Download or read book Infrared Surface Brightness Distributions of Galaxies written by A. J. Adamson and published by . This book was released on 1983 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Infrared Surface Brightness and Absolute Magnitude of Spiral Galaxies written by Sidney Van den Bergh and published by . This book was released on 1981 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Surface Brightness Distribution of Virgo Cluster Galaxies written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We have acquired near-IR H and optical $g$, $r$, $i$, $z$ imaging for a sample of 299 Virgo cluster galaxies down to a limiting magnitude of B$_T$=16.0 mag. The low sensitivity of near-IR wavelengths to dust extinction is crucial for an unbiased geometric deprojection of fundamental galaxy parameters. We find, in agreement with Tully and Verheijen (1997), a clear dichotomy between high and low surface brightness galaxy disks. The difference between the low and high brightness peaks of Virgo galaxies is $\sim$2 H-mag arcsec$^{-2}$, significantly larger than any systematic errors. The high surface brightness galaxies have two distinct classes of bulge with high and low concentration, while low surface brightness galaxies have only low concentration bulges. The distribution of the effective surface brightnesses of our entire sample shows that early-type galaxies exhibit a similar structural bimodality though offset from that of spiral galaxies towards higher surface brightnesses. We find that the structural bimodality is uncorrelated with colour or any other structural parameter except, perhaps, the circular velocity. Simulations of realistic surface brightness profiles show that a bimodality in effective surface brightness is unexpected based on normal distributions of fundamental bulge and disk parameters. Rather, the structural bimodality is likely linked to the galaxy dynamics, namely the specific angular momentum of the galaxy; high surface brightness galaxies have low angular momentum and can collapse to form dynamically important disks, while low surface brightness galaxies are dominated by the dark halo everywhere. Finally, our bulge-disk decompositions of all the sample galaxy images using various fitting functions have revealed that galaxies of all morphologies, including flattened and spheroidal systems, exhibit a ``disk'' component which is best described by a generalized ``Sersic'' function. We also find that the majority of galaxy disks show significant devi.
Download or read book The Detection of Low Surface Brightness Galaxies in the Infrared written by and published by . This book was released on 2011 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Surface Brightness Distribution of Virgo Cluster Galaxies written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We have acquired near-IR H and optical $g$, $r$, $i$, $z$ imaging for a sample of 299 Virgo cluster galaxies down to a limiting magnitude of B$_T$=16.0 mag. The low sensitivity of near-IR wavelengths to dust extinction is crucial for an unbiased geometric deprojection of fundamental galaxy parameters. We find, in agreement with Tully and Verheijen (1997), a clear dichotomy between high and low surface brightness galaxy disks. The difference between the low and high brightness peaks of Virgo galaxies is $\sim$2 H-mag arcsec$^{-2}$, significantly larger than any systematic errors. The high surface brightness galaxies have two distinct classes of bulge with high and low concentration, while low surface brightness galaxies have only low concentration bulges. The distribution of the effective surface brightnesses of our entire sample shows that early-type galaxies exhibit a similar structural bimodality though offset from that of spiral galaxies towards higher surface brightnesses. We find that the structural bimodality is uncorrelated with colour or any other structural parameter except, perhaps, the circular velocity. Simulations of realistic surface brightness profiles show that a bimodality in effective surface brightness is unexpected based on normal distributions of fundamental bulge and disk parameters. Rather, the structural bimodality is likely linked to the galaxy dynamics, namely the specific angular momentum of the galaxy; high surface brightness galaxies have low angular momentum and can collapse to form dynamically important disks, while low surface brightness galaxies are dominated by the dark halo everywhere. Finally, our bulge-disk decompositions of all the sample galaxy images using various fitting functions have revealed that galaxies of all morphologies, including flattened and spheroidal systems, exhibit a ``disk'' component which is best described by a generalized ``Sersic'' function. We also find that the majority of galaxy disks show significant devi.
