Sweta Shah

Radboud University, Nijmegen

Research

GWs from compact binary systems

My contribution to this emerging new observational field has been to predict how GWs can help us in learning about the white dwarfs. Relating to these systems, I have investigated how much the knowledge of electromagnetic observations improve the GW parameters and how much does our overall knowledge of these systems improve when we combine all possibe EM and GW observations. I have also investigated the feasibility of doing tidal studies with synergy of GW and EM data on these Galactic binaries where atleast one component is a white-dwarf. Below there is an illustration that uses EM data on inclination to constrain the GW amplitude of the binary (shown in the green 1-sigma ellipses).

Using electromagnetic observations to aid gravitational-wave parameter estimation of compact binaries observed with LISA
S. Shah, M. van der Sluys, G. Nelemans
Astronomy & Astrophysics 544, A153 (2012); arXiv:1207.6770

Correlations between GW parameters

It turns out that due to the relative geometry of the binary source with respect to eLISA detector, several correlations between parameters (relating to their orientation) arise and the global view of these correlations as a function of those orientation parameters are complex. Below is illustration of normalised correlations between various parameters (polarisation, phase, sky position, amplitude and inclination) as a function of ecliptic latitude.

Using electromagnetic observations to aid gravitational-wave parameter estimation of compact binaries observed with LISA II. The effect of knowing the sky position
S. Shah, G. Nelemans, M. van der Sluys
Astronomy & Astrophysics 553, A82 (2013); arXiv:1303.6116

Coombining EM and GW data

coming soon

Tides in detached white-dwarf binaries