We have shown previously that many of the properties of persistent accretion-powered millisecond pulsars can be understood if their X-ray emitting areas are near their spin axes and move as the accretion rate and structure of the inner disk vary. Here, we show that this 'nearly aligned moving spot model' may also explain the intermittent ...

The only known accretion-powered millisecond X-ray pulsar SAX J1808.4-3658 exhibited an outburst in January and Februay of this year. The exact starting date is unknown because the source was unobservable by RXTE until 2000 Jan. 21, due to its proximity to the sun. The 401 Hz X-ray pulsations were detected in ...

We investigate further a model of the accreting millisecond X-ray pulsars we proposed earlier. In this model, the X-ray-emitting regions of these pulsars are near their spin axes but move. This is to be expected if the magnetic poles of these stars are close to their spin axes, so that accreting gas is channeled there. As the accretion rate and the ...

The illumination of companion stars in very low mass X-ray binaries by various kinds of radiation from the neighborhood of the neutron star after accretion has terminated or during accretion is considered. If a neutron star's spun-up period approaches 0.001 s, pulsar kHz radiation can quench accretion by pushing surrounding plasma away from the neutron star, and may ...

We present X-ray observations of the transient accretion-powered millisecond pulsar IGR J00291+5934 during quiescence. IGR J00291+5934 is the first source among accretion-powered millisecond pulsars to show signs of a thermal component in its quiescent spectrum. Fitting this component with a ...

The heating associated with the deposition of ?-rays in an accretion disk is proposed as a mechanism to facilitate the transformation of a low-mass X-ray binary to the radio millisecond pulsar (MSP) phase. The ?-ray emission produced in the outer gap accelerator in the pulsar magnetosphere likely irradiates the surrounding disk, resulting in its heating ...

We report on a Chandra/ACIS-S observation of the eclipsing accretion-powered millisecond pulsar SWIFT J1749.4-2807, which has recently been reported in a fading outburst during 2010 April 11-21 (ATels #2548, #2561, #2565, #2569, #2576, #2579). Our 1080 s observation was made on April 25 (12:25 TT). Using the pulsar orbital parameters (ATel #2569), the ...

RXTE observations have shown that weak-field neutron stars in low-mass X-ray binary systems (LMXBs) produce three distinct types of millisecond X-ray oscillations. These are generated directly or indirectly by the star's magnetic field and rotation and can therefore be used to determine the spin rates and estimate the magnetic fields ...

Over 5 years of daily hard X-ray (>20 keV) monitoring of the 2 minute accretion-powered pulsar GX

This grant, titled 'X-Ray Emission from Two Nearby Millisecond Pulsars,' included ROSAT observations

Isolated (solitary or non-accreting) millisecond pulsars with observed X-ray emission can be divided

A unified description of the properties of 14 X-ray pulsars is presented and compared with the current theoretical understanding of these systems. The sample extends over six orders of magnitude in luminosity, with the only trend in the phase averaged spe...

We will describe a Thomson X-ray polarimeter developed for a small satellite mission. The instrument works in the 5-30 keV band and will be suitable for X-ray polarisation measurement in about 50 hard X-ray sources. The accretion powered X-ray pulsars, black hole X-ray ...

through it. In the X-ray band is where we see most of the accretion power coming from these sources population, a stellar population, would make high mass binaries. If you look at the population sources in X-rays you really see that they have different characteristics. Which X-ray sources interest you the most

pulsars. Its October 2002 outburst is of particular interest because of the discovery of kilohertz quasi-periodic oscillations ...

The Rossi X-ray Timing Explorer has observed five outbursts from the transient 2.5 ms accretion-powered pulsar SAX J1808.4-3658 during 1998-2008. We present a pulse timing study of the most recent outburst and compare it with the previous timing solutions. The spin frequency of the source continues to decrease at a rate of (-5.5 {+-} 1.2) x 10{sup -18} Hz ...

In this paper we report on our analysis of three Chandra observations of the accretion-powered millisecond X-ray pulsar IGR J00291+5934 obtained during the late stages of the 2004 outburst. We also report the serendipitous detection of the source in quiescence by ROSAT during MJD 48830-48839 (1992 July 26-August 4). The detected 0.3-10 keV source count ...

The accretion-powered millisecond pulsar IGR J00291+5934 underwent two ~10 day long outbursts during 2008, separated by 30 days in quiescence. Such a short quiescent period between outbursts has never been seen before from a neutron star X-ray transient. X-ray pulsations at the 599 Hz spin frequency are detected throughout both ...

