iMaNGA: mock MaNGA galaxies based on IllustrisTNG and MaStar SSPs - II. The catalogue

Strengthening the synergy between simulations and observations is essential to test galaxy formation and evolution theories. To achieve this goal, in the first paper of this series, we presented a method to generate mock SDSS-IV/Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) integral-field spectroscopic galaxy observations from cosmological simulations. In this second paper, we build the iMaNGA catalogue consisting of similar to 1000 unique galaxies from the TNG50 cosmological simulations, selected to mimic the SDSS-IV/MaNGA-Primary sample selection. Here, we present and discuss the iMaNGA sample and its comparison to the MaNGA Primary catalogue. The iMaNGA sample well recovers the MaNGA-Primary sample in terms of stellar mass versus angular size relation and spatial resolution. The Sersic index versus angular size relation, instead, is not reproduced well by the simulations, mostly because of a paucity of high-mass elliptical galaxies in TNG50. We also investigate our ability to recover the galaxy kinematics and stellar population properties with full-spectral fitting. We demonstrate that 'intrinsic' and 'recovered' stellar kinematics, stellar ages, and metallicities are consistent, with residuals compatible with zero within 1 sigma. Also 'intrinsic' and 'recovered' star formation histories display a great resemblance. We conclude that our mock generation and spectral fitting processes do not distort the 'intrinsic' galaxy properties. Therefore, in the third paper of this series, we can meaningfully test the cosmological simulations, comparing the stellar population properties and kinematics of the iMaNGA mock galaxies and the MaNGA observational results.

Automated summary

Strengthening the synergy between simulations and observations is crucial for testing galaxy formation and evolution theories. In this study, we introduce a method to generate mock observations from cosmological simulations to mimic the SDSS-IV/MaNGA-Primary sample selection. The comparison between the iMaNGA sample and the MaNGA Primary catalogue shows that the iMaNGA sample successfully recovers the stellar mass versus angular size relation and spatial resolution. However, the simulations do not reproduce the Sersic index versus angular size relation well, mainly due to a lack of high-mass elliptical galaxies.