A5019695211- Astronomy and Astrophysical Research
- Gamma-ray bursts and supernovae
- Stellar, planetary, and galactic studies
- Pulsars and Gravitational Waves Research
- Adaptive optics and wavefront sensing
- Astrophysics and Cosmic Phenomena
- Radio Astronomy Observations and Technology
- Scientific Research and Discoveries
- Astrophysical Phenomena and Observations
- Thermal properties of materials
- Spacecraft Design and Technology
- Astronomical Observations and Instrumentation
- Astro and Planetary Science
- Cosmology and Gravitation Theories
- Material Dynamics and Properties
- Astrophysics and Star Formation Studies
- Advanced Thermodynamics and Statistical Mechanics
Liverpool John Moores University
2019-2021
University of La Serena
1998-1999
The EROS and MACHO collaborations have each published upper limits on the amount of planetary mass dark matter in Galactic Halo obtained from gravitational microlensing searches. In this paper two are combined to give a much stronger constraint abundance low MACHOs.
We investigate the shape of jet break in within-beam gamma-ray burst (GRB) optical afterglows for various lateral structure profiles. consider cases with and without spreading a range inclinations within core half-opening angle, $\theta_c$. fit model observed afterglow lightcurves smoothly-broken power-law function free-parameter $\kappa$ that describes sharpness break. find is sharper ($\kappa$ greater) when included than absence spreading. For profiles sharp-edged core, parameter has broad...
We discuss the properties of stellar mass black hole (BH) mergers induced by tidal encounters with a massive BH at galactic centres or potentially in dense star clusters. The disruption binaries is known to produce hypervelocity stars. However, such encounter does not always lead break-up binaries. Since surviving tend become hard and eccentric, this process can principle. For initially circular binaries, we show that gravitational wave (GW) merger times shorter factor more than $10^{2}$...
For gravitational wave (GW) detected neutron star mergers, one of the leading candidates for electromagnetic (EM) counterparts is afterglow from an ultra-relativistic jet. Where this observed, it will likely be viewed off-axis, such as following GW170817/GRB 170817A. The temporal behaviour off-axis observed GRB can used to reveal lateral jet structure, and statistical model fits put constraints on various free-parameters. Amongst these parameters inclination system line sight. Along with GW...
ABSTRACT Very long baseline interferometry radio images recently proved to be essential in breaking the degeneracy ejecta model for neutron star merger GW170817. We discuss properties of synthetic jet afterglows by using semi-analytical models laterally spreading or non-spreading jets. The image centroid initially moves away from explosion point sky with apparent superluminal velocity. After reaching a maximum displacement, its motion is reversed. This behaviour line that found full...
We study the connection between heat transport properties of systems coupled to different thermal baths in two separate regions and their underlying nonequilibrium dynamics. consider classical interacting particles that may exhibit a certain degree delocalization whose effective dimensionality can be modified through controlled variation global trapping potential. focus on Coulomb crystals trapped ions, which offer versatile playground shed light role spatial constraints play transport. use...
Recent surveys monitoring millions of light curves resolved stars in the LMC have discovered several microlensing events. Unresolved could however significantly contribute to rate towards LMC. Monitoring pixels, as opposed individual stars, should be able detect stellar variability a variation pixel flux. We present first application this new type analysis (Pixel Method) Bar. describe complete procedure applied EROS 91-92 data (one tenth existing CCD set) order monitor fluxes. First,...
We present final results from the first phase of EROS search for gravitational microlensing stars in Magellanic Clouds by unseen deflectors (machos: MAssive Compact Halo Objects). The is sensitive to events with time scales between 15 minutes and 200 days corresponding deflector masses range 1.e-7 a few solar masses. Two were observed that are compatible objects mass about 0.1 Mo. By comparing expected number various models Galaxy, we conclude machos [1.e-7, 0.02] Mo make up less than 20%...
For gravitational wave (GW) detected neutron star mergers, one of the leading candidates for electromagnetic (EM) counterparts is afterglow from an ultra-relativistic jet. Where this observed, it will likely be viewed off-axis, such as following GW170817/GRB 170817A. The temporal behaviour off-axis observed GRB can used to reveal lateral jet structure, and statistical model fits put constraints on various free-parameters. Amongst these parameters inclination system line sight. Along with GW...
Very long base interferometry (VLBI) radio images recently proved to be essential in breaking the degeneracy ejecta model for neutron star merger GW170817. We discuss properties of synthetic jet afterglows by using semi-analytic models laterally spreading or non-spreading jets. The image centroid initially moves away from explosion point sky with apparent superlumianal velocity. After reaching a maximum displacement its motion is reversed. This behavior line that found full hydrodynamics...