The impact of baryonic physics on the structure of dark matter haloes: the view from the FIRE cosmological simulations
Abstract
We study the distribution of cold dark matter (CDM) in cosmological simulations from the FIRE (Feedback In Realistic Environments) project, for M_* ∼ 10^(4–11) M_⊙ galaxies in M_h ∼ 10^(9–12) M_⊙ haloes. FIRE incorporates explicit stellar feedback in the multiphase interstellar medium, with energetics from stellar population models. We find that stellar feedback, without 'fine-tuned' parameters, greatly alleviates small-scale problems in CDM. Feedback causes bursts of star formation and outflows, altering the DM distribution. As a result, the inner slope of the DM halo profile (α) shows a strong mass dependence: profiles are shallow at M_h ∼ 10^(10)–10^(11) M_⊙ and steepen at higher/lower masses. The resulting core sizes and slopes are consistent with observations. This is broadly consistent with previous work using simpler feedback schemes, but we find steeper mass dependence of α, and relatively late growth of cores. Because the star formation efficiency M_*/M_h is strongly halo mass dependent, a rapid change in α occurs around M_h ∼ 10^(10) M_⊙ (M_* ∼ 10^6–10^7 M_⊙), as sufficient feedback energy becomes available to perturb the DM. Large cores are not established during the period of rapid growth of haloes because of ongoing DM mass accumulation. Instead, cores require several bursts of star formation after the rapid build-up has completed. Stellar feedback dramatically reduces circular velocities in the inner kpc of massive dwarfs; this could be sufficient to explain the 'Too Big To Fail' problem without invoking non-standard DM. Finally, feedback and baryonic contraction in Milky Way-mass haloes produce DM profiles slightly shallower than the Navarro–Frenk–White profile, consistent with the normalization of the observed Tully–Fisher relation.
Additional Information
© 2015 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. Accepted 2015 September 16. Received 2015 September 14; in original form 2015 July 9. First published online October 17, 2015. We would like to thank N. Murray, J. Bullock, M. Boylan-Kolchin and P. Salucci for useful discussion. DK and TKC were supported in part by NSF grant AST-1412153, Hellman Fellowship and funds from the University of California San Diego. Support for PFH was provided by an Alfred P. Sloan Research Fellowship, NASA ATP Grant NNX14AH35G, and NSF Collaborative Research Grant no. 1411920. EQ was supported in part by NASA ATP grant 12-APT12-0183, a Simons Investigator award from the Simons Foundation, and the David and Lucile Packard Foundation. CAFG was supported by NSF through grant AST-1412836, by NASA through grant NNX15AB22G, and by Northwestern University funds. The simulation presented here used computational resources granted by the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by National Science Foundation grant no. OCI-1053575, specifically allocations TG-AST120025 (PI Kereš), TG-AST130039 (PI Hopkins) and TG-AST1140023 (PI Faucher-Giguère).Attached Files
Published - MNRAS-2015-Chan-2981-3001.pdf
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Additional details
- Eprint ID
- 64277
- Resolver ID
- CaltechAUTHORS:20160205-120908533
- NSF
- AST-1412153
- Hellman Fellowship
- University of California, San Diego
- Alfred P. Sloan Foundation
- NASA
- NNX14AH35G
- NSF
- 1411920
- NASA
- 12-APT12-0183
- Simons Foundation
- David and Lucile Packard Foundation
- NSF
- AST-1412836
- NASA
- NNX15AB22G
- Northwestern University
- NSF
- OCI-1053575
- NSF
- TG-AST120025
- NSF
- TG-AST130039
- NSF
- TG-AST1140023
- Created
-
2016-02-08Created from EPrint's datestamp field
- Updated
-
2021-11-10Created from EPrint's last_modified field
- Caltech groups
- TAPIR