A Sequence of Outbursts from the Transient X�Ray Pulsar GS 0834--430 Colleen A. Wilson, Mark H accretion�powered pulsar, has been observed in seven outbursts with the BATSE large area detectors on the Compton Gamma Ray Observatory. The first 5 outbursts observed by BATSE occurred at intervals of about 107

We report the discovery of burst oscillations from the intermittent accretion-powered millisecond pulsar (AMP) HETE J1900.1-2455, with a frequency ~1 Hz below the known spin frequency. The burst oscillation properties are far more similar to those of the non-AMPs and Aql X-1 (an intermittent AMP with a far lower duty cycle), than those of the AMPs SAX ...

The discovery of millisecond pulsations from neutron stars in low mass X-ray binary (LMXB) systems has substantiated the theoretical prediction that links millisecond radio pulsars (MSRPs) and LMXBs. Since then, the process that produces millisecond radio pulsars from LMXBs, followed by spin-down due to dipole ...

We performed a study of 93 radio sources belonging to the same 3CRR sample but characterized by different radio and optical classifications. Two main results are presented: 1) FRI sources are less efficient than FRII in converting gravitational energy into radiation; 2) The accretion flow is an important X-ray component in all the FRII radio sources except for Low Excitation ...

Jul 15, 2004 ... "X-Ray Bursts from the Accreting Millisecond Pulsar XTE J1814-338", ... ``Bounds on Compactness for LMXB Neutron Stars from X-ray Burst ...

We report on the discovery and the timing analysis of the first eclipsing accretion-powered millisecond X-ray pulsar (AMXP): SWIFT J1749.4-2807. The neutron star rotates at a frequency of ~517.9 Hz and is in a binary system with an orbital period of 8.8 hr and a projected semimajor axis of ~1.90 lt-s. Assuming a neutron star between ...

The identification of Geminga, the discovery of X-ray emission from millisecond pulsars and the identification of cooling neutron stars are only a few of ...

observed in the 650 - 1100 Hz range. Both QPO increased in frequency. together, maintaining a nearly constant frequency separation of about 363 Hz, ...

The results of a Fourier analysis to detect fast periodic and quasi-periodic pulsations in the X-ray

We report here a study of the long term properties of Quasi Periodic Oscillations (QPO) in an unusual accreting X-ray pulsar, 4U 1626-67. This is a unique accretion powered X-ray pulsar in which we have found the QPOs to be present during all sufficiently long X-ray observations with a wide ...

An approximation theory of the acceleration of particles in low-density shear flows is developed and is applied to a number of astrophysical flows including accretion disks, radial accretion, and convective turbulence. In the disk application, the theory suggests a mechanism by which the bulk of the accretion power may be converted to particle ...

This grant, titled 'X-Ray Emission from Two Nearby Millisecond Pulsars,' included ROSAT observations of the nearby pulsars PSR J2322+20 and PSR J2019+24. Neither was detected, although the observations were among the most sensitive ever made towards milli...

Recent data on low-mass X-ray binaries (LMXBs) and millisecond pulsars (MSPs) pose a challenge to evolutionary theories which neglect the effects of disk and comparison irradiation. Here we discuss the main features of a radiation-driven (RD) evolutionary...

Most biological or polymer samples are radiation sensitive materials. A study of these materials at synchrotron radiation sources is challenging in order to minimize and systematically quantify exposure to the period of actual measurements. Since damage can occur on a scale of milliseconds there is a requirement for a beam shutter which can close and open in ...

It is now more than eleven years since the discovery of the first accreting millisecond X-ray pulsar. Since then, eleven additional systems have been found, two of them during the last year. Here I briefly discuss the most recent developments with respect to these systems.

We analyzed seven, target ID 31686, Swift follow-up observations of the neutron-star X-ray transient Swfit J1749.4-2807 (Wijnands et al. 2009) currently in outburst and which was found to be an accreting millisecond X-ray pulsar (ATel #2565). The observations span from April 11 to April 20.

We present a timing solution for the 598.89 Hz accreting millisecond pulsar, IGR J00291+5934, using Rossi X-ray Timing Explorer data taken during the two outbursts exhibited by the source on 2008 August and September. We estimate the neutron star spin frequency and we refine the system orbital solution. To achieve the highest possible accuracy in the ...

