On the distribution of frequency ratios of kHz QPOs (2009)
Boutelier, Martin, Barret, Didier, Lin, Yongfeng, Torok, Gabriel
The width (W), root mean squared amplitude (Rs) of lower and upper kHz quasi-periodic oscillations (QPOs) from accreting neutron stars vary with frequency. Similarly, the QPO frequency varies with...
kHz Quasi-Periodic Oscillations in the low-mass X-ray binary 4U 0614+09 (2009)
Boutelier, Martin, Barret, Didier, Miller, M. Coleman
We report on a comprehensive analysis of the kilohertz (above 300 Hz) quasi-periodic oscillations (kHz QPOs) detected from the neutron star low-mass X-ray binary 4U0614+09 with the Rossi X-ray Timing...
X-ray Timing of Stellar Mass Black Holes (2009)
Tomsick, John A., Remillard, Ronald A., Homan, Jeroen, Kaaret, Philip, Barret, Didier, Schnittman, Jeremy
X-ray timing observations of accreting stellar mass black holes have shown that they can produce signals with such short time scales that we must be probing very close to the innermost stable...
The Dynamic X-ray Sky of the Local Universe (2009)
Soderberg, Alicia M., Grindlay, Jonathan E., Bloom, Joshua S., Gezari, Suvi, Piro, Anthony L., Belloni, Tomaso, ...
Over the next decade, we can expect time domain astronomy to flourish at optical and radio wavelengths. In parallel with these efforts, a dedicated transient "machine" operating at higher energies...
XEUS: the physics of the hot evolving universe (2009)
Arnaud, Monique, Barcons, Xavier, Barret, Didier, Bautz, Marshall, Bellazzini, Ronaldo, Bleeker, Johan, ...
A Swift BAT Look at Super-Orbital X-ray Binaries (2008)
Farrell, Sean A., Barret, Didier, Skinner, Gerald
We present the results of a study with the Swift Burst Alert Telescope in the 14 - 195 keV range of the long-term variability of 5 low mass X-ray binaries with reported or suspected super-orbital...
Spotting Symbols in Line Drawing Images Using Graph Representations (2008)
Rashid Jalal Qureshi, Jean-yves Ramel, Didier Barret, Hubert Cardot
Abstract. Many methods of graphics recognition have been developed throughout the years for the recognition of pre-segmented graphics symbols but very few techniques achieved the objective of symbol...
Symbol Spotting in Graphical Documents Using Graph Representations (2008)
Rashid Jalal Qureshi, Jean-yves Ramel, Didier Barret, Hubert Cardot
Abstract. Many methods of graphics recognition have been developed throughout the years for the recognition of pre-segmented graphics symbols but very few techniques achieved the objective of symbol...
The XEUS focal plane instruments (2008)
Strüder, Lothar, Barret, Didier, Bellazzini, Ronaldo, Duband, Lionel, Martin, Didier, ...
Discovery of the upper kilo-Hz QPO from the X-ray transient Aql X-1 (2007)
Barret, Didier, Boutelier, Martin, Miller, M. Coleman
We report on a comprehensive analysis of the kilo-Hz (>~600 Hz) quasi-periodic oscillations (kHz QPOs) detected from the neutron star X-ray transient Aquila X-1 (Aql X-1) with the Rossi X-ray Timing...
Advection-Dominated Accretion Model of the Black Hole V404 Cyg in Quiescence (2007)
Ramesh Narayan Didier, Didier Barret, Jeffrey E. Mcclintock
We have analyzed archival ASCA data on the soft X-ray transient source V404 Cyg in quiescence. We find that in the energy range 0.7 to 8.5 keV the spectrum is a hard power-law with a photon spectral...
Barret, Didier, Olive, Jean-Francois, Miller, M. Coleman
Analysis of archival RXTE data on neutron stars binaries has shown that for several sources the quality factor (Q) of the lower kilohertz Quasi-Periodic Oscillations (QPO) drops sharply beyond a...
X-ray Timing beyond the Rossi X-ray Timing Explorer (2006)
With its ability to look at bright galactic X-ray sources with sub-millisecond time resolution, the Rossi X-ray Timing Explorer (RXTE) discovered that the X-ray emission from accreting compact stars...
The coherence of kHz quasi-periodic oscillations in the X-rays from accreting neutron stars (2006)
Barret, Didier, Olive, Jean-Francois, Miller, M. Coleman
We study in a systematic way the quality factor of the lower and upper kHz QPOs in a sample of low luminosity neutron star X-ray binaries, showing both QPOs varying over a wide frequency range. The...
