Suzaku Observations of the Radio Galaxy 3C 33 (2009)
Evans, Daniel A., Reeves, James N., Hardcastle, Martin J., Kraft, Ralph P., Lee, Julia C., Virani, Shanil N.
We present results from a new 100-ks Suzaku observation of the nearby radio galaxy 3C 33, and investigate the nature of absorption, reflection, and jet production in this source. We model the 2-70...
Lee, Julia C., Xiang, Jingen, Ravel, Bruce, Kortright, Jeffrey, Flanagan, Kathryn
We present a new technique for determining the *quantity and composition* of dust in astrophysical environments using
The accretion disk corona and disk atmosphere of 4U 1624-490 as viewed by the Chandra-HETGS (2009)
Xiang, Jingen, Lee, Julia C., Nowak, Michael A., Wilms, Jörn, Schulz, Norbert S.
We present a detailed spectral study (photoionization modelling and variability) of the "Big Dipper" 4U 1624-490 based on a \chandra-High Energy Transmission Gratings Spectrometer (HETGS) observation...
Jet Suppression by Accretion Disk Winds in the Microquasar GRS 1915+105 (2009)
Neilsen, Joseph, Lee, Julia C.
Stellar-mass black holes with relativistic jets, also known as microquasars, mimic the behavior of quasars and active galactic nuclei. Because timescales around stellar-mass black holes are orders of...
Solid State Astrophysics: Probing Interstellar Dust and Gas Properties with X-rays (2009)
Lee, Julia C., Smith, Randall K., Canizares, C. R., Costantini, E., De Vries, C., Drake, J., ...
The abundances of gas and dust (solids and complex molecules) in the interstellar medium (ISM) as well as their composition and structures impact practically all of astrophysics. Fundamental...
Spectroscopic Signatures of the Superorbital Period in the Neutron Star Binary LMC X-4 (2009)
Neilsen, Joseph, Lee, Julia C., Nowak, Michael A., Dennerl, Konrad, Vrtilek, Saeqa Dil
We present the first high-resolution X-ray study of emission line variability with superorbital phase in the neutron star binary LMC X-4. Our analysis provides new evidence from X-ray spectroscopy...
Multi-Satellite Observations of Cygnus X-1 to Study the Focused Wind and Absorption Dips (2008)
Hanke, Manfred, Wilms, Joern, Boeck, Moritz, Nowak, Michael A., Schulz, Norbert S., Pottschmidt, Katja, ...
High-mass X-ray binary systems are powered by the stellar wind of their donor stars. The X-ray state of Cygnus X-1 is correlated with the properties of the wind which defines the environment of mass...
Hanke, Manfred, Wilms, Joern, Nowak, Michael A., Pottschmidt, Katja, Schulz, Norbert S., Lee, Julia C.
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...
XMM-Newton Observations of the Nuclei of the Radio Galaxies 3C 305, DA 240, and 4C 73.08 (2008)
Evans, Daniel A., Hardcastle, Martin J., Lee, Julia C., Kraft, Ralph P., Worrall, Diana M., Birkinshaw, Mark, ...
We present new XMM-Newton EPIC observations of the nuclei of the nearby radio galaxies 3C 305, DA 240, and 4C 73.08, and investigate the origin of their nuclear X-ray emission. The nuclei of the...
A Radio Through X-ray Study of the Jet/Companion-Galaxy Interaction in 3C 321 (2007)
Evans, Daniel A., Fong, Wen-Fai, Hardcastle, Martin J., Kraft, Ralph P., Lee, Julia C., Worrall, Diana M., ...
We present a multiwavelength study of the nucleus, environment, jets, and hotspots of the nearby FRII radio galaxy 3C 321, using new and archival data from MERLIN, the VLA, Spitzer, HST, and Chandra....
A Highly Concurrent Transaction Management Model (2007)
Lawrence J. Henschen, Julia C. Lee
We describe a methodology for transforming sets of database transactions into sets of conflict-free transactions which can be executed independently and in parallel. The method identifies conflicting...
Evans, Daniel A., Lee, Julia C., Turner, T. Jane, Weaver, Kimberly A., Marshall, Herman L.
We present results from Chandra HETGS (250 ks over two epochs) and XMM-Newton EPIC and RGS (60 ks) observations of NGC 2110, which has been historically classified as a Narrow Emission Line Galaxy...
Xiang, Jingen, Lee, Julia C., Nowak, Michael A.
We present X-ray dust scattering halo results based on our 76 ks {\it Chandra} ACIS-S/HETGS observation of the LMXB dipping source 4U 1624-490. Through analysis of the halo light curves with 2-6 keV...
Evans, Daniel A., Lee, Julia C., Kamenetska, Maria, Gallagher, Sarah C., Kraft, Ralph P., Hardcastle, Martin J., ...
We present results from new Chandra and archival HST and VLA imaging observations of the circumnuclear extended emission in the nearby Type 2 Seyfert galaxy NGC 2110. We find resolved soft-band X-ray...
Scott, Jennifer E., Kriss, Gerard A., Lee, Julia C., Quijano, Jessica Kim, Brotherton, Michael, Canizares, Claude R., ...
We present simultaneous X-ray, far-ultraviolet, and near-ultraviolet spectra of the Seyfert 1 galaxy NGC 7469 obtained with the Chandra X-Ray Observatory, the Far Ultraviolet Spectroscopic Explorer,...
We investigate the ability of high resolution X-ray spectroscopy to directly probe the grain composition of the interstellar medium. Using iron K-edge experimental data of likely ISM dust candidates...
Scott, Jennifer E., Kriss, Gerard A., Lee, Julia C., Arav, Nahum, Ogle, Patrick, Roraback, Kenneth, ...
We present a study of the intrinsic X-ray and far-ultraviolet absorption in the Seyfert 1.5 galaxy Markarian 279 using simultaneous observations from the Chandra X-ray Observatory, the Space...
Probing X-ray Emitting Plasma with High Resolution Chandra and XMM-Newton Spectra (2003)
Highlights of interesting astrophysical discoveries are reviewed in the context of high resolution X-ray spectroscopy made possible with Chandra and XMM-Newton, and its relevance to atomic physics...
The X-Ray Position and Infrared Counterpart of the Eclipsing X-Ray Pulsar OAO 1657-415 (2002)
Chakrabarty, Deepto, Wang, Zhongxiang, Juett, Adrienne M., Lee, Julia C., Roche, Paul
We have measured the precise position of the 38-s eclipsing X-ray pulsar OAO 1657-415 with the Chandra X-Ray Observatory: RA = 17h00m48.90s, Dec = -41d39m21.6s, equninox J2000, error radius = 0.5...
The Ionized Stellar Wind in Vela X-1 During Eclipse (2001)
Schulz, Norbert S., Canizares, Claude R., Lee, Julia C., Sako, Masao
We present a first analysis of a high resolution X-ray spectrum of the ionized stellar wind of Vela X-1 during eclipse. The data were obtained with the High Energy Transmission Grating Spectrometer...
Double-Peaked X-Ray Lines from the Oxygen/Neon-Rich Accretion Disk in 4U1626-67 (2001)
Schulz, Norbert S., Chakrabarty, Deepto, Marshall, Herman L., Canizares, Claude R., Lee, Julia C., Houck, John
We report on a 39 ks observation of the 7.7-s low-mass X-ray binary pulsar 4U1626-67 with the High Energy Transmission Grating Spectrometer (HETGS) on the Chandra X-Ray Observatory. This ultracompact...