X-ray polarimetry promises to give qualitatively new information about high-energy sources. Examples of interesting source classes are binary black hole systems, rotation and accretion powered neutron stars, microquasars, active galactic nuclei and gamma-ray bursts. Furthermore, X-ray polarimetry affords the ...

X-ray polarimetry promises to give qualitatively new information about high-energy sources. Examples of interesting source classes are binary black hole systems, rotation and accretion powered neutron stars, Microquasars, Active Galactic Nuclei and Gamma-Ray Bursts. Furthermore, X-ray polarimetry affords the ...

Recent INTEGRAL/IBIS hard X-ray surveys have detected about 10 young pulsars. We show hard X-ray properties of these 10 young pulsars, which have a luminosity of 1033-1037 erg s-1 and a photon index of 1.6-2.1 in the energy range of 20-100 keV. The correlation between X-ray luminosity and spin-down power of LX propto Lsd1.31suggests ...

The discovery of millisecond pulsations from neutron stars in low mass X-ray binaries (LMXBs) has substantiated the theoretical prediction that links millisecond radio pulsars (MSRPs) and LMXBs. Since then, the recycling process that produces MSRPs on a spin-up region from LMXBs, followed by spin-down due to dipole radiation has been ...

We report multi-wavelength observations of an unidentified Fermi object in the first-year Fermi catalog. The Fermi source has a candidate X-ray counterpart from Swift and Chandra data. We also identify a possible optical counterpart using the X-ray data. Its X-ray and gamma-ray properties are consistent with known gamma-ray millisecond ...

The X-ray evidence from several experiments is reviewed, with special emphasis on those characteristics which appear to distinguish Cygnus X-1 from other compact X-ray emitting objects. Data are examined within the context of a model in which millisecond ...

This report consists of a collection of vugraphs accompanied by brief descriptions. The purpose of this report is to describe in some detail the construction and fielding techniques for the thin foil thermal dosimeters that we have developed for pulsed x-...

Oct 25, 2005 ... GOF, RXTE Finds the First Millisecond Pulsar in an Accreting X-ray ... the times at which the signals from the pulsar arrival at the Earth. ...

Cyg X-1 was observed on two occasions separated by a year by the same X-ray rocket payload. High resolution temporal and spectral data reveal that Cyg X-1 was essentially unchanged in these two observations a year apart, with bursts of millisecond duratio...

Dec 15, 2010 ... Thesis: ``The Wind Interaction Regions of the Vela Pulsar: a Pulsar Jet and Bow Shock ... RXTE PCA studies of millisecond X-ray pulsars ...

We report the detection of a recent torque reversal to spin-up in 4U 1626-67. This is an accretion powered X-ray pulsar and shows slow gradual intensity and pulse period variation on a few years of timescale. Recently, a significant increase in the X-ray flux was observed in the long term RXTE-ASM and Swift-BAT light curve (Krimm et ...

We report the optical detection of a faint star consistent with the known position of the 401 Hz transient accreting millisecond X-ray pulsar IGR J17498-2921 (ATel #3551, #3555, #3556, #3558, #3559, #3560, #3561, #3562, #3563, #3568, #3601, #3606). On 2011-08-25 and 2011-08-26 (MJD 55798.4 - 55799.5) we observed the field of IGR J17498-2921 with the 2-m ...

Recent data on low-mass X-ray binaries (LMXBs) and msec pulsars (MSPs) pose a challenge to evolutionary models which neglect the effects of disk and companion irradiation. Here we discuss the main features of a radiation-driven (RD) evolutionary model tha...

The qualification of many electronic and structural components often requires radiation tests under realistic pulsed conditions, and such tests may include vulnerability to x rays. A family of thin-foil thermal dosimeters with less than or equal to1 ms re...

The authors describe the design, construction and use of a parallel readout Multiwire Linear Detector, capable of recording X-ray patterns at high counting rates. The data acquisition system, built in conjunction with the detector, allows time-resolved measurements with 1 millisecond resolution. The detector and electronics has been tested at the SRS, ...

