were not disturbed. The maintainability of II-32B, and the male sterility and general combining ability of II-32A, were not affected by the Bt introgression. This study demonstrates a simple and fast approach to develop Bt hybrid rice.  相似文献   

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