The formation of millisecond pulsars is addressed. Evolutionary scenarios involving the spinning up of pulsars by accretion disks are discussed, and the implications of the P(dot)-P diagram for a large sample of radio pulsars are examined. 13 references.
Energy Citations Database
Jul 2, 2003 ... Caption for Animation 1: ACCRETION SPINS PULSAR TO MILLISECOND RANGE. If a pulsar -- a dense star with strong gravitational attraction -- is ...
NASA Website
Neutron Stars, Pulsars, Millisecond Pulsars, and Gravitational Radiation: GLOSSARY. Accretion disk: The flattened, pancake-like structure formed by matter ...
Isolated (solitary or non-accreting) millisecond pulsars with observed X-ray emission can be divided
NASA Technical Reports Server (NTRS)
The 2002 outburst of the accretionpowered millisecond pulsar SAX J1808.43658. Askar Ibragimov and prof. Juri Poutanen. University of Oulu, Finland ...
Observations of millisecond pulsars are discussed, taking into account a review of millisecond pulsars, arrival time observations of the 1.6 millisecond pulsar 1937 + 214, a 6.1 millisecond binary pulsar, polarimetry of the two ...
... Hamilton 2001; Hansen 2002), but all generally rely on an accretion disk around the pulsar within which the planets form. Millisecond pulsars are a ...
DTIC Science & Technology
We review recent results from the X-ray timing of accreting millisecond pulsars in LMXBs. This is the first time a timing analysis is performed on accreting millisecond pulsars, and for the first time we can obtain information on the behavior of a very fast ...
NASA Astrophysics Data System (ADS)
The nature of pulsars that exhibit quasi-periodic oscillations (QPOs) is discussed. It is shown how QPOs are produced by an interaction between the accretion disk surrounding a neutron star with the neutron star's magnetic field. The possible relationship between pulsars that exhibit QPOs and millisecond ...
that this is already greater than one Earth mass, this may mean that isolated millisecond pulsars either have planetary MILLISECOND PULSARS M. COLEMAN MILLER AND DOUGLAS P. HAMILTON Department of Astronomy, University of Maryland the millisecond pulsar PSR 1257]12. We show ...
E-print Network
I review the basic observational properties of accreting millisecond pulsars that are important for understanding the physics involved in formation of their pulse profiles. I then discuss main effects responsible for shaping these profiles. Some analytical results that help to understand the results of simulations are presented. ...
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 ...
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 ...
... is one of the smallest telescopes used for millisecond pulsar observations, we succeeded in detecting several millisecond pulsars by using our new ...
... Abstract : Millisecond pulsars attract attentions as a future reference clock in ... system to measure the pulse timing of millisecond pulsar precisely, and ...
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. ...
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 present an evolutionary scenario for the spin-up and evolution of binary millisecond pulsars, according to which the companion of the pulsar PSR J1740-5340 , recently discovered as a binary with orbital period of 32.5 hrs in the Globular Cluster NGC 6397, is presently in a phase of `radio--ejection' mass loss from the system.
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 of these stars. Periodic ...
Millisecond pulsars, both during and after accretion, stand a class apart from the general pulsar population due to the much weaker field strength at their surface. The prevailing view is that accretion of matter on to a neutron star causes a decay of its magnetic field strength, as viewed by ...
... related to the lifetime of the pulsar, the new millisecond pulsar J1713 + 0747 ... Over the fast five years, dozens of new millisecond pulsars have been ...
We review recent results of our group on X-ray timing of accreting millisecond pulsars in LMXBs. The good quality of the RXTE data allow us to obtain information on the behavior of a very fast pulsar subject to accretion torques. We find both spin-up and spin-down behaviors, from which, using ...
... 473 Page 5. and use it to observe other millisecond pulsars for contributing to the construction of pulsar time scale. ACKNOWLEDGMENTS ...
Pulsars inside binary systems can accrete matter that arrives up to the pulsar surface provided that its period is long enough. During the accretion process, matter has to be accelerated to the rotational velocity of the pulsar magnetosphere at the distance where the balance between the ...
We study accretion-induced collapse of magnetized white dwarfs as an origin of millisecond pulsars. We apply magnetized accretion disk models to the precollapse accreting magnetic white dwarfs and calculate the white dwarf spin evolution. If the pulsar magnetic field ...
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 ...
