Dec 31, 2008 ... 2) Accretion also leads to thermonuclear X-ray bursts; brief but bright flashes of thermal X-ray radiation shining through the neutron star ...
NASA Website
X-ray flashes from accreting neutron stars are considered. A number of possible explanations for the phenomenon are reviewed. A physical picture is drawn, and numerical models are discussed. 3 figures. (RWR)
Energy Citations Database
... the hard X-ray Galactic continuum could be the superposition of unresolved point sources such as accreting neutron stars or black holes. ...
DTIC Science & Technology
Jan 13, 2011 ... High-resolution X-ray spectra of bursting, accreting neutron stars show redshifted absorption lines that reveal the neutron star mass and ...
neutron stars would have important implications for nuclear and particle physics. While many of these objects are in binary systems ( X-ray binaries ), where ...
Dec 31, 2008 ... The line widths are influenced by rotation of the star via the Doppler effect. Since the spin rates of many of these accreting neutron stars ...
Jan 13, 2011 ... The neutron star surface will be probed via X-ray absorption spectroscopy: metals deposited at the surface via accretion provide spectroscopic ...
Dec 31, 2008 ... It is known from observations of burst oscillations that some of these accreting neutron stars produce an X-ray hot spot during some X-ray ...
Recent work on a unified model of accretion flows and X-ray emission in low mass X-ray binaries is summarized. In this model, a weakly magnetic neutron star accretes gas simultaneously from a Keplerian disk and a corona above the inner part of the disk. P...
National Technical Information Service (NTIS)
This paper discusses a search for the centrifugal barrier in transient X-ray pulsars with RXTE. The RXTE observation associated with this research involved monitoring the X-ray intensities and pulse profiles of six transient x-ray pulsars on five different occasions. The goal was to determine whether the so-called "centrifugal barrier" effects exists for ...
NASA Astrophysics Data System (ADS)
Rare isotopes from the proton drip line to the neutron drip line are produced on the surface and crust of accreting neutron stars. Understanding their properties is essential to address the open questions raised by a variety of new observations of X-ray binaries, in particular X-ray bursters and transients. This ...
accreting star. Roughly half the known X�ray novae contain BH candidates and the rest contain NSs. X of the accreting star. As discussed in the Introduction, the accretion rate in a typical X�ray nova spans a wide in which the compact accreting primary stars are too ...
E-print Network
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 ...
The prime scientific objectives of the Rossi X-Ray Timing Explorer (RXTE) were the study of astrophysical compact objects: black holes (galactic and extragalactic), many types of neutron stars, and accreting white dwarfs. RXTE was successful in achieving ...
The basic ideas of accretion onto magnetized neutron stars are outlined. These are applied to a simple model of the structure of the plasma mound sitting at the magnetic poles of such a star, in which upward diffusion of photons is balanced by their downw...
Jun 19, 2006 ... Long Term Intensity Variations in X-ray Binaries ... has led to a number of new insights into accretion onto magnetized neutron stars. ...
observed in the 650 - 1100 Hz range. Both QPO increased in frequency. together, maintaining a nearly constant frequency separation of about 363 Hz, ...
The basic theoretical ideas in the models of regularly pulsating X-ray sources are discussed, and put in relation to the observations. The topics covered include physics of the magnetosphere of an accreting neutron star, hydrodynamics of the accretion column, physical processes close to the surface of the ...
It is stated that as accreted material falls to the surface of a magnetized neutron star, like Cen X-3 or Her X-1, it is arrested by radiation pressure in such a manner that a hot, dense mound of nearly stationary gas protrudes above each magnetic pole. Energy released above the mound diffuses out as moderately hard x ...
The exchange of angular momentum between accreting matter and the magnetosphere of a neutron star is studied as a possible explanation for the soft X-ray emission of X-ray pulsars. The flux of soft X-radiation from Her X-1 may be related to dissipation of rotational energy of accreting matter into a layer of the ...
