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The Sunyaev -Zeldovich effect as a probe of black hole feedback

Posted on:2010-06-21Degree:Ph.DType:Dissertation
University:University of PittsburghCandidate:Chatterjee, SuchetanaFull Text:PDF
GTID:1440390002972537Subject:Physics
Abstract/Summary:
Feedback from supermassive black holes has a substantial but only partially understood impact on structure formation in the universe. The Sunyaev-Zeldovich signal from the hot gas that is present in black hole environments serves, as a potential probe of this feedback mechanism. Using a simple one-dimensional Sedov-Taylor model of energy outflow we calculate the angular power spectrum of the Sunyaev-Zeldovich distortion. The amplitude of temperature fluctuation is of the order of a micro-Kelvin in the cosmic microwave background at arcminute scales. This signal is at or below the noise level of current microwave experiments including the Atacama Cosmology Telescope and the South Pole Telescope.;To further investigate this effect we have constructed microwave maps of the resulting distortion around individual black holes from a cosmological hydrodynamic simulation. The simulation employs a self-consistent treatment of star formation, supernova feedback and accretion and feedback from supermassive black holes. We show that the temperature distortion scales approximately with the black hole mass and accretion rate, with a typical amplitude up to a few micro-Kelvin on angular scales around 10 arcseconds. We also discuss the possible techniques for detection of this signal which includes pointed observations from high resolution millimeter wave telescopes and cross-correlation of optical quasar catalogs with microwave maps.;We perform a cross-correlation analysis of the signal, by stacking microwave maps of quasars identified in the Sloan Digital Sky Survey. We use the microwave data from the Wilkinson Microwave Anisotropy Probe experiment to do this analysis. We perform a two-component (SZ+Dust) fit to the cross-correlation spectrum. Our results yield a best fit y parameter of (5:8 +/- 1:8) x 10-7. This signal is likely to be originating from the Sunyaev-Zeldovich distortions from intervening large scale structures. We show that the Atacama Cosmology Telescope will be able to constrain this signal with a much higher statistical significance.;In this work we have shown that a traditional tool of cosmology, namely the microwave background, can be used as a potential probe of feedback from supermassive black holes, which is an interesting problem in theories of galaxy evolution.;Keywords. cosmic microwave background---cosmology:theory---galaxies:intergalactic medium---quasars:general---submillimeter.
Keywords/Search Tags:Black hole, Feedback, Microwave, Probe
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