Related papers: Intermittent pulsations in an accretion-powered mi…
We are reporting a discovery of X-ray pulsations from the source AX J1749.1-2733 with the period of ~132 s based on the XMM-Newton data obtained in March 2007. The observed pulse profile has a double-peaked structure with the pulse fraction…
The accreting millisecond X-ray pulsar Swift J1756.9$-$2508 went into outburst in April 2018 and June 2019, 8.7 yr after the previous activity period. We investigated the temporal, timing and spectral properties of these two outbursts using…
We report on intermittent X-ray pulsations with a frequency of 442.36 Hz from the neutron-star X-ray binary SAX J1748.9--2021 in the globular cluster NGC 6440. The pulsations were seen during both 2001 and 2005 outbursts of the source, but…
We report accretion-powered pulsations for the first time during thermonuclear bursts in hard X-rays, which were observed with Insight-HXMT in 2022 during the outburst of the accreting X-ray millisecond pulsar MAXI J1816-195. By stacking 73…
We have discovered four X-ray bursts, recorded with the Rossi X-ray Timing Explorer Proportional Counter Array between 2003 September and 2004 April, that we show to originate from the transient magnetar candidate XTE J1810-197. The burst…
We present the pulsar timing analysis of the accreting millisecond X-ray pulsar SWIFT J1749.4-2807 monitored by NICER and XMM-Newton during its latest outburst after almost eleven years of quiescence. From the coherent timing analysis of…
We report on the results obtained for the millisecond transient X-ray pulsar XTE J1807-294 in a 40 min orbital period system, based on an XMM-Newton ToO observation carried out during March 2003. The source was found at a luminosity level…
We report an analysis of Insight-HXMT observations of the newly discovered accreting millisecond pulsar SRGA J144459.2$-$604207. During the outburst, detected in 2024 February by SRG/ART-XC, the broadband persistent spectrum was well fitted…
The precise origins of the millisecond radio pulsars, discovered in the early 1980s, remain uncertain until this day. They plausibly evolve from accreting low magnetic-field neutron stars in X-ray binary systems. If so, these stars should…
We investigate the thermonuclear bursting behaviour of IGR J17473-2721, an X-ray transient that in 2008 underwent a six month long outburst, starting (unusually) with an X-ray burst. We detected a total of 57 thermonuclear bursts throughout…
A new X-ray source, XTE J1855-026, was discovered during RXTE scans along the galactic plane. The source shows pulsations at a period of 361 s and also modulation at a period of 6.1 days which we interpret as the orbital period of the…
Aims. Soft X-ray excesses have been detected in several Be/X-ray binaries and interpreted as the signature of hard X-ray reprocessing in the inner accretion disk. The system XMMU J054134.7-682550, located in the LMC, featured a giant Type…
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…
We present a timing analysis of the 2009 outburst of the accreting millisecond X-ray pulsar Swift J1756.9-2508, and a re-analysis of the 2007 outburst. The source shows a short recurrence time of only ~2 years between outbursts. Thanks to…
We report the discovery of the X-ray transient SAX J2103.5+4545 which was active from February to September 1997. The observed peak intensity of 20 mCrab (2 to 25 keV) occurred on April 11. An analysis of data obtained around the time of…
We present phase resolved optical photometry and spectroscopy of the accreting millisecond pulsar HETE J1900.1-2455. Our R-band light curves exhibit a sinusoidal modulation, at close to the orbital period, which we initially attributed to…
The fourth transient accreting millisecond pulsar XTE J1807-294 was observed during its February/March 2003 outburst by INTEGRAL, partly simultaneously with the XMM-Newton and RXTE satellites. We present here the first study of the 0.5-200…
We report on the discovery of the new accreting millisecond X-ray pulsar SRGAJ144459.2-604207 using the SRG/ART-XC data. The source was observed twice in February 2024 during the declining phase of the outburst. Timing analysis revealed a…
We present an analysis of the first high-resolution spectra measured from an accretion-driven millisecond X-ray pulsar in outburst. We observed XTE J1751-305 with XMM-Newton on 2002 April 7 for approximately 35 ksec. Using a simple absorbed…
The newly discovered 11 Hz accreting pulsar, IGR J17480-2446, located in the globular cluster Terzan 5, has shown several bursts with a recurrence time as short as few minutes. The source shows the shortest recurrence time ever observed…