Related papers: Constraining Brans-Dicke Gravity with Millisecond …
The ultra-compact Low Mass X-ray Binary (LMXB) X1916-053, composed of a neutron star and a semi-degenerated white dwarf, exhibits periodic X-ray dips with variable width and depth. We have developed new methods to parameterize the dip to…
The ultra-compact dipping source \object{XB 1916-053} has an orbital period of close to 50 min and a companion star with a very low mass (less than 0.1 M$_{\odot}$). The orbital period derivative of the source was estimated to be $1.5(3)…
We review the current observational status of the ROSAT sources RX J1914.4+2456 and RX J0806.3+1527, and the evidence that these are ultra-short period (<10min) binary systems. We argue that an Intermediate Polar interpretation can be ruled…
As presented by Nice et al. (2000), long-term timing of the eclipsing binary PSR B1744-24A shows that the orbital period of this system decreases with a time-scale of only ~ 200 Myr. To explain the much faster orbital period decay than that…
Ultra-compact X-ray binaries (UCXBs) are low-mass X-ray binaries with ultra-short orbital periods (usually less than 1 hour) and hydrogen-poor donor stars, which are proposed to be the potential LISA sources. In this work, we firstly employ…
The couplings between supermassive black-hole binaries and their environments within galactic nuclei have been well studied as part of the search for solutions to the final parsec problem. The scattering of stars by the binary or the…
Intermediate/Extreme mass ratio inspiral (I/EMRI) system provides a good tool to test the nature of gravity in strong field. Based on the method of osculating orbits, we compute the orbital evolutions of I/EMRIs on quasi-elliptic orbits in…
I describe a computationally simple, efficient, and sensitive method to search long observations for pulsars in binary systems. The technique looks for orbitally induced sidebands in the power spectrum around a nominal spin frequency,…
We present the latest developments to the phase modulation method for finding binaries among pulsating stars. We demonstrate how the orbital elements of a pulsating binary star can be obtained analytically, that is, without converting time…
It is thought that neutron stars in low-mass binary systems can accrete matter and angular momentum from the companion star and be spun-up to millisecond rotational periods. During the accretion stage, the system is called a low-mass X-ray…
We have carried out high-precision timing measurements of the binary millisecond pulsar PSR J2051$-$0827 with the Effelsberg 100-m radio telescope of the Max-Planck-Institut f\"ur Radioastronomie and with the Lovell 76-m radio telescope at…
The detection of pulsations from an X-ray binary is an unambiguous signature of the presence of a neutron star in the system. When the pulsations are missed in the radio band, their detection at other wavelengths, like X-ray or gamma-rays,…
We revisit the decay of the orbital period in binary systems that occurs due to the emission of gravitational waves in the context of modified gravity models where the coupling $G_{gw}$ between matter and on-shell gravitons is allowed to…
Radio pulsars with millisecond spin periods are thought to have been spun up by transfer of matter and angular momentum from a low-mass companion star during an X-ray-emitting phase. The spin periods of the neutron stars in several such…
Dipole-radiation-like deviations from general relativity are most prominent during the early inspiral of compact binaries, making space-ground multiband observations a potential probe of such effects. In the same regime, orbital…
Millisecond and binary pulsars are the most stable natural frequency standards which admits to introduce modified versions of universal and ephemeris time scales based correspondingly on the intrinsic rotation of pulsar and on its orbital…
Thousands of tight ($<1$ AU) main sequence binaries have been discovered, but it is uncertain how they formed. There is likely too much angular momentum in a collapsing, fragmenting protostellar cloud to form such binaries in situ,…
The existence of millisecond pulsars with planet-mass companions (Bailes et al., 2011) in close orbits is challenging from the stellar evolution point of view. We calculate in detail the evolution of binary systems self-consistently,…
We report eclipse timing variation analyses of 26 compact hierarchical triple stars comprised of an eccentric eclipsing ('inner') binary and a relatively close tertiary component found in the {\em Kepler} field. We simultaneously fit the…
In the Galaxy, close binaries with compact objects are important low-frequency gravitational wave (GW) sources. As potential low-frequency GW sources, neutron star/white dwarf (WD) ultra-compact X-ray binaries (UCXBs) have been investigated…