NIRVANA forward models galaxy velocity fields using a second-order nonaxisymmetric model. This enables it to reproduce bisymmetric features like bars. It also accounts for beam smearing and velocity dispersion in the resolved spectra.
MaNGA-NIRVANA will be a Value Added Catalog included in SDSS Data Release 17, the final data release for the SDSS-IV project MaNGA. It will contain rotation curves for several thousand rotating galaxies in the local Universe with quantified maps of bisymmetric irregularities.