Download or read book Spatially resolved Stellar Kinematics and Radial Molecular Gas Flows in the Nuclear Regions of Luminous Infrared Galaxies written by Alejandro Crespo Gómez and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since their discovery, Luminous and Ultraluminous Infrared Galaxies (U/LIRGs) have been the subject of numerous studies due to their characteristically intense star formation rate (SFR). These objects are the perfect laboratory to study in detail the physical and dynamical processes that govern the creation of stars from gas reservoirs and are therefore critical for the evolution of galaxies. Furthermore, although these galaxies are not common in the local Universe, they are the dominant population to the energy density at z>1. Understanding the behaviour of gas and stars in these objects is therefore critical to our knowledge of what the Universe was like more than 8 billion years ago. Gas kinematic studies in these objects have revealed that their behaviour encompasses a wide range of dynamical states, from those dominated by the rotating-disc motions to much more complex ones driven by gravitational interaction processes. It is also worth noting that the intense starbursts and the presence of active galactic nuclei (AGN) in these objects yields a scenario where the presence of gas ejections, in any of their phases, is not uncommon. In this scenario, the stellar component is really relevant, since stars area better tracer of the gravitational potential as they are less reactive to local events that may perturb their kinematics. However, the stellar kinematics of these objects remains largely unknown, partly due to the difficulty of obtaining a signal-to-noise value (S/N) high enough to observe the stellar continuum, and has only been studied for a small number of objects, generally from the integrated and/or nuclear spectra...
Download or read book High resolution Observations of the Molecular Gas in Luminous Infrared Galaxies written by Peter M. Bryant and published by . This book was released on 1997 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Active Galactic Nuclei written by Francoise Combes and published by John Wiley & Sons. This book was released on 2022-08-23 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: All galaxies host a super-massive black hole in their center. These black holes grow their mass in symbiosis with their host galaxy and moderate their star formation. When matter is driven towards the nucleus, an accretion disk is formed to transfer angular momentum and considerable energy is released when the material falls into the black hole: this is the phenomenon of active galactic nuclei (AGN). A nucleus can shine one thousand times more brightly than the entire galaxy with its 200 billion stars. The nuclear activity can take many forms, from very powerful quasars to more ordinary Seyfert galaxies, passing by radio-galaxies, which eject a collimated plasma at ten times the radius of the galaxy. This book examines all of these manifestations and presents a unified view. When two galaxies merge, a binary black hole is formed and the two black holes will spiral inwards and merge, emitting long gravitational waves, which could be detected by the future LISA satellite.
Download or read book Quantifying Feedback from Narrow Line Region Outflows in Nearby Active Galaxies written by Mitchell D. Revalski and published by . This book was released on 2019 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: Observations reveal that supermassive black holes (SMBHs) grow through the accretion of gas at the centers of galaxies as luminous active galactic nuclei (AGN), releasing radiation that drives powerful outflows of ionized and molecular gas. These winds are thought to play a critical role in galaxy evolution by regulating star formation and the growth of galaxies and their SMBHs. To test this model, we must quantify the dynamic impact of outflows by measuring their mass outflow rates and energetics. Using spatially resolved spectroscopy and imaging from the Hubble Space Telescope and Cloudy photoionization models we mapped the ionized gas kinematics and mass distributions of narrow line region (NLR) outflows in nearby active galaxies. We find that the outflows contain up to several million solar masses of ionized gas and are limited to distances of 1 - 2 kiloparsecs from the nucleus. The maximum mass outflow rates are M = 3 - 12 solar masses per year and the outflow gas mass, velocity, radial extent, and energetics are positively correlated with AGN luminosity. We use our results to test simplified techniques with less stringent data requirements and find that they significantly overestimate the gas mass. These results are crucial for modeling powerful outflows at higher redshift that may considerably influence star formation rates and the formation of galactic structure.
Download or read book The Kiloparsec Scale Structure and Kinematics of High Redshift Star Forming Galaxies written by David R. Law and published by Universal-Publishers. This book was released on 2008-09 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt: We study the spatially resolved properties of star-forming galaxies at redshift z 2 - 3 on scales 1 kpc using a combination of morphological and kinematic analyses in an effort to characterize the major mechanisms of galaxy formation in the young universe. Using a sample of 216 galaxies which have been spectroscopically confirmed to lie between redshifts z = 1.8 - 3.4 in the GOODS-N field we demonstrate that rest-UV morphology (as seen by the Hubble Space Telescope) is statistically uncorrelated with physical properties such as star formation rate and is therefore unable to support the hypothesis that the prevalence of irregular morphologies indicates a high major merger fraction. Further, we present a sample of 13 galaxies observed with the OSIRIS integral field spectrograph and the Keck laser-guide star adaptive optics system which demonstrate the prevalence of high velocity dispersions 80 km/s and generally little in the way of spatially resolved velocity gradients, inconsistent with favored rotating disk models. We discuss the implications of these results for galaxy formation models, including gas accretion via cold flows and gravitational instability of early gas-rich galactic disks. There is some evidence for a trend towards stronger rotational signatures in galaxies with more massive stellar populations.