################ Revised Version hep�ph/9905356 v2 21 May 1999 Is SAX J1808.4�3658 A Strange Star of the newly discovered millisecond X�ray pulsar SAX J1808.4�3658 with the Rossi X�Ray Timing Explorer place firm constraint on the radius of the compact star. Comparing the mass � radius relation of SAX J1808

The accreting millisecond pulsar SAX J1808.4-3658 may be a transition object between accreting X-ray binaries and millisecond radio pulsars. We have constrained the thermal radiation from its surface through XMM-Newton X-ray observations, providing strong evidence for neutrino cooling processes from the neutron ...

We report on pre-outburst optical (VRIHalpha) and near-infrared (NIR; JHKs) imaging observations of the field containing the newly discovered transient accreting milli-second X-ray pulsar IGR J17498-2921 (ATel #3551). The observations were done with the Mosaic (optical) and ISPI (NIR) cameras on the CTIO-4m Blanco telescope as part of our ...

Nuclear-powered oscillations during Type-I X-ray bursts have so far revealed the spin of about twenty accreting millisecond pulsars in low-mass X-ray binaries. We study the properties of such burst oscillations by means of numerical computations of hot spots on the neutron star surface. We use adaptive mesh refinement hydrodynamical ...

Context. It is commonly believed that millisecond radio pulsars have been spun up by transfer of matter and angular momentum from a low-mass companion during an X-ray active mass transfer phase. A subclass of low-mass X-ray binaries is that of the accreting millisecond X-ray pulsars, transient systems that show ...

Nucleic acid fragmentation (footprinting) by �OH radicals is used often as a tool to probe nucleic acid structure and nucleic acid�protein interactions. This method has proven valuable because it provides structural information with single base pair resolution. Recent developments in the field introduced the �synchrotron X-ray footprinting� method, which uses a ...

A class of low-mass X-ray binary sources are known to be both X-ray burst sources and millisecond pulsars at the same time. A new source of this class was discovered by High Energy Transient Explorer 2 (HETE-2) on 14 June 2005 as a source of type-I X-ray bursts, which was named HETE J1900.1-2455. Three (two ...

The authors report a carbon nanotube (CNT) field emission multipixel x-ray array source for microradiotherapy for cancer research. The developed multipixel x-ray array source has 50 individually controllable pixels and it has several distinct advantages over other irradiation source including high-temporal resolution (millisecond ...

The authors report a carbon nanotube (CNT) field emission multipixel x-ray array source for microradiotherapy for cancer research. The developed multipixel x-ray array source has 50 individually controllable pixels and it has several distinct advantages over other irradiation source including high-temporal resolution (millisecond ...

Radio pulsars with millisecond spin periods are thought to have been spun up by the transfer of matter and angular momentum from a low-mass companion star during an x-ray-emitting phase. The spin periods of the neutron stars in several such low-mass x-ray binary (LMXB) systems have been shown to be in the millisecond regime, but no ...

Radio pulsars with millisecond spin periods are thought to have been spun up by the transfer of matter and angular momentum from a low-mass companion star during an x-ray-emitting phase. The spin periods of the neutron stars in several such low-mass x-ray binary (LMXB) systems have been shown to be in the millisecond regime, but no ...

We report here a study of the long-term properties of quasiperiodic oscillations (QPOs) in an unusual accreting X-ray pulsar, 4U 1626-67. This is a unique accretion-powered X-ray pulsar in which we have found the QPOs to be present during all sufficiently long X-ray observations with a wide range of X-ray ...

The flat segment, lasting ~104 s, in the X-ray afterglow of GRB 051221A represents the first clear case of strong energy injection in the external shock of a short gamma-ray burst (GRB) afterglow. In this work, we show that a millisecond pulsar with a dipole magnetic field ~1014 Gauss could well account for that energy injection. The good quality X-ray ...

We describe the use of a flow-focusing microfluidic reactorto measure the kinetics of theCdSe-to-Ag2Se nanocrystal cation exchangereaction using micro-X-ray absorption spectroscopy (mu XAS). The smallmicroreactor dimensions facilitate the millisecond mixing of CdSenanocrystal and Ag+ reactant solutions, and the transposition of thereaction time onto ...

Cataclysmic variables provide the most accessible view of accretion physics. They are the most numerous accretion powered X-ray sources, and there are thus many relatively bright, nearby examples. Known examples include several bright eclipsing systems that allow a quantitative determination of the accretion geometry. Perhaps most ...

Context. The burst-only source Swift J1749.4-2807 was discovered in a high X-ray-active state, during an INTEGRAL observations of the Galactic bulge on 2010 April 10. Pulsations at 518 Hz were discovered in the RXTE data, confirming previous suggestions of possible associations between burst-only sources and accreting millisecond X-ray ...

