Results for "M. J. Coe"

total 318877took 0.15s
Be stars in X-ray binary systemsNov 15 1999This paper will review the status of our observations and understanding of Be stars in X-ray binary systems. In virtually all cases the binary partner to the Be star is a neutron star. The circumstellar disk provides the accretion fuel and hence stimulates ... More
An estimate of the SN kick velocities for High Mass X-ray Binaries in the SMCJan 24 2005This work investigates the possible supernova kick velocities imposed on HMXB systems in the Small Magellanic Cloud. Comparisons are made between the location of such systems and the locations of young, stellar clusters on the premise that these may represent ... More
Catalogue of Be/X-ray binary systems in the Small Magellanic Cloud: X-ray, optical & IR propertiesJun 05 2015This is a catalogue of approximately 70 X-ray emitting binary systems in the Small Magellanic Cloud (SMC) that contain a Be star as the mass donor in the system and a clear X-ray pulse signature from a neutron star. The systems are generally referred ... More
OGLE observations of four X-ray binary pulsars in the SMCAug 27 1999Aug 31 1999This paper presents analysis and interpretation of OGLE photometric data of four X-ray binary pulsar systems in the Small Magellanic Cloud: 1WGA J0054.9-7226, RX J0050.7-7316, RX J0049.1-7250, and 1SAX J0103.2-7209. In each case, the probable optical ... More
Optical, ultraviolet and infrared observations of X-ray binariesAug 01 2003Oct 24 2003This chapter for the new CUP book "Compact Stellar Sources" reviews the state of work on multi-wavelength observations of high mass and low mass X-ray binaries. Both neutron star and black hole systems are considered for this work.
Deep IR and optical studies of the fields of 3 proposed TZO remnantsApr 30 1998Deep infrared and optical images are presented of three proposed remnants of Thorne-Zytkow Objects (TZO). In particular, the IR data go several infrared magnitudes deeper than previous observations and in at least one case reveal the existence of weak ... More
AX J0049.4-7323 - a close look at a neutron star interacting with a circumstellar diskFeb 02 2004Detailed evidence on the system AX J0049.4-7323 is presented here to show how the passage of the neutron star in the binary system disrupts the circumstellar disk of the mass donor Be star. A similar effect is noted in three other Be/X-ray binary systems. ... More
Optical counterparts to four X-ray sources in the Small Magellanic CloudSep 17 2002Sep 19 2002We report on the spectroscopic and photometric analysis of possible optical counterparts to four X-ray sources in the Small Magellanic Cloud: AX J0049.4-7323, AX J0057.4-7325, RX J0058.2-7321 and RX J0101.1-7206. In the case of the last two, we suggest ... More
Calculations of Potential Energy Surfaces Using Monte Carlo Configuration InteractionDec 11 2012We apply the method of Monte Carlo configuration interaction (MCCI) to calculate ground-state potential energy curves for a range of small molecules and compare the results with full configuration interaction. We show that the MCCI potential energy curve ... More
Cyclical behaviour and disc truncation in the Be/X-ray binary A0535+26May 12 2003A0535+26 is shown to display quantised IR excess flux states, which are interpreted as the first observational verification of the resonant truncation scheme proposed by Okazaki and Negueruela (2001) for BeXRBs. The simultaneity of X-ray activity with ... More
Monte Carlo configuration interaction applied to multipole moments, ionisation energies and electron affinitiesJan 21 2013The method of Monte Carlo configuration interaction (MCCI) [1,2] is applied to the calculation of multipole moments. We look at the ground and excited state dipole moments in carbon monoxide. We then consider the dipole of NO, the quadrupole of the nitrogen ... More
The Be/X-ray Transient V0332+53: Evidence for a tilt between the orbit and the equatorial plane?Mar 15 1999We present optical and infrared observations of BQ Cam, the optical counterpart to the Be/X-ray transient system V0332+53. BQ Cam is shown to be an O8-9Ve star, which places V0332+53 at a distance of ~7 kpc. H-alpha spectroscopy and infrared photometry ... More
