X-ray images and spectra of 5 cataloged supernova remnants (SNRs), G12.0−0.1, G346.6−0.2, G348.5+0.1, G348.7+0.3, and G355.6−0.0, observed in the ASCA galactic plane survey are presented. The sizes of X-ray emission from G12.0−0.1, G348.5+0.1, G348.7+0.3, and G355.6−0.0 are comparable to their radio structures, while that of G346.6−0.2 is smaller than the radio structure. The X-ray spectra of a...

We show from modeling the Fe Kα line in the ASCA spectra of four X-ray bright narrow emission line galaxies (Seyfert types 1.9 and 2) that two equally viable physical models can describe the observed line profile. The first is discussed by Turner et al. (1998) and consists of emission from a nearly pole-on accretion disk. The second, which is statistically preferred, is a superposition of emiss...

We present a Chandra X-ray observation of G12.82−0.02, a shell-like radio supernova remnant coincident with the TeV gamma-ray source HESS J1813−178. We resolve the X-ray emission from the co-located ASCA source into a compact object surrounded by structured diffuse emission that fills the interior of the radio shell. The morphology of the diffuse emission strongly resembles that of a pulsar win...

We present the RXTE PCA X-ray spectrum of SN 1006. This data exhibits evidence of highenergy non-thermal X-ray emission. An analysis of the RXTE PCA data and data from the ASCA SIS and ROSAT PSPC detectors suggests that the entire broad-band X-ray spectrum of SN 1006 may be t with a single non-equilibrium ionization thermal component and a nonthermal component described by a broken power law wi...

We analyze the simultaneous ASCA/RXTE observation of Cyg X-1 in the soft state on 1996 May 30. We apply a multi-color disk model with a torque-free boundary condition in the pseudo-Newtonian potential, and point out the main discrepancies between the commonly-used simplified 'diskbb' model and our one. We estimate the black hole mass and the accretion rate, and show that during this observation...

We report results from the first simultaneous X-ray (RXTE) and optical (SAAO) observations of the low-mass X-ray binary GS 1826–24 in June 1998. A type-I burst was detected in both X-ray and optical wavelengths. Its energy-dependent profile, energetics and spectral evolution provide evidence for an increase in the X-ray burning area but not for photospheric radius expansion. However, we may sti...

We have obtained the first large sample of accurate temperatures for clusters at z > 0.14 from ASCA. We compare the luminosity temperature (L-T) distribution for these clusters with the low redshift sample of David et al (1993) and find that there is no evidence for evolution. We also find that the intrinsic variance in this relation is roughly constant with redshift. Additionally, there is no ...

For the first time, we explore the application of active contours in the moclulation domain by computing snakes on image modulations. As we demonstrate in the examples, such snakes are able to utilize information inherent in the dominant image modulations to acquire and track visually and semantically meaningful structures within the image. We use nonlinear AM-FM image representations to captur...

We study three prominent bi-modal X-ray clusters: A3528, A1750 and A3395. Using observations taken with ROSAT and ASCA, we analyze the temperature and surface brightness distributions. We also analyze the velocity distributions of the three clusters using new measurements supplemented with previously published data. We examine both the overall cluster properties, as well as the two sub-cluster ...