Dan Lazarz | Searcharxiv

arXiv2023

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/MaNGA integral-field spectroscopic galaxy observations from cosmological simulations. In this second paper, we build the iMaNGA catalogue consisting of $\sim$1,000 unique galaxies from the TNG50 cosmological simulations, selected to mimic the SDSS-IV/MaNGA-Primary sample selection. Here we present and discuss the iMaNGA sample and its comparison to the MaNGA Primary catalogue. The iMaNGA sample well recovers the MaNGA-Primary sample in terms of stellar mass vs angular size relation and spatial resolution. The Sérsic index vs angular size relation, instead, is not reproduced well by the simulations, mostly because of a paucity of high-mass elliptical galaxies in TNG50. We also investigate our ability to recover the galaxy kinematics and stellar population properties with full-spectral fitting. We demonstrate that 'intrinsic' and `recovered' stellar kinematics, stellar ages and metallicities are consistent, with residuals compatible with zero within 1$-σ$. 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.

astro-ph.GA↗

arXiv2022

iMaNGA: mock MaNGA galaxies based on IllustrisTNG and MaStar SSPs. I. Construction and analysis of the mock data cubes

Galaxy formation and evolution simulations are essential tools to probe poorly known astrophysics processes, but particular care is needed to compare simulations with galaxy observations, as observed data need to be modelled as well. We present a method to generate mock galaxies from the hydro-dynamical IllustrisTNG simulations which are suited to compare with integral field spectroscopic observation of galaxies from the SDSS-IV/MaNGA survey. Firstly, we include the same instrumental effects and procedures as adopted in the acquisition and analysis of real data. Furthermore, we generate the galaxy spectra from the simulations using new stellar population models based on the MaNGA stellar library (MaStar). In this way, our mock data cubes have the same spatial sampling, cover the same wavelength range (3600-10300 Å), and share the same spectral resolution ($R\approx1800$) and flux calibration of real MaNGA galaxy spectra. In this first paper, we demonstrate the method over an early-type and a late-type simulated galaxy from TNG50. We analyse the correspondent mock MaNGA-like data cubes with the same full spectral fitting code, \textsc{FIREFLY}, which was used for the observed spectra. We find that the intrinsic and recovered age and metallicity gradients are consistent within 1$σ$, with residuals over all tassels consistent with $0$ at the 68$\%$ confidence level. We also perform the challenging test at comparing intrinsic and recovered star formation histories, finding a close resemblance between input and output. In follow-up papers, we will present a full simulated MaNGA-like catalogue ($\approx10,000$ galaxies) with a comprehensive comparison of TNG50 simulations to MaNGA observational results.

astro-ph.GA↗