Timescale Analysis of Spectral Lags

A technique for timescale analysis of spectral lags performed directly in the time domain is developed. Simulation studies are made to compare the time domain technique with the Fourier frequency analysis for spectral time lags. The time domain technique is applied to studying rapid variabilities of X-ray binaries and γ-ray bursts. The results indicate that in comparison with the Fourier analysis the timescale analysis technique is more powerful for the study of spectral lags in rapid variabilities on short time scales and short duration flaring phenomena.

Optical Photometric Observations of 7-Ray Loud Blazars

We report results of our optical photometric observations of ten gamma-ray loud blazers, namely: 0219+428 (3C66A), PKS 0420-014 (OA 129), S5 0716+714, 0754+100 (OI 090.4), 0827+243 (OJ248), 1652+398 (Mrk 501), 2200+420 (BL Lacertae), 2230+114 (CTA 102), 2251+158 (3C 454.3) and 2344+514. The observations were carried out in September-October, 2000 using the 70 cm optical telescope at Abstumani Observatory, Georgia. We found intra-day variations in 0420-014, S5 0716+714, BL Lacertae and CTA 102. A variation of 0.3 magnitude over a time scale of about 3 hours was observed in the R passband in BL Lacertae on JD 2451827. We did not detect any variation in 3C 66A, Mrk 501, or 3C 454.3 during our observations. Nor did we detect any clear evidence of variation in 1ES 2344+514 during our two weeks' observing run of the TeV gamma-ray source.

Corrected Stefan-Boltzmann Law and Lifespan of a Black Hole

在一个概括无常原则的框架的黑洞的改正的 StefanBoltzmann 法律通过热放射的普朗克常数方程被导出。结果与扁平的 spacetime 不同：概括无常原则导致的一项改正的 T 6 条款出现；当相关时， T 4 条款的系数不再与在事件地平线和薄电影模型的附近的 spacetime 是一个常数。使用这改正了法律到黑洞放射，在有普朗克常数质量的顺序的一个团的放射和相应残余的最后的时间的最高的温度被获得。然而，黑洞的 lifespan 也被改正修正是极其小的。

The Correlation between Gamma-ray and Radio Emissions in γ-ray Loud Blazars

We collect 119 γ-ray-loud blazars (97 flat spectrum radio quasars (FSRQs) and 22 BL Lacertae objects (BL Lacs)), and investigate possible correlations between their γ-ray emission (maximum, minimum and average values) at 1 GeV and the radio emission at 8.4 GHz. Our main results are as follows. For the lower state γ-ray data, there is no correlation between the γ-ray and radio flux density; For the high state γ-ray data, there are good correlations for the whole 119 blazars and 97 FSRQs, and a weak correlation for the 22 BL Lac objects; For the average γ-ray data, there are good correlations. According to our analysis, we propose that the γ-rays are associated with the radio emission from the jet, and that the γ-ray emission is likely from the SSC process in this case.

Chandra Observations of the Flat Spectrum Seyfert-2 Galaxies NGC 2110 and NGC 7582

Chandra observations of the Seyfert-2 galaxies NGC 2110 and NGC 7582 arepresented. With the superb spatial resolution of Chandra we found that in NGC 7582 the soft (≤2keV) and hard (2-10 keV) X-rays are emitted in different regions, consistent with the report by Xueet al. By comparing the present X-ray data with the previous infrared data, we determined that thesoft X-ray region is the site of starburst activities. We found no significant temporal variationsduring our observations. We confirm the previous finding that NGC 2110 and NGC 7582 areflat-spectrum sources. We argue that the flat spectra may result from a cold absorbing material suchas envisaged in the 'dual absorbed' model. Strong FeK_α emission feature is detected in 6～7keV.Its equivalent width is so large that it cannot be reproduced by using the Galactic column densityof ～ 10^(22) cm^(-2).

The Binary Black Hole Scenario for the BL Lacertae Object AO 0235+16

Recent analysis of the long term radio light curve of the extremely variableBL Lacertae object AO 0235+16 by Raiteri et al. have revealed the presence of recurrent outburstswith a period of ～ 5.7 +- 0.5 yr. Periodicity analysis of the optical light curve also showsevidence for a shorter period. Here we discuss whether such a behavior can be explained by a binaryblack hole model where the accretion disk of one of the supermassive black holes is precessing dueto the tidal effects of the companion. We estimate the mass of the accreting hole and analyzeconstraints on the secondary mass and the orbital parameters of the system. It is possible toprovide a viable interpretation of the available multiwavelength data.

