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.
from simulations to observations
NOVAs has been developed in order to bridge the gap between observational data (energy spectra, lightcurves...) and theoretical models of accretion processes around Kerr BHs. It also allows to investigate the influence of variables such as the source inclination or the instrumental response. It is composed of:
1) GR-AMRVAC (Casse et al. 2017), a general-relativistic (GR) magneto-hydrodynamical (MHD)
finite-volume fluid code based on MPI-AMRVAC (Keppens et al. 2012), to evolve
accretion/ejection flows around compact objects ;
2) GYOTO (Vincent et al. 2011), a GR ray-tracing code to generate synthetic observations ;
3) An observation-oriented extension, e.g. SIXTE (Dauser et al. 2019): a package allowing
to incorporate instrumental effects on those idealized synthetic observational data.
The output format allows for data analysis with standard tools such as xspec.
NOVAs has been used to study the observables from accreting, single BHs (e.g. Vincent et al. 2013, Varniere & Vincent 2016, Casse & Varniere 2018, Mignon-Risse et al. 2021).
