Presentation #129.06 in the session “Dwarf & Irregular Galaxies”.
This poster shows the results of a simulated stellar and gaseous galactic bar with spiralarms, produced using the N-body simulation code Charm N-body Gravity Solver (ChaNGa) [H. Menon, et al., Comp. Astro. Cosm. 2, 1, (2015)], and builds upon the pedagogical aspects of the previous iPoster+, presented at the 235th AAS meeting [J.W. Powell, B.Cummings, and W. Lum, B. Am. Astron. Soc. 52 (2020)]. The star formation physics can be learned first through a junior-level textbook by M. D. Smith [M. D. Smith, The Origin of Stars. (Imperial College Press, London, 2004)]. The literature on bars can be accessed by the outstanding article: [M. D. Weinberg and Neal Katz, MNRAS 375, 426 (2007)]. As in last year’s iPoster+ the computational learning curves — especially with respect to star formation — will be emphasized here because they are much less well documented than the underlying physics. An undergraduate treatment of ChaNGa cosmological simulations, is available in [B. Cummings, Thesis Reed College, 2020]. The results of this work, Figs. 1 — face-on with bars, and 2 side-on showing disk, were obtained by running ChaNGa compiled with GRACKLE [B.D. Smith, MNRAS, 466, 2217(2017)] on NSF’s XSEDE Comet supercomputer. A detailed version of the ChaNGa installation is described in [L. Caudill, https://github.com/N-body-group-Reed/]. Much of the work involved in obtaining these images of a barred, gaseous and stellar spiral is in constructing the IC (initial conditions) file by using the pyICs github code [J. Herpich, G. S. Stinson, H.-W. Rix, M. Martig and A. A. Dutton, MNRAS 470, 4941 (2017)]. PyICs has a well-documented site and is specifically tailored to obtaining galactic bars from isolated galaxy simulations. The parameter file for this star formation simulation required by ChaNGa was modified using the parameters crucial to star formation wereprovided by B. Keller. Finally, the visualization — and proof of star formation — in the present work was achieved using pynbody [A. Pontzen, R. Roskar, G. Stinson, R. Woods, http://adsabs.harvard.edu/abs/2013ascl.soft05002P].