Download or read book Radial Gas Flows and Star Formation in Spiral Galaxies written by Tony Hao Wong and published by . This book was released on 2000 with total page 696 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dense Molecular Gas in Galaxies and the Evolution of Luminous Infrared Galaxies written by Yu Gao and published by . This book was released on 1996 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Astrophysics Of Gas Nebulae and Active Galactic Nuclei written by Donald E. Osterbrock and published by University Science Books. This book was released on 2006 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thoroughly revised and expanded throughout, the new edition is a graduate-level text and reference book on gaseous nebulae, nova and supernova remnants. Much of the new data and new images are from the Hubble Space Telescope with two wholly new chapters being added along with other new features. The previous edition which was tried and tested for thirty years has now been succeeded by a revised, updated, larger edition, which will be valuable to anyone seriously interested in astrophysics.
Download or read book Galactic Bulges written by Eija Laurikainen and published by Springer. This book was released on 2015-09-29 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book consists of invited reviews on Galactic Bulges written by experts in the field. A central point of the book is that, while in the standard picture of galaxy formation a significant amount of the baryonic mass is expected to reside in classical bulges, the question what is the fraction of galaxies with no classical bulges in the local Universe has remained open. The most spectacular example of a galaxy with no significant classical bulge is the Milky Way. The reviews of this book attempt to clarify the role of the various types of bulges during the mass build-up of galaxies, based on morphology, kinematics and stellar populations and connecting their properties at low and high redshifts. The observed properties are compared with the predictions of the theoretical models, accounting for the many physical processes leading to the central mass concentration and their destruction in galaxies. This book serves as an entry point for PhD students and non-specialists and as a reference work for researchers in the field.
Download or read book The Molecular Gas Content of Ultraluminous Infrared Galaxies written by Stefano Venturini and published by . This book was released on 2004 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physics of Nearby Galaxies written by Xuan Thuan Trinh and published by Atlantica Séguier Frontières. This book was released on 1992 with total page 558 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physics Briefs written by and published by . This book was released on 1994 with total page 1248 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Molecular Gas Content and Ionization Processes in Distant Powerful Radio Galaxies and Hyperluminous Infrared Galaxies written by Aaron S. Evans and published by . This book was released on 1996 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Most Interesting Galaxies in the Universe written by Joel L Schiff and published by Morgan & Claypool Publishers. This book was released on 2018-09-13 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: Prior to the 1920s it was generally thought, with a few exceptions, that our galaxy, the Milky Way, was the entire Universe. Based on the work of Henrietta Leavitt with Cepheid variables, astronomer Edwin Hubble was able to determine that the Andromeda Galaxy and others had to lie outside our own. Moreover, based on the work of Vesto Slipher, involving the redshifts of these galaxies, Hubble was able to determine that the Universe was not static, as had been previously thought, but expanding. The number of galaxies has also been expanding, with estimates varying from 100 billion to 2 trillion. While every galaxy in the Universe is interesting just by its very fact of being, the author has selected 51 of those that possess some unusual qualities that make them of some particular interest. These galaxies have complex evolutionary histories, with some having supermassive black holes at their core, others are powerful radio sources, a very few are relatively nearby and even visible to the naked eye, whereas the light from one recent discovery has been travelling for the past 13.4 billion years to show us its infancy, and from a time when the Universe was in its infancy. And in spite of the vastness of the Universe, some galaxies are colliding with others, embraced in a graceful gravitational dance. Indeed, as the Andromeda Galaxy is heading towards us, a similar fate awaits our Milky Way. When looking at a modern image of a galaxy, one is in awe at the shear wondrous nature of such a magnificent creation, with its boundless secrets that it is keeping from us, its endless possibilities for harboring alien civilizations, and we remain left with the ultimate knowledge that we are connected to its glory.
Download or read book A Spatially Resolved Survey of the Mid infrared Aromatic Features in Nearby Galaxies written by Carl A. Starkey and published by . This book was released on 2016 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mid-infrared spectra of almost all astronomical objects reveal a rich array of emission features largely attributed to the IR florescence of polycyclic aromatic hydrocarbons (PAHs). These features can account for a significant portion of the total infrared luminosity but exhibit a dependence on their local environment, including metalicity, that is not yet well understood. We present deep 5 to 38 um spectroscopic data taken with the SL and LL IRS instrument of the Spitzer space telescope of three high radial abundance gradient nearby galaxies: NGC5457, NGC0628, and NGC2403. Available data are subdivided into 13" extraction regions in order to maximize the resolution of our analysis while still presenting a reasonable signal to noise. We measure the strength of the PAH features in each sub-region by performing a multi-dimensional fit of the underlying continuum due to aggregate dust temperatures, PAH features, and electronic transitions using the IDL routine PAHFIT. We also present Herschel PACS 70,100,160, GALEX FUV and NUV data on our targeted regions. We show for the first time that the well known correlation of total PAH intensity to total Infrared intensity and oxygen abundance on galactic scales also hold on sub kpc scales within these galaxies. We examine the impact that the local abundance, intensity and hardness of the radiation field has on PAH intensity and the physical conditions implied by PAH band ratios and that all play a significant role.
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1999 with total page 934 pages. Available in PDF, EPUB and Kindle. Book excerpt:
