Discovery of an optical counterpart to the hyperluminous X-ray source in ESO 243-49 (2009)
Soria, Roberto, Hau, George K. T., Graham, Alister W., Kong, Albert K. H., Kuin, N. Paul M., Li, I-Hui, ...
The existence of black holes of masses ~ 10^3-10^4 Msun has important implications for the formation and evolution of star clusters and galaxies. The strongest candidate so far is the hyperluminous...
Molecular Line Profiles of Collapsing Gas Clouds (2009)
Gao, Yang, Lou, Yu-Qing, Wu, Kinwah
Emission line profiles of tracer molecule H$_2$CO 140 GHz transition from gravitational core collapsing clouds in the dynamic process of forming protostars are calculated, using a simple ray-tracing...
Magnetic Interaction in Ultra-compact Binary Systems (2009)
This article reviews the current works on ultra-compact double-degenerate binaries in the presence of magnetic interaction, in particular, unipolar induction. The orbital dynamics and evolution of...
X-ray polarization from accreting white dwarfs and associated systems (2009)
Wu, Kinwah, McNamara, Aimee, Kuncic, Zdenka
We present our results of Monte-Carlo simulations of polarized Compton X-rays from magnetic cataclysmic variables, with realistic density, temperature and velocity structures in the accretion flow....
Polarization of Compton X-rays from Jets in AGN (2009)
McNamara, Aimee, Kuncic, Zdenka, Wu, Kinwah
We investigate the polarization of Compton scattered X-rays from relativistic jets in active galactic nuclei using Monte Carlo simulations. We consider three scenarios: scattering of photons from an...
Relativistic reflection X-ray spectra of accretion disks (2009)
Lee, Khee-Gan, Wu, Kinwah, Fuerst, Steven V., Branduardi-Raymont, Graziella, Crowley, Oliver
We have calculated the relativistic reflection component of the X-ray spectra of accretion disks in active galactic nuclei (AGN). Our calculations have shown that the spectra can be significantly...
X-ray Polarization in Relativistic Jets (2009)
McNamara, Aimee L., Kuncic, Zdenka, Wu, Kinwah
We investigate the polarization properties of Comptonized X-rays from relativistic jets in Active Galactic Nuclei (AGN) using Monte Carlo simulations. We consider three scenarios commonly proposed...
A Magnetohydrodynamic Model for the Formation of Episodic Jets (2008)
Yuan, Feng, Lin, Jun, Wu, Kinwah, Ho, Luis C.
Episodic ejection of plasma blobs have been observed in many black hole systems. While steady, continuous jets are believed to be associated with large-scale open magnetic fields, what causes the...
Structures, oscillations and solitons in large-scale multi-component self-gravitating systems (2008)
Wu, Kinwah, Younsi, Ziri, Saxton, Curtis J.
We investigate the structure of dynamics of large self-gravitating astrophysical systems using a self-interacting two-component model. We consider two cases, galaxy clusters and cosmic walls, for...
Radiative transfer in black hole systems (2008)
Wu, Kinwah, Ball, Warrick, Fuerst, Steven V.
We present a convariant formulation for radiative transfer in curved space time and demonstrate some applications in the black-hole systems. We calculate the emission from semi-transparent accretion...
Periodicities in the high-mass X-ray binary system RX J0146.9+6121/LS I+61 235 (2008)
Sarty, Gordon E., Kiss, Laszlo L., Huziak, Richard, Catalan, Lionel J. J., Luciuk, Diane, Crawford, Timothy R., ...
The high-mass X-ray binary RX J0146.9+6121, with optical counterpart LS I+61 235 (V831 Cas), is an intriguing system on the outskirts of the open cluster NGC 663. It contains the slowest X-ray pulsar...
Radial structure, inflow & central mass of stationary radiative galaxy clusters (2008)
We analyse the radial structure of self-gravitating spheres consisting of multiple interpenetrating fluids, such as the X-ray emitting gas and the dark halo of a galaxy cluster. In these dipolytropic...