The SMC X-ray transient XTE J0111.2-7317 : a Be/X-ray binary in a SNR?Dec 10 1999We report observations which confirm the identity of the optical/IR counterpart to the Rossi X-ray Timing Explorer transient source XTE J0111.2-7317. The counterpart is suggested to be a B0-B2 star (luminosity class III--V) showing an IR excess and strong ... More
Applying Monte Carlo configuration interaction to transition metal dimers: exploring the balance between static and dynamic correlationMay 22 2014We calculate potential curves for transition metal dimers using Monte Carlo configuration interaction (MCCI). These results, and their associated spectroscopic values, are compared with experimental and computational studies. The multireference nature ... More
Large-scale perturbations in the circumstellar envelopes of Be/X-ray binariesApr 28 1998We investigate the spectroscopic characteristics of the optical components of Be/X-ray binary systems, using data collected during our seven-year monitoring campaign. We find examples of major changes in the emission line profiles associated with Type ... More
A detailed study of the modulation of the optical light from Sk160/SMC X-1May 02 2013May 03 2013Eight years of optical photometry from OGLE-III are presented of the optical counterpart to the High Mass X-ray Binary system, SMC X-1. The optical data provide the best view to date of the modulation of the light from the system at the binary period ... More
The optical counterparts to Be/X-ray binaries in the Magellanic CloudsJun 07 1999The fields of 8 X-ray sources in the Magellanic Clouds believed to be Be/X-ray binaries have been searched for possible Be star counterparts. BVR and H alpha CCD imaging was employed to identify early type emission stars through colour indices and H alpha ... More
Swift J0513.4-6547 = LXP 27.2 : a new Be/X-ray binary system in the Large Magellanic CloudDec 04 2014An exceptionally bright new X-ray source in the Large Magellanic Cloud was discovered by the Swift/BAT telescope on MJD 54923 (2 April 2009), and shown to have a pulse period of 27s using follow-up observations by RXTE/PCA. We report here on detailed ... More
The distances to the X-ray binaries LSI +61 303 and A0535+262Mar 10 1998Chevalier & Ilovaisky (1998) use Hipparcos data to show that the X-ray binary systems LSI+61 303 and A0535+262 are a factor of ten closer (i.e. d = few hundred pc) than previously thought (d = 2 kpc). We present high quality CCD spectra of the systems, ... More
Exploring accretion theory with X-ray binaries in the SMCAug 29 2009The understanding of the accretion process on to compact objects in binary systems is an important part of modern astrophysics. Theoretical work, primarily that of Ghosh & Lamb (1979), has made clear predictions for the behaviour of such systems which ... More
XMM-Newton observation of the highly magnetised accreting pulsar Swift J045106.8-694803: Evidence of a hot thermal excessSep 10 2013Several persistent, low luminosity (L_X 10^{34} erg s^{-1}), long spin period (P>100 s) High Mass X-ray Binaries have been reported with blackbody components with temperatures >1 keV. These hot thermal excesses have correspondingly small emitting regions ... More
Lattice Density-Functional Theory for Quantum ChemistryFeb 22 2019Feb 28 2019We propose a lattice density-functional theory for {\it ab initio} quantum chemistry or physics as a route to an efficient approach that approximates the full configuration interaction energy and orbital occupations for molecules with strongly-correlated ... More
SXP 323 - an unusual X-ray binary system in the Small Magellanic CloudJun 28 2005Spectroscopic observations taken with the VLT/UVES telescope/instrument are presented of the unusual Small Magellanic Cloud (SMC) X-ray binary system SXP 323 = AX J0051-733. This system shows a clear modulation at 0.71d in long term optical photometry ... More
Lattice Density-Functional Theory for Quantum ChemistryFeb 22 2019We propose a lattice density-functional theory for {\it ab initio} quantum chemistry or physics as a route to an efficient approach that approximates the full configuration interaction energy and orbital occupations for molecules with strongly-correlated ... More
The population of massive X-ray binaries I. The Large Magellanic CloudJan 28 2002We present high resolution blue spectroscopy of an almost complete sample of optical counterparts to massive X-ray binaries in the Large Magellanic Cloud (LMC) and derive their spectral classification. We find an spectral type B0II for the optical counterpart ... More
