%0 Generic %1 topping2017understanding %A Topping, Michael W. %A Shapley, Alice E. %A Steidel, Charles C. %A Naoz, Smadar %A Primack, Joel R. %D 2017 %K SSA22 mock protocluster simulations %T Understanding substructure in the SSA22 protocluster region using cosmological simulations %U http://arxiv.org/abs/1709.06572 %X We investigate the nature and evolution of substructure within the SSA22 protocluster region at $z=3.09$ using cosmological simulations. A redshift histogram constructed from current spectroscopic observations of the SSA22 protocluster reveals two separate peaks at $z = 3.065$ (blue) and $z = 3.095$ (red). Based on these data, we report updated overdensity and mass calculations for the SSA22 protocluster. We find $\delta_b,gal=4.8 1.8$, $\delta_r,gal=9.5 2.0$ for the blue and red peaks, respectively, and $\delta_t,gal=7.61.4$ for the entire region. These overdensities correspond to masses of $M_b = (0.76 0.17) 10^15 h^-1 M_ødot$, $M_r = (2.15 0.32) 10^15 h^-1 M_ødot$, and $M_t=(3.19 0.40) 10^15 h^-1 M_ødot$ for the red, blue, and total peaks, respectively. We use the Small MultiDark Planck (SMDPL) simulation to identify comparably massive $z3$ protoclusters, and uncover the underlying structure and ultimate fate of the SSA22 protocluster. For this analysis, we construct mock redshift histograms for each simulated $z3$ protocluster, quantitatively comparing them with the observed SSA22 data. We find that the observed double-peaked substructure in the SSA22 redshift histogram corresponds not to a single coalescing cluster, but rather the proximity of a $10^15h^-1 M_ødot$ protocluster and at least one $>10^14 h^-1 M_ødot$ cluster progenitor. Such associations in the SMDPL simulation are easily understood within the framework of hierarchical clustering of dark matter halos. We finally find that the opportunity to observe such a phenomenon is incredibly rare, with an occurrence rate of $8h^3 Gpc^-3$.

@misc{topping2017understanding, abstract = {We investigate the nature and evolution of substructure within the SSA22 protocluster region at $z=3.09$ using cosmological simulations. A redshift histogram constructed from current spectroscopic observations of the SSA22 protocluster reveals two separate peaks at $z = 3.065$ (blue) and $z = 3.095$ (red). Based on these data, we report updated overdensity and mass calculations for the SSA22 protocluster. We find $\delta_{b,gal}=4.8 \pm 1.8$, $\delta_{r,gal}=9.5 \pm 2.0$ for the blue and red peaks, respectively, and $\delta_{t,gal}=7.6\pm 1.4$ for the entire region. These overdensities correspond to masses of $M_b = (0.76 \pm 0.17) \times 10^{15} h^{-1} M_{\odot}$, $M_r = (2.15 \pm 0.32) \times 10^{15} h^{-1} M_{\odot}$, and $M_t=(3.19 \pm 0.40) \times 10^{15} h^{-1} M_{\odot}$ for the red, blue, and total peaks, respectively. We use the Small MultiDark Planck (SMDPL) simulation to identify comparably massive $z\sim 3$ protoclusters, and uncover the underlying structure and ultimate fate of the SSA22 protocluster. For this analysis, we construct mock redshift histograms for each simulated $z\sim 3$ protocluster, quantitatively comparing them with the observed SSA22 data. We find that the observed double-peaked substructure in the SSA22 redshift histogram corresponds not to a single coalescing cluster, but rather the proximity of a $\sim 10^{15}h^{-1} M_{\odot}$ protocluster and at least one $>10^{14} h^{-1} M_{\odot}$ cluster progenitor. Such associations in the SMDPL simulation are easily understood within the framework of hierarchical clustering of dark matter halos. We finally find that the opportunity to observe such a phenomenon is incredibly rare, with an occurrence rate of $8h^3 \mbox{ Gpc}^{-3}$.}, added-at = {2017-09-21T10:23:20.000+0200}, author = {Topping, Michael W. and Shapley, Alice E. and Steidel, Charles C. and Naoz, Smadar and Primack, Joel R.}, biburl = {https://www.bibsonomy.org/bibtex/2799dd81bdc0adaaef0f6d629dabbc28f/miki}, description = {[1709.06572] Understanding substructure in the SSA22 protocluster region using cosmological simulations}, interhash = {0bcac3132c62f0634ef4f2f1f6d7b566}, intrahash = {799dd81bdc0adaaef0f6d629dabbc28f}, keywords = {SSA22 mock protocluster simulations}, note = {cite arxiv:1709.06572Comment: 13 pages, 8 figures, submitted to ApJ}, timestamp = {2017-09-21T10:23:20.000+0200}, title = {Understanding substructure in the SSA22 protocluster region using cosmological simulations}, url = {http://arxiv.org/abs/1709.06572}, year = 2017 }