@clarence.gsfc.nasa.gov, craigm@milkyway. gsfc.nasa.gov. 483 The Astrophysical Journal, 619: 483�491, 2005 January 20 # 2005
The broadened iron lines observed from accreting compact objects are most easily interpreted in terms of reflection onto the accretion disc of the hard X-ray photons emitted by the central source. In this context, such a broadness is due to the relativistic motion of the reflecting plasma, in the deep gravitational well of the compact object, and can thus ...
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 ...
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 ...
... laboratory time from pulsars would be more easily defined if a number of pulsars with stability similar to that of the millisecond pulsar were available ...
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 ...
... Proportion to n. Pulsar VLBl for Millisecond Pulsars We plan to make VLBl experiment also for millisecond pulsar. In the ...
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 ...
The recycling model suggested that low-mass X-ray binaries (LMXBs) could evolve into binary millisecond pulsars (BMSPs). In this work, we attempt to investigate the progenitor properties of BMSPs formed by the recycling evolutionary channel, and if submillisecond pulsars can be produced by this channel. Using Eggleton's stellar ...
In this contribution we discuss how neutron stars are produced and retained in globular clusters, outlining the most important dynamical channels and evolutionary events that affect the population of mass-transferring binaries with neutron stars and result in the formation of recycled pulsars. We confirm the importance of electron-capture supernovae in globular clusters as the ...
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 ...
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 ...
PubMed
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 ...
millisecond pulsar SAX J1808.4-3658 during its 2002 outburst: evidence for a receding disc Askar Ibragimov1 2009 July 31. Received 2009 July 30; in original form 2008 December 29 ABSTRACT An outburst in the course of the outburst together with the reflection amplitude. These trends are in agreement
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 ...
... of the instabilities or "glitches" which reduce the utility of many pulsars as precise time references. Study of this millisecond pulsar therefore yields ...
... a pulsar time scale with a system using a small antenna. Descriptors : *RADIO BEAMS, *NEUTRON BEAMS, *MAGNETIC DIPOLES, *PULSARS, ...
... It concludes that an ensemble pulsar time based on a number of selected millisecond pulsars should have a fractional frequency stability close to 2 ...
... when the Earth happens to lie on the path of the beam. In 1982 the first element of a new class of pulsars, millisecond pulsars, was discovered, ...
We report the optical discovery of the companion to the 2 M sun millisecond pulsar PSR J1614�2230. The optical colors show that the 0.5 M sun companion is a 2.2 Gyr old He-CO white dwarf. We infer that \\dot{M} during the accretion phase is {<}10^{-2}\\,\\dot{M}_edd. We show that the pulsar was born with a ...
Millisecond pulsars are neutron stars that are thought to have been spun-up by mass accretion from a stellar companion. It is not known whether there is a natural brake for this process, or if it continues until the centrifugal breakup limit is reached at submillisecond periods. Many neutron stars that are ...
A brief discussion on the characteristics of pulsars is given followed by a review of millisecond pulsar discoveries including the very first, PRS B1937+21, discovered in 1982. Methods of timing millisecond pulsars and the accuracy of millisecond ...
X-ray timing of the accretion-powered pulsations during the 2003 outburst of the accreting millisecond pulsar XTE J1814-338 has revealed variation in the pulse time of arrival residuals. These can be interpreted in several ways, including spin-down and wandering of the fuel impact point around the magnetic pole. In ...
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 ...
XTE(ASM) and BATSE links to Accreting Pulsars. Last Updated: December 6, 2002 ... Undetermined Companion, Anomalous X-ray Pulsars (non-accretion objects) ...
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 ...
We report on an XMM-Newton Director Discretionary Time ToO observation of the newly discovered Accreting Millisecond Pulsar IGR J17511-3057 (ATEL #2196, #2197, #2198, #2199, and #2215) during its ongoing outburst. XMM-Newton spotted the source for 70 ks starting on 2009 Sep 21.01. The EPIC MOS1 camera, operated in Small Window mode, ...
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 ...
We show that the r-mode instability can generate strong toroidal fields in the core of accreting millisecond quark stars by inducing differential rotation. We follow the spin frequency evolution on a long time-scale, taking into account the magnetic damping rate in the evolution equations of r-modes. The maximum spin frequency of the star is only ...
In rotating neutron stars the existence of the Coriolis force allows the presence of the so-called Rossby oscillations (r-modes) which are known to be unstable to emission of gravitational waves. Here, for the first time, we introduce the magnetic damping rate in the evolution equations of r-modes. We show that r-modes can generate very strong toroidal fields in the core of ...
