Day 86

Tuesday.  Must finish Reina's paper review.  I still don't have an apartment!  It's getting depressing.


1109.3708
Observational constraints on the redshift evolution of X-ray scaling relations of galaxy clusters out to z~1.5
Reichert, Böhringer, Fassbender, Mühlegger


Current literature provides a diverse and inhomogeneous picture of scaling relation evolution.  Provide overall view of scaling relation evolution with recently discovered high-z cluster; normalize with other cluster data.  Study M-T, Lx-T, and M-Lx relation combining 14 published data sets supplemented with recently published data of distant clusters and new results from follow-up observations of the XMM-Newton Distant Cluster Project (XDCP).  Find: evolution of the M-T relation is consistent with self-similar prediction, while evolution of X-ray luminosity for a given temperature and mass for a given X-ray luminosity is slower than predicted.  Best fit results for the evolution factor E(z)^alpha are alpha=-1.04pm0.07 for the M-T relation, alpha=-0.23p0.12m0.62 for the L-T relation, and alpha=-0.93p0.62m0.12 for the M-Lx relation.  Find that selection biases are the most likely reason for apparent inconsistencies between different published data sets.  New results provide the most robust calibration high-z cluster mass estimates based on X-ray luminosity and temperature; helps improve the prediction of the number of clusters to be found in  future galaxy cluster X-ray surveys, such as eROSITA.  Comparison of evolution results with hydrodynamical cosmological simulations suggests that early preheating of the ICM provides the most suitable scenario to explain the observed evolution.


* I want to read this paper and get the physical picture.  


1109.3709
On the cluster physics of SZ surveys I: the influence of feedback, non-thermal pressure and cluster shapes on Y-M scaling relations
Battaglia, Bond, Pfrommer, Sievers


Y-M relation = SZ-flux-to-mass relation.  Explore how non-thermal pressure and anisotropic shape of the gas distribution of the ICM impacts Y-M scaling using SPH simulations.  Contrast results for models with different treatments of entropy injection and transport (radiative cooling, star formation and accompanying SNe feedback, cosmic rays, energetic feedback from AGN).  The gas kinetic-to-thermal pressure ratio from internal bulk motions depends on the cluster mass, and increases in the outer-cluster due to enhanced substructure, as does the asphericity of the ICM gas.  3D ellipticities can be inferred from the observed (projected) ellipticity.  Simulated Y-M slope roughly follows the self-similar prediction, except for a steepening due to a deficit of gas in lower mass clusters at low redshift in simulations with AGN feedback.  AGN feedback enhances the overall Y-M scatter by 2% to 13%, a reflection of accretion history variations due to cluster merging.  If we split the cluster system into lower, middle and upper bands of both P_kin/P_th and long-to-short axis ratio, find a ~10% effect on Y-M.  Identifying observable second parameters related to internal bulk flows and anisotropy for cluster-selection to minimize Y-M scatter in a "fundamental plane" would allow tighter cosmological parameter constraints.


1109.3711
On the cluster physics of SZ surveys II: Deconstructing the thermal SZ power spectrum
Battaglia, Bond, Pfrommer, Sievers


CMB secondary anisotropies resulting from tSZ--its amplitude depends critically on the average thermal pressure profile of galaxy groups and clusters.  Use a suite of SPH simulations that include radiative cooling, star formation, SNe, and AGN feedback.  Examine in detail how the pressure profile depends on cluster radius, mass, and redshift and provide and empirical fitting function.  Employ three different approaches for calculating the tSZ power spectrum  Analytical that uses pressure profile fit; semi-analytical method of pasting pressure fit onto simulated clusters, and direct numerical integration of the simulated volumes.  Demonstrate that the detailed structure of the intracluster medium and cosmic web affect the tSZ power spectrum.  Particularly: the substructure and asphericity of the clusters increase the tSZ power spectrum by 10-20% at l=2000-8000, with most of the additional power being contributed by substructures.  Contributions to the power spectrum from radii larger than R_500 is ~20% at l=3000, thus cluster interiors (r<R_500) dominated the power spectrum amplitude at these angular scales.


1109.3713
The origin of metals in the circum-galactic medium of massive galaxies at z=3
Shen, Madau, Aguirre, Guedes, Mayer, Wadsley


Detailed study of the metal-enriched circum-galactic medium of a massive galaxy at z=3 from the "Eris" suite of new cosmological hydrodynamic "zoom-in" simulations in whch a close analog of a MW disk galaxy arises at the present epoch.  At z=3, the main progenitor resembles a Ly-break galaxy of M_vir=2.4e11 solar mass and r_vir=48kpc, with SFR 18 Msun/yr, and its metal-enriched CGM (?) extends as far as 200 (physical) kpc from its center. 41% hot (T>3e5K), 9% warm (2e5>T>3e4K), 50% cold (T<3e4K) gas-phase metals.  Main host is responsible for 60% of all metals found within 3r_vir; satellite progenitors give origin to 28% and 5% of all metals within and beyond 3r_vir, respectively; satellite dwarf companions give origin to 12% and 95%, respectively.  Late (z<5) superwinds account for only 9% of all the metals observed beyond 2r_vir, the bulk having been released at redshifts 5<z<8 by early SF and outflows.  In the IGM, lower overdensities are typically enriched by 'older', colder metals.  Heavy elements are accreted onto Eris along filaments via low-metallicity cold inflows, and are ejected hot via galactic outflows at a few hundred km/s.  The outflow mass-loading factor as a function of redshift ranges between 0.1 and 1.2, and shows no correlation with the mass of the host.