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The ASCA SIS and the ROSAT PSPC spectral data of the SNR 3C397 are analysed with a two-component non-equilibrium ionization model. Besides, the ASCA SIS0 and SIS1 spectra are also fitted simultaneously in an equilibrium case. The resulting…

Astrophysics · Physics 2009-10-31 Yang Chen , Ming Sun , Zhen-Ru Wang , Q. F. Yin

We present models for the X-ray spectrum of the Seyfert 2 galaxy NGC 1068. These are fitted to data obtained using the High Energy Transmission Grating (HETG) on the Chandra X-ray observatory. The data show line and radiative recombination…

High Energy Astrophysical Phenomena · Physics 2015-06-17 T. Kallman , D. A. Evans , H. Marshall , C. Canizares , A. Longinotti , M. Nowak , N. Schulz

(Abridged) The results of a Chandra X-ray Observatory High-Energy Transmission Grating (HETG) observation of the nova-like cataclysmic binary AE Aqr are described. First, the X-ray spectrum is that of an optically thin multi-temperature…

Solar and Stellar Astrophysics · Physics 2014-11-20 Christopher W. Mauche

We fit Chandra HETGS data obtained for the unusual X-ray binary SS 433. While line strengths and continuum levels hardly change, the jet Doppler shifts show aperiodic variations that probably result from shocks in interactions with the…

We present an X-ray study of the radio bright supernova remnant (SNR) 3C 397 with ROSAT, ASCA, and RXTE. A central X-ray spot seen with the ROSAT High-Resolution Imager hints at the presence of a pulsar-powered component, and gives this SNR…

We study the properties of hot gaseous halos in 10 nearby ultraluminous IRAS galaxies observed with the ACIS instrument on board Chandra. For all sample galaxies, diffuse soft X-ray emissions are found within ~10 kpc of the central region;…

Astrophysics · Physics 2008-11-26 Z. Y. Huo , X. Y. Xia , S. J. Xue , S. Mao , Z. G. Deng

We present evidence for X-ray line emitting and absorbing gas in the nucleus of the Broad-Line Radio Galaxy (BLRG), 3C 445. A 200ks Chandra LETG observation of 3C 445 reveals the presence of several highly ionized emission lines in the soft…

High Energy Astrophysical Phenomena · Physics 2015-05-20 J. N. Reeves , J. Gofford , V. Braito , R. Sambruna

We present a quantitative analysis of the X-ray spectrum of the eclipsing high mass X-ray binary Vela X-1 (4U 0900-40) using archival data from ASCA. The observation covers a time interval centered on eclipse of the X-ray pulsar by the…

Astrophysics · Physics 2009-10-31 Masao Sako , Duane A. Liedahl , Steven M. Kahn , Frits Paerels

We present the XMM-Newton observations obtained during four revolutions in Spring and Summer 2004 of CXOGC J174540.0-290031, a moderately bright transient X-ray source, located at only 2.9" from SgrA*. We report the discovery of sharp and…

Astrophysics · Physics 2009-11-11 D. Porquet , N. Grosso , G. Belanger , A. Goldwurm , F. Yusef-Zadeh , R. S. Warwick , P. Predehl

We present the results of a multi-site photometric campaign carried out in 2004-2008 for the Algol-type eclipsing binary system CT Her, the primary component of which shows Delta Scuti-type oscillations. Our data consist of differential…

A Chandra ACIS-S imaging observation of the nearby galaxy M81 (NGC 3031) reveals 9 luminous soft X-ray sources. The local environments, X-ray spectral properties, and X-ray light curves of the sources are presented and discussed in the…

Astrophysics · Physics 2009-11-07 Douglas Swartz , Kajal Ghosh , Valery Suleimanov , Allyn Tennant , Kinwah Wu

We study the resonant x-ray scattering at Si and Al K-edges from chiral materials, $\alpha$-quartz and $\alpha$-berlinite. We derive the general form of the scattering matrix for the dipole transition by summing up the local scattering…

Materials Science · Physics 2012-10-03 Jun-ichi Igarashi , Manabu Takahashi

The eclipsing polar CSS081231 turned bright (V_max ~ 14.5) in late 2008 and was subsequently observed intensively with small and medium-sized telescopes. A homogeneous analysis of this comprehensive dataset comprising 109 eclipse epochs is…

Solar and Stellar Astrophysics · Physics 2015-06-23 A. D. Schwope , F. Mackebrandt , B. D. Thinius , C. Littlefield , P. Garnavich , A. Oksanen , T. Granzer

The results of Chandra snapshot observations of 11 LINERs (Low-Ionization Nuclear Emission-line Regions), three low-luminosity Seyfert galaxies, and one HII-LINER transition object are presented. Our sample consists of all the objects with…

Astrophysics · Physics 2007-05-23 Yuichi Terashima , Andrew S. Wilson

The core-dominated radio-loud quasar PKS 0637-752 (z = 0.654) was the first celestial object observed with the Chandra X-ray Observatory, offering the early surprise of the detection of a remarkable X-ray jet. Several observations with a…

We present high-resolution soft-X-ray spectra of the prototypical Seyfert 2 galaxy, NGC 1068, taken with XMM-Newton RGS and Chandra LETGS. Its rich emission-line spectrum is dominated by recombination in a warm plasma (bright, narrow…

1RXS J201607.0251645 is identified to be an eclipsing binary for the first time. We present the preliminary observations in V band with the 0.6-m telescope for three years and the extensive observations in V and R band with the 0.8-m…

Solar and Stellar Astrophysics · Physics 2010-02-04 Hua-Li Li , Yuan-Gui Yang , Wei Su , Hui-Juan Wang , Jian-Yan Wei

We present the results of a 17 ks Chandra ACIS-S observation of the nearby dwarf spiral galaxy NGC 4395. Chandra affords the first high-quality, broadband X-ray detection of the active nucleus of this object that is uncontaminated by nearby…

The narrow-line quasar PHL 1092 was observed by XMM-Newton at two epochs separated by nearly thirty months. Timing analyses confirm the extreme variability observed during previous X-ray missions. A measurement of the radiative efficiency…

Astrophysics · Physics 2009-09-17 L. C. Gallo , Th. Boller , W. N. Brandt , A. C. Fabian , D. Grupe

We present an update on the results of our monitoring observations of the X-ray remnant of supernova (SN) 1987A with the {\it Chandra X-Ray Observatory}. As of 2002 December, we have performed a total of seven observations of SN 1987A. The…

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