Related papers: The $\textit{False Widow}$ Link Between Neutron St…
We compare the rotation rate of neutron stars in low-mass X-ray binaries (LMXBs) with the orbital period of the binaries. We find that, while short orbital period LMXBs span a range of neutron star rotation rates, all the long period LMXBs…
Redback and black widow pulsars are two classes of peculiar binary systems characterized by very short orbital periods, very low mass companions, and, in several cases, regular eclipses in their pulsed radio signal. Long-term timing…
In the absence of constraints from the binary companion or supernova remnant, the standard method for estimating pulsar ages is to infer an age from the rate of spin-down. While the generic spin-down age may give realistic estimates for…
A spinning neutron star (NS) that is asymmetric with respect to its spin axis can emit continuous gravitational wave (GW) signals. The spin frequencies and their distribution of radio millisecond pulsars (MSPs) and accreting MSPs provide…
We present the first measurement of a non-zero magnetic field in the eclipsing material of a black widow pulsar. Black widows are millisecond pulsars which are ablating their companions; therefore they are often proposed as one potential…
High-mass X-ray binaries (HMXBs) represent an important phase in the evolution of massive binary systems. HMXBs provide unique diagnostics to test massive-star evolution, to probe the physics of radiation-driven winds, to study the process…
Low-mass X-ray binaries (LMXBs) with neutron stars show quite different features which depend on the rate of mass transfer from the donor star. With a high transfer rate the Z sources are in a persistent soft spectral state, with a moderate…
Low energy X-ray emission (0.1-10 keV) from all six millisecond radio pulsars (MSPs) for which such emission has been reported support a proposed pulsar magnetic field evolution previously compared only to radiopulse data: old, very…
Most X-ray pulsars in high-mass X-ray binary (HMXB) systems exhibit both global and local trends of spin acceleration (spin-up) and deceleration (spin-down). Moreover, decades-long monitored objects display even more general spin-up trends…
We report on the discovery of gamma-ray pulsations from five millisecond pulsars (MSPs) using the Fermi Large Area Telescope (LAT) and timing ephemerides provided by various radio observatories. We also present confirmation of the gamma-ray…
We present the results of a systematic study of the evolution of low- and intermediate-mass X-ray binaries (LMXBs and IMXBs). Using a standard Henyey-type stellar-evolution code and a standard model for binary interactions, we have…
Multiwavelength followup of unidentified Fermi sources has vastly expanded the number of known galactic-field "black widow" and "redback" millisecond pulsar binaries. Focusing on their rotation-powered state, we interpret the radio to X-ray…
Binary millisecond pulsars (MSPs) provide several opportunities for research of fundamental physics. However, finding them can be challenging. Several subdwarf B (sdB) binary systems with possible neutron star companions have been…
Millisecond pulsars represent an evolutionarily distinct group among rotation-powered pulsars. Outside the radio band, the soft X-ray range ($\sim 0.1$--10 keV) is most suitable for studying radiative mechanisms operating in these…
Neutron stars spin down over time due to a number of energy-loss processes. We provide tantalizing population-based evidence that millisecond pulsars (MSPs) have a minimum ellipticity of $\epsilon\approx10^{-9}$ around their spin axis and…
PSR J1306--40 is a millisecond pulsar binary with a non-degenerate companion in an unusually long $\sim$1.097 day orbit. We present new optical photometry and spectroscopy of this system, and model these data to constrain fundamental…
Transitional millisecond pulsars (tMSPs) are neutron-star systems that alternate between a rotation-powered radio millisecond pulsar state and an accretion-disk-dominated low-mass X-ray binary (LMXB)-like state on multi-year timescales.…
The Fermi Gamma-ray Space Telescope has revolutionized our knowledge of the gamma-ray pulsar population, leading to the discovery of almost 100 gamma-ray pulsars and dozens of gamma-ray millisecond pulsars (MSPs). Although the outer-gap…
We present the timing solution for the 5.31-ms spider millisecond pulsar (MSP) J1242-4712, discovered with the GMRT. PSR J1242-4712 orbits a companion of minimum mass 0.08 M$_{\odot}$ with an orbital period of 7.7 hrs and occupies a…
The coalescence of binary neutron stars (NSs) may in some cases produce a stable massive NS remnant rather than a black hole. Due to the substantial angular momentum from the binary, such a remnant is born rapidly rotating and likely…