Related papers: How rapidly do neutron stars spin at birth?
NGC 4631 X-8 is an ultraluminous X-ray pulsar (ULXP) having a spin period of about 9.7 s, discovered using XMM-Newton observations in 2025. The pulsar is known to show one of the largest spin-up rates ($\sim -9.6 \times 10^{-8}$ s s$^{-1}$)…
For about half a century the radio pulsar population was observed to spin in the ~0.002-12s range, with different pulsar classes having a spin-period evolution that differs substantially depending on their magnetic fields or past accretion…
The birth mass function of neutron stars encodes rich information about supernova explosions, double star evolution, and properties of matter under extreme conditions. To date, it has remained poorly constrained by observations, however.…
Recently the first finding of a spin period of an accreting neutron star in M31 is reported. The observed spin period is 1.2 s and it shows 1.27 d modulations due to orbital motion. From the orbital information, the mass donor could not be…
We suggest that neutron stars experienced at birth three related physical changes, which may originate in magneto-rotational instabilities: (i) an increase in period from the initial value P_0 to the current value P_s, implying a change of…
We report the discovery of an X-ray pulsar in the young, massive Galactic star cluster Westerlund 1. We detected a coherent signal from the brightest X-ray source in the cluster, CXO J164710.2-455216, during two Chandra observations on 2005…
X-ray surveys allow to identify young, main-sequence stars in the solar neighborhood. Young, stellar samples, selected according to their activity, can be used to determine the stellar birthrate in the last billion years. The ROSAT North…
It is argued that the superfluid core of a neutron star super-rotates relative to the crust, because stratification prevents the core from responding to the electromagnetic braking torque, until the relevant dissipative (viscous or…
Bright, ultracompact X-ray binaries observed in dense star clusters, such as Galactic globular clusters, must have formed relatively recently, since their lifetimes as persistent bright sources are short (e.g., ~10^8 yr above 10^36 erg/s…
The internal-plateau X-ray emission of gamma-ray bursts (GRBs) indicates that a newly born magnetar could be the central object of some GRBs. The observed luminosity and duration of the plateaus suggest that, for such a magnetar, a rapid…
The newly discovered Be/X-ray binary in the Small Magellanic Cloud, SXP 1062, provides the first example of a robust association with a supernova remnant (SNR). The short age estimated for the SNR qualifies SXP 1062 as the youngest known…
This paper presents a detailed investigation of the dependence of pulsar spin-velocity alignment, which has been observed for a sample of 58 pulsars, on pulsar age. At first, our study considers only pulsar characteristic ages, resulting in…
The evolution of neutron stars in close binary systems with a low-mass companion is considered assuming the magnetic field to be confined within the solid crust. We adopt the standard scenario of the evolution in a close binary system in…
Young massive stars in compact stellar clusters could end their evolution as core-collapse supernovae a few million years after the cluster was built. The blast wave of a supernova propagates through the inner cluster region with multiple…
During the search for counterparts of very-high-energy gamma-ray sources, we serendipitously discovered large, extended, low surface brightness emission from PWNe around pulsars with the ages up to ~100 kyrs, a discovery made possible by…
The NuSTAR experiment detected a hard X-ray emission (10-70 keV) with a period of 8.68917 s and a pulse-phase modulation at 55 ks, or half this value, from the anomalous X-ray pulsar (AXP) 4U 0142+61. It is shown here that this evidence is…
Recent proper motion and parallax measurements for the pulsar PSR B1508+55 indicate a transverse velocity of ~1100 km/s, which exceeds earlier measurements for any neutron star. The spin-down characteristics of PSR B1508+55 are typical for…
The acceleration of ultrahigh energy nuclei in fast spinning newborn pulsars can explain the observed spectrum of ultrahigh energy cosmic rays and the trend towards heavier nuclei for energies above $10^{19}\,$eV as reported by the Auger…
The origin and fate of magnetars (young, extremely magnetized neutron stars, NSs) remain unsolved. Probing their evolution is therefore crucial for investigating possible links to other species of isolated NSs, such as the X-ray dim NSs…
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,…