A 0535+26: Back in businessFeb 06 2006In May/June 2005, after 10 years of inactivity, the Be/X-ray binary system A 0535+26 underwent a major X-ray outburst. In this paper data are presented from 10 years of optical, IR and X-ray monitoring showing the behaviour of the system during the quiescent ... More
Timing and Spectral Analysis of the Unusual X-Ray Transient XTE J0421+560/CI CamelopardalisNov 14 2012We present a detailed X-ray study of the 2003 XMM-Newton observation of the High Mass X-ray Binary XTE J0421+560/CI Cam. The continuum of the X-ray spectrum is well described by a flat power law (Gamma=1.0+/-0.2) with a large intrinsic absorbing column ... More
The Be/X-ray binary LS 992/RX J0812.4-3114: physical parameters and long-term variabilityNov 15 2000We present the first long-term optical and infrared study of the optical counterpart to the source RX J0812.4-3114, an X-ray pulsar with a Be type companion. During the period covered by the observations the profile of some Balmer lines changed from absorption ... More
The First Year of S-CUBED: The Swift Small Magellanic Cloud SurveyOct 12 2018The Swift Small Magellanic Cloud Survey, S-CUBED, is a high cadence shallow X-ray survey of the SMC. The survey consists of 142 tiled pointings covering the optical extent of the SMC, which is performed weekly by NASA's Neil Gehrels Swift Observatory, ... More
Observations of the unusual counterpart to the X-ray pulsar AX J0051-733Jan 18 2002We report optical and IR observations of the ASCA X-ray pulsar system AX J0051-733. The relationship between the X-ray source and possible optical counterparts is discussed. Long term optical data from over 7 years are presented which reveal both a 1.4d ... More
Optical Spectroscopy of V635 Cassiopeiae/4U 0115+63Feb 07 1998V635 Cas is the optical counterpart of the X-ray binary system 4U 0115+63. It was previously tentatively identified as a Be star based on its optical colours and the presence of H alpha emission. Our observations indicate that it is an O9e star. This ... More
Spin period change and the magnetic fields of neutron stars in Be X-ray binaries in the Small Magellanic CloudNov 18 2013Nov 27 2013We report on the long-term average spin period, rate of change of spin period and X-ray luminosity during outbursts for 42 Be X-ray binary systems in the Small Magellanic Cloud. We also collect and calculate parameters of each system and use these data ... More
On the periodicities present in the optical light curves of SMC Be/X-ray binariesApr 24 2012We present a comprehensive study of the periodic variations observed in OGLE I-band light curves of SMC Be/X-ray binaries, discovering new optical periodicities in 9 systems. We find that these periodicities derive from a number of mechanisms, notably ... More
XTE J0111.2-7317 : a nebula-embedded X-ray binary in the SMCJun 05 2003The observed characteristics of the nebulosity surrounding the SMC High Mass X-ray Binary XTE J0111.2-7317 are examined in the context of three possible nebular types: SNR, bowshock and HII region. Observational evidence is presented which appears to ... More
Spectral distribution of Be/X-ray binaries in the Small Magellanic CloudApr 30 2008The spectral distributions of Be/X-ray binaries in the Large Magellanic Cloud and Galaxy have been shown to differ significantly from the distribution of isolated Be stars in the Galaxy. Population synthesis models can explain this difference in spectral ... More
Disc loss and renewal in A0535+26Oct 20 1999This paper presents observations of the Be/X-ray binary system A0535+26 revealing the first observed loss of its circumstellar disc, demonstrated by the loss of its JHK infrared excess and optical/IR line emission. However optical/IR spectroscopy reveals ... More
A major outburst from the X-ray binary RX J0520.5-6932Jan 26 2004We report on the analysis of 8 years of MAssive Compact Halo Objects (MACHO) data for the source RX J0520.5-6932. A regular period of 24.4 days has been confirmed, however this is manifest almost entirely in the red part of the spectrum. A major outburst, ... More
Optical properties of SMC X-ray binariesOct 04 2004This work represent the first major study of the optical and IR characteristics of the mass donor companions to the X-ray pulsars in the Small Magellanic Cloud (SMC). In this work several new counterparts have been identified, and possible ones confirmed, ... More
