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Topic: Large scale structure of the cosmos

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The aim of COSMOS is to throughly map the morphology of galaxies as a function of local environment (density) and epoch, all the way from high redshift (z > 3) to the nearby (z < 0.5) Universe.
An example of a large structure found in COSMOS at redshift 0.8 is shown in Figure 2.
In the COSMOS survey redshift (corresponding to depth along the line of sight or lookback time) is obtained to ~ 5% accuracy from Subaru imaging photometry and photometric redshifts for approximately a million galaxies.
www.astro.caltech.edu /cosmos/astronomer/tech.html   (587 words)

 Large-scale structure of the cosmos: Definition and Links by Encyclopedian.com
The existence of this structure escaped notice for so long because it requires locating the position of galaxies in three dimensions which involves combining location information about the galaxies with distance information from redshift.
In its vicinity there is a preponderance of large old galaxies, many of which are colliding with their neighbours, and/or radiating large amounts of radio waves.
This is a collection of absorption lines which appear in the spectral lines of light from quasars, which are interpreted as indicating the existence of huge thin sheets of intergalactic (mostly Hydrogen) gas.
www.encyclopedian.com /la/Large-scale_structure_of_the_cosmos.html   (625 words)

 dark matter
Within a spiral galaxy, the stars move as if large quantities of dark matter exist around the galaxy's disk; similarly, within clusters of galaxies, the individual galaxies move as if many times more matter is present than that visible in the form of stars and interstellar gas and dust.
By the middle of the decade the conclusion that large amounts of unseen matter lurk in the outskirts of galaxies was being supported by theoretical work on galactic structure and stability.
A study of large galaxies that act as gravitational lenses revealed that about 2% of their mass must be in the form of dwarf galaxies – equivalent to thousands of these small systems – to explain the lensing effects.
www.daviddarling.info /encyclopedia/D/darkmat.html   (1974 words)

 Chapter 14: Dark Matter and Large Scale Structure
At the scale of individual galaxy disks, much of the dark matter can be attributed to stellar ashes such as white dwarfs, neutron stars, and fl holes, as well as to extremely faint objects such as very low-mass stars and brown dwarfs.
These enormous structures cannot be gravitationally bound for a universe of age 10 to 20 billion years; they must have been somehow present in the early conditions, or else they must be in the process of formation.
Structure formation in the early universe is one of the most active fields of current cosmological research, so answers to our many questions may be forthcoming in the foreseeable future.
www.astro.virginia.edu /~jh8h/Foundations/chapter14.html   (1564 words)

 Universe in a box: formation of large-scale structure   (Site not responding. Last check: 2007-11-03)
The current theory of structure formation, the extension of the Big Bang model called the Cold Dark Matter (CDM) scenario, predicts that massive galaxies and galaxy clusters were built from smaller galaxies that collided and merged, inducing bursts of star formation and resulting in the different types of structures observed today.
The growth of structures is thought to be governed by mysterious "dark matter" which constitutes about 85% of all matter in the Universe.
The entire history of the cosmos in all its complexity is governed by a handful of cosmological parameters, such as the density of ordinary matter (baryons), the density of ``dark matter'', thought to consist of weakly interactive particles, and ``dark energy''.
cosmicweb.uchicago.edu   (253 words)

 ScienceDaily: Large-scale structure of the cosmos   (Site not responding. Last check: 2007-11-03)
Astronomy and cosmology examine the universe to understand the large-scale structure of the cosmos.
Currently, many large structures have been found; stars are organised into galaxies which in turn appear to form clusters and superclusters, separated by voids.
Large-scale structure of the cosmos -- Astronomy and cosmology examine the universe to understand the large-scale structure of the cosmos.
sciencedaily.com /encyclopedia/Large-scale_structure_of_the_cosmos   (1418 words)

 Large-scale structure of the cosmos - Wikipedia, the free encyclopedia
In physical cosmology, the term large-scale structure refers to the characterization of observable distributions of matter and light on the largest scales (typically on the order of billions of light-years).
The organization of structure appears to follow as a hierarchical model with organization up to the scale of superclusters and filaments.
The organization of structure arguably begins at the stellar level, though most cosmologists rarely address astrophysics on that scale.
en.wikipedia.org /wiki/Large-scale_structure_of_the_cosmos   (1021 words)

 COSMOS Pages at the IfA
ACS is a superb instrument to conduct imaging surveys for the study of galaxy evolution and Large Scale Structure.
The two gray scale images represent the distribution of dark matter (gray background) and galaxies (fl dots, the size indicating the brightness of the galaxies) at z=1 and 2 from simulations of the Virgo Consortium.
A spectroscopic survey to measure the redshifts of galaxies in the COSMOS field and map the 3 dimensional structure, using European Southern Observatory Telescopes.
www.ifa.hawaii.edu /~aussel/Cosmos/index.html   (567 words)

