%0 Generic %1 elahi2015nifty %A Elahi, Pascal J. %A Knebe, Alexander %A Pearce, Frazer R. %A Power, Chris %A Yepes, Gustavo %A Cui, Weiguang %A Cunnama, Daniel %A Kay, Scott T. %A Sembolini, Federico %A Beck, Alexander M. %A Davé, Romeel %A February, Sean %A Huang, Shuiyao %A Katz, Neal %A McCarthy, Ian G. %A Murante, Giuseppe %A Perret, Valentin %A Puchwein, Ewald %A Saro, Alexandro %A Teyssier, Romain %D 2015 %K cluster comparison galaxy simulation %T nIFTY galaxy cluster simulations III: The Similarity & Diversity of Galaxies & Subhaloes %U http://arxiv.org/abs/1511.08255 %X We examine subhaloes and galaxies residing in a simulated LCDM galaxy cluster ($M^crit_200=1.1\times10^15M_ødot/h$) produced by hydrodynamical codes ranging from classic Smooth Particle Hydrodynamics (SPH), newer SPH codes, an adaptive mesh code and a moving mesh scheme. These codes use subgrid models to capture galaxy formation physics. We compare how well these codes reproduce the same subhaloes/galaxies in gravity only, non-radiative hydrodynamics and full radiative physics runs by looking at the overall subhalo/galaxy distribution and on an individual objects basis. We find the subhalo population is reproduced to within $łesssim10\%$ for both dark matter only and non-radiative runs, with individual objects showing code-to-code scatter of $łesssim0.1$ dex, although the gas in non-radiative simulations shows significant scatter. Including radiative physics significantly increases the diversity seen. The subhalo mass and $V_max$ distributions vary by $\approx20\%$, a result of feedback moving significant baryonic mass around. Galaxies also show striking code-to-code variations. Although the Tully-Fisher relation is similar in almost all codes, the number of galaxies with $10^9M_ødot/hM_*10^12M_ødot/h$ can differ by a factor of 4. Individual galaxies show code-to-code scatter of $\sim0.5$ dex in stellar mass. Moreover, strong systematic differences exist, with some codes producing galaxies $70\%$ smaller than others. The diversity partially arises from the inclusion/absence of AGN feedback. Our results combined with our companion papers, Sembolini et al. (2015a,b), demonstrate that subgrid physics is not just subject to fine-tuning, but the complexity of building galaxies in all environments remains a challenge. We argue that even basic galaxy properties, such as the stellar mass to halo mass, should be treated with errors bars of $\sim0.2-0.5$ dex.

@misc{elahi2015nifty, abstract = {We examine subhaloes and galaxies residing in a simulated LCDM galaxy cluster ($M^{\rm crit}_{200}=1.1\times10^{15}M_\odot/h$) produced by hydrodynamical codes ranging from classic Smooth Particle Hydrodynamics (SPH), newer SPH codes, an adaptive mesh code and a moving mesh scheme. These codes use subgrid models to capture galaxy formation physics. We compare how well these codes reproduce the same subhaloes/galaxies in gravity only, non-radiative hydrodynamics and full radiative physics runs by looking at the overall subhalo/galaxy distribution and on an individual objects basis. We find the subhalo population is reproduced to within $\lesssim10\%$ for both dark matter only and non-radiative runs, with individual objects showing code-to-code scatter of $\lesssim0.1$ dex, although the gas in non-radiative simulations shows significant scatter. Including radiative physics significantly increases the diversity seen. The subhalo mass and $V_{max}$ distributions vary by $\approx20\%$, a result of feedback moving significant baryonic mass around. Galaxies also show striking code-to-code variations. Although the Tully-Fisher relation is similar in almost all codes, the number of galaxies with $10^{9}M_\odot/h\lesssim M_*\lesssim 10^{12}M_\odot/h$ can differ by a factor of 4. Individual galaxies show code-to-code scatter of $\sim0.5$ dex in stellar mass. Moreover, strong systematic differences exist, with some codes producing galaxies $70\%$ smaller than others. The diversity partially arises from the inclusion/absence of AGN feedback. Our results combined with our companion papers, Sembolini et al. (2015a,b), demonstrate that subgrid physics is not just subject to fine-tuning, but the complexity of building galaxies in all environments remains a challenge. We argue that even basic galaxy properties, such as the stellar mass to halo mass, should be treated with errors bars of $\sim0.2-0.5$ dex.}, added-at = {2015-11-30T10:11:47.000+0100}, author = {Elahi, Pascal J. and Knebe, Alexander and Pearce, Frazer R. and Power, Chris and Yepes, Gustavo and Cui, Weiguang and Cunnama, Daniel and Kay, Scott T. and Sembolini, Federico and Beck, Alexander M. and Davé, Romeel and February, Sean and Huang, Shuiyao and Katz, Neal and McCarthy, Ian G. and Murante, Giuseppe and Perret, Valentin and Puchwein, Ewald and Saro, Alexandro and Teyssier, Romain}, biburl = {https://www.bibsonomy.org/bibtex/22985d70d0959fda477bca1571f74c66c/miki}, description = {[1511.08255] nIFTY galaxy cluster simulations III: The Similarity & Diversity of Galaxies & Subhaloes}, interhash = {58d678da7f3505404317fd3c04c21683}, intrahash = {2985d70d0959fda477bca1571f74c66c}, keywords = {cluster comparison galaxy simulation}, note = {cite arxiv:1511.08255Comment: 17 pages (+4 page appendix), 16 figures, 2 tables; submitted to MNRAS}, timestamp = {2015-11-30T10:11:47.000+0100}, title = {nIFTY galaxy cluster simulations III: The Similarity & Diversity of Galaxies & Subhaloes}, url = {http://arxiv.org/abs/1511.08255}, year = 2015 }