Sarty, Gordon E., Saxton, Curtis J., Wu, Kinwah
The temperatures of electrons and ions in the post-shock accretion region of a magnetic cataclysmic variable (mCV) will be equal at sufficiently high mass flow rates or for sufficiently weak magnetic...
X-ray Polarization Signatures of Compton Scattering in Magnetic Cataclysmic Variables (2008)
McNamara, Aimee, Kuncic, Zdenka, Wu, Kinwah
Compton scattering within the accretion column of magnetic cataclysmic variables (mCVs) can induce a net polarization in the X-ray emission. We investigate this process using Monte Carlo simulations...
The bizarre X-ray binary Cir X-1 (2007)
Helen Johnston Robert, Robert P. Fender, Kinwah Wu
. Cir X-1 is one of the most puzzling X-ray binaries known. Like the peculiar systems SS 433 and Cyg X-3, it cannot easily be classified into any of the major categories of X-ray binaries. We present...
The Emission from Post-Shock Flows in mCVs (2007)
Mark Cropper Kinwah, Kinwah Wu, Gavin Ramsay
We re-examine the vertical structure of the post-shock flow in the accretion region of mCVs, and the X-ray emission as a function of height. We then predict X-ray light curves and phase-resolved...
Detection of the optical counterpart of the proposed double degenerate polar RX J1914+24 (2007)
Gavin Ramsay, Mark Cropper, Kinwah Wu, K. O. Mason, Pasi Hakala
We have detected the optical counterpart of the proposed double degenerate polar RX J1914+24. The I band light curve is modulated on the 9.5 min period seen in Xrays. There is no evidence for any...
Continuum and Line emission from Post-shock Flows (2007)
Mark Cropper Kinwah, Kinwah Wu, Gavin Ramsay
. The post-shock flow in the accretion region of MCVs is considered to be a magnetically confined cooling flow. The X-ray spectrum from this hot plasma is emitted from a range of temperatures and...
A comparison of white dwarf mass estimators using the Intermediate Polar XY Ari (2007)
Gavin Ramsay, Mark Cropper, Coel Hellier, Kinwah Wu
We determine the mass of the white dwarf in the eclipsing intermediate polar XY Ari following the method given in Cropper, Ramsay & Wu using a multi-temperature bremsstrahlung model. By fitting...
Is Gx 339-4 A Black Hole Candidate? Optical Spectroscopy And Photometry (2007)
Roberto Soria, Kinwah WU, Helen M. JOHNSTON
. We carried out spectroscopic and photometric observations of the candidate black-hole binary GX 339\Gamma4 during its low-hard and high-soft X-ray states. We have found that the emission lines from...
High resolution optical and infrared spectroscopic observations of Cir X-1 (2007)
We present new optical and infrared (IR) observations of Cir X-1 taken near apastron. Both sets of spectra show asymmetric emission lines. Archival optical observations show that an asymmetric Hff...
White Dwarf Masses in Magnetic CVs: Multi-temperature Fits to Ginga Data (2007)
One method of obtaining the mass of the white dwarf in magnetic CVs is through their hard X-ray spectra. However, previous mass estimates using this method give lower limits because the temperature...
Kinwah Wu, Gavin Ramsay, Aysegul Kocabiyik
Received: We have calculated the temperature and density structure of the hot postshock plasma in magnetically confined accretion flows, including the gravitational potential. This avoids the...
Characteristic temperatures and spectral appearance of ULX disks (2007)
Soria, Roberto, Wu, Kinwah, Kuncic, Zdenka
A standard disk around an accreting black hole may become effectively optically-thin and scattering dominated in the inner region, for high accretion rates (as already predicted by the...
Line emission from optically thick relativistic accretion tori (2007)
We calculate line emission from relativistic accretion tori around Kerr black holes and investigate how the line profiles depend on the viewing inclination, spin of the central black hole, parameters...
