Download or read book Resolving Black Hole and Star Formation Activity in Nearby Galaxies written by Mallory Elyse Molina and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Black hole accretion and star formation exhibit different properties with observed spatial scale. To fully understand them, we must consider the local environment's impact on measured global properties. My dissertation focuses on the spatially resolved excitation mechanisms that power observed emission, and the dust that obscures it. Low ionization nuclear emission regions (LINERs) are common in nearby galaxies, and are often explained by photoionization by low luminosity active galactic nuclei (AGNs). But this energy source is not sufficient to power the observed emission lines that define LINERs on 100 pc scales. Using the Hubble Space Telescope, I resolved the nuclear regions of three nearby LINERs on the 10 pc scale to track the dominant power source with distance from the nucleus. The resulting physical model involved photoionization from the AGN within the central 20 pc, and shock excitation at larger distances. I conclude that integrated LINER-like emission can be explained by a combination of photoionization by the AGN and shocks on different spatial scales.The advancement and cessation of star formation within a galaxy is vital for understanding galaxy evolution. Furthermore, the rest-frame ultra violet (UV) and optical bands are crucial for disentangling the star formation history, metallicity and age of systems. To that end, I construct a data set of 150 galaxies with Swift Ultra Violet Optical Telescope (UVOT) UV photometry and Sloan Digital Sky Survey-IV Mapping Nearby Galaxies at Apache Point Observatory (SDSS-IV/MaNGA) optical IFU spectroscopy. I present properties of the data set, and use it to quantify relations between the UV and H-alpha star formation rate proxies.Unfortunately, our understanding of star formation is highly dependent on dust attenuation, which itself depends on the spatial scales and properties on which it is observed. This is especially true in the UV band, where the attenuation laws from literature differ dramatically. Therefore, any attempts to understand star formation histories in using the Swift+MaNGA data catalog will be subject to this systematic. To address this, I studied the attenuation law of kiloparsec-sized star forming regions using a subset of 29 galaxies. I compared the attenuation from the individual regions with that of the parent galaxy, and find the attenuation of the optical nebular emission is similar between the two physical scales, but that of the UV stellar continuum is not. I attribute this difference to sightline-dependencies of the stellar continuum attenuation and dilution of the UV light by older stars.Through spatially resolved studies of black hole accretion and star formation activity in nearby galaxies, my dissertation work provides context for the integrated properties of nearby galaxies, and provides context for future statistical surveys.

Download or read book The Interplay Among Black Holes Stars and ISM in Galactic Nuclei IAU S222 written by International Astronomical Union. Symposium and published by Cambridge University Press. This book was released on 2004 with total page 608 pages. Available in PDF, EPUB and Kindle. Book excerpt: How massive are the largest and smallest nuclear black holes in galaxies? Why are the masses of nuclear black holes proportional to those of their host galaxy bulges? How is nuclear activity triggered? What are the observational signatures of such processes? What are the connections between the active nucleus, stars and interstellar medium in galaxies? Answers to these questions are addressed in this book, which presents a compilation of 191 works covering recent observations from X-rays to radio wavelengths, as well as theoretical modeling of accretion disks, stellar populations and galaxy and black hole evolution. This volume presents the nuclear activity as a phase in the life of a galaxy, which is intimately connected to the evolution of its stars and interstellar medium. It brings together recent developments in topics covering most aspects of galaxy evolution, and is a valuable resource for astronomers and graduate students working in extragalactic astronomy.

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 Modeling the Evolution of Galaxies and Massive Black Holes Across Cosmic Time written by Daniel Anglés-Alcázar and published by . This book was released on 2014 with total page 207 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

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 Formation and Evolution of Black Holes in the Galaxy written by Gerald Edward Brown and published by World Scientific. This book was released on 2003 with total page 530 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

