Download or read book Scaling Relations Between Super massive Black Holes Galaxies and Dark Matter Halos written by Adam Larkin and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Joint Evolution of Black Holes and Galaxies written by M. Colpi and published by CRC Press. This book was released on 2006-01-27 with total page 482 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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
Download or read book Supermassive Black Holes in the Distant Universe written by A.J. Barger and published by Springer Science & Business Media. This book was released on 2013-11-09 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt: Quasars, and the menagerie of other galaxies with "unusual nuclei", now collectively known as Active Galactic Nuclei or AGN, have, in one form or another, sparked the interest of astronomers for over 60 years. The only known mechanism that can explain the staggering amounts of energy emitted by the innermost regions of these systems is gravitational energy release by matter falling towards a supermassive black hole --- a black hole whose mass is millions to billions of times the mass of our Sun. AGN emit radiation at all wavelengths. X-rays originating at a distance of a few times the event horizon of the black hole are the emissions closest to the black hole that we can detect; thus, X-rays directly reveal the presence of active supermassive black holes. Oftentimes, however, the supermassive black holes that lie at the centers of AGN are cocooned in gas and dust that absorb the emitted low energy X-rays and the optical and ultraviolet light, hiding the black hole from view at these wavelengths. Until recently, this low-energy absorption presented a major obstacle in observational efforts to map the accretion history of the universe. In 1999 and 2000, the launches of the Chandra and XMM-Newton X-ray Observatories finally broke the impasse. The impact of these observatories on X-ray astronomy is similar to the impact that the Hubble Space Telescope had on optical astronomy. The astounding new data from these observatories have enabled astronomers to make enormous advances in their understanding of when accretion occurs.
Download or read book The X ray Background written by Xavier Barcons and published by Cambridge University Press. This book was released on 1992-07-31 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt: A review of the current observational knowledge and understanding of the cosmic X-ray background.
Download or read book Coevolution of Black Holes and Galaxies Volume 1 Carnegie Observatories Astrophysics Series written by Luis C. Ho and published by Cambridge University Press. This book was released on 2004-09-09 with total page 502 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book was originally published in 2004. Black holes are among the most mysterious objects in the Universe. Weighing up to several billion Suns, massive black holes have long been suspected to be the central powerhouses of energetic phenomena such as quasars. Advances in astronomy have not only provided spectacular proof of this long-standing paradigm, but have revealed the unexpected result that far from being rare, exotic beasts, they inhabit the center of virtually all large galaxies. Candidate black holes have been identified in increasingly large numbers of galaxies, both inactive and active, to the point where statistical studies are possible. Fresh work has highlighted the close connection between the formation, growth, and evolution of supermassive black holes and their host galaxies. This volume contains the invited lectures from an international symposium that was held to explore this exciting theme, and is a valuable review for professional astronomers and graduate students.