 ETHZ Institute of Astronomy: What we do
The primary goal of the COSMOS program is to establish the links between the evolution of galaxies and their central fl holes, their environments and the large-scale structure in which they are embedded.
We are conducting a large survey of CO J=1-0, 2-1, 3-2, 4-3 and HCN 1-0, 2-1, 4-3 in local ULIRGs with the JCMT and the 30-m IRAM.
We are coordinating a large project in computational astrophysics that involves the comparison between SPH and grid codes (including AMR codes) on a variety of test problems that are of interest to cosmology, physics of the interstellar medium, star and planet formation.
www.exp-astro.phys.ethz.ch /projects.html   (3044 words)

Interspersed among these superclusters are large voids of space in which few galaxies exist.
No clusters of supercluters are known, but the existence of bigger structures than supercluster is debated.
See Large-scale structure of the cosmos for a discussion.
www.ebroadcast.com.au /lookup/encyclopedia/su/Supercluster.html   (140 words)

 The Largest Structure In The Universe
The only previous known structures with such a high density are much smaller, measuring about 50 million light-years in scale.
The researchers found that these large concentrations of gas are located near the overlap regions of the filaments.
This is the first time that so many large concentrations of gas, known to astronomers as Lyman alpha blobs, have been discovered in the distant universe.
www.sciencenewsden.com /2006/thelargeststructureintheuniverse.shtml   (798 words)

 Large Scale Structure
The study of the local Universe, including its peculiar motions and its clustering on scales exceeding 100 Mpc, is an essential ingredient in the connection between the origin of structure in the early Universe and the subsequent formation of galaxies and their evolution to the state we observe today.
Figure 1 is an attempt to encapsulate our present understanding of the large scale structure that embodies the local Universe.
However, note the large scatter in the redshift distribution per mag interval -- this is due to galaxies with intrinsically different luminosity -- from the brightest ellipticals to the faintest dwarf galaxies.
spider.ipac.caltech.edu /staff/jarrett/papers/LSS   (4053 words)

 Marcella Carollo
Part of the group is involved in large observational astronomical surveys (optical and near-infrared, photometric and spectroscopic, groundbased and Hubble Space Telescope, HST) to study the nature and origin of galaxies through observations of nearby and distant galaxies.
COSMOS is a global collaboration built around an HST Treasury Program of ACS images covering an unprecedentedly large 2square-degree field with extensive follow-up observations, over a broad range of wavelengths, using forefront facilities around the world.
COSMOS is thus built to study the galaxy versus large-scale structure relation at high redshifts, matching similar local efforts such as the SLOAN survey.
www.exp-astro.phys.ethz.ch /carollo   (654 words)

 Physics > Cosmology
Cosmology is the study of the large-scale structure and history of the universe.
Large Scale Structure of the Cosmos - few 100 Mpc - a few percent of the horizon
According to the proposed extreme circumstances during the first minutes of the universe's history, Big Bang cosmologists often co-operate with scientists from areas such as Particle physics.
www.physics.teleactivities.net /subfields/cosmology.html   (121 words)

 Astronomy Information and Facts
This image shows several blue, loop-shaped objects that are multiple images of the same galaxy, duplicated by the gravitational lens effect of the cluster of yellow galaxies near the middle of the photograph.
The large-scale structure of the cosmos is represented by groups and clusters of galaxies.
This structure is organized in a hierarchy of groupings, with the largest being the superclusters.
www.mbceo.com /science/index.php?c=Astronomy   (4606 words)

 www.xuzo.com - What is a Black Hole   (Site not responding. Last check: 2007-11-03)
Michell computed that a body with 500 times the radius of the Sun and of the same density would have, at its surface, an escape velocity equal to the speed of light, and therefore would be invisible.
A second is by large amounts of mass accreting onto a "seed" fl hole of stellar mass.
This process is extremely efficient and can convert about 50% of the rest mass energy of an object into radiation, as opposed to nuclear fusion which can only convert a few percent of the mass to energy.
www.xuzo.com /astronomy/largescale-structure-of-the-cosmos/what-is-a-black-hole.html   (2286 words)

 Let's make a galaxy: astronomers have identified a cosmic infant "nearby"—70 million light-years from Earth - Out ...
Hence, the study of the origin of galaxies is one of the most important topics in modern astronomical research.
Large collections of clumps created deep gravity wells that sucked in smaller groups of clumps, even as those collections coalesced to make single, larger bodies.
Today, billions of years later, we observe the resultant hierarchy of cosmic structure: subgalactic clumps that combined to form galaxies, which in turn gathered into groups and clusters, which then collected into filaments and superclusters.
www.findarticles.com /p/articles/mi_m1134/is_2_112/ai_98254969   (889 words)

 BBC News | SCI/TECH | When the Universe was 'spongy'
Astronomers determined the distances to some very faint galaxies in the neighbourhood of a distant quasar - a very bright distant object thought to be a massive fl hole swallowing matter - and plotted their positions on a three-dimensional map.
All recent computer simulations of the early Universe have one prediction in common: the first large-scale structures to form were long filaments connected at their ends by "nodes".
Recent observations, with the European Southern Observatory's (ESO) Very Large Telescope at Paranal, of a region around a quasar, whose light set off when the Universe was only 15% of its present age, have now identified a string of galaxies that map out a tight filament in the early Universe.
news.bbc.co.uk /2/hi/science/nature/1345134.stm   (562 words)