Over the past decade our understanding of accreting neutron stars has been revolutionized. Observations with NASA's Rossi X-ray Timing Explorer (RXTE) have resulted in the discovery of fast, coherent X-ray intensity oscillations (hereafter, ``burst oscillations'') during thermonuclear X-ray bursts from 13 low mass ...

We have detected an x-ray nebula around the binary millisecond pulsar B1957+20. A narrow tail, corresponding to the shocked pulsar wind, is seen interior to the known Halpha bow shock and proves the long-held assumption that the rotational energy of millisecond pulsars is dissipated through relativistic winds. Unresolved x-ray emission ...

X-ray pulses with millisecond-long FWHM have been detected in RXTE (Rossi X-Ray Timing Explorer) satellite observations of Cyg XR-1. Their identity as short-timescale variations in the X-ray luminosity of the source, and not stochastic variability in the X-ray flux, is established by their simultaneous occurrence and similar pulse ...

Variability studies represent a powerful tool to assess the emission mechanism(s) at work in the quiescent state of transient low mass X-ray binaries. Here we report on Chandra and XMM-Newton observations of two well known transient sources: Aql X-1 and Cen X-4. Long and short term variability is observed. This variability can be easily interpreted in view of an active ...

High-intensity, ``pink'' beam from an undulator was used in conjunction with microfabricated rapid-fluid mixing devices to monitor the early events in protein folding with time resolved small angle x-ray scattering. This Letter describes recent work on the protein bovine ?-lactoglobulin where collapse from an expanded to a compact set of states was directly observed on the ...

X-ray camera techniques developed in laser fusion have been applied to view tokamak discharges in 1 to 3 keV light. The camera consists of an image intensifier fluor combination viewing the plasma tangentially through a pinhole. The resultant image is optically coupled to a standard CCD television camera for remote viewing. The first intensifier is gated so that the camera ...

The authors demonstrate the use of millisecond x-ray phase-contrast imaging for velocity measurement of particle-laden flows in an optically opaque vessel. Taking advantage of particle size polydispersity, this single-particle tracking approach is extremely effective on flows with tracer particles exhibiting a great size distribution ranging from 1 ...

Extreme conditions of density and temperature of interest to DNT are similar to conditions of low-altitude atmospheres of neutron stars. Consequently, HED experimental capabilities being developed at LLNL (NIF, petawatt lasers) will open the door to laboratory studies of neutron star atmospheres. This capability will seed a new era in the study of extreme physics generated by strongly radiation ...

Black hole and neutron star accretion flows display unusually high levels of hard coronal emission in comparison to all other optically thick, gravitationally bound, turbulent astrophysical systems. Since these flows sit in deep relativistic gravitational potentials, their random bulk motions approach the speed of light, therefore allowing turbulent Comptonization to be an important effect. We ...

Black hole and neutron star accretion flows display unusually high levels of hard coronal emission in comparison to all other optically thick, gravitationally bound, turbulent astrophysical systems. Since these flows sit in deep relativistic gravitational potentials, their random bulk motions approach the speed of light, therefore allowing turbulent Comptonization to be an important effect. We ...

Recent observations support the suggestion that short-duration gamma-ray bursts are produced by compact star mergers. The x-ray flares discovered in two short gamma-ray bursts last much longer than the previously proposed postmerger energy-release time scales. Here, we show that they can be produced by differentially rotating, millisecond pulsars after the mergers of binary ...

High-sensitivity search techniques for millisecond periods are presented and applied to data from the Japanese satellite Ginga and HEAO 1. The search is optimized for pulsed signals whose period, drift rate, and amplitude conform with what is expected for low-class X-ray binary (LMXB) sources. Consideration is given to how the current understanding of ...

Millisecond pulsars (MSPs) probably achieve their fast rotation by mass transfer from their companion stars in low-mass x-ray binaries (LMXBs). The lack of MSPs and LMXBs rotating near breakup has been attributed to the accretion torque being balanced, at fast rotation, by gravitational radiation, perhaps caused by an unstable oscillation mode. It has been ...

Nuclear-powered oscillations during Type-I X-ray bursts have so far revealed the spin of about twenty accreting millisecond pulsars in low-mass X-ray binaries. Constraining strong gravity through the emission from the hot spots on the neutron star surface requires understanding of the properties of such burst oscillations. We use ...

