article published yes Jorryt J Matthee author 7439a258-f3c0-11ec-9501-9df22fe067200000-0003-2871-127X Joop Schaye author Robert A. Crain author Matthieu Schaller author Richard Bower author Tom Theuns author We use the hydrodynamical EAGLE simulation to study the magnitude and origin of the scatter in the stellar mass–halo mass relation for central galaxies. We separate cause and effect by correlating stellar masses in the baryonic simulation with halo properties in a matched dark matter only (DMO) simulation. The scatter in stellar mass increases with redshift and decreases with halo mass. At z = 0.1, it declines from 0.25 dex at M200, DMO ≈ 1011 M⊙ to 0.12 dex at M200, DMO ≈ 1013 M⊙, but the trend is weak above 1012 M⊙. For M200, DMO < 1012.5 M⊙ up to 0.04 dex of the scatter is due to scatter in the halo concentration. At fixed halo mass, a larger stellar mass corresponds to a more concentrated halo. This is likely because higher concentrations imply earlier formation times and hence more time for accretion and star formation, and/or because feedback is less efficient in haloes with higher binding energies. The maximum circular velocity, Vmax, DMO, and binding energy are therefore more fundamental properties than halo mass, meaning that they are more accurate predictors of stellar mass, and we provide fitting formulae for their relations with stellar mass. However, concentration alone cannot explain the total scatter in the Mstar−M200,DMO relation, and it does not explain the scatter in Mstar–Vmax, DMO. Halo spin, sphericity, triaxiality, substructure and environment are also not responsible for the remaining scatter, which thus could be due to more complex halo properties or non-linear/stochastic baryonic effects. Oxford University Press2017 eng Space and Planetary ScienceAstronomy and Astrophysicsgalaxies: evolutiongalaxies: formationgalaxies: haloescosmology: theory 0035-8711 1365-2966 1608.0821810.1093/mnras/stw2884 46522381-2396 yes J.J. Matthee, J. Schaye, R.A. Crain, M. Schaller, R. Bower, T. Theuns, Monthly Notices of the Royal Astronomical Society 465 (2017) 2381–2396. Matthee JJ, Schaye J, Crain RA, Schaller M, Bower R, Theuns T. 2017. The origin of scatter in the stellar mass–halo mass relation of central galaxies in the EAGLE simulation. Monthly Notices of the Royal Astronomical Society. 465(2), 2381–2396. Matthee JJ, Schaye J, Crain RA, Schaller M, Bower R, Theuns T. The origin of scatter in the stellar mass–halo mass relation of central galaxies in the EAGLE simulation. <i>Monthly Notices of the Royal Astronomical Society</i>. 2017;465(2):2381-2396. doi:<a href="https://doi.org/10.1093/mnras/stw2884">10.1093/mnras/stw2884</a> J. J. Matthee, J. Schaye, R. A. Crain, M. Schaller, R. Bower, and T. Theuns, “The origin of scatter in the stellar mass–halo mass relation of central galaxies in the EAGLE simulation,” <i>Monthly Notices of the Royal Astronomical Society</i>, vol. 465, no. 2. Oxford University Press, pp. 2381–2396, 2017. Matthee, Jorryt J., et al. “The Origin of Scatter in the Stellar Mass–Halo Mass Relation of Central Galaxies in the EAGLE Simulation.” <i>Monthly Notices of the Royal Astronomical Society</i>, vol. 465, no. 2, Oxford University Press, 2017, pp. 2381–96, doi:<a href="https://doi.org/10.1093/mnras/stw2884">10.1093/mnras/stw2884</a>. Matthee, Jorryt J, Joop Schaye, Robert A. Crain, Matthieu Schaller, Richard Bower, and Tom Theuns. “The Origin of Scatter in the Stellar Mass–Halo Mass Relation of Central Galaxies in the EAGLE Simulation.” <i>Monthly Notices of the Royal Astronomical Society</i>. Oxford University Press, 2017. <a href="https://doi.org/10.1093/mnras/stw2884">https://doi.org/10.1093/mnras/stw2884</a>. Matthee, J. J., Schaye, J., Crain, R. A., Schaller, M., Bower, R., &#38; Theuns, T. (2017). The origin of scatter in the stellar mass–halo mass relation of central galaxies in the EAGLE simulation. <i>Monthly Notices of the Royal Astronomical Society</i>. Oxford University Press. <a href="https://doi.org/10.1093/mnras/stw2884">https://doi.org/10.1093/mnras/stw2884</a> 115652022-07-12T12:25:08Z2024-10-14T11:36:05Z