On the orbital parameters of Be/X-ray binaries in the Small Magellanic CloudJun 01 2011The orbital motion of a neutron star about its optical companion presents a window through which to study the orbital parameters of that binary system. This has been used extensively in the Milky Way to calculate these parameters for several high-mass ... More
Color, 3D simulated images with shapeletsJul 03 2008We present a method to simulate color, 3-dimensional images taken with a space-based observatory by building off of the established shapelets pipeline. The simulated galaxies exhibit complex morphologies, which are realistically correlated between, and ... More
Optical studies of two LMC X-ray transients : RX J0544.1-7100 and RX J0520.5-6932Jan 11 2001We report observations which confirm the identities of the optical counterpart to the transient sources RX J0544.1-7100 and RX J0520.5-6932. The counterparts are suggested to be a B-type stars. Optical data from the observations carried out at ESO and ... More
Correlated V/R and IR photometric variations in the Be/X-ray binary LS I +61 235/RX J0146.9+6121May 02 2000We report on the long-term variability of the Be/X-ray binary LS I +61 235/RX J0146.9+6121. New optical spectroscopic and infrared photometric observations confirm the presence of global one-arm oscillations in the circumstellar disc of the Be star and ... More
Long-term optical/IR variability of the Be/X-ray binary LS V +44 17/RX J0440.9+4431Jun 10 2005We present the first long-term study of the optical counterpart to the X-ray pulsar LS V +44 17/RX J0440.9+4431. The results of our photometric and spectroscopic analysis show that LS V +44 17/RX J0440.9+4431 contains a moderately reddened, E(B-V)=0.65+-0.05, ... More
The Be/X-ray transient 4U 0115+63/V635 Cas: II. Outburst mechanismsJan 12 2001We present multi-wavelength long-term monitoring observations of V635 Cas, the optical counterpart to the transient X-ray pulsar 4U0115+63. The evolution of emission lines and photometric magnitudes indicates that the Be star undergoes relatively fast ... More
A Decade in the Life of EXO 2030+375: A Multi-wavelength Study of an Accreting X-ray PulsarJan 14 2002Using BATSE and RXTE observations from 1991 April to 2001 August we have detected 71 outbursts from 82 periastron passages of EXO 2030+375, a 42-second transient X-ray pulsar with a Be star companion, including several outbursts from 1993 August to 1996 ... More
Long Term Behavior of X-ray Pulsars in the Small Magellanic CloudJun 18 2004Jun 02 2005Results of a 4 year monitoring campaign of the SMC using the Rossi X-ray timing Explorer (RXTE) are presented. This large dataset makes possible detailed investigation of a significant sample of SMC X-ray binaries. 8 new X-ray pulsars were discovered ... More
Hard X-ray lightcurves of High Mass X-ray binariesSep 05 2002Using the 9 years of continuous data now available from the Burst And Transient Source Experiment (BATSE) aboard CGRO, we have measured orbital periods and produced folded lightcurves for 8 High Mass X-ray Binaries (HMXB). Given the length of the datasets, ... More
On the relationship between circumstellar disc size and X-ray outbursts in Be/X-ray binariesSep 15 2016We present long term H$\alpha$ monitoring results of five Be/X-ray binaries to study the Be disc size variations and their influence on Type II (giant) X-ray outbursts. The work is done in the context of the viscous decretion disc model which predicts ... More
Equilibrium spin pulsars unite neutron star populationsNov 08 2013Many pulsars are formed with a binary companion from which they can accrete matter. Torque exerted by accreting matter can cause the pulsar spin to increase or decrease, and over long times, an equilibrium spin rate is achieved. Application of accretion ... More
X-Ray and Optical Observations of XTE J0052-723 a Transient Be/X-Ray Pulsar in the Small Magellanic CloudOct 17 2002On December 27th 2000 during our regular SMC monitoring program with Rossi X-ray Timing Explorer, strong pulsations were detected with a period of 4.78 seconds. Subsequent slew observations performed on Jan 9th and 13th across the field of view allowed ... More
