Related papers: Millisecond Oscillations in X-Ray Binaries
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 in an 0.198-day orbit with a ~0.2 solar-mass…
I review some recent developments in the field of X-ray pulsars: the discovery of millisecond pulsations in the Low Mass Binary System SAX J1808.4-3658, the large number of transient Be systems discovered in the Magellanic Clouds and the…
We report the detection of 376.05 Hz (2.66 ms) coherent X-ray pulsations in NICER observations of a transient outburst of the low-mass X-ray binary IGR J17494-3030 in 2020 October/November. The system is an accreting millisecond X-ray…
In this article I will review the theory behind the gravitational wave driven r-mode instability in rapidly rotating neutron stars and discuss which constraints can be derived from observations of spins and temperatures in Low Mass X-ray…
The detection of fast quasi-periodic variability from accreting black holes and neutron stars has been used to constrain their masses, radii, and spins. If the observed oscillations are linear modes in the accretion disks, then bounds can…
Typical radio pulsars are magnetized neutron stars that are born rapidly rotating and slow down as they age on time scales of 10 to 100 million years. However, millisecond radio pulsars spin very rapidly even though many are billions of…
Numerous X-ray bursts show strong oscillations in their flux at several hundred Hz as revealed by RXTE. Analyzing one such oscillation from the X-ray binary Aql X-1, I find that low energy photons (3.5-5.7 keV) lag high energy photons (>5.7…
There is a general consensus that the frequencies of the kilohertz Quasi-Periodic Oscillations (kHz QPOs) in neutron-star low-mass X-ray binaries are directly linked to the spin of the neutron star. The root of this idea is the apparent…
There exists a special class of X-ray pulsars that exhibit very slow pulsation of $P_{\rm spin}>1000$ s in the high mass X-ray binaries (HMXBs). We have studied the temporal and spectral properties of these superslow pulsation neutron star…
Strongly magnetized, accreting neutron stars show periodic and aperiodic variability over a wide range of time scales. By obtaining spectral and timing information on these different time scales, we can have a closer look into the physics…
Several relatively bright, persistent X-ray sources display regular pulses, with periods in the range of 700-10000 s. These sources are identified with massive close binaries in which a neutron star accretes material onto its surface. The…
The discovery of high-amplitude brightness oscillations at the spin frequency or its first overtone in six neutron stars in low-mass X-ray binaries during type~1 X-ray bursts provides a powerful new way to constrain the compactness of these…
The giant flares produced by highly magnetized neutron stars, "magnetars," are the brightest sources of high energy radiation outside our solar system. Serendipitous observations with NASA's Rossi X-ray Timing Explorer (RXTE) of the two…
Transitional millisecond pulsars (tMSPs) have emerged in the last decade as a unique class of neutron stars at the crossroads between accretion- and rotation-powered phenomena. In their (sub-luminous) accretion disk state, with X-ray…
On 2025 January 10, a thermonuclear (Type I) X-ray burst from the neutron star low-mass X-ray binary \textit{4U~0614+091} was detected with the ECLAIRs instrument on board the \textit{SVOM} mission. We present here a time-resolved…
A comprehensive review of aperiodic rapid X-ray variability (QPO and noise) in X-ray binaries with neutron stars and black holes.
In latest years, the high sensitivity of the instruments on-board the XMM-Newton and Chandra satellites allowed us to explore the properties of the X-ray emission from hot subdwarf stars. The small but growing sample of X-ray detected hot…
I shall briefly review the observational properties of radio-emitting jets from Galactic X-ray binaries in relation with other wavebands: infrared, optical and X-ray. Special attention is paid to recent results obtained with the Spitzer…
Pairs of quasi-periodic oscillations (QPOs) at kilohertz frequencies are a common phenomenon in several neutron-star low-mass X-ray binaries. The frequency separation of the QPO peaks in the pair appears to be constant in many sources and…
Kilohertz Quasi-Periodic Oscillations (QPOs) have been detected in many accreting X-ray binaries. It has been suggested that the highest QPO frequencies observed in the modulation of the X-ray flux reflect a non-linear resonance between two…