Project Overview and Results¶

Can someone tell me how to make the figures appear smaller in redmine?

Mass Function parametrization¶

I chose to use the parametrization used in Tinker+08:

The parameters A, a, b have an additional redshift dependence parametrized as (1+z)**X, with X denoted as A_z, a_z, b_z.

Mass Function¶

The figure shows:

• Upper plots: Mass function dN/dM for Tinker+08 in black, DM in green, and hydro in blue. You can't tell a difference here. The error bars are the Poisson error in each bin.
• Lower plots: Relative difference between our simulations and the Tinker MF. The shaded regions correspond to the area enclosed within the 5th and 95th percentile (roughly the 2sigma region)

Mass Function parameters¶

I'll provide a table, but qualitatively you'll learn more from the figure. DM is in green, hydro in purple.

Consequences¶

I analyze the cluster sample extracted from the hydro sims, which we think is representative for the "real" Universe. I do this three times, assuming the Tinker+08 MF, our DM MF, and our hydro MF. The result is summarized in the figure, where hydro is in blue, and DM in green.

• The DM mass functions underestimate Omega_m by roughly 0.01
• This is MUCH smaller than the -0.03 from Cusworth+14
• Strangely, the constraints on sigma_8 are identical for the hydro and Tinker MF, but differ for our dark matter MF.

To Do¶

I think that the project is pretty advanced, and that the main results are basically in place. It will probably be a rather short paper, about 5-8 pages with figures.

However, some things are still needed:

• Repeat with M_vir in order to estimate intrinsic scatter using Chi2
• Provide a MF for M500_c for X-ray and SZ people. We decided to simply fit for the parameters, so there's no conversion as in Tinker+08.
• Relate our results, especially the Omega_m-sigma_8 figure, to current and future constraints.
• Maybe mention other MF than Tinker+08, e.g. Watson+13.

Literature¶

Hydro sims¶

• Illustris: Vogelsberger+14 http://adsabs.harvard.edu/abs/2014MNRAS.444.1518V
• Gadget-3 (OWLS): Velliscig+14 http://adsabs.harvard.edu/abs/2014MNRAS.442.2641V
• RAMSES: Martizzi+14 http://adsabs.harvard.edu/abs/2014MNRAS.440.2290M
• Cui+11: Impact of baryons http://adsabs.harvard.edu/abs/2012MNRAS.423.2279C
• Cui+14 Impact of AGN http://adsabs.harvard.edu/abs/2014MNRAS.441.1769C
• Eagle: Schaller+14 http://adsabs.harvard.edu/abs/2014arXiv1409.8617S

Feedback model¶

• Cusworth+14 http://adsabs.harvard.edu/abs/2014MNRAS.439.2485C

Dark matter sims¶

• Tinker+08 http://adsabs.harvard.edu/abs/2008ApJ...688..709T
• Watson+13 http://adsabs.harvard.edu/abs/2013MNRAS.433.1230W

Paper Draft¶

The current paper draft is here magneticum_MF.pdf