Long-term Properties of Accretion Disks in X-ray Binaries: II. Stability of Radiation-Driven WarpingApr 03 2003A significant number of X-ray binaries are now known to exhibit long-term ``superorbital'' periodicities on timescales of $\sim$ 10 - 100 days. Several physical mechanisms have been proposed that give rise to such periodicities, in particular warping ... More
Modelling the observable behaviour of SXP 5.05Apr 12 2019SXP 5.05 is a Be/X-ray binary with a neutron star companion located in the Small Magellanic Cloud. It was first detected in 2013, and later that year, SXP 5.05 underwent a massive optical and X-ray outburst. This outburst dwarfs any other optical event ... More
Monitoring and Discovering X-ray Pulsars in the Small Magellanic CloudFeb 02 2004Regular monitoring of the SMC with RXTE has revealed a huge number of X-ray pulsars. Together with discoveries from other satellites at least 45 SMC pulsars are now known. One of these sources, a pulsar with a period of approximately 7.8 seconds, was ... More
Discovery of a new Transient X-ray Pulsar in the Small Magellanic CloudJan 29 2002Rossi X-Ray Timing Explorer observations of the Small Magellanic Cloud have revealed a previously unknown transient X-ray pulsar with a pulse period of 95s. Provisionally designated XTE SMC95, the pulsar was detected in three Proportional Counter Array ... More
Long-term optical variability of high-mass X-ray binaries. II. SpectroscopyMar 28 2016Apr 25 2016We present the results of our monitoring program to study the long-term variability of the Halpha line in high-mass X-ray binaries. We have carried out the most complete optical spectroscopic study of the global properties of high-mass X-ray binaries ... More
Swift J053041.9-665426, a new Be/X-ray binary pulsar in the Large Magellanic CloudSep 03 2013We observed the newly discovered X-ray source Swift J053041.9-665426 in the X-ray and optical regime to confirm its proposed nature as a high mass X-ray binary. We obtained XMM-Newton and Swift X-ray data, along with optical observations with the ESO ... More
Simulating the X-ray luminosity of Be X-ray binaries: the case for black holes versus neutron starsApr 16 2018There are over 100 Be stars that are known to have neutron star companions but only one such system with a black hole. Previous theoretical work suggests this is not due to their formation but due to differences in X-ray luminosity. It has also been proposed ... More
The Discovery of an Outburst and Pulsed X-ray Flux from SMC X-2 from RXTE ObservationsNov 22 2000Rossi X-ray Timing Explorer All Sky Monitor observations of SMC X-2 show that the source experienced an outburst in January to April 2000 reaching a peak luminosity of greater than ~10^38 ergs s^-1. RXTE Proportional Counter Array observations during ... More
The Search for High-Mass X-ray Binaries in the Phoenix Dwarf GalaxyFeb 21 2012We report on the first X-ray images of the Phoenix dwarf galaxy, taken with \emph{XMM-Newton} in July 2009. This local group dwarf galaxy shares similarities with the Small Magellanic Cloud (SMC) including a burst of star formation $\sim$50 Myr ago. The ... More
A Comprehensive Library of X-ray Pulsars in the Small Magellanic Cloud: Time Evolution of their Luminosities and Spin PeriodsMar 15 2017We have collected and analyzed the complete archive of {\itshape XMM-Newton\} (116), {\itshape Chandra\} (151), and {\itshape RXTE\} (952) observations of the Small Magellanic Cloud (SMC), spanning 1997-2014. The resulting observational library provides ... More
The X-ray Transient XTE J2012+381Mar 18 1999We present optical and infrared observations of the soft X-ray transient (SXT) XTE J2012+381 and identify the optical counterpart with a faint red star heavily blended with a brighter foreground star. The fainter star is coincident with the radio counterpart ... More
XTE J1946+274 = GRO J1944+26: An Enigmatic Be/X-ray BinaryNov 06 2002XTE J1946+274 = GRO J1944+26 is a 15.8 s Be/X-ray pulsar discovered simultaneously in 1998 September with the Burst and Transient Source Experiment (BATSE) on the Compton Gamma Ray Observatory (CGRO) and the All-Sky Monitor (ASM) on the Rossi X-ray Timing ... More
Modelling decretion discs in Be/X-ray binariesJun 27 2019As the largest population of high mass X-ray binaries, Be/X-ray binaries provide an excellent laboratory to investigate the extreme physics of neutron stars. It is generally accepted that Be stars possess a circumstellar disc, providing an additional ... More