A search for electron cyclotron maser emission from compact binaries (2007)
Ramsay, Gavin, Brocksopp, Catherine, Wu, Kinwah, Slee, Bruce, Saxton, Curtis
Unipolar induction (UI) is a fundamental physical process, which occurs when a conducting body transverses a magnetic field. It has been suggested that UI is operating in RX J0806+15 and RX J1914+24,...
X-ray emissions from two-temperature accretion flows within a dipole magnetic funnel (2007)
Saxton, Curtis J., Wu, Kinwah, Canalle, Joao. B. G., Cropper, Mark, Ramsay, Gavin
We investigate the hydrodynamics of accretion channelled by a dipolar magnetic field (funnel flows). We consider situations in which the electrons and ions in the flow cannot maintain thermal...
On the Nature of Ultra-Luminous X-ray Sources from Optical/IR Measurements (2007)
Cropper, Mark, Copperwheat, Christopher, Wu, Kinwah, Soria, Roberto
We present a model for the prediction of the optical/infra-red emission from ULXs. In the model, ULXs are binary systems with accretion taking place through Roche lobe overflow. We show that...
Finding Periods in High Mass X-Ray Binaries (2007)
Sarty, Gordon E., Kiss, Laszlo L., Johnston, Helen M., Huziak, Richard, Wu, Kinwah
This is a call for amateur astronomers who have the equipment and experience for producing high quality photometry to contribute to a program of finding periods in the optical light curves of high...
A Chandra Search for Coronal X Rays from the Cool White Dwarf GD 356 (2006)
Weisskopf, Martin C., Wu, Kinwah, Trimble, Virginia, O'Dell, Stephen L., Elsner, Ronald F., Zavlin, Vyacheslav E., ...
We report observations with the Chandra X-ray Observatory of the single, cool, magnetic white dwarf GD 356. For consistent comparison with other X-ray observations of single white dwarfs, we also...
Multivariate characterization of hydrogen Balmer emission in cataclysmic variables (2006)
The ratios of hydrogen Balmer emission line intensities in cataclysmic variables are signatures of the physical processes that produce them. To quantify those signatures relative to classifications...
Chandra observations of the globular cluster M54 (2005)
We have carried out a Chandra observation of the globular cluster M54. We detected 7 sources located within the half-mass radius of M54, at a flux limit of 1.5x10^-15 erg/s/cm in the 0.3-8 keV energy...
On the nature of the ultraluminous X-ray transient in Cen~A (NGC 5128) (2005)
Ghosh, Kajal K., Finger, Mark H., Swartz, Douglas A., Tennant, Allyn F., Wu, Kinwah
We combine 9 ROSAT, 9 Chandra, and 2 XMM-Newton observations of the Cen~A galaxy to obtain the X-ray light curve of 1RXH J132519.8-430312 (=CXOU J132519.9$-$430317) spanning 1990 to 2003. The source...
The First Chandra Field (2005)
Weisskopf, Martin C., Aldcroft, Thomas L., Cameron, Robert A., Gandhi, Poshak, Foellmi, Cédric, Elsner, Ronald F., ...
Before the official first-light images, the Chandra X-Ray Observatory obtained an X-ray image of the field to which its focal plane was first exposed. We describe this historic observation and report...
Optical and Infrared Signatures of ULX's (2005)
Copperwheat, Christopher, Cropper, Mark, Soria, Roberto, Wu, Kinwah
We have constructed a model to describe the optical emission from ultra-luminous X-ray sources (ULXs). We assume a binary model with a black hole accreting matter from a Roche lobe filling companion...
Saxton, Curtis, Wu, Kinwah, Cropper, Mark, Ramsay, Gavin
We use a two-temperature hydrodynamical formulation to determine the temperature and density structures of the post-shock accretion flows in magnetic cataclysmic variables (mCVs) and calculate the...
