The role of feedback in shaping the structure of the interstellar medium

Walker, A. P.; Gibson, B. K.; Pilkington, K.; Brook, C. B.; Dutta, P.; Stanimirovi?, S.; Stinson, G. S.; Bailin, J.

Abstract

We present an analysis of the role of feedback in shaping the neutral hydrogen (H i) content of simulated disc galaxies. For our analysis, we have used two realizations of two separate Milky Way-like (~L{black star}) discs - one employing a conservative feedback scheme (McMaster Unbiased Galaxy Survey), the other significantly more energetic [Making Galaxies In a Cosmological Context (MaGICC)]. To quantify the impact of these schemes, we generate zeroth moment (surface density) maps of the inferred H i distribution; construct power spectra associated with the underlying structure of the simulated cold interstellar medium, in addition to their radial surface density and velocity dispersion profiles. Our results are compared with a parallel, self-consistent, analysis of empirical data from The H iNearby Galaxy Survey (THINGS). Single power-law fits (P ∝ k γ ) to the power spectra of the stronger feedback (MaGICC) runs (over spatial scales corresponding to ~0.5 to ~20 kpc) result in slopes consistent with those seen in the THINGS sample (γ ~ -2.5). The weaker feedback (MUGS) runs exhibit shallower power-law slopes (γ ~ -1.2). The power spectra of the MaGICC simulations are more consistent though with a two-component fit, with a flatter distribution of power on larger scales (i.e. γ ~ -1.4 for scales in excess of ~2 kpc) and a steeper slope on scales below ~1 kpc (γ ~ -5), qualitatively consistent with empirical claims, as well as our earlier work on dwarf discs. The radial H i surface density profiles of the MaGICC discs show a clear exponential behaviour, while those of the MUGS suite are essentially flat; both behaviours are encountered in nature, although the THINGS sample is more consistent with our stronger (MaGICC) feedback runs.

Citation

Walker, A. P., Gibson, B. K., Pilkington, K., Brook, C. B., Dutta, P., Stanimirović, S., …Bailin, J. (2014). The role of feedback in shaping the structure of the interstellar medium. Monthly notices of the Royal Astronomical Society, 441(1), 525-531. https://doi.org/10.1093/mnras/stu419

• Journal Article Type: Article
• Acceptance Date: Mar 3, 2014
• Online Publication Date: Apr 27, 2014
• Publication Date: Jun 11, 2014
• Deposit Date: Apr 14, 2016
• Publicly Available Date: Apr 14, 2016
• Journal: Monthly notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Electronic ISSN: 1365-2966
• Publisher: Oxford University Press
• Peer Reviewed: Peer Reviewed
• Volume: 441
• Issue: 1
• Pages: 525-531
• DOI: https://doi.org/10.1093/mnras/stu419
• Keywords: ISM : structure, Galaxies : evolution, Galaxies : formation, Galaxies : spiral
• Public URL: https://hull-repository.worktribe.com/output/435973
• Publisher URL: http://mnras.oxfordjournals.org/content/441/1/525
• Additional Information: This article has been accepted for publication in Monthly notices of the Royal Astronomical Society ©: 2014 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.