Central black hole masses of galaxies

In this paper, the stellar velocity dispersions in the host galaxies are used to estimate the central black hole masses for a sample of elliptical galaxies. We find that the central black hole masses are in the range of 10(5.5-9.5) M⊙. Based on the estimated masses in this paper and those by Woo & Urry (2002) and the measured host galaxy absolute magnitude,a relation, log(MBH/M⊙) = -(0.25 ± 4.3 × lO^-3)MR + (2.98 ± 0.208) is found for central black hole mass and the host galaxy magnitude. Some discussions are presented.

Analytical Potential Energy Function for the Ground State X1∑^＋ of Lanthanum Monofluoride

The equilibrium geometry, harmonic frequency and bond dissociation energy of lanthanum monofluoride have been calculated using Density-Functional Theory (DFT), post-HF methods MP2 and CCSD(T) with the energyconsistent relativistic effective core potentials. The possible electronic state and reasonable dissociation limit of the ground state of LaF are determined based on atomic and molecular reaction statics. Potential energy curve scans for the ground state X 1∑+ have been performed at B3LYP and CCSD(T) levels, due to their better results of harmonic frequency and bond dissociation energy. We find that the potential energy calculated with CCSD(T) is about 0.6 eV larger than the bond dissociation energy, when the internuclear distance is as large as 0.8 nm. The problem that single-reference ab initio methods do not meet dissociation limit during calculations of lanthanide heavy-metal elements is analyzed. We propose the calculation scheme to derive the analytical Murrell-Sorbie potential energy function. Vibrotational spectroscopic constants Be, ωe, ωeχe, αe, βe, De and He obtained by the standard Dunham treatment coincide well with the results of rotational analyses on spectroscopic experiments.

Mass-Temperature Relation of X-ray Clusters in Triaxial Halo

We investigate the mass-temperature relation of clusters for both the spherical NFW halo model and a concentric triaxial halo model. We study the temperature and density distributions of both an isothermal and a polytropic intra-cluster gas in hydrostatic equilibrium. We find that both the uncertainties in the concentration parameter and in the eccentricities (in case of the triaxial halo) lead to a greater scatter in the emission-weighted temperature at a given halo mass for less massive clusters. This may be helpful when determining the intrinsic statistical error of the σ8 normalization of the linear power spectrum from cluster abundance.

Rhombic Cell Analysis. Ⅱ. Application to the IRAS/PSCz Catalogue

Rhombic cell analysis as outlined in the first paper of the present series is applied to samples of varying depths and liming luminosities of the IRAS/PSCz Catalogue. Numerical indices are introduced to summarize essential information. Because of the discrete nature of the analysis and of the space distribution of galaxies, the indices for a given sample must be regarded as each having an irreducible scatter. Despite the scatter, the mean indices show remarkable variations across the samples. The underlying factor for the variations is shown to be the limiting luminosity rather than the sampling depth. As samples of more and more luminous galaxies are considered over a range of some 2.5 magnitudes (a factor of some 75 in space density), the morphology of the filled and empty regions defined by the galaxies degrades steadily towards insignificance, and the degrading is faster for the filled than the empty region.

Superluminal Motion and Polarization in Blazars

A relativistic beaming model has been successfully used to explain the observed properties of active galactic nuclei (AGNs). In this model there are two emission components, a boosted one and an unbeamed one, shown up in the radio band as the core and lobe components. The luminosity ratio of the core to the lobe is defined as the core-dominance parameter (R = (LCore/LLobe)). The de-beamed radio luminosity (Ljetdb) in the jet is assumed to be proportional to the unbeamed luminosity (Lub) in the co-moving frame, i.e., f = (Ljetdb/Lub), and f is determined in our previous paper. We further discuss the relationship between BL Lacertae objects (BLs) and flat spectrum radio quasars (FSRQs), which are subclasses of blazars with different degrees of polarization, using the calculated values of the ratio f for a sample of superluminal blazars. We found 1) that the BLs show smaller averaged Doppler factors and Lorentz factors, larger viewing angles and higher core-dominance parameters than do the FSRQs, and 2) that in the polarization-core dominance parameter plot (P-log R) the BLs and FSRQs occupy a scattered region, but in a revised plot (log (P/c(m)) ? log R), they gather around two different lines, suggesting that they have some different intrinsic properties.

