[PDF] Modeling The Evolution Of Galaxies And Massive Black Holes Across Cosmic Time eBook

Author : Daniel Anglés-Alcázar
Publisher :
Page : 207 pages
File Size : 21,20 MB
Release : 2014
Category :
ISBN :

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I use cosmological hydrodynamic simulations to investigate different aspects of the evolution of galaxies and massive black holes across cosmic time. First, I present high resolution "zoom-in" simulations including various prescriptions for galactic outflows designed to explore the impact of star-formation driven winds on the morphological, dynamical, and structural properties of individual galaxies from early times down to z = 2. Simulations without winds produce massive, compact galaxies with low gas fractions, super-solar metallicities, high bulge fractions, and much of the star formation concentrated within the inner kpc. I show that strong winds are required to suppress early star formation, maintain high gas fractions, redistribute star-forming gas and metals over larger scales, and increase the velocity dispersion of simulated galaxies, more in agreement with the large, extended, turbulent disks typical of high-redshift star-forming galaxies. Next, I combine cosmological simulations with analytic models of black hole growth to investigate the physical mechanisms driving the observed connection between massive black holes and their host galaxies. I describe a plausible model consistent with available observations in which black hole growth is limited by galaxy-scale torques. In this torque-limited growth scenario, black holes and host galaxies evolve on average toward the observed scaling relations, regardless of the initial conditions, and with no need for mass averaging through mergers or additional self-regulation processes. Outflows from the accretion disk play a key role by providing significant mass loss, but there is no need for strong interaction with the inflowing gas in order to regulate black holes in a non-linear feedback loop. I discuss some of the main implications of this scenario in the context of current observations, including the distribution and evolution of Eddington ratios, the connection between major galaxy mergers, star formation, and nuclear activity, and the rapid growth of the first black holes in the early universe. Finally, I present preliminary results from simulations including a fully consistent treatment of black hole accretion and feedback indicating that the effects of powerful accretion-driven outflows on black hole growth itself may have a more limited impact than previously thought.

Author : M. Colpi
Publisher : CRC Press
Page : 482 pages
File Size : 31,41 MB
Release : 2006-01-27
Category : Science
ISBN : 1420012096

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Black holes are among the most mysterious objects that the human mind has been capable of imagining. As pure mathematical constructions, they are tools for exploiting the fundamental laws of physics. As astronomical sources, they are part of our cosmic landscape, warping space-time, coupled to the large-scale properties and life cycle of their host

Author : G. Hensler
Publisher : Springer Science & Business Media
Page : 684 pages
File Size : 31,43 MB
Release : 2013-11-11
Category : Science
ISBN : 9401733155

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Galaxies have a history: distant galaxies, formed early in the life of the universe, differ from the nearby ones. This book addresses the modeling of galaxy evolution from their cosmological formation to their presently observable structures, presenting the state of the art in the field.

Author : Chi-hun Kim
Publisher : Stanford University
Page : 189 pages
File Size : 11,75 MB
Release : 2011
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While mounting observational evidence suggests the coevolution of galaxies and their embedded massive black holes (MBHs), a comprehensive astrophysical understanding which incorporates both galaxies and MBHs has been missing. To tackle the nonlinear processes of galaxy formation, we develop a state-of-the-art numerical framework which self-consistently models the interplay between galactic components: dark matter, gas, stars, and MBHs. Utilizing this physically motivated tool, we present an investigation of a massive star-forming galaxy hosting a slowly growing MBH in a cosmological LCDM simulation. The MBH feedback heats the surrounding gas and locally suppresses star formation in the galactic inner core. In simulations of merging galaxies, the high-resolution adaptive mesh allows us to observe widespread starbursts via shock-induced star formation, and the interplay between the galaxies and their embedding medium. Fast growing MBHs in merging galaxies drive more frequent and powerful jets creating sizable bubbles at the galactic centers. We conclude that the interaction between the interstellar gas, stars and MBHs is critical in understanding the star formation history, black hole accretion history, and cosmological evolution of galaxies. Expanding upon our extensive experience in galactic simulations, we are well poised to apply this tool to other challenging, yet highly rewarding tasks in contemporary astrophysics, such as high-redshift quasar formation.

Author : Nicholas James McConnell
Publisher :
Page : 356 pages
File Size : 40,7 MB
Release : 2012
Category :
ISBN :

