Related papers: Is the high mass binary pulsar PSR J 1614-2230 a l…
The recent discovery of a 2 M_sun binary millisecond pulsar (Demorest et al. 2010) has not only important consequences for the equation-of-state of nuclear matter at high densities but also raises the interesting question if the neutron…
Magnetars are a special kind of neutron stars. There may also be accreting magnetars. From the studies of isolated magnetars, it is known that a neutron star with a strong dipole field only is not a magnetar. Super-slow X-ray pulsars may…
Millisecond pulsars are thought to be neutron stars that have been spun-up by accretion of matter from a binary companion. Although most are in binary systems, some 30% are solitary, and their origin is therefore mysterious. PSR J1719-1438,…
The low braking-index pulsar PSR J1734$-$3333 could be born with superhigh internal magnetic fields $B_{\rm in}\sim10^{15}-10^{16}$ G, and undergo a supercritical accretion soon after its formation in a supernova explosion. The buried…
The maximum mass of a neutron star has important implications across multiple research fields, including astrophysics, nuclear physics and gravitational wave astronomy. Compact binary millisecond pulsars (with orbital periods shorter than…
The formation of a $2.7\ \rm M_{\odot}$ supermassive neutron star is explored, as the possible companion of PSR J0514--4002E. Magnetars may experience super-Eddington accretion. Observationally they may manifest themselves as ultraluminous…
It is conventionally thought that the state equation of dense matter softens and thus cannot result in high maximum mass if pulsars are quark stars, and that a recently discovered $2M_\odot$ pulsar (PSR J1614-2230) may make quark stars to…
Recent measurement of a high millisecond pulsar mass (PSR J1614-2230, 1.97+-0.04 Msun) compared with the low mass of PSR J0751+1807 (1.26+-0.14 Msun) indicates a large span of masses of recycled pulsars and suggests a broad range of neutron…
If the theoretical relationship between white dwarf mass and orbital period for wide-orbit binary radio pulsars is assumed to be correct, then the neutron star mass of PSR J2019+2425 is shown to be ~1.20 M_sun. Hence the mass of the neutron…
We report on the discovery of PSR J1141-6545, a radio pulsar in an eccentric, relativistic 5-hr binary orbit. The pulsar shows no evidence for being recycled, having pulse period P = 394 ms, characteristic age tau_c = 1.4 x 10^6 yr, and…
We present observations of fields containing eight recently discovered binary millisecond pulsars using the telescopes at MDM Observatory. Optical counterparts to four of these systems are detected, one of which, PSR J2214+3000, is a novel…
PSR J1640+2224 is a binary millisecond pulsar (BMSP) with a white dwarf (WD) companion. Recent observations indicate that the WD is very likely to be a $\sim 0.7\,M_{\odot}$ CO WD. Thus the BMSP should have evolved from an intermediate-mass…
We report the discovery of PSR J1847-0130, a radio pulsar with a 6.7-s spin period, in the Parkes multibeam survey of the Galactic plane. The slowdown rate for the pulsar, 1.3x10^{-12} s/s, is high and implies a surface dipole magnetic…
The recent determination of the mass of the pulsar PSR J1614-2230 with $1.97 \pm 0.04 M_\odot$ by \cite{Demorest}, renewed the discussions about the possibility of exotic matter being present at the core of neutron stars. Since the…
Magnetars are slowly rotating, highly magnetized young neutron stars that can show transient radio phenomena for radio pulses and fast radio bursts. We conducted radio observations of from two magnetars SGR$~$J1935+2154 and…
Recent studies have shown possible connections between highly magnetized neutron stars ("magnetars"), whose X-ray emission is too bright to be powered by rotational energy, and ordinary radio pulsars. In addition to the magnetar SGR…
Situation with highly magnetized neutron stars in binary systems is not yet certain. On the one hand, all best studied magnetars seem to be isolated objects. On the other, there are many claims based on model-dependent analysis of spin…
The recent measurement of the Shapiro delay in the radio pulsar PSR J1614-2230 yielded a mass of 1.97 +/- 0.04 M_sun, making it the most massive pulsar known to date. Its mass is high enough that, even without an accompanying measurement of…
PSR J2140$-$2311B is a 13-ms pulsar discovered in 2001 in a 7.8-hour Green Bank Telescope (GBT) observation of the core-collapsed globular cluster M30 and predicted to be in a highly eccentric binary orbit. This pulsar has eluded detection…
We report the discovery of PSR J1753-2240 in the Parkes Multibeam Pulsar Survey database. This 95-ms pulsar is in an eccentric binary system with a 13.6-day orbital period. Period derivative measurements imply a characteristic age in excess…