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 ...
Simulations of the Galactic pulsar population are reviewed. These include snapshot and time-dependent models of normal pulsars as well as binary and milli-second pulsars.
Millisecond pulsars are thought to be neutron stars that have been spun-up by accretion of matter from a binary companion. Although most are in binary systems, some 30% are solitary, and their origin is therefore mysterious. PSR J1719-1438, a 5.7 ms pulsar, was detected in a recent survey with the Parkes 64�m ...
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 ...
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 ...
Accreting millisecond X-ray pulsars like IGR J00291+5934 are important because they can be used to test theories of pulsar formation and evolution. They give also the possibility of constraining gravitational wave emission theories and the equation of state of ultra-dense matter. Particularly crucial to our ...
Millisecond pulsars have attracted attention as future reference clocks in place of present atomic clocks. The Communications Research Laboratory (CRL) has been developing an observation system to measure the pulse timing of a millisecond pulsar precisely...
National Technical Information Service (NTIS)
We review the application of millisecond pulsars to define a precise long-term time standard and positional reference system is nearly inertial reference frame. We quantify the current timing precision of the best millisecond pulsars and define the requir...
Pulsars with pulsation periods in the millisecond range are thought to be neutron stars that have acquired an extraordinarily short spin period through the accretion of stellar material spiraling down onto the neutron star from a nearby companion. Nearly all the angular momentum and most of the mass of the companion star is transferred ...
In this paper we discuss the spin equilibrium of accreting neutron stars in low-mass X-ray binaries (LMXBs). We demonstrate that, when combined with a naive spin-up torque, the observed data lead to inferred magnetic fields which are at variance with those of Galactic millisecond radio pulsars. This indicates the need for either ...
PSR J1903+0327, a millisecond pulsar in an eccentric (e= 0.44) 95-d orbit with an �1 M? companion poses a challenge to our understanding of stellar evolution in binary and multiple-star systems. Here we describe optical and radio observations which rule out most of the scenarios proposed to explain formation of this system. Radio timing measurements of ...
A neutron star in binary orbit with a low-mass non-degenerate companion becomes a source of x-rays with millisecond variability when mass accretion spins it up. Centrifugally driven changes in density profile may initiate a phase transition in a growing region of the core parallel to what may take place in an isolated millisecond ...
DOE Information Bridge
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 ...
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 ...
This grant, titled 'X-Ray Emission from Two Nearby Millisecond Pulsars,' included ROSAT observations
... of planetary companions around the nearby millisecond radio pulsar PSR B1257 ... If planetary formation is common around millisecond pulsars and if ...
... Millisecond pulsars are expected to supply a source ... Another millisecond pulsar PSR1713+07 has been ... QZS orbit projected onto the earth and the ...
... Millisecond pulsars attract attentions as a future reference clock in place of prwnt atomic clocks, by reason of their highly stable pulse timing. ...
Mar 4, 2003 ... For about 20 years astrophysicists have suspected that the most rapidly spinning neutron stars known, the millisecond radio pulsars, ...
... the discovery of the millisecond pulsar, PSR 1937 ... on frequency stability between millisecond pulsars and atomic clocks on or near the earth. ...
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 ...
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.
pho- tons scattered many times are beamed in the di- Nuclear Physics B (Proc. Suppl.) 132 (2004) 640 making an angle 50 -60o from the nor- mal. In the Comptonization process, scattering also shift photons is produced by Comptonization in a hot slab of Thomson optical depth es 1 at the neutron star surface. We
We discuss the properties of HD49798/RXJ0648.0-4418 the only known X-ray binary composed by a hot sub-dwarf and an X-ray pulsar. We recently found evidence that the pulsations are due to a very massive (1.28 Msolar), fast rotating (13 s) white dwarf. The future evolution of this post common envelope binary will involve a new phase of mass accretion through ...
... For Earth-bound clocks, this is limited to some ... Millisecond pulsars can be wed as stable clocks to ... to understanding how such a pulsar time scale ...
pulsars. Its October 2002 outburst is of particular interest because of the discovery of kilohertz quasi-periodic oscillations ...
accreting pulsar systems. These have given new insights into the processes by ... Observations of transient pulsars with BATSE and OSSE have provided ...
Binary radio pulsars are generally believed to have been spun up to millisecond periods (i.e. recycling) via mass accretion from their donor stars, and they are the descendants of neutron star low-mass X-ray binaries. However, some studies indicate that the formation of pulsars from the ...