Download or read book Study of the Far Infrared Emission of Nearby Spiral Galaxies written by Willie Drouhet and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In my PHD work I explored the links between the physical properties of interstellar dust and other components of nearby spiral galaxies especially their stellar content. I worked on 46 disk galaxies from KINGFISH with IRAC/MIPS/PACS/SPIRE maps (3.6 - 500 microns). A bias is usually introduced in estimating disk orientations by using only a single surface brightness isophote. Thus I devised different surface brightness levels separated by constant steps in surface brightness and extracted isophotes at these levels in all FIR maps as well as in all IRAC 4.5 microns maps. To further assess the coherence of the shapes of isophotes across galactic disks, I built a quantitative indicator of the difference in shape between two ellipses with same center and same semi-major axis.I defined an acceptable level of difference between isophote shapes, by comparing disk orientations found in litterature. Using this level, I found regions inside the galactic disks where the isophotal shapes are similar. From these, I extracted one disk orientation per wavelength band. I found in the vast majority of the disk galaxy maps, be it dominated by stellar or dust emission, that a large fraction of the isophotes I extracted are coherent with the idea of an underlying disk. Comparing, for each galaxy, disk orientations extracted at all wavelengths, I found evidence in 20 galaxies out of 46, that on radial ranges as large as 1/3 of the visible disk (as measured by R25), the shapes of isophotes are morphologically similar. Thus for these 20 galaxies I devised consistent disk orientations both for the stellar and dust content. These 20 galaxies are less luminous, less emitting in the IR w.r.t. the optical, less barred, and characterized by later stage types than average. I also found that the disk orientations devised by my photometric method yield results more similar to H-alpha kinematic orientations than other photometric studies based on a single isophote level.Using the orientations I found and H-alpha dynamics disk orientations, I averaged azimuthally surface brightnesses to produce radial spectral energy distributions (SED) profiles. Once fitted with a cosmic dust emission model, they resulted in radial profiles of dust and stellar content properties. I found the dust intercepted power to be proportionnal to the product of the total dust mass and the average ISRF shining on dust. This former quantity is better correlated with the bolometric stellar luminosity than any of the dust mass or the dust heating ISRF separately. Thus the old stellar populations may be an important heating source for dust. The power intercepted by dust is also very well correlated with the total infrared power. The dust intercepts a larger quantity of power coming from stars in more actively star forming galaxies.Dust exhibit radial mass surface density profiles less well described by Sersic functions than stellar ones. When both profiles are well fitted by Sersic functions, stellar density profiles have smaller half mass radii than the isophotal optical radius (R25) separately in later type galaxies, but also in more quiescent galaxies. Sersic index and half mass radius distributions have larger widths for dust than for stellar surface density profiles.I also found that the ratio of dust over stellar surface density is an important factor to explain the variations with galactic morphological type of the ratio of dust intercepted power over the power emitted by old stellar populations. This later link could be intertwined with spiral structure strength in stage types later than 2.
Download or read book Far infrared Emission from Rich Clusters of Galaxies written by Caroline Virginia Cox and published by . This book was released on 1995 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Infrared Surface Brightness Fluctuations and the Extragalactic Distance Scale written by Joseph B. Jensen and published by . This book was released on 1997 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Exploring the Optical and Infrared Evolution of Galaxies written by Jason Melbourne and published by . This book was released on 2006 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Astrophysics with Infrared Arrays written by Richard Elston and published by . This book was released on 1990 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spiral Galaxies in the Near IR written by Dante Minniti and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 351 pages. Available in PDF, EPUB and Kindle. Book excerpt: From June 7-9, 1995, the European Southern Observatory (ESO) and the Max Plank Institut fiir Astrophysik (MPA) jointly held the Workshop on Spiral Galaxies in the Near-IR. This meeting took place at the ESO headquarters in Garching bei Miinchen, Germany. The weather waschanging, with the biergarten closed, but that did not stop 85 people from allover the world from attending the meeting. The three days were intensive, with talks and coffee and posters from 9 am to 6 pm, and very productive indeed for everyone. The topics covered the stellar populations of the Milky Way and other more distant spirals, the role of dust, the dynamics of spiral galaxies, and the nuclear activity seen at near-IR wavelengths. This volume presents the original contributions from the participants, including several papers that review the state-of-the-art knowledge in these various subjects. The editors would like to thank first and foremost Christina Stoffer, for she took care of everything. The meeting would not have been so successful without her expertise and efficiency. We are deeply indebted to the directors of MPA and ESO Science, Simon White and Jacqueline Bergeron, for their support and encouragement. We would also like to thank the other members of the scientific organizing committee: R. Genzel, K. Freeman, A. Moorwood, S. White, M. Rieke and E. Athannasoula, for their advice with the organization of the program. We also thank G. Rieke, R. Genzel, L. Athannasoula, A. Renzini and R.
