Browsing by Author "Elson, E."

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    The baryonic Tully–Fisher relation in the SIMBA simulation
    (Oxford University Press, 2020) Glowacki, M.; Elson, E.; Dave, R.
    We investigate the Baryonic Tully–Fisher relation (BTFR) in the (100h−1Mpc)3SIMBA hydrodynamical galaxy formation simulation together with a higher resolution (25h−1Mpc)3SIMBA run, for over 10 000 disc-dominated, H I-rich galaxies. We generate simulated galaxy rotation curves from the mass distribution, which we show yields similar results to using the gas rotational velocities. From this, we measure the galaxy rotation velocity Vcirc using four metrics: Vmax,Vflat,V2Re, and Vpolyex. We compare the predicted BTFR to the SPARC observational sample and find broad agreement. In detail, however, SIMBA is biased towards higher Vcirc by up to 0.1 dex. We find evidence for the flattening of the BTFR in Vcirc > 300  km s−1 galaxies, in agreement with recent observational findings.
  • Thumbnail Image
    Item
    A multi-scale study of the star formation law in nearby galaxies
    (University of the Western Cape, 2020) Isaacs, Narusha; Elson, E.; For, B.; Santos, M.
    This research aimed to evaluate the effects of changing length-scales on the star formation laws and star formation efficiencies for our selected sample of galaxies. We have combined high-resolution Hi data from The Hi Nearby Galaxy Survey, CO data from HERA CO–Line Extragalactic Survey and the Nobeyama CO Atlas of Nearby Spiral Galaxies and 12 𝜇m data from the Wide-field Infrared Survey Explorer of a sample of five nearby galaxies to study the relationship between star formation rate surface density, ΣSFR, and gas surface density, Σgas, at various length-scales. In order to probe the star formation law of each galaxy, all image sets were placed on common astrometric grids and evaluated on a pixel-by-pixel basis over a range of sub-kpc length-scales. We investigated whether the star formation law changes with length-scales and found that as resolution becomes coarser, the Kennicutt Schmidt power-law index decreases for the correlation between ΣSFR and ΣH2 . Our results show that the index values are close to unity but are not consistent with it.