In the absence of constraints from the binary companion or supernova remnant, the standard method for estimating pulsar ages is to infer an age from the rate of spin-down. While the generic spin-down age may give realistic estimates for normal pulsars, it can fail for pulsars with very short periods. Details of the spin-up process ...
millisecond binary pulsar challenges the standard model of pulsar formation. Pulsars are rapidly spinning with periods ranging from about 1 ms to 8 s. Of the ~1600 pulsars known in the disk of our galaxy, some 5% have pulse periods shorter than 10 ms (1). Most of these ...
Accretion-powered millisecond pulsars (AMPs) are very interesting astrophysical objects. Mat-ter from accretion disk is captured by star's magnetic field and falls along the field lines, creating "hotspots" near magnetic poles of the star. Typical spectrum of an AMP contains a disk emis-sion, blackbody emission of ...
We present a coherent timing analysis of the 2003 outburst of the accreting millisecond pulsar (AMXP) XTE J1807-294. We find a 95% confidence interval for the pulse frequency derivative of (+0.7, + 4.7) x 10{sup -14} Hz s{sup -1} and (-0.6, + 3.8) x 10{sup -14} Hz s{sup -1} for the fundamental and second harmonics, respectively. The ...
We study the statistics of 61 measured masses of neutron stars (NSs) in binary pulsar systems, including 18 double NS (DNS) systems, 26 radio pulsars (10 in our Galaxy) with white dwarf (WD) companions, 3 NSs with main-sequence companions, 13 NSs in X-ray binaries, and one undetermined system. We derive a mean value of M = 1.46 � 0.30 M?. When the 46 NSs ...
Accreting millisecond pulsars show significant variability of their pulse profiles, especially at low accretion rates. On the other hand, their X-ray spectra are remarkably similar with not much variability over the course of the outbursts. For the first time, we have discovered that during the 2008 outburst of SAX ...
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 several short ...
Globular clusters (GCs) with their ages of the order of several billion years contain many final products of evolution of stars such as: neutron stars, white dwarfs and probably also black holes. These compact objects can be at present responsible for the acceleration of particles to relativistic energies. Therefore, ?-ray emission is expected from GCs as a result of radiation processes occurring ...
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 ...
We present the results of a targeted search for radio pulsars in globular clusters, supernova remnants (SNRs) and transient X-ray sources. 85 globular clusters, 29 SNRs and three transient X-ray sources were observed in the course of the search, during which four pulsars were found. For each object searched, the sensitivity limit is given. The four new ...
Population of Rotation-powered Pulsars and Magnetars ... Normal and millisecond pulsars. - Review Emission Models, Comparison with. Observations ...
... to 15,000 light year path from the pulsar to the ... FREE ELECTRONS, RANDOM WALK, INTERSTELLAR SPACE, PULSARS, DATA ACQUISITION ...
... It is not practical to derive exact numerical values for the stability of pulsars because the pulsar timing data are actually residuals to a multi ...
We report the first detection of extreme ultraviolet (EUV) emission from a millisecond pulsar. The EUV flux is not consistent with standard models used to describe the X-ray flux from this object. The size of an EUV-emitting hot polar cap disagrees with the size derived from the X-ray data by a factor from � 3 to 25. However, a blackbody with a ...
We present a comprensive phase-coherent timing study of the most extreme accreting millisecond pulsar (AMP) XTE J1807-294 (5.2 ms spin period). This is the AMP with the strongest timing noise contamination in the post-fit timing residuals among the 10 known AMPs and shows an enigmatic linear anticorrelation between the fractional ...
SWIFT J1756.9-2508 is one of the few accreting millisecond pulsars (AMPs) discovered to date. We report here the results of our analysis of its aperiodic X-ray variability, as measured with the Rossi X-Ray Timing Explorer during the 2007 outburst of the source. We detect strong (~35%) flat-topped broadband noise throughout the outburst ...
The key contribution of the discovery of nuclear-powered pulsations from the accretion-powered millisecond pulsars (AMPs) has been the establishment of burst oscillation frequency as a reliable proxy for stellar spin rate. This has doubled the sample of rapidly-rotating accreting neutron stars and revealed the ...
The capabilities of XMM-Newton have been fully exploited to detect a broadened iron K? emission line from the 2.5 ms Accreting Millisecond Pulsar, SAX J1808.4-3658. The energy of the transition is compatible with fluorescence from neutral/lowly ionized iron. The observed large width (FWHM more than 1 keV) can be explained through ...
