Discrete Effects in Stellar Feedback: Individual Supernovae, Hypernovae, and IMF Sampling in Dwarf Galaxies
Abstract
Using high-resolution simulations from the FIRE-2 (Feedback In Realistic Environments) project, we study the effects of discreteness in stellar feedback processes on the evolution of galaxies and the properties of the interstellar medium (ISM). We specifically consider the discretization of supernovae (SNe), including hypernovae (HNe), and sampling the initial mass function (IMF). We study these processes in cosmological simulations of dwarf galaxies with z = 0 stellar masses M_∗∼10^4--3×10^6 M_⊙ (halo masses ∼10^9--10^(10) M_⊙). We show that the discrete nature of individual SNe (as opposed to a model in which their energy/momentum deposition is continuous overtime, similar to stellar winds) is crucial in generating a reasonable ISM structure and galactic winds and in regulating dwarf stellar masses. However, once SNe are discretized, accounting for the effects of IMF sampling on continuous mechanisms such as radiative feedback and stellar mass-loss (as opposed to adopting IMF-averaged rates) has weak effects on galaxy-scale properties. We also consider the effects of rare HNe events with energies ∼10^(53) erg. The effects of HNe are similar to the effects of clustered explosions of SNe – which are already captured in our default simulation setup – and do not quench star formation (provided that the HNe do not dominate the total SNe energy budget), which suggests that HNe yield products should be observable in ultra-faint dwarfs today.
Additional Information
© 2018 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/about_us/legal/notices) Accepted 2018 July 17. Received 2018 July 2; in original form 2017 December 6. Support for PFH was provided by Alfred P. Sloan Research Fellowship, NASA ATP Grant NNX14AH35G, and NSF Collaborative Research Grant #1411920 and CAREER grant #1455342. The Flatiron Institute is supported by the Simons Foundation. Numerical calculations were run on the Caltech compute cluster 'Zwicky' (NSF MRI award #PHY-0960291) and allocation TG-AST130039 granted by the Extreme Science and Engineering Discovery Environment (XSEDE) supported by the NSF. D. Kereš was supported by NSF grants AST-1412153 and AST-1715101 and the Cottrell Scholar Award from the Research Corporation for Science Advancement. CAFG was supported by NSF through grants AST-1412836, AST-1517491, AST-1715216, and CAREER award AST-1652522, and by NASA through grant NNX15AB22G. MBK acknowledges support from NSF grant AST-1517226 and from NASA grants NNX17AG29G and HST-AR-13888, HST-GO-14191, HST-AR-14282, and HST-AR-14554 from the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS5-26555. M. Orr is supported by the NSF GFRP under grant No 1144469.Attached Files
Published - sty1928.pdf
Accepted Version - nihms-997002.pdf
Submitted - 1712.02795.pdf
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Additional details
- PMCID
- PMC6301068
- Eprint ID
- 91526
- Resolver ID
- CaltechAUTHORS:20181205-163501557
- Alfred P. Sloan Foundation
- NNX14AH35G
- NASA
- AST-1411920
- NSF
- AST-1455342
- NSF
- Simons Foundation
- PHY-0960291
- NSF
- TG-AST130039
- NSF
- AST-1412153
- NSF
- AST-1715101
- NSF
- Cottrell Scholar of Research Corporation
- AST-1412836
- NSF
- AST-1517491
- NSF
- AST-1715216
- NSF
- AST-1652522
- NSF
- NNX15AB22G
- NASA
- AST-1517226
- NSF
- NNX17AG29G
- NASA
- HST-AR-13888
- NASA
- HST-GO-14191
- NASA
- HST-AR-14282
- NASA
- HST-AR-14554
- NASA
- NAS5-26555
- NASA
- DGE-1144469
- NSF Graduate Research Fellowship
- Created
-
2018-12-06Created from EPrint's datestamp field
- Updated
-
2021-11-16Created from EPrint's last_modified field
- Caltech groups
- TAPIR, Astronomy Department