Polarization in Gamma-Ray Bursts Produced by Pinch Discharge

Large-voltage, high-temperature plasma columns produced by pinch discharge can generate γ-ray flashes with energy spectra and spectral evolution consistent with what are observed in γ-ray bursts (GRBs), and the inverse Compton scattering (ICS) during the discharge process can produce high linear polarization. Our calculation indicates that the observed polarization depends on the angle between the line-of-sight to the GRB and the direction of the pinch discharge, but only weakly depends on observed γ-ray energy.

The Hybrid Nature of 0846+51W1: a BL Lac Object with a Narrow Line Seyfert 1 Nucleus

We found a NLS1 nucleus in the extensively studied eruptive BL Lac object, 0846+51W1, out of a large sample of NLS1s compiled from the spectroscopic dataset of SDSS DR1. Its optical spectrum can be well decomposed into three components: a power law component from the relativistic jet, a stellar component from the host galaxy, and a component from a typical NLS1 nucleus. The emission line properties of 0846+51W1, FWHM (Hβ) (?) 1710 km s-1 and [OⅢ]λ5007/Hβ(?)0.32 from its SDSS spectrum observed when it was in the faint state, fulfil the conventional definition of NLS1. Strong Fell emission is detected in the SDSS spectrum, which is also typical of NLS1s. We tried to estimate its central black hole mass using various techniques and found that 0846+51W1 is very likely emitting at a few ×10% of the Eddington luminosity. We speculate that Seyfert-like nuclei, including NLS1s, might be concealed in a significant fraction of BL Lacs but have remained largely unobserved because, often, their optical-UV continuum is overwhelmed by the synchrotron emission.

Relation between Starlight and Nebular Emission Lines of Star-Forming Galaxies

We present an exercise that intends to establish a relationship between the strength of nebular emission lines and optical stellar features in the spectrum of a galaxy. After accurately subtracting the stellar continuum and the underlying stellar absorption, we made reliable measurements of the emission lines of all the galaxies in the Sloan Digital Sky Survey Data Release 2 (SDSS DR2). More than 4000 star-forming galaxies with high S/N ratio of both the stellar spectrum and the emission lines are selected. These galaxy spectra are fitted with the 10 PCs of Yip et al., after all the emission line regions have been filtered out. We find that the flux of hydrogen Balmer emission lines, Ha and Hβ can be well recovered from the PCs, while the metal lines are not well reproduced. The fluxes of Ha and Hβ measured from the PC-reconstructed spectra and from the observed spectra agree well with an rms scatter of only - 0.1 dex. This result suggests that, with moderate spectral resolution and S/N ratio, the optical stellar spectrum of a galaxy can serve as an indicator of star formation rate.

Relations between the IR-UV-X-ray Continuum and Emission Lines for a Large Composite Sample of Narrow Line and Normal Seyfert 1 Galaxies

We report on our research on the UV, optical line parameters and the infrared through UV to soft X-ray continuum parameters for a composite sample of narrow line and normal Seyfert 1 galaxies. The strong correlations among the line width of HB, optical line strength of Fell and the soft X-ray slope are confirmed. We found no correlations between the UV line parameters, the equivalent widths of Lya and CIV and their ratio on one hand and the optical line parameters on the other. The UV and X-ray luminosities strongly correlate with the line widths of HB and the Fe II/HB ratio. No significant correlation is found between the infrared-soft X-my continuum slope aix and the line width of HB.