Canalle, Joao B. G., Saxton, Curtis J., Wu, Kinwah, Cropper, Mark, Ramsay, Gavin
Field-channelled accretion flows occur in a variety of astrophysical objects, including T Tauri stars,magnetic cataclysmic variables and X-ray pulsars. We consider a curvilinear coordinate system and...
A Multi-wavelength Study of the X-ray Sources in NGC 5018 (2005)
Ghosh, Kajal K., Swartz, Douglas A., Tennant, Allyn F., Wu, Kinwah, Saripalli, Lakshmi
The E3 giant elliptical galaxy NGC5018 was observed with the Chandra X-ray Observatory on 14 April 2001. Results of analysis of these X-ray data as well as of complementary optical, infrared, and...
XMM-Newton observations of the ultra-compact binary RX J1914+24 (2004)
Ramsay, Gavin, Hakala, Pasi, Wu, Kinwah, Cropper, Mark, Mason, K. O., Cordova, F. A., ...
We present XMM-Newton observations of the 569 sec period system RX J1914+24 (V407 Vul). This period is believed to represent the binary orbital period making it an ultra-compact binary system. By...
Retter, Alon, Richards, Mercedes T., Wu, Kinwah
Extensive radio data of two Algol systems and two RS CVn binaries were re-analyzed. We found evidence for a new periodicity that we interpret as a superhump in Algol, in which it may have been...
The star-forming environment of a ULX in NGC 4559: an optical study (2004)
Soria, Roberto, Cropper, Mark, Pakull, Manfred, Mushotzky, Richard, Wu, Kinwah
We have studied the candidate optical counterparts and the stellar population in the star-forming complex around a bright ULX in NGC4559, using HST/WFPC2, XMM-Newton/OM, and ground-based data. We...
The Ultra-Luminous X-ray Source Population from the Chandra Archive of Galaxies (2004)
Swartz, Douglas A., Ghosh, Kajal K., Tennant, Allyn F., Wu, Kinwah
One hundred fifty-four discrete non-nuclear Ultra-Luminous X-ray (ULX) sources, with intrinsic X-ray luminosities >1e39 ergs/s, are identified in 82 galaxies observed with Chandra's Advanced CCD...
XMM-Newton observations of polars in low accretion states (2004)
Ramsay, Gavin, Cropper, Mark, Wu, Kinwah, Mason, Keith, Cordova, France, Priedhorsky, William
We have made a series of snap-shot observations of 37 polars using XMM-Newton. We found that 16 of these systems were in a low, or much reduced, accretion state. Of those, 6 were not detected in...
An ultra-relativistic outflow from a neutron star accreting gas from a companion (2004)
Fender, Rob, Wu, Kinwah, Johnston, Helen, Tzioumis, Tasso, Jonker, Peter, Spencer, Ralph, ...
Collimated relativistic outflows, or jets, are amongst the most energetic and relativistic phenomena in the Universe. They are associated with supermassive black holes in distant active galactic...
Fender, Rob, Wu, Kinwah, Johnston, Helen, Tzioumis, Tasso, Jonker, Peter, Spencer, Ralph, ...
Collimated relativistic outflows—also known as jets—are amongst the most energetic phenomena in the Universe. They are associated with supermassive black holes in distant active galactic nuclei1,...
On the Nature of the Bright Short-Period X-ray Source in the Circinus Galaxy Field (2003)
Weisskopf, Martin C., Wu, Kinwah, Tennant, Allyn F., Swartz, Douglas A., Ghosh, Kajal K.
The spectrum and light curve of the bright X-ray source CG X-1 in the field of the Circinus galaxy are re-examined. Previous analyses have concluded that the source is an accreting black hole of...
Probable intermediate mass black holes in NGC4559: XMM-Newton spectral and timing constraints (2003)
Cropper, Mark, Soria, Roberto, Mushotzky, Richard F., Wu, Kinwah, Markwardt, Craig B., Pakull, Manfred
We have examined X-ray and optical observations of two ultra-luminous X-ray sources, X7 and X10 in NGC4559, using XMM-Newton, Chandra and HST. The UV/X-ray luminosity of X7 exceeds 2.1e40 erg/s in...