It is shown by Monte Carlo simulation that high-energy X-rays are produced through Compton scattering in a boundary layer of an accreting neutron star. The following is the mechanism for the high-energy X-ray production. An accreting neutron star has a boundary layer ...
X-ray bursters are considered to be neutron stars with a weak magnetic field that are undergoing disk-type accretion. If the field is weak enough, the disk will reach to the neutron star surface; next to the surface, a narrow boundary layer will develop, girdling the star. Using available formulations for ...
The accretion of low-velocity (..nu..<300km/sec) stellar wind by neutron stars could be a nonsteady process and might be responsible for such phenomena as transient x-ray sources and x-ray bursters.
ries containing weakly magnetized neutron stars, and to recently suggested models of accretion-powered emission from anomalous X-ray pulsars. ...
During the period 15 April 1997 through 15 April 2000 we have been supported in part by NASA grant NAG5-4115 to pursue a 'Search for the Centrifugal Barrier in Transient X-ray Pulsars' with the Rossi X-Ray Timing Explorer (RXTE). The RXTE observations associated with this research involved monitoring the X-ray intensities and pulse profiles of six ...
The authors examine the possibility of neutron viscosity as the mechanism responsible for the dissipation of kinetic energy into luminosity in the innermost parts (r < 100 R sub s) of accretion disks surrounding compact objects. They present simplified models of such self-consistent, steady state accretion flows in which the ...
Observations with NASA's Rossi X-ray Timing Explorer (RXTE) have shown that the X-ray flux during thermonuclear X-ray bursts from accreting neutron stars is often strongly pulsed at frequencies as high as 620 Hz. We now know that these oscillations are produced by spin modulation of the thermonuclear flux from the ...
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.
Nuclear reactions, proceeding in the crust of an accreting neutron star, produce heat a few hundred meters below star's surface. This process of deep crustal heating is important for understanding the luminosity of soft x-ray transients in quiescence. We describe different models of deep crustal heating. We show that the total heating ...
Dec 31, 2008 ... The simulated spectrum of the early phases of the X-ray bursts from the accreting neutron star EXO 0748-676 using the Constellation-X (100 ...
... Understanding of accretion disks, accretion flows, X-ray induced winds, compact obect evolution are all in a primitive state. ...
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 ...
We calculate the rapid proton ( rp) capture process of hydrogen burning on the surface of an accreting neutron star with an updated reaction network that extends up to Xe, far beyond previous work. In both steady-state nuclear burning appropriate for rapidly accreting neutron stars (such as the magnetic polar caps ...
PubMed
A final report is given of two research projects dealing with magnetic fields of neutron stars. These are the modulation of thermal x-rays from cooling neutron stars and plasma instabilities in neutron star accretion columns. (DWL)
DOE Information Bridge
A final report is given of two research projects dealing with magnetic fields of neutron stars. These are the modulation of thermal x-rays from cooling neutron stars and plasma instabilities in neutron star accretion columns. (ERA citation 12:044375)
An initial study of the evolution of a neutron star in a close-binary orbit of high eccentricity discloses a special class of systems that will never achieve a state of pure, steady accretion: the neutron star will continually oscillate between an accreting state and a propeller state. This may be what is happening ...
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 ...
We report on a Chandra Director's Discretionary Time observation of the globular cluster Terzan 5, carried out �7 weeks after the cessation of the 2010 outburst of the newly discovered transiently accreting 11-Hz X-ray pulsar. We detect a thermal spectrum that can be fitted with a neutron star atmosphere model with a temperature for ...
In late 2008, the quasi-persistent neutron star X-ray transient and eclipsing binary EXO 0748-676 started a transition from outburst to quiescence, after it had been actively accreting for more than 24 years. In a previous work, we discussed Chandra and S...
The relation between the spin period (Ps) and the orbital period (Po) in high-mass X-ray binaries is investigated. Be/X-ray binaries and SG/X-ray binaries occupy different areas in the Corbet diagram. The supergiant fast X-ray transients, IGR J18483-0311 and IGR J11215-5952, however, fall into the area occupied by Be/X-ray binaries. ...