Fast timing with XEUS: evaluation of different detector concepts (2006)
Kendziorra, Eckhard, Martin, Michael, Santangelo, Andrea, Wilms, Jörn, Barret, Didier, Skinner, Gerry, ...
Barret, Didier, Olive, Jean-Francois, Miller, M. Coleman
Using all available archival data from the Rossi X-ray Timing Explorer (RXTE), we follow the frequency of the kilo-Hz QPOs in three low luminosity neutron star low mass X-ray binaries; namely 4U...
Accretion flows around stellar mass black holes and neutron stars (2005)
In this review, I summarize the main X-ray/hard X-ray properties of the accretion flows around black holes and neutron stars based on recent broad-band spectral and timing observations performed by...
XTRA: The fast X-ray timing detector on XEUS (2005)
The Rossi X-ray Timing Explorer (RXTE) has demonstrated that the dynamical variation of the X-ray emission from accreting neutron stars and stellar mass black holes is a powerful probe of their...
Simultaneous BeppoSAX and Rossi X-ray Timing Explorer observations of 4U1812-12 (2005)
Barret, Didier, Olive, Jean-Francois, Oosterbroek, Tim
4U1812-12 is a faint persistent and weakly variable neutron star X-ray binary. It was observed by BeppoSAX between April 20th and 21st, 2000 in a hard spectral state with a bolometric luminosity of...
ECLAIRs is a French microsatellite devoted to the observation of the prompt optical and X-ray emission of GRBs. For about 100 GRBs/yr, independent of their duration, ECLAIRs will provide high time...
A peculiar spectral state transition of 4U1705--44: when an Atoll looks like a Z (2005)
Barret, Didier, Olive, Jean-Francois
We report on a clear spectral state transition of the neutron star low-mass X-ray binary 4U1705-44 observed by the Rossi X-ray Timing Explorer. In the X-ray color-color diagram (CCD), the source,...
ECLAIRs: A microsatellite for the prompt optical and X-ray emission of Gamma-Ray Bursts (2005)
The prompt gamma-ray emission of Gamma-Ray Bursts (GRBs) is currently interpreted in terms of radiation from electrons accelerated in internal shocks in a relativistic fireball. On the other hand,...
The broad band X-ray/hard X-ray spectra of accreting neutron stars (2005)
I review the energy spectra of low mass X-ray binaries (LMXBs) containing weakly magnetized accreting neutron stars (NS), emphasizing the most recent broad band (0.1-200 keV) spectral and timing...
An abrupt drop in the coherence of the lower kilohertz QPO in 4U 1636-536 (2005)
Barret, Didier, Olive, Jean-Francois, Miller, M. Coleman
Using archival data from the Rossi X-ray Timing Explorer (RXTE), we study in a systematic way the variation of the quality factor and amplitude of the lower and upper kHz quasi-periodic oscillations...
Faint X-ray sources in globular clusters in the XMM-Newton and Chandra era (2004)
Webb, Natalie A., Barret, Didier
X-ray imaging and spectroscopy can be used to probe the binary content of globular clusters. Binaries are thought to play a key role in the dynamical evolution of the clusters by serving as an...
XTRA: The fast X-ray timing detector on XEUS (2004)
The Rossi X-ray Timing Explorer (RXTE) has demonstrated that the dynamical variation of the X-ray emission from accreting neutron stars and stellar mass black holes is a powerful probe of their...
Accretion flows around stellar mass black holes and neutron stars (2004)
In this review, I summarize the main X-ray/hard X-ray properties of the accretion flows around black holes and neutron stars based on recent broad-band spectral and timing observations performed by...
Accretion flows around stellar mass black holes and neutron stars (2004)
In this review, I summarize the main X-ray/hard X-ray properties of the accretion flows around black holes and neutron stars based on recent broad-band spectral and timing observations performed by...
XTRA: The fast X-ray timing detector on XEUS (2004)
The Rossi X-ray Timing Explorer (RXTE) has demonstrated that the dynamical variation of the X-ray emission from accreting neutron stars and stellar mass black holes is a powerful probe of their...
Accretion flows around stellar mass black holes and neutron stars (2004)
In this review, I summarize the main X-ray/hard X-ray properties of the accretion flows around black holes and neutron stars based on recent broad-band spectral and timing observations performed by...
