Reconstructed star-formation histories in MaNGA galaxies: Dependence on host galaxy properties and radial trends

Tobias Looser Cambridge Fluids Network - fluids-related seminars 1 June 2022 1:15pm The Hoyle Lecture Theatre + Zoom We developed a new methodology to reconstruct reliable non-parametric Star Formation Histories (SFHs) from full spectral fitting using the penalized pixel fitting code pPXF (Cappellari, 2017), and by adopting a bootstrapping re-sampling scheme in combination with weight regularization. We have applied this technique to 10,000 MaNGA SDSS galaxies and explored the SFHs as a function of galactocentric radius, host galaxy properties like stellar mass and star-formation state with high statistical significance. Our spatially resolved analysis reveals cases of inside-out quenching in high mass galaxies and bulge building in low mass galaxies. Further, we recover the expected trends in the chemical enrichment histories of galaxies and the stellar fundamental metallicity relation (FMR). Additionally, very interestingly, our technique gives room for speculation about pristine gas accretion or lack thereof. Indeed, our analysis of MaNGA galaxies indicates the existence of young metal-poor populations (YMPP) in some populations of galaxies, potentially tracing stars formed by the recent accretion of metal-poor gas. Our spatially resolved analysis reveals cases of both centrally concentrated and extended YMPP. However, these findings are still subject to significant doubts and require further testing. Finally, I will give a brief outlook to our planned investigation of the first quenched galaxies at high redshift from the cycle 1 observations obtained within the JWST NIRSpec GTO programme, and by using an adapted version of the methodology described above.