Accreting neutron stars can produce jets only if they are weakly magnetized (B ~ 108 G). On the other hand, neutron stars are compact objects born with strong surface magnetic fields (B ~ 1012 G). In this work we study the conditions for jet formation in a binary system formed by a neutron star and a massive donor ...
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 ...
Abstract. The accretion process onto a magnetized isolated neutron star, which captures material from the interstellar medium, is discussed. The evolutionary track of such a star can be presented as a sequence of four states: ejector, supersonic propeller, subsonic propeller, andsteady accretor. Ishowthatsubsonic propeller ? accretor transition does not ...
With the help of a very simple two-zone model we deomonstrate the possiblity of periodic thermal relaxation (limit cycle) oscillations in the helium burning envelope of accreting neutron stars. Physically reasonable model parameters can be chosen which yield agreement with the observed features of X-ray bursts. We suggest that this limit cycle is operative ...
X�1 is the only neutron star x�ray nova in which we can mount a reasonable observing pro� gram of a delay between the x�ray and optical rise will allow the confirmation of the ADAF model in a neutron star with NO similar increase in accretion onto the neutron star. Given the relatively ...
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 ...
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 ...
An unusual Eddington-limited thermonuclear X-ray burst was detected from the accreting neutron star in 2S 0918-549 with the Rossi X-ray Timing Explorer. The burst commenced with a brief (40 ms) precursor and maintained near-Eddington fluxes during the initial 77 s. These characteristics are indicative of a ...
We have analyzed Rossi X-Ray Timing Explorer pointed observations of the outbursts of black hole and neutron star soft X-ray transients in which an initial low/hard state, or ``island'' state, followed by a transition to a softer state was observed. In three sources-the black hole transient XTE J1550-564, the ...
Matter swirls around the compact object in the accretion disk like water going down the drain. Because a black hole is invisible and a neutron star is so ...
Mar 25, 1998 ... This one of 12 known transient accreting X-ray pulsars with no visible companion . Pulsars - rotating neutron stars - are among the most ...
Neutron viscosity is investigated as a possible mechanism for the dissipation of kinetic energy into luminosity in the innermost parts of accretion disks around compact objects. Simplified models are presented of the self-consistent, steady-state accretion flows in which viscosity is provided by neutron collisions ...
Observations of neutron stars in low mass X-ray binaries give us an opportunity to probe nuclear physics of both proton rich and neutron rich nuclei. I will describe how observations of Type I X-ray bursts and cooling of neutron stars after long accretion outbursts ...
Accreting neutron stars provide the bulk of high luminosity X-ray sources. Decade long studies of low-mass X-ray binaries have provided a wealth of information about the various nature of X-ray emissions and proposed emission sites include the neutron star surface, an immediate boundary layer, ...
We propose to study a complete X-ray sample in the luminosity of 0.5-5 x 10^35 erg/s in the Galactic bulge, containing 10 unidentified sources detected in the ROSAT All Sky Survey. Our goal is to obtain, for the first time, a clear picture about X-ray populations in the bulge with detailed X-ray spectroscopic studies of these sources. ...
In the recent years, the discovery of a new class of Galactic transients with fast and bright flaring X-ray activity, the supergiant fast X-ray transients, has completely changed our view and comprehension of massive X-ray binaries. These objects display X-ray outbursts which are difficult to be explained in the ...
Narayan and Heyl (2002) have developed a theoretical framework to convert suitable upper limits on type I X-ray bursts from accreting black hole candidates (BHCs) into evidence for an event horizon. However, no appropriate observational limit exists in th...
Narayan and Heyl have developed a theoretical framework to convert suitable upper limits on type I X-ray bursts from accreting black hole candidates (BHCs) into evidence for an event horizon. However, no appropriate observational limit exists in the liter...
NGC 6814 shows (approx) 12,200s periodicity in ME X-ray light curve of the EXOSAT observation. Recently, it has been suggested that this behaviour is due to the gravitational lensing of a bright spot orbiting very closely around a supermassive black hole....
