Formation of the binary pulsars J1141-6545 and B2023+46

We have performed detailed numerical calculations of the non-conservative evolution of close X-ray binary systems with intermediate-mass (2.0-6.0 M_sun) donor stars and a 1.3 M_sun accreting neutron star. We calculated the thermal response of the donor star to mass loss, in order to determine its stability and follow the evolution of the mass transfer. Under the assumption of the "isotropic re-emission model" we demonstrate that in many cases it is possible for the binary to ...

We study the evolution of close binary systems in order to account for the existence of the recently observed binary system containing the most massive millisecond pulsar ever detected, PSR J0740+6620, and its ultra-cool helium white dwarf companion. In order to find a progenitor for this object we compute the evolution of several binary systems composed by a neutron star and a normal donor star employing our stellar code. We assume conservative mass transfer. We also explore...

The most recent member of the millisecond pulsar with very low-mass companions and short orbital periods class, PSR J1311-3430 (Pletsch et al. 2012) is a remarkable object in various senses. Besides being the first discovered in gamma-rays, its measured features include the very low or absent hydrogen content. We show in this Letter that this important piece of information leads to a very restricted range of initial periods for a given donor mass. For that purpose, we calcula...

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 X-ray binary (IMXB). However, previous investigations on IMXB evolution predict that the orbital periods of the resultant BMSPs are generally $<40$ days, in contrast with the 175 day orbital period of PSR J1640+2224. In this paper, we expl...

(abridged) PSR J1903+0327, a millisecond pulsar in an eccentric (e = 0.44) 95-day orbit with a (~ 1Msun) companion poses a challenge to our understanding of stellar evolution in binary and multiple-star systems. Here we describe optical and radio observations which rule out most of the scenarios proposed to explain formation of this system. Radio timing measurements of three post-Keplerian effects yield the most precise measurement of the mass of a millisecond pulsar to date:...

We have performed detailed numerical calculations of the non-conservative evolution of close binary systems with low-mass (1.0-2.0 M_sun) donor stars and a 1.3 M_sun accreting neutron star. Rather than using analytical expressions for simple polytropes, we calculated the thermal response of the donor star to mass loss, in order to determine the stability and follow the evolution of the mass transfer. Tidal spin-orbit interactions and Reimers wind mass-loss were also taken int...

The recent mass measurements of two binary millisecond pulsars, PSR J1614-2230 and PSR J0751+1807 with a mass M=1.97+/-0.04 Msun and M= 1.26 +/- 0.14 Msun, respectively, indicate a wide range of masses for such objects and possibly also a broad spectrum of masses of neutron stars born in core-collapse supernovae. Starting from the zero-age main sequence binary stage, we aim at inferring the birth masses of PSR J1614-2230 and PSR J0751+1807 by taking the differences in the e...

Pulsars in close, eccentric binary systems are usually assumed to have another neutron star as a companion. These double neutron star binaries have proven to be the best laboratories for experimental General Relativity and are the most secure candidates for gravitational wave interferometers. We present deep B, V, and R images of the field containing the eccentric binary pulsar system PSR B2303+46. We find a faint, blue object (B=26.60+/-0.09; (B-R)_0=-0.4+/-0.2) coincident w...

We report on radio timing observations of PSR J0210+5845 which reveal large deviations from typical pulsar spin-down behaviour. We interpret these deviations as being due to binary motion around the $V=13.5$ star 2MASS J02105640$+$5845176, which is coincident in celestial position and distance with the pulsar. Archival observations and new optical spectroscopy identify this star as a B6V star with a temperature of $T_\mathrm{eff}\approx 14\,000$K and a mass of $M_\mathrm{c}= ...

We find that the orbital period (2.4 hours), eccentricity (0.09), dipole magnetic field strength (6.9 x 10^9 Gauss) and spin period (22 ms) of the new highly relativistic double neutron star system PSR J0737-3039 can all be consistently explained if this system originated from a close helium star plus neutron star binary (HeS-NS) in which at the onset of the evolution the helium star had a mass in the range 4.0 to 6.5 M_sun and an orbital period in the range 0.1 to 0.2 days. ...