Properties of discrete X-ray sources in the starburst spiral galaxy M83 (2003)
We have identified 127 discrete sources in a Chandra observation of M83, with a detection limit of ~ 3 x 10^{36} erg/s in the 0.3-8.0 keV band. We discuss the individual properties of about 20 bright...
Spin up in RX J0806+15 - the shortest period binary (2003)
Hakala, Pasi, Ramsay, Gavin, Wu, Kinwah, Hjalmarsdotter, Linnea, Jarvinen, Silva, Jarvinen, Arto, ...
RX J0806+15 has recently been identified as the binary system with the shortest known orbital period. We present a series of observations of RX J0806+15 including new optical observations taken one...
Electron-cyclotron maser emission from white-dwarf pairs and white-dwarf planetary systems (2003)
By analogy to Jovian radio emissions powered by the electromagnetic interaction between Jupiter and its moons, we propose that close magnetic-nonmagnetic white-dwarf pairs and white-dwarf planetary...
The radio flaring behaviour of GRO J1655-40: an analogy with extragalactic radio sources? (2003)
Stevens, J. A., Hannikainen, D. C., Wu, Kinwah, Hunstead, R. W., McKay, D. J.
At radio frequencies, the current evidence for the microquasar-quasar connection is based on imaging observations showing that relativistic outflows/jets are found in both classes of objects. Some...
Ultra-Short Period Double-Degenerate Binaries (2003)
Cropper, Mark, Ramsay, Gavin, Wu, Kinwah, Hakala, Pasi
We review the current observational status of the ROSAT sources RX J1914.4+2456 and RX J0806.3+1527, and the evidence that these are ultra-short period (
Accretion Flow Along a Dipolar Field: Application to Intermediate Polars (2003)
Canalle, J. B. G., Wu, Kinwah, Cropper, Mark, Ramsay, Gavin, Saxton, Curtis
A hydrodynamic formulation for accretion flow channeled by a dipolar magnetic field is constructed using a curvi-linear coordinate system natural to the field structure. We solve the hydrodynamic...
Chandra X-ray Observations of the Spiral Galaxy M81 (2002)
Swartz, Douglas A., Ghosh, Kajal K., McCollough, Michael L., Pannuti, Thomas G., Tennant, Allyn F., Wu, Kinwah
A Chandra X-Ray Observatory ACIS-S imaging observation is used to study the population of X-ray sources in the nearby Sab galaxy M81 (NGC 3031). A total of 177 sources are detected with 124 located...
Chandra Discovery of Luminous Supersoft X-Ray Sources in M81 (2002)
Swartz, Douglas, Ghosh, Kajal, Suleimanov, Valery, Tennant, Allyn, Wu, Kinwah
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...
We have studied the face-on, barred spiral M83 (NGC 5236) with Chandra. Eighty-one point sources are detected (above 3.5-sigma) in the ACIS S3 image: 15 of them are within the inner 16 arcsec region...
State transitions in LMC X-3 (2002)
Soria, Roberto, Page, Mat, Wu, Kinwah
We carried out a multiwavelenght study of the black-hole candidate LMC X-3 with XMM-Newton. The system showed a transition to a low-hard state, in which the X-ray spectrum was well fitted by a simple...
Multi-wavelength behaviour of IIIZw2 (2002)
Salvi, Nikita, Page, Mat J., Stevens, Jason A., Mason, Keith O., Wu, Kinwah
IIIZw2 was observed with XMM-Newton in July 2000. Its X-ray spectrum can be described by a powerlaw of photon index Gamma = 1.7 with a Gaussian line at 6.7 keV. There is no significant evidence of...