Download or read book Characterizing the Nanohertz Gravitational Wave Background Produced by a Cosmological Population of Binary Supermassive Black Holes written by Elinore Roebber and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "The subject of this thesis is modelling the gravitational wave signal produced by binary supermassive black holes in the nHz frequency band. We begin with a review of large scale structure and galaxies as well as supermassive black holes and their origins, relation to their host galaxies, and potential to form binaries, followed by a review of gravitational wave formalism and its application to binary supermassive black holes and the pulsar timing arrays which could detect such a signal.The review finished, we develop population synthesis models in to make statistical predictions about the total population of binary supermassive black holes expected to be emitting gravitational waves at z ≲ 4. The population synthesis models are based on large N-body simulations and empirical scaling relations between dark matter halos, galaxy properties, and supermassive black holes. We use this simulated population to make predictions on the spectrum of the low-frequency stochastic gravitational wave background and discuss the variance due to Poisson noise in the population, astrophysical and cosmological uncertainties, and frequency resolution. Subsequently, we present a framework for treating the angular information in the pulsar timing array response to a general gravitational wave background. We show that the angular power spectrum of the all-sky maps of gravitational redshift induced by the gravitational waves is mathematically equivalent to the standard Hellings & Downs curve analysis, but has its own advantages. We use this equivalence to examine the expected variance on the Hellings & Downs curve for the cases of individual strong sources of gravitational waves and for a stochastic gravitational wave background. Finally, we discuss the sensitivity of pulsar timing arrays to the angular power spectrum." --
Download or read book Supermassive Black Holes and Their Host Galaxies written by Ronald Läsker and published by . This book was released on 2013 with total page 169 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Interplay Between Supermassive Black Holes and Their Host Galaxies written by Sabine Thater and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Supermassive black holes reside in the hearts of almost all massive galaxies. Their evolutionary path seems to be strongly linked to the evolution of their host galaxies, as implied by several empirical relations between the black hole mass (M BH ) and different host galaxy properties. The physical driver of this co-evolution is, however, still not understood. More mass measurements over homogeneous samples and a detailed understanding of systematic uncertainties are required to fathom the origin of the scaling relations. In this thesis, I present the mass estimations of supermassive black holes in the nuclei of one late-type and thirteen early-type galaxies. Our SMASHING sample extends from the intermediate to the massive galaxy mass regime and was selected to fill in gaps in number of galaxies along the scaling relations. All galaxies were observed at high spatial resolution, making use of the adaptive-optics mode of integral field unit (IFU) instruments on state-of-the-art telescopes (SINFONI, NIFS, MUSE). I extracted the ...
Download or read book Black Hole Masses in Nearby Brightest Cluster Galaxies written by Nicholas James McConnell and published by . This book was released on 2012 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Mergers of Elliptical Galaxies and Dark Matter Halos written by Michael Robert Boylan-Kolchin and published by . This book was released on 2006 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Galaxy Formation and Mergers with Stars and Massive Black Holes written by Chi-hun Kim and published by Stanford University. This book was released on 2011 with total page 189 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Coevolution of Supermassive Black Holes and Their Host Galaxies written by Kyle Devon Hiner and published by . This book was released on 2012 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Black Holes written by Steff Jaywan and published by Dedona Publishing. This book was released on with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book consists of two titles, which are the following: Galaxies - Galaxies are dynamic entities, constantly evolving through processes like mergers, collisions, and interactions with neighboring galaxies. When galaxies merge, their stars, gas, and dust can undergo dramatic transformations, leading to the formation of new stars and restructuring of the galaxy's shape. These interactions can trigger intense bursts of star formation and feed supermassive black holes at the galaxies' centers, leading to the emission of powerful jets of radiation. Supermassive Black Hole - Black holes form through various processes that involve the collapse of massive astronomical objects and the merging of smaller black holes. One primary method is the stellar collapse. Stars, during their lifecycle, fuse hydrogen into helium in their cores. When the hydrogen is depleted, they begin fusing heavier elements until iron is produced. For stars more than 20 times the mass of the Sun, the end of this fusion process leads to a supernova explosion. The core of the star collapses rapidly due to gravity, and if the core's mass is sufficiently large (typically more than about three times the mass of the Sun), it will continue collapsing into a singularity, forming a stellar-mass black hole.
Download or read book The Role of Halo Substructure in Gamma Ray Dark Matter Searches written by Miguel A. Sánchez-Conde and published by MDPI. This book was released on 2020-05-28 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: An important, open research topic today is to understand the relevance that dark matter halo substructure may have for dark matter searches. In the standard cosmological model, halo substructure or subhalos are predicted to be largely abundant inside larger halos, for example, galaxies such as ours, and are thought to form first and later merge to form larger structures. Dwarf satellite galaxies—the most massive exponents of halo substructure in our own galaxy—are already known to be excellent targets for dark matter searches, and indeed, they are constantly scrutinized by current gamma-ray experiments in the search for dark matter signals. Lighter subhalos not massive enough to have a visible counterpart of stars and gas may be good targets as well, given their typical abundances and distances. In addition, the clumpy distribution of subhalos residing in larger halos may boost the dark matter signals considerably. In an era in which gamma-ray experiments possess, for the first time, the exciting potential to put to test the preferred dark matter particle theories, a profound knowledge of dark matter astrophysical targets and scenarios is mandatory should we aim for accurate predictions of dark matter-induced fluxes for investing significant telescope observing time on selected targets and for deriving robust conclusions from our dark matter search efforts. In this regard, a precise characterization of the statistical and structural properties of subhalos becomes critical. In this Special Issue, we aim to summarize where we stand today on our knowledge of the different aspects of the dark matter halo substructure; to identify what are the remaining big questions, and how we could address these; and, by doing so, to find new avenues for research.