XTRA: The fast X-ray timing detector on XEUS (2004)
The Rossi X-ray Timing Explorer (RXTE) has demonstrated that the dynamical variation of the X-ray emission from accreting neutron stars and stellar mass black holes is a powerful probe of their...
Fast timing instrument for XEUS: Scientific expectations (2004)
Wilms, Jörn, Kendziorra, Eckhard, Martin, Michael, Barret, Didier, Nowak, Michael A., Strüder, Lothar, ...
XTRA: The fast X-ray timing detector on XEUS (2004)
Barret, Didier, Médale, Jean-Louis, Rohde, Martin, Skinner, Gerry K., Strüder, Lothar
Discovery of a quiescent neutron star binary in the globular cluster M13 (2003)
Gendre, Bruce, Barret, Didier, Webb, Natalie A.
We have discovered with XMM-Newton an X-ray source in the core of the globular cluster M13, whose X-ray spectral properties suggest that it is a quiescent neutron star X-ray binary. The spectrum can...
Simultaneous BeppoSAX and Rossi X-ray Timing Explorer observations of 4U1812-12 (2003)
Barret, Didier, Olive, Jean-Francois, Oosterbroek, Tim
4U1812-12 is a faint persistent and weakly variable neutron star X-ray binary. It was observed by BeppoSAX between April 20th and 21st, 2000 in a hard spectral state with a bolometric luminosity of...
Simultaneous BeppoSAX and Rossi X-ray Timing Explorer observations of 4U1812-12 (2003)
Barret, Didier, Olive, Jean-Francois, Oosterbroek, Tim
4U1812-12 is a faint persistent and weakly variable neutron star X-ray binary. It was observed by BeppoSAX between April 20th and 21st, 2000 in a hard spectral state with a bolometric luminosity of...
Simultaneous BeppoSAX and Rossi X-ray Timing Explorer observations of 4U1812-12 (2003)
Barret, Didier, Olive, Jean-Francois, Oosterbroek, Tim
4U1812-12 is a faint persistent and weakly variable neutron star X-ray binary. It was observed by BeppoSAX between April 20th and 21st, 2000 in a hard spectral state with a bolometric luminosity of...
An XMM-Newton observation of the globular cluster Omega Centauri (2002)
Gendre, Bruce, Barret, Didier, Webb, Natalie A.
We report on a deep XMM-Newton EPIC observation of the globular cluster Omega Cen performed on August 13th, 2001. We have detected 11 and 27 faint X-ray sources in the core and half mass radii,...
ECLAIRs is a French microsatellite devoted to the observation of the prompt optical and X-ray emission of GRBs. For about 100 GRBs/yr, independent of their duration, ECLAIRs will provide high time...
A peculiar spectral state transition of 4U1705--44: when an Atoll looks like a Z (2002)
Barret, Didier, Olive, Jean-Francois
We report on a clear spectral state transition of the neutron star low-mass X-ray binary 4U1705-44 observed by the Rossi X-ray Timing Explorer. In the X-ray color-color diagram (CCD), the source,...
ECLAIRs is a French microsatellite devoted to the observation of the prompt optical and X-ray emission of GRBs. For about 100 GRBs/yr, independent of their duration, ECLAIRs will provide high time...
A peculiar spectral state transition of 4U1705--44: when an Atoll looks like a Z (2002)
Barret, Didier, Olive, Jean-Francois
We report on a clear spectral state transition of the neutron star low-mass X-ray binary 4U1705-44 observed by the Rossi X-ray Timing Explorer. In the X-ray color-color diagram (CCD), the source,...
ECLAIRs is a French microsatellite devoted to the observation of the prompt optical and X-ray emission of GRBs. For about 100 GRBs/yr, independent of their duration, ECLAIRs will provide high time...
A peculiar spectral state transition of 4U1705--44: when an Atoll looks like a Z (2002)
Barret, Didier, Olive, Jean-Francois
We report on a clear spectral state transition of the neutron star low-mass X-ray binary 4U1705-44 observed by the Rossi X-ray Timing Explorer. In the X-ray color-color diagram (CCD), the source,...
Maximum entropy models for skin detection (2002)
Bruno Jedynak, Huicheng Zheng, Mohamed Daoudi, Didier Barret
We consider a sequence of three models for skin detection built from a large collection of labelled images. Each model is a maximum entropy model with respect to constraints concerning marginal...
Phase-resolved X-ray spectroscopy of the millisecond pulsar SAX J1808.4-3658 (2001)
Gierlinski, Marek, Done, Chris, Barret, Didier
We present new results based on RXTE observations of SAX J1808.4-3658. The X-ray spectrum can be fitted by a two-component model. We interpret the soft component as blackbody emission from a heated...
