Emission from a theoretical Shakura-Sunyaev disk near a binary black one with one having a null spin and the other max spin. The system is viewed at a 10 degree angle.
extended-Numerical Observatory of Violently Accreting systems
It is the first European code to evolve any type of spacetime as it solves the equations of
GR-(magneto-) hydrodynamics and to compute synthetic observations in the same metric. In particular,
it handles dynamical spacetimes for which, by definition, gravitational waves are emitted:
e-NOVAs is, thus, built for the multi-messenger era.
GW - related effects in the outer disk around a BBH
Further away from the BBH than a GW wavelength retardation effects, In the inner regions of the circumbinary disk, the BBH metric creates a low-density (intrinsically linked to GWs) become large. We investigated their impact on the gas. We witnessed the formation of a spiral-like pattern in the gas density. This leads to a weak but persistent modulation of the thermal lightcurve in the lower energy band corresponding to the outer disk.
Raphaël Mignon-Risse, Peggy Varniere, Fabien Casse, MNRAS, Volume 519, Issue 2, February 2023, Pages 2848-2861.
Gravitational waves or x-ray counterpart? No need to choose
Raphael Mignon-Risse, Peggy Varniere, Fabien Casse, Astronomische Nachrichten, Volume 344, Issue 4, may 2023, article id. e20220130.
Inner circumbinary disk around a BBH
In the inner regions of the circumbinary disk, the BBH metric creates a low-density cavity, spiral arms/streams, and an overdensity dubbed lump. These non-axisymmetries modulate the thermal lightcurve in the higher-energy band. The largest-amplitude modulation is due to the lump orbiting at several times the BBH period. The smaller-amplitude modulation is due to the spiral arms and has the semi-BBH period.
On the origin of the lump in circumbinary discs
Raphael Mignon-Risse, Peggy Varniere, Fabien Casse, MNRAS, Volume 520, Issue 1, March 2023, Pages 1285-1295.