We present the X-ray spectroscopy of cluster PKS 0745-191 with XMM-Newton in this paper.

We present soft X-ray results from observations with Chandra (HETGS) of the Seyfert I AGN NGC 4593 and Mrk 509. We discuss the photoionized outflows associated with Seyfert I AGN in terms of their absorption spectral signatures and discuss their kinematics, column density and ionization state. We discuss the link between UV and X-ray absorbers in Mrk 509 (which was simultaneously observed with Chandra and HST-STIS). We also briefly discuss the possibility of absorption due to neutral Fe embedded in the warm absorber of NGC 4593 versus an interpretation of the data in terms of soft X-ray relativistic emission lines. We conclude with a summary of what is being learnt about warm absorbers in type I AGN from high resolution spectroscopy.

We present measurements of the Fe-Kα line for nine Seyfert I galaxies using Chandra High Energy Transmission Grating Spectrometer (HETGS) data. The centroid energies are narrowly dispersed (6.403 ± 0.062 keV) and indicate an origin of the line cores in cold matter. If all the lines in this sample were the peaks of a relativistically broadened disk line, it would require unrealistically fine tuning. However, at least three of the nine AGN clearly show a complex Fe-Kα line with an underlying broad component, possibly from a disk. In the others, an apparently narrow Fe-Kα line (even if it is resolved by Chandra) may still be due to the peak of a disk line. To distinguish this scenario from an origin in distant matter requires variability information.

We compare Seyfert 2 galaxies(Sy2s) with detected polarized broad emission lines(PBL) with Sy2s without detected PBL and find that the majority of Sy2s without PBL are those sources with less powerful AGN activity, most likely caused by low accretion rates. This implies that the detectability of polarized broad emission lines in Sy2s mainly depends on their central AGN activity in most cases. We also find that Sy2s without PBL follow the exactly same FIR-radio relation as normal and starburst galaxies.

We present the optical emission line properties of a sample of 155 bright X-ray selected ROSAT Seyfert 1 type AGN. The measured properties are gathered for correlation analysis. The strong correlations between Hβ redshift, flux ratios of Fe II to Hβ broad component and [O III] to Hβ narrow component are found.

In order to elucidate the physics of the Fe Kα line emissions from Seyfert (-like) AGNs, we propose a thin-torus model in Kerr metric and fit it to three galaxies (i.e., NGC 3516, 3C 273, and NGC 5548). It is found that only spinning-BH galaxies radiate observable line flux from a region within tens of gravitational radii of a central BH. Besides, the observer's inclination angle is around 30°.

With the determined black-hole (BH) spin of 3C 273 by data-fitting to the detected iron Kα line emission in the soft X-ray band, the BH mass of the galaxy is predicted by formulations of both the observed disk-luminosity in the optical-UV band and the observed jet-precession in the radio band. The multiband synthesis suggests that the BH is supermassive, 2.4 × 109M⊙. Simultaneously, other physical parameters are self-consistently obtained at the precessing radius of 230.2rg: the accretion rate of the disk is 74.9M⊙ yr−1, the Shakura-Sunyaev viscosity α is 0.134, and the radial & orbital velocities of fluid elements are 4.3 × 10−8 and 6.6 × 10−2, respectively.

This paper presents a analysis of X-ray variability for a assembled sample of broad-line Seyfert 1, narrow-lines Seyfert 1 galaxies and QSOs observed by ASCA, whose central black masses have been estimated. We find the significant relation between X-ray variability and the central black masses is different for Broad-line and Narrow-lines galaxies. The higher excess variance of narrow-line galaxies can be explained that they have smaller size of X-ray emission region compare to the broad-line objects. Our findings favor the hypothesis that the narrow-line galaxies have rotational black hole and hence maybe have the jets.

Centaurus A (NGC 5128) is a giant early-type galaxy containing the nearest radio-bright AGN. The high-angular resolution Chandra images of Cen A reveal multi-scale X-ray structures with unprecedented detail and clarity. We present results from our study of X-ray structures surrounding the Cen A nuclear region, including the discovery of giant arc-like structures, extending to about 8 kpc in the direction perpendicular to the jet. We compare the X-ray structures with observations in other wavelengths and discuss their implication for a global understanding of the morphology of Cen A.

A model of the H2O maser disk observed in the nucleus of the galaxy NGC4258 is presented. The hot-gas–cold-dust pumping mechanism based on the difference between gas and dust temperatures and special features of the ice spectrum is used. Conditions for the maser level inversion are calculated in the case of unsaturated maser. It is shown based on the observational data that the maser in NGC 4258 seems to be unsaturated. In that case the spectrum of the maser radiation at λ = 1.35 cm including the central and high velocity components is calculated. The key parameters of the molecular maser disk are determined by comparing results of numerical simulations with the data.