Download or read book Supermassive Black Hole written by Celestial Angell and published by Dedona Publishing. This book was released on with total page 43 pages. Available in PDF, EPUB and Kindle. Book excerpt: A black hole is a region in space where the gravitational pull is so strong that nothing, not even light, can escape from it. This occurs when a massive amount of matter is compressed into a very small area, creating a powerful gravitational field. Black holes form through various processes that involve the collapse of massive astronomical objects and the merging of smaller black holes. One primary method is the stellar collapse. Stars, during their lifecycle, fuse hydrogen into helium in their cores. When the hydrogen is depleted, they begin fusing heavier elements until iron is produced. For stars more than 20 times the mass of the Sun, the end of this fusion process leads to a supernova explosion. The core of the star collapses rapidly due to gravity, and if the core's mass is sufficiently large (typically more than about three times the mass of the Sun), it will continue collapsing into a singularity, forming a stellar-mass black hole. Another way black holes can form is through accretion and growth. A compact object like a neutron star or a white dwarf can accumulate matter from a companion star or its surroundings. As this matter accumulates, the mass of the compact object increases, and it may eventually reach a critical mass where it collapses into a black hole.
Download or read book From Supermassive Black Holes to Supersymmetric Dark Matter written by Savvas Michael Koushiappas and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: It is without doubt that in recent years cosmology has entered an era where cosmological parameters are now measured precisely enough to derive conclusions about the underlying characteristics of the Universe. I present an overview of the methods used to estimate the parameters that lead to the standard cosmological model. After a brief detour on the current understanding of the mechanisms that lead to galaxy formation, I present a model in which the seeds of supermassive black holes observed in galactic spheroids form out of the lowest angular momentum gas in proto-galaxies at high redshift. I assume that the gas in early-forming, rare-peak halos has a distribution of specific angular momentum similar to that derived for the dark matter. In halos more massive than a critical threshold, proto-galactic disks are gravitationally unstable and experience an efficient viscosity that transfers angular momentum outward allowing mass inflow. This process continues until the first massive stars disrupt the disk. The seed black holes created in this manner have a characteristic mass scale, roughly independent of the redshift of formation. By the redshift of reionization, the comoving mass density is comparable to that inferred from observations, with room for appropriate additional luminous growth during a later quasar accretion phase. The hierarchical merger process naturally leads to a linear correlation between black-hole mass and stellar spheroid mass. Quite orthogonal to this study, I estimate the probability of detecting gamma-rays from the annihilation of neutralino dark matter in the Milky Way substructure. I characterize substructure statistically based on Monte Carlo realizations of the formation of a Milky Way-like halo. I find that it may be possible for upcoming experiments to detect gamma-rays from dark matter substructure if the neutralino is relatively light, while for a heavy neutralino such a detection would be unlikely. I find that the probability of detection is sensitive to poorly-constrained input parameters, particularly those that characterize the primordial power spectrum. I conclude that the lack of a detected gamma-ray signal gives very little information about the supersymmetric parameter space due to uncertainties associated with both the properties of substructure and cosmological parameters.
Download or read book The Dark Matter Effect on the Scaling Relations written by Chiara Marmo and published by . This book was released on 2003 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt:
