相关论文: A complex environment around Cir X-1

We have analyzed a Chandra HETGS spectrum of the Galactic black hole Cygnus X-1, obtained at a source flux which is approximately twice that commonly observed in its persistent low-intensity, spectrally-hard state. We find a myriad of…

High resolution spectral studies were undertaken at orbital phases 0, 0.25 and 0.5 on the high-mass X-ray binary (HMXB) Vela X-1 using archival Chandra data. We present (a) the first detailed analysis of the multiple strong narrow emission…

We present results from a study of 2-8 keV X-ray sources detected by the Advanced CCD Imaging Spectrometer (ACIS) instrument on the Chandra X-ray Observatory in the field of the z=0.516 cluster CRSS J0030.5+2618. In our 63.5 arcmin^2 search…

We present Chandra X-ray observations of the nearby Seyfert 1.5 galaxy NGC 4151. The images show the extended soft X-ray emission on the several hundreds of pc scale with better sensitivity than previously obtained. The spectrum of the…

We present data from simultaneous Chandra, XMM-Newton and BeppoSAX observations of the Seyfert 1 galaxy NGC 3516, taken during 2001 April and Nov. We have investigated the nature of the very flat observed X-ray spectrum. Chandra grating…

The time-averaged 30 ks Chandra HETGS observation of the micro-quasar GRS 1915+105 in the low hard state reveals for the first time in this source neutral K absorption edges from Fe, Si, Mg, & S. Ionized resonance absorption from H-, and…

We present the X-ray properties of a sample of 17 radio sources observed with the Chandra X-ray Observatory as part of a project aimed at studying the X-ray emission from their radio jets. In this paper, we concentrate on the X-ray…

We report the discovery of eight X-ray sources with periodic variability in 487 ks of observations of the Galactic center with Chandra. The sources are identified from a sample of 285 objects detected with 100-4200 net counts. Their periods…

We study the X-ray properties of LINER sources with definite detection of a broad H(alpha) emission line in their optical spectra, LINER 1s from Ho et al. sample. These objects preferentially harbor a low luminosity active nucleus at the…

Chandra ACIS-I data of the molecular cloud and HII region complex NGC 6334 were analyzed. The hard X-ray clumps detected with ASCA (Sekimoto et al. 2000) were resolved into 792 point sources. After removing the point sources, an extended…

We examine the X-ray spectra and variability of the sample of X-ray sources with L_X = 10^{31}-10^{33} erg s^{-1} identified within the inner 9' of the Galaxy. Very few of the sources exhibit intra-day or inter-month variations. We find…

We report on strong X-ray variability and the Fe K band spectrum of the Seyfert galaxy IRAS 18325-5926 obtained from the 2001 XMM-Newton EPIC pn observation of a 120 ks duration. While the X-ray source is highly variable, the 8-10 keV band…

We present Chandra observations of the enigmatic galaxy IRAS00317-2142, which is classified as a star-forming galaxy on the basis of the ionization level of its emission lines. However, a weak broad H\alpha wing and a high X-ray luminosity…

Accretion conditions and morphologies of X-ray transients containing neutron stars are still poorly understood. Circinus X-1 is an enigmatic case where we observe X-ray flux changes covering four orders of magnitude. We observed Circinus…

When observed by XMM-Newton in 2003 the type 1 QSO 2MASS 0918+2117 was found to in a low flux state, some ~4-5 times fainter than during an earlier Chandra observation. The 2-6 keV spectrum was unusually hard, with evidence for a…

We present the results from simultaneous Chandra HETGS and RXTE observations of the microquasar GRS 1915+105 in its quasi-stable "soft state" (or State A) performed on 2007 August 14, several days after the state transition from "hard…

We present analyses of a 50 ks observation of the supergiant X-ray binary system Cygnus X-1/HDE 226868 taken with the Chandra High Energy Transmission Grating Spectrometer (HETGS). Cyg X-1 was in its spectrally hard state and the…

We present the results of a 50 ks long Chandra observation of the dipping source XB 1916-053. During the observation two X-ray bursts occurred and the dips were not present at each orbital period. From the zero-order image we estimate the…

We present the results of a Suzaku study of a bright point-like source in the 6.7 keV intensity map of the Galactic center region. We detected an intense FeXXV 6.7 keV line with an equivalent width of ~1 keV as well as emission lines of…

Cen X-3 is a compact, high-mass X-ray binary (HMXRB), likely powered by Roche lobe overflow. We present a phase-resolved X-ray spectral and timing analysis of a target of opportunity \textit{Chandra} observation made during a low-flux to…