X-ray emission properties of galaxies in Abell 3128     

Russell J. Smith 《Monthly notices of the Royal Astronomical Society》2003,344(2):L17-L21

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Mapping the inner accretion disc of the Galactic black hole J1550–564 through its rise to outburst     

Colin D. Wilson  Chris Done 《Monthly notices of the Royal Astronomical Society》2001,325(1):167-177

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RXTE observations of 4U 1630−47 during the peak of its 1998 outburst     

Sergey P. Trudolyubov  Konstantin N. Borozdin  William C. Priedhorsky 《Monthly notices of the Royal Astronomical Society》2001,322(2):309-320

We present an analysis of the RXTE observations of 4U 1630−47 during its 1998 outburst. The light curve and the spectral evolution of the outburst were significantly different from the outbursts of the same source in 1996 and 1999. Special emphasis was placed on observations taken during the initial rise and during the maximum of the outburst. The maximum of the outburst was divided into three plateaux, with almost constant flux within each plateau, and fast jumps between them. The spectral and timing parameters are stable for each individual plateau, but significantly different between the plateaux. The variability detected on the first plateau is of special interest. During these observations the source exhibits quasi-regular oscillations with a period of ∼ 10–20 s. Our analysis revealed a difference in temporal behaviour of the source at high and low fluxes during this period of time. The source behaviour can be generally explained in the framework of the two-phase model of accretion flow, involving a hot inner Comptonization region and surrounding optically thick disc.
The variability and spectral evolution of the source were similar to what was observed earlier for other X-ray novae. We show that 4U 1630−47 resembles, in several aspects, other transient and persistent black hole binaries.  相似文献   

Erratum: Probable intermediate-mass black holes in NGC 4559: XMM–Newton spectral and timing constraints     

Mark Cropper  Roberto Soria  Richard F. Mushotzky  Kinwah Wu  Craig B. Markwardt  Manfred Pakull 《Monthly notices of the Royal Astronomical Society》2004,353(3):1024-1024

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Evolution of massive binary black holes     

QingjuanYu 《Monthly notices of the Royal Astronomical Society》2002,331(4):935-958

Since many or most galaxies have central massive black holes (BHs), mergers of galaxies can form massive binary black holes (BBHs). In this paper we study the evolution of massive BBHs in realistic galaxy models, using a generalization of techniques used to study tidal disruption rates around massive BHs. The evolution of BBHs depends on BH mass ratio and host galaxy type. BBHs with very low mass ratios (say, ≲0.001) are hardly ever formed by mergers of galaxies, because the dynamical friction time-scale is too long for the smaller BH to sink into the galactic centre within a Hubble time. BBHs with moderate mass ratios are most likely to form and survive in spherical or nearly spherical galaxies and in high-luminosity or high-dispersion galaxies; they are most likely to have merged in low-dispersion galaxies (line-of-sight velocity dispersion ≲90 km s⁻¹) or in highly flattened or triaxial galaxies.
The semimajor axes and orbital periods of surviving BBHs are generally in the range  10^-3–10 pc  and  10–10⁵ yr;  they are also larger in high-dispersion galaxies than in low-dispersion galaxies, larger in nearly spherical galaxies than in highly flattened or triaxial galaxies, and larger for BBHs with equal masses than for BBHs with unequal masses. The orbital velocities of surviving BBHs are generally in the range  10²–10⁴ km s^-1  . The methods of detecting surviving BBHs are also discussed.
If no evidence of BBHs is found in AGNs, this may be either because gas plays a major role in BBH orbital decay or because nuclear activity switches on soon after a galaxy merger, and ends before the smaller BH has had time to spiral to the centre of the galaxy.  相似文献   

黑洞发光环谱线轮廓的精确解     

邓铁如 《中国天文和天体物理学报》1996,(3)

围绕黑洞作开普勒运动的环状发光物所发射的光，将受到多普勒颇移和引力的综合作用．本文用光子输运方程方法，针对洛仑兹型发射谱线，求出在Schwarzschild度规下谱线轮廓的精确解，并讨论了Hercules星系团中类星体1604＋179光谱的认证．  相似文献   

某灌注桩施工中遇到的问题及处治对策     

贾刚强 《地球科学与环境学报》2002,24(3):21-22

通过工程实践介绍了如何处理混凝土灌注桩施工过程中的串桩、塌孔等问题 ,总结点滴经验 ,对于施工现场及时作出科学决策 ,采取有效的技术措施 ,保证工程质量有着积极的指导意义。  相似文献   

Erratum: Chandra observations of five ultraluminous X-ray sources in nearby galaxies     

T. P. Roberts  R. S. Warwick  M. J. Ward  M. R. Goad 《Monthly notices of the Royal Astronomical Society》2004,350(4):1536-1536

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Ultraluminous X-ray sources and star formation     

A. R. King 《Monthly notices of the Royal Astronomical Society》2004,347(2):L18-L20

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绳索取心钻进在祁连下沟矿区斜孔中的应用     

张宁禹  张庆海 《青海国土经略》1993,(2)

小口径金刚石钻头绳索取心钻进,在青海祁连下沟矿区取得明显的质量效应。该工艺及设备投入后获得的岩心采取率达95.93%,矿心采取率98.87%,优质孔率100%,孔斜超差率低,占月效率平均达464.48m。结合使用:可退式套管、钻杆两用卡管器”专用设备后更收益匪浅。文章对此给予了总结分析和比较。  相似文献