The evolutionary scenario of neutron star binaries is still an essential enigma in both stellar astrophysics and high energy astrophysics. In order to explore the scenario, we include the accumulation of data on the orbits and spins of compact binaries in multi-wavelength ranging from radio to X-ray, such as radio pulsar binaries, HMXBs, and LMXBs, filling them into the so ...
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 ...
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 ...
Context. PSR J1713+0747 is a binary system comprising millisecond radio pulsar with a spin period of 4.57 ms, and a low-mass white dwarf (WD) companion orbiting the pulsar with a period of 67.8 days. Using the general relativistic Shapiro delay, the masses of the WD and pulsar components were previously found to be ...
The following topics were dealt with: pulsar progenitors, pulsar/SNR associations, pulsar velocities, pulsar beam shape, magnetospheric models, radio emission models, millisecond pulsar radiation properties, gamma-ray pulsars, timing noise and glitches, ...
Astronomers have discovered a unique double-star system that represents a "missing link" stage in what they believe is the birth process of the most rapidly-spinning stars in the Universe -- millisecond pulsars. "We've thought for some time that we knew how these pulsars get 'spun up' to rotate so swiftly, and this system looks like ...
We present the results of our spectral and timing analysis of the accreting millisecond pul-sar SAX J1808.4-3658 during the peak of its 2008 outburst. The source was monitored with both Swift and Rossi X-ray Timing Explorer (RXTE) satellites from September 24th to Oc-tober 2nd. This enabled us to have broad spectral coverage (0.5-100 ...
The formation of 'photon bubbles' in a convectively stable scattering atmosphere supported against gravity entirely by radiation pressure is studied by means of linear stability theory. A simple model is developed for the 2D structure of a plasma mound formed by laminar accretion onto the magnetic poles of a neutron star, in which upward photon diffusion ...
from PSR 1257+12 suggested that there were two Earth�mass planets around this pulsar (Wolszczan & FrailImplications of the PSR 1257+12 Planetary System for Isolated Millisecond Pulsars M. Coleman Miller@astro.umd.edu,hamilton@astro.umd.edu ABSTRACT The first extrasolar planets were discovered in 1992 around the ...
Binary and Millisecond Pulsars D. R. Lorimer Max Planck Institut fur Radioastronomie, Auf dem H, Germany Abstract Our knowledge of binary and millisecond pulsars has greatly increased in re- cent years pulsars turn out to be superb celestial clocks. In this review we summarise the main ...
We propose a 100-ks XMM-Newton observation of the transiently accreting neutron star Swift J1749.4-2807 during its quiescent state. The detection of coherent pulsations at a frequency of 518 Hz and X-ray eclipses recurring every 8.82 h during an outburst observed in 2010 have recently established Swift J1749.4-2807 as the first eclipsing millisecond X-ray ...
The twelfth accretion-powered millisecond pulsar, IGR J17511-3057, was discovered in 2009 September. In this work we study its spectral and timing properties during the 2009 outburst based on Swift and RXTE data. Our spectral analysis of the source indicates only slight spectral shape evolution during the entire outburst. The ...
Therefore it is commonly referred to as "the Bursting Pulsar". The X-rays observed by RXTE come from accretion onto a pulsar with a spin period of 0.467 s ...
In this Letter we present a new analysis of the torques acting on the accreting millisecond X-ray pulsars SAX J1808.4-3658 and XTE J1814-338, and show how our results can be used to constrain theoretical models of the spin evolution. In particular, we find upper limits on any spin-up/down phase of XTE J1814-338 of |\\dot{\
In order to search for the counterpart of the recently discovered accreting millisecond pulsar IGR J17498-2921 (Atel #3551), we investigated recent near-infrared (NIR) data of the Galactic Bulge region obtained as part of the VVV survey (Minniti et al. 2010, New Astronomy, Volume 15, 433). The observations took place while the source ...
Results are presented for 10 evolutionary sequences of close binary systems of extreme mass ratio. Angular momentum loss associated with material outflow from the system, a consequence of the ineffectiveness of tidal torques, as well as gravitational radiation is included in the calculations. We find that a previously described mass transfer instability is extremely sensitive to the amount of ...
The optical counterpart of the transient, millisecond X-ray pulsar SAX J1808.4-3658 was observed in four colours (BVRI) for five weeks during the 2005 June-July outburst. The optical fluxes declined by ~2 mag during the first 16d and then commenced quasi-periodic secondary outbursts, with time-scales of several days, similar to those seen in 2000 and 2002. ...