Download or read book The Evolution of Galaxies and Their Environment written by David J. Hollenbach and published by . This book was released on 1993 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Galaxies at High Redshift written by I. Pérez-Fournon and published by Cambridge University Press. This book was released on 2003-03-20 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume presents lectures of the XI Canary Islands Winter School of Astrophysics written by experts in the field.
Download or read book The 12 UM Contribution of Nearby Galaxies to the Infrared Background written by and published by . This book was released on 1993 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The far infrared properties of normal non-infrared-bright galaxies were studied as a function of their morphological type using a sample of 1544 galaxies of magnitude less than 14.5. Most of the far infrared color trends as a function of galaxian morphological type can be reproduced by dust models with three components, combined with an appropriate dust heating spectral energy distribution. Work has been done on the use of far infrared luminosity as a star formation indicator in galaxies. The trends observed are consistent with a two- component model, with the citrus fraction as the second parameter and the star formation rate as the first parameter. Observations have been made and studies performed on dwarf and low surface brightness galaxies and starburst galaxies at intermediate red shifts.
Download or read book Outskirts of Galaxies written by Johan H. Knapen and published by Springer. This book was released on 2017-07-09 with total page 367 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book consists of invited reviews written by world-renowned experts on the subject of the outskirts of galaxies, an upcoming field which has been understudied so far. These regions are faint and hard to observe, yet hide a tremendous amount of information on the origin and early evolution of galaxies. They thus allow astronomers to address some of the most topical problems, such as gaseous and satellite accretion, radial migration, and merging. The book is published in conjunction with the celebration of the end of the four-year DAGAL project, an EU-funded initial training network, and with a major international conference on the topic held in March 2016 in Toledo. It thus reflects not only the views of the experts, but also the scientific discussions and progress achieved during the project and the meeting. The reviews in the book describe the most modern observations of the outer regions of our own Galaxy, and of galaxies in the local and high-redshift Universe. They tackle disks, haloes, streams, and accretion as observed through deep imaging and spectroscopy, and guide the reader through the various formation and evolution scenarios for galaxies. The reviews focus on the major open questions in the field, and explore how they can be tackled in the future. This book provides a unique entry point into the field for graduate students and non-specialists, and serves as a reference work for researchers in this exciting new field.
Download or read book Low Surface Brightness Galaxies in the Infra red written by and published by . This book was released on 2011 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Impact of Large Scale Near IR Sky Surveys written by F. Garzón and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: After a year's successful operation, the European DENIS project is now a scientific reality and its close cousin 2MASS (USA) is about to come into operation. The observational and data reduction processes of both DENIS and 2MASS are fully described in this volume. Already the impact of DENIS is making itself felt in the astronomical community in areas of research as diverse as cosmology, the evolution of galaxies, the interstellar medium, the search for brown dwarfs, and stellar structure and evolution. The first routine results from DENIS and the preliminary results from the 2MASS prototype camera are discussed and compared with other surveys across the wavelength spectrum, both space- and ground-based, including the Digitized Sky Survey, ISO and ROSAT.