A triple peaked 1.24 sec. pulse profile in a 1-minute rocket borne exposure to Her X-1 was measured, in contrast to the doublepeaked profiles expected from models which maximize the X ray emission at the magnetic equator of an accreting neutron star. The ...
Matter accretion onto compact stars has been considered as a likely process of x-ray emission from stellar x-ray sources. The accreting matter forms a circumstellar envelope that absorbs a part of x rays emitted from the central star. The ionization equilibrium due to the ...
We have investigated the influence of X-ray irradiation on the vertical structure of the outer accretion disk in low-mass X-ray binaries by performing a self-consistent calculation of the vertical structure and X-ray radiation transfer in the disk. Penetrating deep into the disk, the field of scattered X-ray photons with energy E ? 10 ...
Here the reader will find a description of the current state of experimental and theoretical investigations of neutron stars in all their manifestations: radio pulsars, X-ray pulsars, X-ray bursters, transient X-ray sources, and so on. The approach adopted stresses the idea that the astrophysical properties of a ...
The self-consistency of the standard model for accreting X-ray pulsars is reexamined, using observational data on two X-ray sources, Her X-1 and 4U0115 + 63, interpreted in the context of the MHD accretion torque theory of Ghosh and Lamb (1979). Within a phenomenologically extended version of this theory, it is ...
I summarize recent work on two aspects of nuclear burning on accreting neutron stars that are particularly sensitive to the details of the rp-process: the lightcurves of Type I X-ray bursts which show long tails powered by rp-process burning, and "superbursts", which are long duration and energetic bursts powered by ignition of carbon ...
We report the detection of optical bursts during a low-amplitude, flat-topped eruption of the soft X-ray transient Aql X-1. The bursts had amplitudes between 0.17 and 0.35 mag and were variable in duration, some lasting longer than 78 s. On one night they recurred quasi-periodically at a mean interval of 1.01 hr. Regularly repeating optical bursts of this kind have not ...
arXiv:astro-ph/9802348v127Feb1998 CONSTRAINTS ON NEUTRON STAR MATTER FROM KILOHERTZ QPOs F. K. LAMB discoveries made so far with the Rossi X-Ray Timing Explorer is that many accreting neutron stars with weak upper bounds on the masses and radii of neutron stars, and important new constraints on ...
The present radio proposal is part of a multi-wavelength campaign focused on the study of the accretion/ejection process in the neutron star X-ray binary system 4U 1728-34. Our intention is to study the behaviour of the inner part of the accretion disc as inferred from the X-ray observations of the Fe emission line ...
Galactic accreting compact objects, such as stellar-mass black holes and neutron stars, can give us a unique perspective into the behavior of matter in extreme conditions. However, the exact nature of accretion onto these objects is not yet well understood. X-ray studies provide us with a means to observe the ...
Galactic accreting compact objects, such as stellar-mass black holes and neutron stars can give us a unique perspective into the behavior of matter in extreme conditions. However, the exact nature of accretion onto these objects is not yet well understood. X-ray studies provide us with a means to observe the ...
We propose to use the IRAC and MIPS camera arrays on Spitzer to establish the mid-infrared spectral energy distribution and search for evidence for jet emission contributions at Spitzer wavelengths for three Z sources: GX 349+2, GX 17+2, and Cyg X-2. These neutron star X-ray binaries are the brightest X-ray sources in the Galaxy and ...
A neutron star high mass X-ray binary (HMXB) is a system consisting of a neutron star and a massive O- or B-type companion star. OB stars, which are young giant stars, have powerful stellar winds and are spreading a fraction of their mass continuously. As the neutron star revolves around the companion star, it ...
We report the detection of 15 X-ray bursts with RXTE and Swift observations of the peculiar X-ray binary Circinus X-1 (Cir X-1) during its 2010 May X-ray re-brightening. These are the first X-ray bursts observed from the source after the initial discovery by Tennant and collaborators, 25 years ago. By studying ...