75 Chapter 6 Discovery of a 5.9�ms Pulsar 1 6.1 Introduction The surveys described in Chapters 4 and 5 were designed to have excellent sen� sitivity to millisecond pulsars. Understanding the formation and evolution of millisecond pulsars requires a large sample of ...
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 ...
... The pulsar PSR B1257+12 is orbited by three planets, and other millisecond pulsars may be orbited by dust disks that represent planets that failed ...
We here investigate the possibility that the ultra-high-energy cosmic-ray (UHECR) events observed above the Greisen-Zatsepin-Kuzmin (GZK) limit are mostly protons accelerated in reconnection sites just above the magnetosphere of newborn millisecond pulsars that are originated by accretion-induced collapse (AIC). We formulate the ...
We present for the first time, the self-consistent solution of the two-dimensional, time-dependent equations of radiation-hydrodynamics governing the accretion of matter onto the highly magnetized polar caps of luminous x-ray pulsars. The calculations show a structure in the accretion column very different from previous one-zone ...
We report the discovery of burst oscillations at the spin frequency in ten thermonuclear bursts from the accreting millisecond X-ray pulsar (AMXP) IGR J17511-3057. The burst oscillation properties are, like those from the persistent AMXPs SAX J1808.4-3658 and XTE J1814-338, anomalous compared to burst oscillations from intermittent ...
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 X-ray binaries (LMXBs). Although many of their detailed ...
The Rossi X-ray Timing Explorer has observed a wide range of sources and is producing valuable science. Its broad-band sensitivity has been key in the observations of both compact, stellar, and nebular objects. RXTE is ideally suited for observing X-rays from both galactic and extragalactic black holes. The range of accretion rates, masses, and possibly angular momenta of ...
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 model that may be applicable to several LMXBs. According to this model, radiation from the ...
It is generally assumed that the magnetic fields of millisecond pulsars (MSPs) are �108 G. We argue that this may not be true and the fields may be appreciably greater. We present six evidences for this: (1) The �108G field estimate is based on magnetic dipole emission losses which is shown to be questionable; (2) The MSPs in low mass X-ray binaries ...
We propose a 100-ks triggered XMM observation of the accreting millisecond pulsar J1808 in its next outburst to gather strong evidence of the inner disk origin of its broad iron emission line. The accretion disk during short-outburst transients is expected to be truncated both at the inner radius (by the neutron ...
The author describes the role pulsars might play in time and frequency technology. Millisecond pulsars are rapidly rotating neutron stars: spherical flywheels some 20 km in diameter, 1.4 times as massive as the Sun, and spinning as fast as several thousand radians per second. Radio noise generated in a pulsar's ...
IAUC 4892 available at Central Bureau for Astronomical Telegrams. IAUC 4892 available at Central Bureau for Astronomical Telegrams.
The accreting millisecond pulsar XTE J1807-294 was observed as a Target of Opportunity (ToO) by XMM-Newton on March 22, 2003 after its discovery on February 21, 2003 by RXTE. The source was detected in its bright phase with an observed average count rate of 33.3 cts s-1 in the EPIC-pn camera in the 0.5-10 keV energy band (3.7 mCrab). ...
The evolution of binary systems containing weakly magnetized neutron stars can be significantly affected by the illumination of low-mass companions by x rays and, possibly, soft gamma-rays produced during accretion and post-accretion phases. A self-sustained mechanism may keep the radiation-induced mass transfer rate near the Eddington limit until the ...
We report on observations of the unusual neutron-star binary system FIRST J102347.6+003841 carried out using the XMM-Newton satellite. This system consists of a radio millisecond pulsar (PSR J1023+0038) in a 0.198 day orbit with a ~0.2 M sun Roche-lobe-filling companion and appears to have had an accretion disk in 2001. We observe a ...
We report on observations of the unusual neutron-star binary system FIRST J102347.6+003841 carried out using the XMM-Newton satellite. This system consists of a radio millisecond pulsar (PSR J1023+0038) in a 0.198 day orbit with a {approx}0.2 M{sub sun} Roche-lobe-filling companion and appears to have had an accretion disk in 2001. We ...
The radio polarization characteristics of millisecond pulsars (MSPs) differ significantly from those of non-recycled pulsars. In particular, the position angle (PA) swings of many MSPs deviate from the S-shape predicted by the rotating vector model, even after relativistic aberration is accounted for, indicating that they have ...
