Related papers: Contrasting behaviour from two Be/X-ray binary pul…

Millisecond radio pulsars are neutron stars that have been spun-up by the transfer of angular momentum during the low-mass X-ray binary phase. The transition from an accretion-powered to a rotation-powered pulsar takes place on evolutionary…

We present broadband X-ray observations of the High Mass X-ray Binary (HMXB) pulsar SMC X-2, using concurrent NuSTAR and NICER observations during its 2022 outburst. The source is found to be spinning with a period of 2.37281(3) s. We…

We report the serendipitous detection of a previously unreported pulsar from the direction of the Small Magellanic Cloud using data from the CHANDRA X-Ray Observatory. Because of the luminosity of about 1.5x10^35 ergs/s, its near lack of…

The relativistic double neutron star binary PSR J0737-3039 shows clear evidence of orbital phase-dependent wind-companion interaction, both in radio and X-rays. In this paper we present the results of timing analysis of PSR J0737-3039…

IGR J00370+6122 is a high-mass X-ray binary, of which the primary is a B1 Ib star, whereas the companion is suggested to be a neutron star by the detection of 346-s pulsation in one-off 4-ks observation. To better understand the nature of…

We are undertaking an extensive X-ray monitoring campaign of the two Crab-like pulsars in the Large Magellanic Clouds, PSR B0540-69 and PSR J0537-6910. We present our current phase-connected timing analysis derived from a set of 50 pointed…

X-ray pulsars (XRPs) consist of a magnetized neutron star (NS) and an optical donor star. The NS accretes matter from the donor star producing pulsed X-ray emission. In most cases the donor stars are Be stars, and accretion is episodic,…

Spectroscopic observations taken with the VLT/UVES telescope/instrument are presented of the unusual Small Magellanic Cloud (SMC) X-ray binary system SXP 323 = AX J0051-733. This system shows a clear modulation at 0.71d in long term optical…

We report on the detection of X-ray pulsations at 2.1 ms from the known X-ray burster IGR J17379-3747 using XMM-Newton. The coherent signal shows a clear Doppler modulation from which we estimate an orbital period of ~1.9 hours and a…

We report the discovery of a new X-ray pulsar, XTE J1810-197. The source was serendipitously discovered on 2003 July 15 by the Rossi X-ray Timing Explorer (RXTE) while observing the soft gamma repeater SGR 1806-20. The pulsar has a 5.54 s…

A scenario of the formation of isolated X-ray pulsars is discussed with an application to one of the best studied objects of this class 1E 161348-5055. This moderately luminous, 10^33 - 10^35 erg/s, pulsar with a relatively soft spectrum,…

The double pulsar system PSR J0737-3039A/B is a double neutron star binary, with a 2.4-hour orbital period, which has allowed measurement of relativistic orbital perturbations to high precision. The low mass of the second-formed neutron…

We made 22 observations on the Small Magellanic Cloud (SMC) and covered full regions by the end of the ASCA mission. We detected 106 discrete sources with a criterion of S/N > 5 and performed systematic analyses on all of the sources. We…

Many X-ray accreting pulsars have a soft excess below 10 keV. This feature has been detected also in faint sources and at low luminosity levels, suggesting that it is an ubiquitous phenomenon. In the case of the high luminosity pulsars (Lx…

We report the discovery with XMM-Newton of 3-s X-ray pulsations from 3XMM J004232.1+411314, a dipping source that dominates the hard X-ray emission of M31. This finding unambiguously assesses the neutron star (NS) nature of the compact…

Rossi X-ray Timing Explorer (RXTE) All-Sky Monitor (ASM) observations of the X-ray binary 2S0114+650 show modulations at periods close to both the optically derived orbital period (11.591 days) and proposed pulse period (~ 2.7 hr). The…

A search for pulsations from the Be X-ray binary SAX J2239.3+6116, through observations with the Narrow Field Instruments on BeppoSAX and the Proportional Counter Array on RXTE, yielded the clear presence of a 1247 s coherent oscillation.…

I review the rotation measurements of accreting neutron stars. Many of the highly magnetic accreting X-ray pulsars have been continuously observed with the Burst and Transient Source Experiment (BATSE) aboard the Compton Gamma-Ray…

Periodic pulsations have been found in emission from the ultra-luminous X-ray source (ULX) M82 X-2, strongly suggesting that the emitter is a rotating neutron star rather than a black hole. However, the radiation mechanisms and accretion…

It has been reported that there are two populations of Be/X-ray pulsars, with the pulse period distribution peaked at $\sim$ 10 s and $\sim$ 200 s, respectively. A possible explanation of this bimodal distribution is related to different…