Global Axisymmetric Stability Analysis for a Composite System of Two Gravitationally Coupled Scale-Free Discs

For a composite system of gravitationally coupled stellar and gaseous discs, we have carried out a linear stability analysis for axisyrnmetric coplanar perturbations using the two-fluid formalism. The background stellar and gaseous discs are taken to be scale-free with all physical variables varying as powers of the cylindrical radius r with compatible exponents. The unstable modes set in as neutral modes or stationary perturbation configurations with angular frequency f33 = 0. The axisyrnmetric stable range is bounded by two marginal stability curves derived from stationary perturbation configurations. Because of the gravitational coupling between the stellar arid the gaseous discs, one only needs to consider the parameter regime of the stellar disc. There exist two unstable regimes in general: a collapse regime corresponding to large-scale perturbations and a ring-fragmentation regime corresponding to short-wavelength perturbations. The composite system will collapse if it rotates too slowly and will succumb to ring-fragmentation instabilities if it rotates sufficiently fast. The overall stable range against axisyrnmetric perturbations is determined by a necessary D-criterion involving the effective Mach number squared Ds2 (the squared ratio of the stellar disc rotation speed to the stellar velocity dispersion up to a numerical factor). Different mass ratio S and sound speed ratio η of the gaseous and stellar disc components will alter the overall stability. For spiral galaxies or circumnuclear discs, we further include the dynamical effect of a massive dark matter halo. Astrophysical applications to disc galaxies, proto-stellar discs and circumnuclear discs are given as examples.

A DWT Power Spectrum Analysis of PSCz Galaxies

The power spectrum estimator based on the Discrete Wavelet Transfor- mation (DWT) is applied to detect the clustering power in the IRAS Point Source Catalog Redshift Survey (PSCz). Comparison with mock samples extracted from N-body simulation shows that the DWT power spectrum estimator could provide a robust measurement of banded fluctuation power over a range of wavenumbers 0.1 ~ 2.0hMpc-1. We have fitted three typical CDM models (SCDM, τCDM and CDM) using the Peacock-Dodds formula including non-linear evolution and redshift distortion. We find that, our results are in good agreement with other statistical measurements of the PSCz.

胆碱酯酶抑制剂治疗阿尔茨海默病神经精神症状和功能损害的效果汇总分析

背景：胆碱酯酶抑制剂是阿尔茨海默病(Alzheimer disease，AD)认知症状的主要治疗药物。胆碱能功能障碍也可能导致神经精神和功能缺陷，但胆碱酯酶抑制剂随机对照试验的结果并不一致。目的：进行系统综述和汇总分析，定量显示胆碱酯酶抑制剂治疗轻至中度AD病人神经精神症状和功能减退的疗效。资料来源：我们应用MEDLINE(1966年1月-2001年12月)、在线论文摘要、PSYCHINFO、BIOSIS、PubMed和Cochrane对照试验登记查找相关试验的文献。我们检索了英语和非英语综述文章，从综述、研究原著及其他相关论文收集参考文献。我们查找了已发表和未发表的试验报告，并与研究者和制药公司取得联系。研究选择：我们入选平行组或交叉随机、双盲、安慰剂对照试验29项，参试者为诊断为轻至中度疑似AD并接受胆碱酯酶抑制剂治疗1个月以上的门诊病人。16项试验包括神经精神症状指标，18项试验包括功能指标。数据提取：两位研究者(N.H．T．和J．H．)分别提取研究方法、偏倚来源和预后指标。神经精神症状的预后采用神经精神症状调查表(NPI，0—120分)和阿尔茨海默病评估量表中的非认知量表(ADAS—noncog，0～50分)进行测定，并采用加权平均差法进行分析。功能的预后采用数项日常生活活动(ADL)量表或器械辅助日常生活活动(IADL)量表测定，用标准平均差法分析。数据综合：关于神经精神症状预后，10项试验有ADAS—noncog测定结果，6项试验有NPI测定结果。与安慰剂相比，随机使用胆碱酯酶抑制剂的病人NPI测定改善了1．72分(95％可信区间[CI]，0．87～2．57分)，A．DAS—noncog测定改善了0．03分(95％CI，0．00—0．05分)。关于生理功能预后，14项试验采用ADL量表，13项试验采用IADL量表。与安慰剂相比，随机使用胆碱酯酶抑制剂的病人ADL量表测定改善了0．1SDs(95％CI，0．00—0．19SDs)，IADL量表测定改善了0．09SDs(95％CI，0．01～0．17SDs)。各种胆碱酯酶抑制剂的疗效无差异。结论：上述结果表明，胆碱酯酶抑制剂对AD病人的神经精神症状和功能预后有一定效果。今后的研究应致力于如何将这种改善转化为病人生活质量、医疗保健机构入住和保健提供者负担等方面的长期后果。