%0 Generic %1 chan2015impact %A Chan, T. K. %A Kereš, D. %A Oñorbe, J. %A Hopkins, P. F. %A Muratov, A. L. %A Faucher-Giguère, C. A. %A Quataert, E. %D 2015 %K dark feedback gas matter simulation %T The Impact of Baryonic Physics on the Structure of Dark Matter Halos: the View from the FIRE Cosmological Simulations %U http://arxiv.org/abs/1507.02282 %X We study the distribution of cold dark matter (CDM) in cosmological zoom-in simulations from the Feedback in Realistic Environments (FIRE) project, for a range of halo mass (10^9-10^12 Msun) and stellar mass (10^4-10^11 Msun). The FIRE simulations incorporate explicit stellar feedback within the multi-phase ISM. We find that stellar feedback, without any "fine-tuned" parameters, can greatly alleviate 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 älpha" shows a strong mass dependence: profiles are shallow at M_h ~ 10^10-10^11 Msun 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 älpha," and relatively late growth of cores. Because the star formation efficiency is strongly halo mass dependent, a rapid change in the central slope occurs at M_h ~10^10 Msun, as sufficient feedback energy becomes available to perturb the DM. We show that large cores are not established during the period of rapid growth of halos because of ongoing DM mass accumulation. Instead, cores require several bursts of star formation after the rapid buildup has completed. The same effects dramatically reduce 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, we study baryonic contraction in Milky Way-mass halos. The net result of stellar feedback and baryonic contraction is to produce DM profiles slightly shallower than the NFW profile, as required by the normalization of the Tully-Fisher relation.

@misc{chan2015impact, abstract = {We study the distribution of cold dark matter (CDM) in cosmological zoom-in simulations from the Feedback in Realistic Environments (FIRE) project, for a range of halo mass (10^9-10^12 Msun) and stellar mass (10^4-10^11 Msun). The FIRE simulations incorporate explicit stellar feedback within the multi-phase ISM. We find that stellar feedback, without any "fine-tuned" parameters, can greatly alleviate 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 "alpha" shows a strong mass dependence: profiles are shallow at M_h ~ 10^10-10^11 Msun 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 "alpha," and relatively late growth of cores. Because the star formation efficiency is strongly halo mass dependent, a rapid change in the central slope occurs at M_h ~10^10 Msun, as sufficient feedback energy becomes available to perturb the DM. We show that large cores are not established during the period of rapid growth of halos because of ongoing DM mass accumulation. Instead, cores require several bursts of star formation after the rapid buildup has completed. The same effects dramatically reduce 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, we study baryonic contraction in Milky Way-mass halos. The net result of stellar feedback and baryonic contraction is to produce DM profiles slightly shallower than the NFW profile, as required by the normalization of the Tully-Fisher relation.}, added-at = {2015-07-10T09:46:40.000+0200}, author = {Chan, T. K. and Kereš, D. and Oñorbe, J. and Hopkins, P. F. and Muratov, A. L. and Faucher-Giguère, C. A. and Quataert, E.}, biburl = {https://www.bibsonomy.org/bibtex/26494fcde68abc456cfd89be4f382fa91/miki}, description = {[1507.02282] The Impact of Baryonic Physics on the Structure of Dark Matter Halos: the View from the FIRE Cosmological Simulations}, interhash = {fe439b83cd6c807877760e05afd0e3fc}, intrahash = {6494fcde68abc456cfd89be4f382fa91}, keywords = {dark feedback gas matter simulation}, note = {cite arxiv:1507.02282Comment: 23 pages, 14 figures, submitted to MNRAS}, timestamp = {2015-07-10T09:46:40.000+0200}, title = {The Impact of Baryonic Physics on the Structure of Dark Matter Halos: the View from the FIRE Cosmological Simulations}, url = {http://arxiv.org/abs/1507.02282}, year = 2015 }