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 ...
Timing noise in the data on accretion-powered millisecond pulsars (AMP) appears as irregular pulse phase jumps on timescales from hours to weeks. A large systematic phase drift is also observed in the first discovered AMP SAX J1808.4 - 3658. To study the origin of these timing features, we use here the data of the well studied 2002 ...
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 ...
Recent data on low-mass X-ray binaries (LMXBs) and msec pulsars (MSPs) pose a challenge to evolutionary which neglect the effects of disk and companion irradiation. Here we discuss the main features of a radiation-driven (RD) evolutionary model that may be applicable to several LMXBs. According to this model, irradiation from the accreting compact star ...
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 triggered and one untriggered) X-ray bursts from ...
The Parkes Pulsar Timing Array project aims to make a direct detection of a gravitational wave background through the timing of millisecond pulsars. In this paper, the main requirements for that endeavour are described and recent and ongoing progress is outlined. We demonstrate that the timing properties of ...
SEARCHING FOR MILLISECOND PULSARS IN GAMMA-RAY DATA USING THE FERMI LAT A Thesis Submitted Pulsar Searches With Fermi 2 Abstract When professor Antony Hewish of Cambridge University set out of their time. The association of their discrete radio signal with a Pulsar, then only a theorized entity
Dense stellar systems such as globular clusters are known to produce many more millisecond pulsars per mass than galaxies. We have begun investigations, theoretically, into the formation and evolution of binary pulsars, and in particular millisecond pulsars. We present preliminary results of ...
A pulsar with a period of about 1.556 milliseconds has been discovered. The discovery of the pulsar has cleared up the mystery surrounding the enigmatic source, 4C21.53. An exposition of the history of the search process, results from the timing program, the pulse waveform, the distance and the origin of the pulsar ...
61 Chapter 5 Discovery of Fourteen Pulsars in Drift Surveys From Arecibo 1 5.1 Introduction with excellent, and consistent sensitivity to millisecond pulsars. This chapter reports on the completion. The most interesting result of the survey so far is the discovery of a binary, millisecond ...
An outburst of the accreting X-ray millisecond pulsar SAX J1808.4-3658 in 2002 October-November was followed by the Rossi X-ray Timing Explorer for more than a month. A detailed analysis of this unprecedented data set is presented. For the first time, we demonstrate how the area covered by the hotspot at the neutron star surface is ...
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 ...
Context. IGR J17511-3057 is the second X-ray transient accreting millisecond pulsar discovered by INTEGRAL. It was in outburst for about a month beginning on September 13, 2009. Aims: We analyze the spectral and timing properties of the object and the characteristics of X-ray bursts with the aim to constrain the physical processes ...
The radiation pressure of a radio pulsar does not necessarily disrupt a surrounding disk. The position of the inner radius of a thin disk around a neutron star, determined by the balance of stresses, can be estimated by comparing the electromagnetic energy density generated by the neutron star as a rotating magnetic dipole in vacuum with the kinetic energy density of the disk. ...
Millisecond pulsars are believed to be old pulsars spun up by a surrounding accretion disc. Magnetic fields are thought to play a leading role in this, both by determining the location of the inner edge of the disc and by exerting an additional torque on the star (as a result of the interaction between the stellar ...
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 ...
Polarization profiles are presented for 20 millisecond pulsars that are being observed as part of the Parkes Pulsar Timing Array project. The observations used the Parkes multibeam receiver with a central frequency of 1369 MHz and the Parkes digital filter bank pulsar signal-processing system PDFB2. Because of the ...
A core collapse supernova marks the death of a star over 8 times the size of the sun. Sometimes in the aftermath of these explosions a spinning, magnetized, neutron star can be left behind, also known as a pulsar. It has recently been discovered that pulsar spins can arise through a spiral spherical accretion shock instability (SASI) ...
The Fermi satellite has detected more than 600 unidentified gamma-ray sources. We know that many of these will be associated with the most energetic and fascinating radio pulsars. By selecting the gamma-ray pulsars showing pulsar-like properties we expect to discover tens of new millisecond and young, energetic ...
The Cygnus X-3 source might represent a long-period accreting pulsar, a companion to a red supergiant in a binary system with an orbital period of several years.
We report on the discovery of the second accreting millisecond X-ray pulsar (AMXP) in the globular cluster NGC 6440. Pulsations with a frequency of 205.89 Hz were detected with RXTE on 2009 August 30, October 1 and October 28, during the decays of lsim4 day outbursts of a newly X-ray transient source in NGC 6440. By studying the ...