First XMM-Newton Observations of the Globular Cluster M22 (2001)
Webb, Natalie A., Gendre, Bruce, Barret, Didier
We have examined preliminary data of the globular cluster, M22, from the EPIC MOS detectors on board XMM-Newton. We have detected 27 X-ray sources within the centre of the field of view, 24 of which...
ECLAIRs: A microsatellite for the prompt optical and X-ray emission of Gamma-Ray Bursts (2001)
The prompt gamma-ray emission of Gamma-Ray Bursts (GRBs) is currently interpreted in terms of radiation from electrons accelerated in internal shocks in a relativistic fireball. On the other hand,...
Phase-resolved spectra of the millisecond pulsar SAX J1808.4-3658 (2001)
Gierlinski, Marek, Done, Chris, Barret, Didier
We analyze the RXTE observations of the April 1998 outburst of SAX J1808.4-3658. We show that the soft blackbody component of the X-ray spectrum is from the hotspot on the neutron star surface, while...
The broad band X-ray/hard X-ray spectra of accreting neutron stars (2001)
I review the energy spectra of low mass X-ray binaries (LMXBs) containing weakly magnetized accreting neutron stars (NS), emphasizing the most recent broad band (0.1-200 keV) spectral and timing...
ECLAIRs: A microsatellite for the prompt optical and X-ray emission of Gamma-Ray Bursts (2001)
The prompt gamma-ray emission of Gamma-Ray Bursts (GRBs) is currently interpreted in terms of radiation from electrons accelerated in internal shocks in a relativistic fireball. On the other hand,...
The broad band X-ray/hard X-ray spectra of accreting neutron stars (2001)
I review the energy spectra of low mass X-ray binaries (LMXBs) containing weakly magnetized accreting neutron stars (NS), emphasizing the most recent broad band (0.1-200 keV) spectral and timing...
ECLAIRs: A microsatellite for the prompt optical and X-ray emission of Gamma-Ray Bursts (2001)
The prompt gamma-ray emission of Gamma-Ray Bursts (GRBs) is currently interpreted in terms of radiation from electrons accelerated in internal shocks in a relativistic fireball. On the other hand,...
The broad band X-ray/hard X-ray spectra of accreting neutron stars (2001)
I review the energy spectra of low mass X-ray binaries (LMXBs) containing weakly magnetized accreting neutron stars (NS), emphasizing the most recent broad band (0.1-200 keV) spectral and timing...
Evolution of AQL X-1 During the Rising Phase of its 1998 Outburst (1998)
Cui, Wei, Barret, Didier, Zhang, S. N., Chen, Wan, Boirin, Laurence, Swank, Jean
We present results from 16 snapshots of Aql X-1 with RXTE during the rising phase of its recent outburst. The observations were carried out at a typical rate of once or twice per day. The source...
Lum, Kenneth S. K., Mohr, Joseph J., Barret, Didier, Grindlay, Jonathan E., Manandhar, Raj P.
We have modelled the hard X-ray background expected for a high-altitude balloon flight of the Energetic X-ray Telescope Experiment (EXITE2), an imaging phoswich detector/telescope for the 20--600 keV...
Energy Spectra and High Frequency Oscillations in 4U 0614+091 (1997)
Ford, Eric C., Kaaret, Philip, Chen, Kaiyou, Tavani, Marco, Barret, Didier, Bloser, Peter, ...
We investigate the behavior of the high frequency quasi-periodic oscillations (QPOs) in 4U 0614+091, combining timing and spectral analysis of RXTE observations. The energy spectra of the source can...
Advection-Dominated Accretion Model of the Black Hole V404 Cyg in Quiescence (1996)
Narayan, Ramesh, Barret, Didier, McClintock, Jeffrey E.
We have analyzed archival ASCA data on the soft X-ray transient source V404 Cyg in quiescence. We find that in the energy range 0.7 to 8.5 keV the spectrum is a hard power-law with a photon spectral...
Models of Quiescent Black Hole Neutron Star Soft X-Ray Transients (1995)
Yi, Insu, Narayan, Ramesh, Barret, Didier, McClintock, Jeffrey E.
When the mass accretion rate onto a black hole (BH) falls below a critical rate, ${\dot M}_{crit}\sim \alpha^2 {\dot M}_{Edd}$, accretion can occur via a hot optically thin flow where most of the...