 Babelfish recent Dutch profile of Loll
To put it briefly, I search for the structure of spacetime, but to be able to understand what I mean by that, you must first of all depart from the common sense idea that we live in a space of three dimensions, in which a clock tells the same time for everyone.
The large problem is however that there is no theory that can explain how the sum of all those microscopic small scrap pieces of quantum foam produce a beautiful continuous four-dimensional reality in the macro world.
To put it briefly, I search for the structure of spacetime, but to be able to understand what I mean by that, you must first of all let go of the common sense idea that we live in a space of three dimensions, in which a clock tells the same time for everyone.
www.physicsforums.com /showthread.php?p=796410   (8056 words)

 Scale :: Models : Gourt
Stanley Stevens' Scales of measurement (1946): nominal, ordinal, interval, ratio
Architect's scale — (or draughtsman's scale) is a ruler-like device, which facilitates the production of technical drawings.
Scale Models - Discussion forum about general subjects, science-fiction, cars, planes, and military models.
recreation.gourt.com /Models/Scale.html   (1311 words)

The Cosmic Evolution Survey (COSMOS) is a pan-chromatic (X-ray to mm) observational project to perform a detailed study of galaxy and super-massive fl hole evolution through cosmic times, with particular emphasis on the influence of environment and large scale structure.
The areal coverage is large enough to avoid cosmic variance, and to delineate structure on the largest relevant scales (~100 Mpc comoving).
This VLA Large Project is the largest radio deep field at this depth and angular resolution.
www.mpia-hd.mpg.de /COSMOS   (516 words)

 Universe Summary
Anschauung, angle, angle of vision, bailiwick, basis, circle, corner, cosmos, creation, domain, eye, footing, frame of reference, framework, light, macrocosm, macrocosmos, megacosm, mental outlook, microcosm, milieu, nature, outlook, place, point of view, position, province, quarter, reference system, regard, respect, side, sight, situation, slant, sphere, stand, standpoint, system, territory, view, viewpoint, world
The evidence seems to confirm the pre-ionization galaxies were less common and that the post-ionization galaxies have 100 times the mass of the dwarf galaxies.
whether the rules of Euclidean geometry are valid on the largest scales, is unknown.
www.bookrags.com /Universe   (2604 words)

 Large Scale Structure   (Site not responding. Last check: 2007-11-03)
Large scale structure refers to the big features of an object, spanning wide regions of space.
The oval shape visible in the upper image is considered to be a large scale structure.
To resolve it, the Very Large Array was set at a low spatial resolution, discerning only large details.
archive.ncsa.uiuc.edu /Cyberia/Bima/LrgSclStruct.html   (177 words)

 Galaxy Formation and the Development   (Site not responding. Last check: 2007-11-03)
The simulated galaxy exhibits a rotationally supported disk structure, a feature that is characteristic of observed spiral galaxies.
The data are taken from a simulation by Frank Summers (Princeton University) which required 140 central processor unit (CPU) hours on a Cray YMP at San Diego Supercomputing Center.
A dynamic range of 1000 in length scales was achieved by using a fully Lagrangian gravity and smoothed particle hydrodynamics code.
archive.ncsa.uiuc.edu /Cyberia/Cosmos/TheWorks1.html   (244 words)

 PhysicsCentral: Catch a Cosmic Microwave: New Findings
A trio of findings about cosmic background radiation may help explain why matter is irregularly distributed throughout the universe with the observed “large-scale structure” of galactic super-clusters.
The first stands for Degree Angular Scale Interferometer, and it used 13 distinct ground-based radio telescopes at the South Pole to measure cosmic background radiation frequencies in the low energy part of the electromagnetic spectrum (weak microwaves).
What is referred to as "large-scale structure" in the cosmos, with matter showing a “lumpiness” in its distribution across the universe, arose from such fluctuations.
www.physicscentral.com /action/2001/microwave-cosmic.html   (998 words)

 Research on galaxy formation, 09-20-99
In the paper, which has been posted on the Internet and will be published in the October 1 issue of Astrophysical Journal Letters, Kolatt and his coauthors explain the observed properties of these distant galaxies in terms of the formation and evolution of structure in the early universe.
Their results suggest that the high-redshift galaxies offer a glimpse of the universe at a stage when the large-scale structure of the cosmos was still forming.
In this standard model of the cosmos, galaxies form within large halos of dark matter.
www.ucsc.edu /currents/99-00/09-20/galaxy.html   (1215 words)

 Big Bang : 'Proofs' and observations
These are the Hubble-type expansion seen in the redshifts of galaxies, the detailed measurements of the cosmic microwave background, and the abundance of light elements.
Instead, we find that these assumptions only apply on extremely large scales, on the order of several hundred million light years.
However, even though we have good evidence that the cosmological principle is valid on these scales, we are limited to only a single vantage point and a finite volume of the universe to examine, so these assumptions must remain exactly that.
www.physicsforums.com /showthread.php?t=115007   (1820 words)

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