Based on the beaming model, a relation between the observed polarization and Doppler factor was obtained for BL Lacertae objects–BLs by Fan et al. (1997). If flat spectral radio quasars—FSRQs fit a similar polarization-Doppler factor relation as BLs, then we can find that the ratio, f, of the de-beamed jet luminosity to the unbeamed luminosity in the source frame in BLs is greater than that in FSRQs. That difference in f is consistent with the result by Fan (2002a), which perhaps accounts for the emission line difference between BLs and FSRQs.

We selected a sample of bright γ-ray (E>100 MeV) blazars whose X-rays in 0.1–10.0 keV band are observed by ROSAT and other X-ray satellites, and make a detailed spectral analysis between the soft (0.1–2.0 keV) and hard band (2.0–10.0keV) as well as between X-ray and γ-ray properties using both un-weighted and weighted analysis methods. Our results indicate: (i) there are significant anti-correlations of the spectral indices between soft X-rays and γ-rays, and between hard X-ray and γ-ray of flat-spectrum radio quasars (FSRQs) and BL Lac objects; (ii) in the X-ray band, the correlation is confusing, there is positive correlation of the spectral indices between soft and hard X-ray band using weighted correlation analysis, but this correlation is negative using un-weighted correlation analysis.

Magnetic Fields are the crucial and most important ingredient involved in the processes of various violent activities in Active Galactic Nuclei and other celestial bodies. The generally accepted 2-sided symmetric-jets model of active galactic nuclei (AGN) does not include the magnetic fields. We present here the first direct detection of helical magnetic field in AGN, and the first direct detection of ejection of large scale magnetic fields from AGN. (CME) 2. The annular (helical) magnetic field is responsible for the collimation of the jet (through Pinch Effect) and may be of crucial importance for extraction of black hole rotational energy. 3. The CMEs are responsible for sporadic ejection of jet components in AGN, while the general accepted 2-sided jets pertain to the quiescent Jets. 4. Observations show that the CME with Asymmetric Jets can explain many phenomena and much of the morphological diversities in AGN.

Extensive observational campaigns of afterglow hunting have greatly enriched our understanding of the gamma-ray burst (GRB) phenomenon. Efforts have been made recently to explore some afterglow properties or signatures that will be tested by the on-going or the future observational campaigns yet come. These include the properties of GRB early afterglows in the temporal domain; the GeV-TeV afterglow signatures in the spectral domain; as well as a global view about the GRB universal structured jet configuration. These recent efforts are reviewed. Within the standard cosmological fireball model, the very model(s) responsible for the GRB prompt emission is (are) not identified. These models are critically reviewed and confronted with the current data.

Based on a refined dynamical model, afterglows from jetted γ-ray burst (GRB) remnants are investigated numerically. Measuring of GRB beaming by using orphan afterglow surveys is addressed. The possible existence of a kind of cylindrical jets is also discussed.

We investigate a black hole-accretion disk system which is dominated by Poynting flux to see whether it can be a possible power house for GRBs. For a set of GRBs for which the isotropic energy and Td are known, the effect of the disk mass and the magnetic field are discussed quantitatively using a simplified model. It is demonstrated explicitly that there is a lower limit on the angular momentum parameter for a given GRB energy. It is found that the most energetic GRBs can only accommodate relatively rapid-rotating black holes at the center.

Gamma-ray bursts (GRBs) are believed to originate from ultra-relativistic fireballs, with initial Lorentz factor η ∼ 102 − 103. However very high energy photons may still suffer from γγ interaction. We show here that in a wide range of model parameters, the resulting pairs may dominate electrons associated with the fireball baryons. This may provide an explanation for the rarity of prompt optical detections. A rapid response to the GRB trigger at the IR band would detect such a strong flash.

We try to explain the different type of GRBs from their properties, most likely the long duration GRBs are the NS-NS collision, short duration ones are the WD-WD collision, and intermediate ones are the NS-WD collision.

The formula of the Doppler effect of fireballs, which shows how the observational flux from fireballs would be expected, is presented. It shows, when the expansion speed is very large, a weak radiation at X-ray bands would be significantly enhanced to detectable levels and shifted to much higher bands to become a gamma-ray source; at the same time, the peak of the spectrum would shift to a much higher energy band as well.

We determine the characteristic variability time scales for 410 bright long GRBs by locating the maximums of their Power Density Spectra (PDSs) defined and calculated in the time domain. The averaged characteristic variability time scale decreases with peak fluxe. This is consistent with the time dilation effect expected by cosmological origin of GRBs. The occurrence distribution of the characteristic variability time scale shows bimodality, which might be interpreted as that the long GRB sample is composed of two sub-classes with different intrinsic characteristic variability time scales.