MaNGA, an integral field unit survey, has produced datacubes for more than 100 galaxies which contain post-starburst (PSB) regions, i.e., regions in which star formation has recently been sharply truncated. Spectral index and emission line maps give us information about the star formation history and, therefore, formation mechanisms of these galaxies. A small fraction of these galaxies show very strong radial gradients in their Balmer absorption line strengths. To investigate the origin of these strong radial gradients, we use Gadget-3 to run a set of binary merger simulations with varied black hole feedback models, progenitor galaxies, and orbits. We develop the SEDMorph code to make mock MaNGA datacubes for the simulated galaxy. Spectral index maps for the simulated post-starburst galaxies are created by combining the star formation history and metallicity of each particle with stellar population synthesis models. A point-spread function and a dithering pattern are also included to make our mock cube more comparable to the MaNGA data.
With the simulations and mock datacubes, we find that only the kinetic blackhole feedback model can create galaxies with strong PSB features. Under this model, we confirm the radial gradients in the Balmer absorption line strengths in these PSBs are caused by a single co-eval burst which was stronger in the central regions, rather than a starburst that has progressed from outside-in.
Our work highlights the potential for IFU observations to provide constraints on mechanisms for rapid quenching of local galaxies, when combined with direct comparison with simulations.
BIO:
I am Yirui Zheng(郑奕锐), a Ph.D. student from the School of Physics and Astronomy, University of St Andrews. I gained my bachelor degree in astronomy in USTC in 2017.
My research is focused on the formation and evolution of post-starburst galaxies. We are using simulations to interpret the observation results of integral field unit surveys like MaNGA.