A multi-observatory database of X-ray pulsars in the Magellanic CloudsMar 14 2017Using hundreds of XMM-Newton and Chandra archival observations and nearly a thousand RXTE observations, we have generated a comprehensive library of the known pulsars in the Small and Large Magellanic Clouds (SMC, LMC). The pulsars are detected multiple ... More
Discovery of Pulsed X-rays from the SMC Transient RX J0052.1-7319Jul 09 2001Coherent 65 mHz pulsations in the X-ray flux of the Small Magellantic Cloud (SMC) transient source RX J0052.1-7319 have been detected by us in an analysis of ROSAT data. We report on the pulsations we detected in ROSAT HRI data and simultaneous detection ... More
X-ray and optical study of the new SMC X-ray binary pulsar system SXP7.92 and its probable optical counterpart, AzV285Jan 15 2009Optical and X-ray observations are presented here of a newly reported X-ray transient system in the Small Magellanic Cloud - SXP7.92. A detailed analysis of the X-ray data reveal a coherent period of 7.9s. A search through earlier X-ray observations of ... More
Optical and X-ray variability of two Small Magellanic Cloud X-ray binary pulsars - SXP46.6 and SXP6.85Nov 26 2007We present long-term optical and RXTE data of two X-ray binary pulsars in the Small Magellanic Cloud, SXP46.6 and SXP6.85. The optical light curves of both sources show substantial (~0.5-0.8 mag) changes over the time span of the observations. While the ... More
The Magellanic Bridge: evidence for a population of X-ray binariesDec 15 2009INTEGRAL observations of the Small Magellanic Cloud region have resulted in the serendipitous detection of two transient hard X-ray sources in the Magellanic Bridge. In this paper we present the timing and spectral characteristics of these sources across ... More
Contrasting behaviour from two Be/X-ray binary pulsars: insights into differing neutron star accretion modesApr 29 2013In this paper we present the identification of two periodic X-ray signals coming from the direction of the Small Magellanic Cloud (SMC). On detection with the Rossi X-ray Timing Explorer (RXTE), the 175.4s and 85.4s pulsations were considered to originate ... More
The supergiant B[e] star LHA 115-S 18 - binary and/or luminous blue variable?May 02 2013The mechanism by which supergiant (sg)B[e] stars support cool, dense dusty discs/tori and their physical relationship with other evolved, massive stars such as luminous blue variables is uncertain. In order to investigate both issues we have analysed ... More
Comparison of the H-alpha circumstellar disks in Be/X-ray binaries and Be starsDec 16 2000We present a comparative study of the circumstellar disks in Be/X-ray binaries and isolated Be stars based upon the H-alpha emission line. From this comparison it follows that the overall structure of the disks in the Be/X-ray binaries is similar to the ... More
Multiwavelength monitoring of BD+53 2790, the optical counterpart to 4U~2206+54Oct 13 2005We present the results of our long-term monitoring of BD+53 2790, the optical counterpart to the X-ray source 4U~2206+54. Unlike previous studies that classify the source as a Be/X-ray binary, we find that its optical and infrared properties differ from ... More
SXP7.92: A Recently Rediscovered Be/X-ray Binary in the Small Magellanic Cloud, Viewed Edge OnJan 06 2017We present a detailed optical and X-ray study of the 2013 outburst of the Small Magellanic Cloud Be/X-ray binary SXP7.92, as well as an overview of the last 18 years of observations from OGLE, RXTE, Chandra and XMM-Newton. We revise the position of this ... More
Multiwaveband studies of the hard ROSAT SMC transient 1WGA J0053.8-7226: a new X-ray pulsarAug 30 2000Aug 31 2000We report on two optical candidates for the counterpart to an X-ray source in the SMC, 1WGA J0053.8-7226, identified as a serendipitous X-ray source from the ROSAT PSPC archive, and also observed by the Einstein IPC. Its X-ray properties, namely the hard ... More
RXTE-PCA Observations of XMMU J054134.7-682550Oct 06 2008May 15 2009We analyzed RXTE-PCA observations of a recent outburst of the X-ray pulsar XMMU J054134.7$-$682550. We calculated the pulse frequency history of the source. We found no sign of a binary companion. The source spins up when the X-ray flux is higher, with ... More