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 Black Hole Growth and Star Formation in a Complete Sample of Seyfert Galaxies written by Aleksandar Diamond-Stanic and published by . This book was released on 2010 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt: I investigate methods for determining black hole accretion rates and star-formation rates in galaxies hosting active galactic nuclei (AGNs) and use these results to identify biases in our census of black hole growth, to probe fundamental differences between obscured and unobscured AGNs, and to explore the connection between black hole growth and galaxy evolution. I show that the mid-infrared [O IV] emission line, which probes high-ionization gas and suffers little dust attenuation, is a useful diagnostic of AGN luminosity. Using [O IV]measurements for a complete sample of Seyfert galaxies, I show that the intrinsic luminosities of obscured and unobscured AGNs are quite similar. This is in contrast to the [O III] optical emission line and hard X-ray continuum luminosities, which are systematically smaller for obscured Seyferts, revealing strong biases in existing AGN surveys. I also explore the effect of AGNs on the mid-infrared aromatic features, which are useful probes of star-formation activity. I find that the 6.2, 7.7, and 8.6 micron features are suppressed relative to the 11.3 micron feature in Seyfert galaxies, and show that this behavior is correlated with the strength of the rotational H2 (molecular hydrogen) emission, which traces shocked gas. This suggests that shocks associated with the AGN modify the structure of aromatic molecules, but I show that the 11.3 micron aromatic feature is robust to the effects of such shock processing, and use it to estimate nuclear star-formation rates for AGN host galaxies. I find an approximately linear relationship between black hole accretion rate and nuclear star-formation rate, and show that high-luminosity AGNs reside in galaxies with more centrally concentrated star formation. This suggests that the strength of AGN activity is driven by the amount of gas in the central few hundred parsecs, and is consistent with models where AGN activity is linked with elevated nuclear star formation.

Download or read book Star Formation Rates of Galaxies written by Andreas Zezas and published by Cambridge University Press. This book was released on 2021-04-29 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt: Star-formation is one of the key processes that shape the current state and evolution of galaxies. This volume provides a comprehensive presentation of the different methods used to measure the intensity of recent or on-going star-forming activity in galaxies, discussing their advantages and complications in detail. It includes a thorough overview of the theoretical underpinnings of star-formation rate indicators, including topics such as stellar evolution and stellar spectra, the stellar initial mass function, and the physical conditions in the interstellar medium. The authors bring together in one place detailed and comparative discussions of traditional and new star-formation rate indicators, star-formation rate measurements in different spatial scales, and comparisons of star-formation rate indicators probing different stellar populations, along with the corresponding theoretical background. This is a useful reference for students and researchers working in the field of extragalactic astrophysics and studying star-formation in local and higher-redshift galaxies.

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 2004-08-03 with total page 322 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 Nuclear Activity in Nearby Galaxies written by Mercedes Esteves Filho and published by . This book was released on 2003 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Variability of Active Galactic Nuclei written by and published by . This book was released on 1991 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Connecting Galaxy and Supermassive Black Hole Growth During the Last 8 Billion Years written by Stephanie Juneau and published by . This book was released on 2011 with total page 454 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Spatially Resolved Star Formation Law in Nearby Galaxies written by Frank Bigiel and published by . This book was released on 2008 with total page 107 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Astrophysical Masers and Their Environments IAU S242 written by International Astronomical Union. Symposium and published by Cambridge University Press. This book was released on 2008-02-14 with total page 564 pages. Available in PDF, EPUB and Kindle. Book excerpt: Astrophysical masers, naturally occurring microwave and radio-wave emissions, provide an important tool to investigate astrophysical environments. Several thousand maser sources have been observed in the interstellar medium and star formation regions, in the expanding winds from evolved stars, in the compressed shells of supernovae remnants, in comets and in the centers of galaxies. Masers are also useful for studying the structure and dynamics of our own galaxy, while masers in other galaxies are now used for cosmological studies and studies of galactic nuclei. This volume contains the latest research on the topic as presented at IAU Symposium 242, only the third international symposium on astrophysical masers. Over 125 astronomers from 18 different countries gathered in Alice Spring, Australia, for discussions on maser research.

Download or read book Formation Of The First Black Holes written by Muhammad Latif and published by World Scientific. This book was released on 2019-04-26 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt: The formation of the first supermassive black holes is one of the main open questions in our understanding of high-redshift structure formation. In this book, we aim to provide a summary of state-of-the-art modern research on this topic, exploring the formation of massive black holes from a fluid-dynamical, stellar-dynamical and chemical perspective. The book thus presents a solid theoretical foundation, a comparison with current observations and future observational perspectives with upcoming missions such as the Square Kilometre Array, the European Extremely Large Telescope, the Euclid satellite as well as possible detections via gravitational waves.