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The most massive galaxies in the Universe live at the centers of galaxy clusters and exhibit a number of extreme properties. Although their evolution broadly resembles that of normal elliptical galaxies, with early gas quenching and gradual assembly from smaller stellar systems, their unique cosmic environments may have offered additional pathways for growth. The extreme stellar mass growth of BCGs is clearly demonstrated by their overall luminosities, but the growth histories and present-day masses of their central black holes are not well known. A key body of evidence for the evolutionary connections between galaxies and supermassive black holes is the set of scaling relations between black hole masses (MBH) and the stellar velocity dispersions ([sigma]), luminosities (L), or bulge masses (Mbulge) of their host galaxies. However, these scaling relations are poorly sampled for BCGs. Populating the relations with direct measurements of MBH could offer new insights to the growth of black holes and stellar systems at the hearts of galaxy clusters. Along with collaborators, I have undertaken a series of observations of the centers of BCGs, using integral-field spectrographs on the Keck, Gemini, and Harlan J. Smith telescopes. In this dissertation, I describe the measurement and analysis of stellar kinematics at the centers of five BCGs, and measurements of their black hole masses using stellar orbit models. The most notable result is the measurement of black holes with approximately 10 billion solar masses in NGC 3842 and NGC 4889. These are the largest black hole masses ever directly measured, and they significantly exceed predictions from both the MBH-[sigma] and MBH-L relations. Their masses are comparable to the biggest black holes powering high-redshift quasars, suggesting a tantalizing link between early sites of prolific black hole growth and rich galaxy clusters today. In contrast, I find that NGC 6086 and NGC 7768 host black holes with only a few billion solar masses. These measurements, as well as my upper limit for MBH in NGC 2832, are more consistent with the existing black hole scaling relations. Recent measurements by my team and others have reshaped the sample of well-measured black hole masses, introducing significant updates to previous compilations. I present a sample of 65 dynamical black hole mass measurements, compiled from published literature through May 2012. In addition to previously reported values of [sigma] and L, I have compiled an updated sample of bulge masses for 34 galaxies. The updated sample yields a steeper MBH-[sigma] relation than previous versions, while the MBH-L and MBH-Mbulge relations experience relatively small changes. I have examined the black hole scaling relations for a variety of galaxy subsamples and find noteworthy variations in the MBH-[sigma] relation for early- versus late-type galaxies and core-profile versus power-law galaxies. Using the new sample, I have measured the empirical scatter in MBH and have attempted to measure the intrinsic scatter for multiple intervals in [sigma], L, and Mbulge. This is an important step forward from previous studies, which have only measured the intrinsic scatter over the full range of a given host galaxy property. Several models of black hole growth over cosmic time have predicted decreasing scatter in MBH as galaxy mass increases, reflecting the influence of hierarchical mergers driving galaxies and black holes toward an average MBH/Mbulge ratio. In contrast, I find nearly constant scatter in MBH over a wide range of galaxy luminosities and bulge masses. My investigations thus far have contributed to a gradual change in astronomers' understanding of the black hole scaling relations. The present-day relations are not as tight as previously reported versions, and evidence is mounting against a universal process for co-evolution between black holes and galaxies. I will use observations of a larger sample of BCGs and massive group galaxies to explore the effects of environment on the growth of individual black holes and on cosmic scatter in MBH.

Author : Houjun Mo
Publisher : Cambridge University Press
Page : 841 pages
File Size : 19,31 MB
Release : 2010-05-20
Category : Science
ISBN : 0521857937

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A coherent introduction for researchers in astronomy, particle physics, and cosmology on the formation and evolution of galaxies.

Author : Laura Brenneman
Publisher : Springer Science & Business Media
Page : 57 pages
File Size : 15,31 MB
Release : 2013-06-26
Category : Science
ISBN : 1461477719

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Measuring the spin distribution of supermassive black holes is of critical importance for understanding how these black holes and their host galaxies form and evolve over time, yet this type of study is only in its infancy. This brief describes how astronomers measure spin in supermassive black holes using X-ray spectroscopy. It also reviews the constraints that have been placed on the spin distribution in local, bright active galaxies over the past six years, and the cosmological implications of these constraints. Finally, it summarizes the open questions that remain in this exciting new field of research and points toward future discoveries soon to be made by the next generation of space-based observatories.

Author : Gerald Edward Brown
Publisher : World Scientific
Page : 530 pages
File Size : 45,46 MB
Release : 2003
Category : Science
ISBN : 9789812382504

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In published papers H A Bethe and G E Brown worked out the collapse of large stars and supernova explosions. They went on to evolve binaries of compact stars, finding that in the standard scenario the first formed neutron star always went into a black hole in common envelope evolution. C-H Lee joined them in the study of black hole binaries and gamma ray bursts. They found the black holes to be the fossils of the gamma ray bursts. From their properties they could reconstruct features of the burst and of the accompanying hypernova explosions. This invaluable book contains 23 papers on astrophysics, chiefly on compact objects, written over 23 years. The papers are accompanied by illuminating commentary. In addition there is an appendix on kaon condensation which the editors believe to be relevant to the equation of state in neutron stars, and to explain why black holes are formed at relatively low masses.

Author : Andrea Cimatti
Publisher : Cambridge University Press
Page : 587 pages
File Size : 30,83 MB
Release : 2019-10-17
Category : Science
ISBN : 1107134765

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A comprehensive examination of nearly fourteen billion years of galaxy formation and evolution, from primordial gas to present-day galaxies.

Author :
Publisher :
Page : 64 pages
File Size : 26,17 MB
Release : 2013
Category : Black holes (Astronomy)
ISBN : 9780716695899

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"An introduction to quasars and black holes with information about their formation and characteristics. Includes diagrams, fun facts, a glossary, a resource list, and an index"--Provided by publisher.