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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

A case for an ultra massive black hole in the galaxy cluster MS0735.6+7421

Movassaghi Jorshari, Razzi 22 June 2012 (has links)
In this work, we study the galaxy cluster MS0735.6+7421 that hosts the most energetic observed active galactic nucleus (AGN) outburst so far. Explaining this very energetic AGN outburst is found to be challenging. McNamara et al. 2009 grappled with this problem and proposed two possible solutions: either the black hole (BH) must be an ultra massive one (with mass $> 10^{10} \ \text{M}_\odot$), or the efficiency of the mass to energy conversion ($\epsilon$) should be higher than the generally assumed value of $\epsilon \sim 0.1$. However, the efficiency of the mass to energy conversion depends on the BH's spin {Benson and Babul 2009}; higher $\epsilon$ can be achieved with a higher spinning BH. Here, we explore the second solution in detail, and ask the question: How did the BH spin up to the very high spins in advance of the outburst? We also explore the attendant physical processes, such as star formation, during the spin-up mode and investigate the associated observational implications. Comparing our results with what is generally expected from simulations and observational studies suggests that for all intents and purposes, the existence of an ultra massive BH is the simplest solution. / Graduate

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