Long-term Properties of Accretion Disks in X-ray Binaries: I. the variable third period in SMC X-1Oct 10 2002Long term X-ray monitoring data from the RXTE ASM and CGRO BATSE reveal that the third (superorbital) period in SMC X-1 is not constant, but varies between 40-60 days. A dynamic power spectrum analysis indicates that the third period has been present ... More
Discovery of a Be/X-ray Binary Consistent with the Position of GRO J2058+42Dec 20 2004GRO J2058+42 is a 195 s transient X-ray pulsar discovered in 1995 with BATSE. In 1996, RXTE located GRO J2058+42 to a 90% confidence error circle with a 4' radius. On 20 February 2004, the region including the error circle was observed with Chandra ACIS-I. ... More
A Multiwavelength Investigation of the Relationship Between 2CG135+1 and LSI+61o 303Nov 24 1997We present the results of a multiwavelength monitoring campaign targeting the gamma-ray source 2CG 135+1 in an attempt to confirm the association of this object with the radio/Be/X-ray binary system LSI +61o 303. The campaign included simultaneous radio, ... More
A new super-soft X-ray source in the Small Magellanic Cloud: Discovery of the first Be/white dwarf system in the SMC?Dec 01 2011The Small Magellanic Cloud (SMC) hosts a large number of Be/X-ray binaries, however no Be/white dwarf system is known so far, although population synthesis calculations predict that they might be more frequent than Be/neutron star systems. XMMUJ010147.5-715550 ... More
A BeppoSAX observation of the X-ray pulsar 1E 2259+586 and the supernova remnant G109.1-1.0 (CTB 109)Sep 25 1997The 7 s X-ray pulsar 1E2259+586 and the supernova remnant (SNR) G109.1-1.0 (CTB 109) were observed by BeppoSAX in 1996 November. The pulse period of 6.978914 +/- 0.000006 s implies that the source continues its near constant spin-down trend. The 0.5-10 ... More
Be/X-ray binary SXP6.85 undergoes large Type II outburst in the Small Magellanic CloudDec 15 2009The Small Magellanic Cloud (SMC) Be/X-ray binary pulsar SXP6.85 = XTE J0103-728 underwent a large Type II outburst beginning on 2008 August 10. The source was consistently seen for the following 20 weeks (MJD = 54688 - 54830). We present X-ray timing ... More
Now you see it, now you don't - the circumstellar disk in the GRO J1008--57 systemApr 19 2007Multiwavelength observations are reported here of the Be/X-ray binary pulsar system GRO J1008-57. Over ten years worth of data are gathered together to show that the periodic X-ray outbursts are dependant on both the binary motion and the size of the ... More
Periodic Emission from the Gamma-ray Binary 1FGL J1018.6-5856Feb 14 2012Gamma-ray binaries are stellar systems containing a neutron star or black hole with gamma-ray emission produced by an interaction between the components. These systems are rare, even though binary evolution models predict dozens in our Galaxy. A search ... More
A Long Look at the Be/X-Ray Binaries of the Small Magellanic CloudFeb 15 2008Mar 06 2008We have monitored 41 Be/X-ray binary systems in the Small Magellanic Cloud over ~9 years using PCA-RXTE data from a weekly survey program. The resulting light curves were analysed in search of orbital modulations with the result that 10 known orbital ... More
High mass X-ray binary SXP18.3 undergoes the longest Type II outburst ever seen in the Small Magellanic CloudOct 08 2008On 30th August 2006 SXP18.3 a high mass X-ray binary (HMXB) in the Small Magellanic Cloud (SMC) with an 18.3s pulse period was observed by Rossi X-ray Timing Explorer (RXTE). The source was seen continuously for the following 36 weeks. This is the longest ... More
Multi-wavelength observations of the Be/X-ray binary IGR J01217-7257 (=SXP 2.16) during outburstDec 02 2016We present simultaneous, multi-wavelength observations of the Small Magellanic Cloud Be/XRB IGR J01217-7257 (=SXP 2.16) during outbursts in 2014, 2015 and 2016. We also present the results of RXTE observations of the Small Magellanic Cloud during which ... More
An optical & X-ray study of the counterpart to the SMC X-ray binary pulsar system SXP327Mar 27 2008Optical and X-ray observations are presented here of a newly reported X-ray transient system in the Small Magellanic Cloud. The data reveal many previously unknown X-ray detections of this system and clear evidence for a 49.995d binary period. In addition, ... More