We report on the discovery of the second accreting millisecond X-ray pulsar (AMXP) in the globular cluster NGC 6440. Pulsations with a frequency of 205.89 Hz were detected with RXTE on 2009 August 30, October 1 and October 28, during the decays of {approx}<4 day outbursts of a newly X-ray transient source in NGC 6440. By ...
, this means the fastest millisecond pulsars are visible up to 1kpc from the earth (see fig. 3). As manywith Ben Stappers We investigate the number and type of pulsars that will be discovered will find approximately 1500 new pulsars, probing the local population of pulsars to a very deep ...
Whirling away at unbelievable speeds, pulsars presented a mystery that required both imagination and precise observation to solve. In this paper, the author gives a review of pulsars from their first discovery in 1968 to today. He also discusses the star models that evolved to explain the pulsar phenomena. Included is the discovery in ...
Magnetically confined mountains on accreting neutron stars are promising sources of continuous-wave gravitational radiation and are currently the targets of directed searches with long-baseline detectors like the Laser Interferometer Gravitational Wave Observatory (LIGO). In this paper, previous ideal-magnetohydrodynamic (ideal-MHD) isothermal mountains are generalised to a ...
We propose to carry out the most ambitious and comprehensive all-sky survey for pulsars and transient sources to date. Using the 20cm multibeam and a new digital filterbank array this survey will create a petabyte digital record of the sky that can be data mined in the future and used to search for relativistic binary and millisecond ...
We report that the new X-ray transient and accretion-driven millisecond X-ray pulsar XTE J1814-338 (IAUC 8144, ATEL #164 and #165) is at a position consistent with the source EXMS B1810-337 listed in the EXOSAT medium-energy slew survey catalogue (Reynolds et al. 1999, A&AS 134, 287, Table 5). The error box of EXMS B1810-337 fully ...
HETE J1900.1-2455 is a highly peculiar accreting millisecond pulsar, as its pulses disappeared soon after the discovery of the source. Therefore, it can be viewed as a prototype of a system in between pulsating and non pulsating low mass X-ray binaries. We propose to observe it for the first time with XMM-Newton, to discriminate ...
We report a refined solution for the accreting millisecond X-ray pulsar IGR J17498-2921 (ATels #3551, #3555, #3556, #3558, #3559, #3560, #3561, #3562, #3563, #3568). Analysis is based on RXTE PCA data in the energy band 2-30 keV between 2011-08-13 and 2011-08-23, for total exposure of 121 ksec. A coherent orbit solution was found ...
We report the detection of a type I X-ray burst with burst oscillations during an RXTE-PCA observation of the recently discovered accreting millisecond pulsar (AMP) IGR J17498-2921 (ATels #3551, #3555, #3556, #3558, #3559, #3560, #3561, #3562, #3563). The burst intensity peaked on 2011-08-16 at 15:21:45 UTC. We find a rise time of ...
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. ...
We have photometrically monitored the optical transient associated with the accretion-powered millisecond pulsar IGRJ00291+5934 (ATEL352,353,354,363) during the period of December 11, 2004 - January 13, 2005, with Russian-Turkish 1.5-m optical telescope (RTT150) at Bakirlitepe (Antalya, Turkey). The R-band light curve is shown at ...
We analyzed the JEM-X light curve (3-35 keV) of the newly discovered accreting millisecond pulsar IGR J17498-2921 (ATEL #3551, #3555, #3556, #3558, #3559) in the time interval from 2011-08-11 22:45 to 2011-08-14 13:41 to look for Type I X-ray bursts. We used bins of 2 s and we searched for excesses of at least three standard ...
We will accurately measure the quiescent lightcurve of SAX J1808.4- 3658 (1808), an accreting millisecond pulsar, over 4 orbital periods in two bands. 1808 shows substantial modulation in quiescence in our previous GMOS lightcurve, which we model using the eclipsing light curve model of Orosz et al. Combined with the known orbital ...
We report on archival Chandra observations of the field containing the currently active accreting millisecond pulsar IGR J17498-2921 (ATels #3351, #3554, #3555, #3558). The observation consists of a 14.2 ks-long ACIS-I image acquired on 2006 Oct 29 23:41 - Oct 30 04:01 TT as part of the bulge Latitude Survey (Grindlay et al. 2005). ...
