Day 725

Tuesday.

1408.3631
Prospects for measuring the mass of black holes at high redshifts with resolved kinematics using gravitational lensing
Hezaveh

Application of the most robust method of measuring black hole masses, spatially resolved kinematics of gas and stars, is presently limited to nearby galaxies.  ALMA and 30-m class telescopes with milli-arcsecond resolution are expected to extend such measurements to larger distances.  Study the possibility of exploiting the angular magnification provided by strong gravitational lensing to measure black hole masses at high z (z~1-6), using resolved gas kinematics with these instruments.  Show that in ~15% and 20% of strongly lensed galaxies, the inner 25 and 50 pc could be resolved, allowing the mass of 1e8 Msun BHs to be dynamically measured with ALMA, if moderately bright molecular gas is present at these small radii.  Given the large number of SLs discovered in current millimeter surveys and future optical surveys, this fraction could constitute a statistically significant population f0or studying the evolution of the M-sigma relation at high z.

1408.3832
Analytical models for non-thermal pressure in galaxy clusters II: comparison with cosmological hydrodynamics simulation
Shi, Komatsu, Nelson, Nagai

Turbulent gas motion inside galaxy clusters provides a non-negligible non-thermal pressure support to the intracluster gas.  If not corrected, it leads to a systematic bias in the estimation of cluster masses from X-ray and SZ observations assuming hydrostatic equilibrium, and affects interpretation of measurements of the SZ PS and observations of cluster outskirts from ongoing and upcoming large cluster surreys.  Recently, Shi & Komatsu 2014 developed an analytical model for predicting the radius, mass, and redshift dependence of the non-thermal pressure contributed by the kinetic random motions of intracluster gas sourced by the cluster mass growth.  In this paper, compare the predictions of this analytical model to a state-of-the-art cosmological hydro sim.  As different mass growth histories result in different non-thermal pressure, perform the comparison on 65 simulated galaxy clusters on a cluster-by-cluster basis.  Find excellent agreement between the modeled and simulated non-termal pressure profiles.  Results open up the possibility of using the analytical model to correct the systematic bias and the mass estimation of galaxy clusters.  Also discuss tests of the physical picture underlying the evolution of intracluster turbulence, as well as a way to further improve the analytical modeling, which may help achieve a unified understanding of non-thermal phenomena in galaxy clusters.