Chandra has resolved the starburst nuclear region of the face-on grand-design spiral M83. Eighty-one point sources are detected above 3.5 sigma in the ACIS S3 image, and 15 of them are within the...
An electrically powered binary star? (2001)
Wu, Kinwah, Cropper, Mark, Ramsay, Gavin, Sekiguchi, Kazuhiro
We propose a model for stellar binary systems consisting of a magnetic and a non-magnetic white-dwarf pair which is powered principally by electrical energy. In our model the luminosity is caused by...
ROSAT/Chandra Observations of a Bright Transient in M81 (2001)
Ghosh, Kajal, Swartz, Douglas, Tennant, Allyn, Wu, Kinwah
We present a 10-year X-ray light curve and the spectra of a peculiar X-ray transient in the spiral galaxy M81. The source was below the detection limit of ROSAT PSPC before 1993, but it brightened...
Secular and orbital variability of Cir X-1 observed in optical spectra (2001)
Johnston, Helen M., Wu, Kinwah, Fender, Rob, Cullen, Jason G.
We have observed variations in the optical emission lines from the X-ray binary Circinus X-1. These variations may be attributed both to orbital variations and to long term secular changes in line...
Low and High Angular Momentum Accretion Flows in BHCs: Case Study of XTE J1550-564 (2001)
Soria, Roberto, Wu, Kinwah, Hannikainen, Diana, McCollough, Mike, Hunstead, Richard
The 1998 outburst of XTE J1550-564 started with a hard X-ray spike, rising in less than a day and declining after 3-4 days; at the same time, the soft X-ray flux was rising with a longer timescale (~...
Ionisation Structure in Accretion Shocks with a Composite Cooling Function (2001)
Wu, Kinwah, Cropper, Mark, Ramsay, Gavin
We have investigated the ionisation structure of the post-shock regions of magnetic cataclysmic variables using an analytic density and temperature structure model in which effects due to...
The lower boundary of the accretion column in magnetic cataclysmic variables (2001)
Using a parameterised function for the mass loss at the base of the post-shock region, we have constructed a formulation for magnetically confined accretion flows which avoids singularities, such as...
Populations of X-ray binaries and the dynamical history of their host galaxies (2001)
The observed luminosity distributions of X-ray sources indicate the presence of several populations of X-ray binaries in the nearby galaxies. Each population has its formation and evolutionary...
We present a general formulation for stability analyses of radiative shocks with multiple cooling processes, longitudinal and transverse perturbations, and unequal electron and ion temperatures....
Formation of optical lines in black-hole binaries (2001)
Wu, Kinwah, Soria, Roberto, Johnston, Helen, Hunstead, Richard
The HI Balmer emission lines of black-hole binaries show double-peaked profiles during the high-soft state and the quiescent state. In the high-soft state the profiles are asymmetric with a stronger...
Properties of the Chandra Sources in M81 (2000)
Tennant, Allyn F., Wu, Kinwah, Ghosh, Kajal K., Kolodziejczak, Jeffery J., Swartz, Douglas A.
The Chandra X-ray Observatory obtained a 50-ks observation of the central region of M81 using the ACIS-S in imaging mode. The global properties of the 97 x-ray sources detected in the inner 8.3x8.3...
XMM-Newton EPIC and RGS observations of LMC X-3 (2000)
Wu, Kinwah, Soria, Roberto, Page, Mathew, Sakelliou, Irini, Kahn, Steven, De Vries, Cor
We report the results of preliminary analysis of the XMM_Newton EPIC and RGS observations of the candidate black-hole binary LMC X-3 between February and June 2000. The observations covered both the...
XMM-Newton Optical Monitor observations of LMC X-3 (2000)
Soria, Roberto, Wu, Kinwah, Page, Mathew, Sakelliou, Irini
We study the optical counterpart of the black-hole X-ray binary LMC X-3, by using XMM-Newton/OM observations carried out during a low-hard X-ray state. We derive a better constraint for the...