The goal of this investigation is to further our understanding of the dynamics of secreting neutron stars and black holes in the hope of using these systems as probes of the physics of strong gravitational fetus. The main focus of this work has been a multi-year program of simultaneous millisecond X-ray timing and spectral observations carried out with the ...

X-ray diffraction studies have been performed up to 38 T in conjunction with synchrotron x-ray beams and a split-pair pulse magnet at the beamline BL19LXU of SPring-8. The magnet consists of coaxial two-coils which are made by winding CuAg wire up to 18 layers. The magnet has four windows with wide aperture angles and the height of 3 mm for passage of the ...

Of the eight X-ray sources now known which may be associated with binary stellar systems, Cygnus X-1 is the most likely candidate for being a black hole. The X-ray evidence from several experiments is reviewed, with special emphasis on those characteristics which appear to distinguish Cygnus X-1 from other compact X-ray emitting objects. Data are examined ...

X-ray computed tomography (CT) is a well established visualization technique in medicine and nondestructive testing. However, since CT scanning requires sampling of radiographic projections from different viewing angles, common CT systems with mechanically moving parts are too slow for dynamic imaging, for instance of multiphase flows or live animals. Here, we introduce an ...

Phase transitions can be triggered by a change of density profile in neutron stars as a result of spin-up caused by mass accretion from a companion star. Such a spin evolution is the pathway from old canonical pulsars to millisecond pulsars. A number of x-ray neutron stars have been recently observed by the Rossi x-ray timing explorer (RXTE). Most of their ...

One of the goals of soft X-ray projection lithography (SXPL) is to devise laser plasma X-ray sources that minimize or entirely eliminate condensed debris. Our progress in developing a computational methodology for analyzing and predicting the formation of target debris in laser generated soft X-ray sources is presented. Our numerical ...

Swift observations suggest that the central compact objects of some gamma-ray bursts (GRBs) could be newly born millisecond magnetars. Therefore, considering the spin evolution of the magnetars against r-mode instability, we investigate the role of magnetars in GRB X-ray afterglow emission. Besides modifying the conventional energy injection model, we pay ...

Swift observations suggest that the central compact objects of some gamma-ray bursts (GRBs) could be newly born millisecond magnetars. Therefore, considering the spin evolution of the magnetars against r-mode instability, we investigate the role of magnetars in GRB X-ray afterglow emission. Besides modifying the conventional energy injection model, we pay ...

The MAXI is a high sensitive X-ray all-sky monitor attached to the Japanese experimental module on the International Space Station. It was succesfully launched on July 16 this year, and it has already been verified that all the proportional counters work nominally. The MAXI will be able to discover many faint X-ray sources with a flux of less than a few 10 ...

The central compact object of some gamma-ray bursts (GRBs) may be a strongly magnetized millisecond pulsar. In this model, there is an energy injection from the pulsar to the external forward shock through the magnetic dipole radiation. The energy injection would give rise to the shallow decay of the early afterglow. Recently, an interesting feature is discovered from many ...

The recycling model argues the existence of an evolutionary connection between low mass X-ray binaries and radio millisecond pulsars. The main difficulties which this model finds in predict the parameters of the fully recycled millisecond pulsars, as mass and spin period, can be overcome by the onset of the so-called radio-ejection ...

Most accretion-powered relativistic jet sources in our Galaxy are transient X-ray binaries (XBs). Efforts to coordinate multiwavelength observations of these objects have improved dramatically over the last decade. Now the challenge is to interpret broadband spectral energy distributions (SEDs) of XBs that are well sampled in both wavelength and time. Here ...

We are currently monitoring the transient hard X-ray/soft gamma ray sky using the Gamma Ray Burst Monitor (GBM) on-board Fermi. The twelve GBM NaI detectors span 8 keV to 1 MeV, while the two GBM BGO detectors span about 150 keV to 40 MeV. With GBM, we detect transient events on multiple timescales. Brief events, such as Gamma Ray Bursts, Solar Flares, and Magnetar Bursts are ...

It is now ten years ago that the first accreting millisecond X-ray pulsar (AMP) was discovered in the low-mass X-ray binary SAX J1808.4-3658. This RXTE discovery confirmed long-standing predictions that low magnetic field neutron stars can be spun up to high spin frequencies by accretion in X-ray binaries. AMPs have since been ...