The Energetic X-ray Imaging Survey Telescope (EXIST) is a proposed NASA mission for scanning the entire sky in intermediate and hard X-rays. The EXIST mission includes a wide field of view High Energy Telescope (HET) covering the 5-600 keV energy range, and an infrared telescope. The HET has the capability to measure the energy dependent ...
Anomalous X-ray pulsars (AXPs) are a class of rare X-ray emitting pulsars whose energy source has been perplexing for some 20 years. Unlike other X-ray emitting pulsars, AXPs cannot be powered by rotational energy or by accretion of matter from a binary companion star, hence the designation 'anomalous'. Many of the ...
Several neutron stars associated with the accretion-powered long-period X-ray pulsars are observed to experience rapid spin-down years-long trends. Modeling of these trends in terms of the canonical spin-down scenario for accretionpowered compact stars in close binaries suggests that the surface field of these ...
... Title : X-RAY AND NEUTRON DIFFRACTION STUDIES OF ZEOLITE INCLUSION COMPLEXES AND OTHER SUBSTANCES. ...
... Accession Number : ADD301170. Title : NEUTRON RADIOGRAPHY COMPLEMENTS X-RAY. Corporate Author : Personal ...
... Accession Number : ADD305820. Title : LASER PRODUCED X-RAYS, NEUTRONS AND ULTRASOUND. Corporate Author : ...
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 pressure of matter and the magnetic field is achieved. At this ...
intense short bursts of x rays and neutrons might have applica- .... negative, x rays and neutrons were detected, but the intensities ...
... Descriptors : *X RAY FLASH, *DOSIMETRY, *NEUTRON FLUX, X RAYS, DOSAGE, GAMMA RAYS, DOSE RATE, NEUTRONS, RADIATION ...
Systematic multi-wavelength studies of neutron stars (NSs) have shown a jet and disk-jet coupling phenomenology which resembles, although with some important differences, that observed in black holes; ultra-relativistic transient ejection, steady compact jets, accretion-ejection cycles are indeed observed in NSs. I will review our observational knowledge ...
The basic ideas of accretion onto magnetized neutron stars are outlined. These are applied to a simple model of the structure of the plasma mound sitting at the magnetic poles of such as star, in which upward diffusion of photons is balanced by their downward advection. This steady flow model of the plasma's dynamical state is used to compute the ...
The basic ideas of accretion onto magnetized neutron stars are outlined. These are applied to a simple model of the structure of the plasma mound sitting at the magnetic poles of such as star, in which upward diffusion of photons is balanced by their downward advection. This steady flow model of the plasma`s dynamical state is used to compute the emission ...
In many X-ray point sources on the sky, the X-ray emission arises because hydrogen and/or helium is accreted onto a neutron star from a nearby donor star. When this matter settles on the neutron star surface, it will undergo nuclear fusion. For a large range of physical parameters the fusion is unstable. The ...
Rossi X-Ray Timing Explorer (RXTE) All-Sky Monitor observations of the X-ray source 4U 2206+54, previously proposed to be a Be star system, show the X-ray flux to be modulated with a period of approximately 9.6 days. If the modulation is due to orbital variability, then this would be one of the shortest orbital periods known for a Be star X-ray source. ...
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 sho...
Accretion from a disk onto a collapsed, relativistic star--a neutron star or black hole--is the mechanism widely believed to be responsible for the emission from compact X-ray binaries. Because of the extreme spatial resolution required, is not yet possib...
Analytical consideration is given to the comptonization of photons and its effects on the radiation emitted from accretion disks of compact X-ray sources, such as black holes and neutron stars. Attention is given to the photon distribution during escape from the disk, the angular distribution of hard radiation from the disk, the ...
We have constructed the first detailed numerical models of X-ray bursts resulting from thermonuclear flashes near the surface of an accreting neutron star. The models assume a nonrotating, nonmagnetized, spherically accreting neutron star of mass 1.4 M/sub sun/, radius 6.6 km, core temperature in the range ...