Wu, Kinwah, Soria, Roberto, Hunstead, Richard W., Johnston, Helen M.
We have carried out observations of the X-ray transient GX339-4 during its high-soft and low-hard X-ray spectral states. Our high-resolution spectroscopic observation in 1999 April suggests that the...
Optical Spectroscopy of GRO J1655-40 (1999)
Soria, Roberto, Wu, Kinwah, Hunstead, Richard
We have obtained optical spectra of the soft X-ray transient GRO J1655-40 during different X-ray spectral states (quiescence, high-soft and hard outburst) between 1994 Aug and 1997 Jun....
Perturbative Analysis of Two-Temperature Radiative Shocks with Multiple Cooling Processes (1999)
The structure of the hot downstream region below a radiative accretion shock, such as that of an accreting compact object, may oscillate due to a global thermal instability. The oscillatory behaviour...
Detection of the optical counterpart of the proposed double degenerate polar RX J1914+24 (1999)
Ramsay, Gavin, Cropper, Mark, Wu, Kinwah, Mason, Keith, Hakala, Pasi
We have detected the optical counterpart of the proposed double degenerate polar RX J1914+24. The I band light curve is modulated on the 9.5 min period seen in X-rays. There is no evidence for any...
The Emission from Post-Shock Flows in mCVs (1999)
Cropper, Mark, Wu, Kinwah, Ramsay, Gavin
We re-examine the vertical structure of the post-shock flow in the accretion region of mCVs, and the X-ray emission as a function of height. We then predict X-ray light curves and phase-resolved...
Optical Spectroscopy of GX339-4 During the High-Soft and Low-Hard States (Paper I) (1999)
Soria, Roberto, Wu, Kinwah, Johnston, Helen
We carried out spectroscopic observations of the candidate black-hole binary GX339-4 during its low-hard and high-soft X-ray states, in 1997 and 1998 respectively. We have found that the spectrum is...
A Study of the New X-ray Transient RXTE J2123-058 during its Post-Outburst State (1999)
Soria, Roberto, Wu, Kinwah, Galloway, Duncan
We carried out I, R, V and B photometric observations of the neutron star X-ray binary RXTE J2123-058 shortly after the end of the X-ray outburst in mid-1998. We adopt the low mass binary model to...
High resolution optical and infrared spectroscopic observations of Cir X-1 (1999)
Johnston, Helen, Fender, Rob, Wu, Kinwah
We present new optical and infrared (IR) observations of Cir X-1 taken near apastron. Both sets of spectra show asymmetric emission lines. Archival optical observations show that an asymmetric...
Cropper, Mark, Wu, Kinwah, Ramsay, Gavin, Kocabiyik, Aysegul
We have calculated the temperature and density structure of the hot postshock plasma in magnetically confined accretion flows, including the gravitational potential. This avoids the inconsistency of...
Continuum and line emission from post-shockc flows (1998)
Cropper, Mark, Wu, Kinwah, Ramsay, Gavin
The post-shock flow in the accretion region of MCVs is considered to be a magnetically confined cooling flow. The X-ray spectrum from this hot plasma is emitted from a range of temperatures and...
An asymmetric arcsecond radio jet from Circinus X-1 (1998)
Fender, Robert, Spencer, Ralph, Tzioumis, Tasso, Wu, Kinwah, Van Der Klis, Michiel, Van Paradijs, Jan, ...
In observations with the Australia Telescope Compact Array we have resolved the radio counterpart of the unusual X-ray binary Cir X-1 into an asymmetric extended structure on arcsecond scales. In...
Measuring the Motion of the Black Hole in GRO J16550-40 (1998)
Soria, Roberto, Wickramasinghe, Dayal T., Hunstead, Richard W., Wu, Kinwah
We report optical spectroscopic observations of the Low Mass X-ray Binary GRO J1655-40 during outbursts in August-September 1994 and in June 1996. The spectra show emission and absorption lines from...