Properties of X-ray Binaries in the Magellanic Clouds from RXTE and Chandra ObservationsOct 27 2008The X-ray binary population of the SMC is very different from that of the Milky Way consisting, with one exception, entirely of transient pulsating Be/neutron star binaries. We have now been monitoring these SMC X-ray pulsars for over 10 years using the ... More
SXP 5.05 = IGR J00569-7226 : using X-rays to explore the structure of a Be stars circumstellar diskDec 10 2014On MJD 56590-1 (2013 Oct 25-26) observations of the Magellanic Clouds by the INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL) observatory discovered a previously-unreported bright, flaring X-ray source. This source was initially given the identification ... More
The XMM-Newton survey of the Small Magellanic Cloud: XMMUJ010633.1-731543 and XMMUJ010743.1-715953, two new Be/X-ray binary systemsApr 26 2012In the course of the XMM-Newton survey of the Small Magellanic Cloud (SMC), two new bright X-ray sources were discovered exhibiting the spectral characteris- tics of High Mass X-ray Binaries - but revealing only weak evidence for pulsations in just one ... More
Orbital Period Determinations for Four SMC Be/X-ray BinariesOct 27 2010We present an optical and X-ray study of four Be/X-ray binaries located in the Small Magellanic Cloud (SMC). OGLE I-band data of up to 11 years of semi-continuous monitoring has been analysed for SMC X-2, SXP172 and SXP202B, providing both a measurement ... More
X-ray and Radio Variabilities of PSR J2032+4127 near PeriastronJul 12 2019We present X-ray and radio monitoring observations of the gamma-ray binary PSR J2032+4127/MT91 213 during its periastron passage in late 2017. Dedicated Chandra, XMM-Newton,NuSTAR X-ray observations and VLA radio observations of this long orbit (50 years), ... More
Optical properties of High-Mass X-ray Binaries (HMXB) in the Small Magellanic CloudSep 16 2008The SMC represents an exciting opportunity to observe the direct results of tidal interactions on star birth. One of the best indicators of recent star birth activity is the presence of signicant numbers of High-Mass X-ray Binaries (HMXBs) - and the SMC ... More
The XMM-Newton survey of the Small Magellanic Cloud: The X-ray point-source catalogueJul 29 2013Local-Group galaxies provide access to samples of X-ray source populations of whole galaxies. The XMM-Newton survey of the Small Magellanic Cloud (SMC) completely covers the bar and eastern wing with a 5.6 deg^2 area in the (0.2-12.0) keV band. To characterise ... More
Study of the cyclotron feature in MXB 0656-072Feb 06 2006We have monitored a Type II outburst of the Be/X-ray binary MXB 0656-072 in a series of pointed RXTE observations during October through December 2003. The source spectrum shows a cyclotron resonance scattering feature at 32.8 +/- 0.5 keV, corresponding ... More
The 2016 super-Eddington outburst of SMC X-3: X-ray and optical properties and system parametersJan 09 2017Jul 21 2017On 2016 July 30 (MJD 57599), observations of the Small Magellanic Cloud by Swift/XRT found an increase in X-ray counts coming from a position consistent with the Be/X-ray binary pulsar SMC X-3. Follow-up observations on 2016 August 3 (MJD 57603) and 2016 ... More
Monitoring the Gamma-Ray Source 2CG 135+1 and the Radio Star LSI+61 303Nov 25 1996We report the results of a CGRO multi-instrument series of observations of the unidentified gamma-ray source 2CG 135+1 and of its possible counterpart, the peculiar radio source GT 0236+610 coincident with the Be star LSI+61 303. We monitored the time ... More
Optical Follow-up of New SMC Wing Be/X-ray BinariesAug 02 2007We investigate the optical counterparts of recently discovered Be/X-ray binaries in the Small Magellanic Cloud. In total four sources, SXP101, SXP700, SXP348 and SXP65.8 were detected during the Chandra Survey of the Wing of the SMC. SXP700 and SXP65.8 ... More
HST/Acs Weak-Lensing and Chandra X-Ray Studies of the High-Redshift Cluster MS 1054-0321Aug 01 2005We present Hubble Space Telescope/Advanced Camera for Surveys (ACS) weak-lensing and Chandra X-ray analyses of MS 1054-0321 at z=0.83, the most distant and X-ray luminous cluster in the Einstein Extended Medium-Sensitivity Survey (EMSS). The high-resolution ... More
On the cyclotron line in Cep X-4May 21 2007Accreting X-ray pulsars provide us with laboratories for the study of extreme gravitational and magnetic fields, hence accurate descriptions of their observational properties contribute to our understanding of this group of objects. We aim to detect a ... More