Quasi-periodic oscillations (QPOs) at frequencies near 1000 Hz have been detected from a number of neutron star x-ray binaries using RXTE. These fast oscillations are likely associated with orbital motion very close to the neutron star and and, thus, give us information about the behavior of the accretion disk in ...
A tiny neutron star orbits incessantly around a massive star with a diameter a million times larger than its own. The high luminosity of the massive star drives a strong wind from its surface. The neutron star crashes through this wind at over 300 kilometers per second. The gravity and X-ray luminosity of the neutron star act to ...
NSDL National Science Digital Library
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 bursters form a class of Low Mass X-Ray Binaries where accreted material from a donor star undergoes rapid thermonuclear burning in the surface layers of a neutron star. The flux released can temporarily exceed the Eddington limit and drive the photosphere to large radii. Such photospheric radius expansion ...
Quiescent X-ray emission from the neutron star low-mass X-ray binaries is seen to be variable on timescales as short as hundreds of seconds and as long as years. Yet, this variability is not understood. Our recent studies of the systems Cen X-4 and Aql X-1 have shown that the thermal component is variable. This poses a serious problem ...
A continuous monitoring of the neutron star spin period in Her X-1 and its X-ray luminosity performed with Swift/BAT over the last five years revealed unexpected behavior of the pulsar that appears to switch between two different regimes of the angular momentum exchange between the neutron star and accretion disc. ...
We calculate the accretion disc temperature profiles, disc luminosities and boundary layer luminosities for rapidly rotating neutron stars considering the full effect of general relativity. We compare the theoretical values of these quantities with their values inferred from EXOSAT data for four low mass X-ray binary sources: XB ...
We present the results of the long-term hard X-ray monitoring of the high-mass X-ray binary 2S 0114+65 with INTEGRAL/IBIS from 2003 to 2008. 2S 0114+65 is a variable hard X-ray source with X-ray luminosities of 1035-4 � 1036 erg s-1 from 20 to 100 keV due to accretion rate changes in different orbital phases. In ...
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 pulsars. However, unfortunately in these studies ...
A theory of polarization of X rays emitted by magnetized neutron stars, white dwarfs and black hole accretion disks is presented and predictions are compared with polarimetric data. Polarization occurs in accreting neutron stars and white dwarfs in binary systems as plasma ...
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 ...
Quasi-periodic oscillations (QPOs) at frequencies near 1000 Hz have been detected from a umber of neutron star x-ray binaries using RXTE. These fast oscillations are likely associated with rbital motion very close to the neutron star and and, thus, give us information about the behavior of the accretion disk in the ...
Observations of neutron stars and their environments, and the emission and absorption of iron, obtained with the Hakucho and Tenma satellites, are examined. The characteristics of X-ray bursts, neutron stars, and accretion disks, in particular spectra, color and effective temperatures, blackbody temperature and radius, the emissivity ...
The present conference considers topics in the fields of rotation-powered pulsars, the relationship of pulsars to SNRs, accretion-powered pulsars, neutron-star formation in theoretical SNs, neutrol stellar evolution, neutron star physics, and other manifestations of neutron stars and their place in ...
The past twelve years have seen the discovery, with NASA's Rossi X-ray Timing Explorer (RXTE), of several long-predicted phenomena associated with the accretion of matter onto a neutron star in a binary (double) star system. These phenomena are observed in the strong X-ray emission produced by these ...
We have followed the thermonuclear runaways which develop in the hydrogen-rich envelopes of 0.476 and 1.41 M/sub sun/ neutron stars. Variations in the neutron star luminosity, CNO abundance of the accreted material, and mass accretion rate have been explored. In all cases, the thermonuclear shell flash led to high ...
Galactic stellar-population-synthesis models, chemical-enrichment models, and possibly gravitational microlensing indicate that about Ntot=108-109 stellar-mass black holes reside in our Galaxy. We study X-ray emission from accretion from the interstellar medium on to isolated black holes. Although black holes may be fewer in number than ...
