Related papers: Intermittent pulsations in an accretion-powered mi…

Swift J1749.4-2807 is the only known eclipsing accreting millisecond X-ray pulsar. In this paper, we report on 7 thermonuclear (Type-I) X-ray bursts observed by NICER during its 2021 outburst. The first 6 bursts show slow rises and long…

NICER observed several rotation-powered millisecond pulsars to search for or confirm the presence of X-ray pulsations. When broad and sine-like, these pulsations may indicate thermal emission from hot polar caps at the magnetic poles on the…

A new pulsating X-ray source, AX J183220-0840, with a 1549.1-s period was discovered at R.A.= 18h32m20s and Dec.=-8d40'30'' (J2000, uncertainty=0.6degree) during an ASCA observation on the Galactic plane. The source was observed two times,…

We present radio coverage of the 2019 outburst of the accreting millisecond X-ray pulsar SAX J1808.4-3658, obtained with MeerKAT. We compare these data to contemporaneous X-ray and optical measurements in order to investigate the coupling…

We report the discovery of several new pulses from the source ASKAP J175534.9-252749.1 (J1755-2527), originally identified from a single 2-min long pulse, confirming it as a long period transient (LPT) with a period of ~1.16 hours. The…

Anomalous X-ray pulsars (AXPs) are slowly rotating neutron stars with very bright and highly variable X-ray emission that are believed to be powered by ultra-strong magnetic fields of >1e14 G, according to the 'magnetar' model. The radio…

We report on the phase-coherent timing analysis of the accreting millisecond X-ray pulsar IGR J17591-2342, using Neutron Star Interior Composition Explorer (NICER) data taken during the outburst of the source between 2018 August 15 and 2018…

We report on the broadband spectral and timing properties of the accreting millisecond X-ray pulsar IGR J17498$-$2921 during its April 2023 outburst using data from NICER (1$-$10 keV), NuSTAR (3$-$79 keV), Insight-HXMT (2$-$150 keV), and…

We report on the highly variable and erratic long-term X-ray luminosity behavior of the only known accretion-driven millisecond X-ray pulsar SAX J1808.4-3658 during its 2000 outburst, as observed with RXTE. The maximum observed luminosity…

In this work we report on observations with the Neutron Star Interior Composition Explorer of the known neutron star X-ray transient XTE J1739-285. We observed the source in 2020 February and March, finding it in a highly active bursting…

MAXI J1807+132 is a low-mass X-ray binary (LMXB) first detected in outburst in 2017. Observations during the 2017 outburst did not allow for an unambiguous identification of the nature of the compact object. MAXI J1807+132 was detected in…

We studied the aperiodic X-ray timing behaviour of the accreting millisecond pulsar SAX J1808.4-3658. The source was recently found to be the first accreting millisecond pulsar that shows the kilohertz quasi-periodic oscillations (kilohertz…

We discuss candidates for non-radial modes excited in a mass accreting and rapidly rotating neutron star to explain the coherent frequency identified in the light curves of a millisecond X-ray pulsar XTE J1751-305. The spin frequency of the…

The accreting millisecond pulsar XTE J1814-338 exhibits oscillations at the known spin frequency during Type I X-ray bursts. The properties of the burst oscillations reflect the nature of the thermal asymmetry on the stellar surface. We…

Millisecond spinning, low magnetic field neutron stars are believed to attain their fast rotation in a 0.1-1 Gyr-long phase during which they accrete matter endowed with angular momentum from a low-mass companion star. Despite extensive…

We present RXTE observations of two recently identified massive X-ray binaries. RX J0440.9+4431/BSD 24-491 and RX J1037.5-564/LS 1698 are confirmed as accreting Be/X-ray systems following the discovery of X-ray pulsations, with barycentric…

We report on the detection of a 400.99018734(1) Hz coherent signal in the Rossi X-ray Timing Explorer light curves of the recently discovered X-ray transient, IGR J17498-2921. By analysing the frequency modulation caused by the orbital…

Until now X-radiation from nine millisecond pulsars has been detected. In the present paper we summarize the observations and show the results of a re-analysis of archival ROSAT data. In addition we present the results of recent…

We report on an XMM-Newton observation of the accreting millisecond pulsar, IGR J17511-3057. Pulsations at 244.8339512(1) Hz are observed with an RMS pulsed fraction of 14.4(3)%. A precise solution for the P_orb=12487.51(2)s binary system…

We introduce a new method for analysing the aperiodic variability of coherent pulsations in accreting millisecond X-ray pulsars. Our method involves applying a complex frequency correction to the time-domain light curve, allowing for the…