A vexing problem in AGN research is that their complex taxonomy & wide range of properties make it difficult to compile a broadly representative sample, particularly one containing obscured sources. The relatively recent results indicating that supermassive black holes may be entrenched in every galaxy bulge give added impetus to conducting a census of accretion ...

The bright and highly variable X-ray and radio source known as Cygnus X-3 was among the first X-ray sources discovered, yet it remains in many ways an enigma. It is known to consist of a massive, Wolf-Rayet primary in an extremely tight orbit with a compact object. However, one of the most basic of parameters-the mass of the compact object-is not known, ...

The interest in X/ ?-ray Astronomy has grown enormously in the last decades thanks to the ability to send X-ray space missions above the Earth�s atmosphere. There are more than half a million X-ray sources detected and over a hundred missions (past and currently operational) devoted to the study of cosmic ...

X-ray timing studies on neutron stars and black holes need large collecting areas, {much gt}10 m{sup 2}, to permit millisecond and submillisecond studies. Physical processes near neutron star surfaces and general relativistic effects could be seen. The key requirement is collecting many photons rapidly, by viewing bright sources with a large aperture. Lack ...

Coronal stars Supernova, nova, recurrent nova remnants Timescales of Interest Milliseconds to years notwithstanding, these are now believed to be mostly accreting neutron stars and black holes in interacting binary their data will not be relevant. The hot coronal emission of late type stars is symptomatic of their internal

Dec 29, 2005... 10:00 a.m. Millisecond Pulsars from X-Ray to Radio D. Chakrabarty 10:20 a.m. Coffee Break 10:50 a.m. Cyg X-1 K. Pottschmidt 11:10 a.m. ...

The transformation from the observed X-ray temperature and surface bright- ness to gas mass depends on the absolute distance of ...... cial aspects of star and planet formation (see Figure 1.) ..... and detections of coherent millisecond variability in ... star pulsars in binary systems by observing spectral ...

We present a self-consistent model to describe X-ray and gamma -ray emission from millisecond pulsars (MSPs). The X-rays of MSPs are produced by the backflow of primary charged particles from the outer gap and most likely consist of three components, two thermal components and one power law component if there is a strong multipole magnetic field on the ...

Millisecond pulsars are believed to descend from low-mass X-ray binaries. Observable parameters of binary millisecond pulsars, e.g. mass of the pulsar, mass of the companion, spin period of the pulsar, orbital period, orbital eccentricity, etc., are used to probe the past accretion history of the millisecond ...

Theoretically, the phase transition between the confined and deconfined phases of quarks can have a remarkable effect on the spin properties of millisecond pulsars and on the spin distribution of the population of x-ray neutron stars in low-mass binaries. In the latter class of stars, the effect has already been observed--a strong clustering in the population in a narrow band ...

From January, 1988 to June, 1989 the solar radio synchronous observational system with high temporal resolution of the Yunnan Observatory was used to carry out observations at a decimetric wavelength (1420 MHz), and the data are analyzed in this paper. The result shows a relation between the millisecond spike radiation of the solar decimetric radio emission and the radio ...

From January 1988 to June 1989, the solar radio synchronous observational system with high temporal resolution of the Yunnan Observatory was used to carry out observations at a decimetric wavelength (1420 MHz), and the data are analyzed in this paper. The result shows a relation between the millisecond spike radiation of the solar decimetric radio emission and the radio bursts ...

In millisecond pulsars the existence of the Coriolis force allows the development of the so-called Rossby oscillations (r-modes) which are know to be unstable to emission of gravitational waves. These instabilities are mainly damped by the viscosity of the star or by the existence of a strong magnetic field. A fraction of the observed millisecond pulsars ...

An evolutionary link between Low Mass X-ray Binaries (LMXBs) and Low Mass Binary Pulsars (LMBPs) has long been proposed. Before the launch of RXTE, the critical missing piece of evidence was the detection of coherent millisecond pulsations from LMXBs that would confirm their millisecond spin rates and essentially confirm the ...

We report on possible orbit solutions of the new accretion powered millisecond pulsar IGR J17498-2921 (ATEL #3551, #3555, #3556, #3558, #3559, #3560). We used RXTE PCA observations from 2011-08-13 (Papitto et al., ATEL #3556) and 2011-08-15 at 20:20 for 3.8 ks exposure. The pulsation signal is strongly detected in both observations. ...