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3 edition of Spectral constraints on models of gas in clusters of galaxies found in the catalog.

Spectral constraints on models of gas in clusters of galaxies

Spectral constraints on models of gas in clusters of galaxies

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  • 36 Currently reading

Published by National Aeronautics and Space Administration, Scientific and Technical Information Branch, For sale by the National Technical Information Service] in [Washington, D.C.], [Springfield, Va .
Written in English

    Subjects:
  • X-ray spectroscopy.,
  • Galaxies -- Clusters.

  • Edition Notes

    StatementMark J. Henriksen, Richarad F. Mushotzky.
    SeriesNASA technical memorandum -- 86188.
    ContributionsMushotzky, R. F., United States. National Aeronautics and Space Administration. Scientific and Technical Information Branch.
    The Physical Object
    FormatMicroform
    Pagination1 v.
    ID Numbers
    Open LibraryOL14662120M

    The ΛCDM (Lambda cold dark matter) or Lambda-CDM model is a parametrization of the Big Bang cosmological model in which the universe contains three major components: first, a cosmological constant denoted by Lambda (Greek Λ) and associated with dark energy; second, the postulated cold dark matter (abbreviated CDM); and third, ordinary is frequently referred to as the standard model. X-ray observations of groups and clusters of galaxies have matured rapidly in the last 6 years with the advent of good quality imaging with Rosat and moderate quality spectra with ASCA, the Japanese-U.S. x-ray spectroscopy mission launched in February,

    Jaffe first suggested that the magnetic field distribution in a cluster would depend on the thermal gas density and on the distribution of massive galaxies and therefore would decline with the cluster radius. Constraints to the radial gradient of the cluster magnetic field strength are provided by observations of clusters hosting a radio halo. The Discovery of Galaxies. Faint star clusters, clouds of glowing gas, and galaxies all appeared as faint patches of light (or nebulae) in the telescopes available at the beginning of the twentieth century.

      Massive clusters of galaxies have been found that date from as early as billion years 1 ( Gyr; z = ) after the Big Bang, containing stars that formed at . We propose a new method to probe a possible time evolution of the fine structure constant α from X-ray and Sunyaev-Zel'dovich measurements of the gas mass fraction (f {sub gas}) in galaxy clusters. Taking into account a direct relation between variations of α and violations of the distance-duality relation, we discuss constraints on α for a.


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Spectral constraints on models of gas in clusters of galaxies Download PDF EPUB FB2

HEAO 1-A2 spectra of clusters of galaxies are used to determine the temperature profile which characterizes the X-ray emitting gas.

Strong evidence of non-isothermality is found for the Coma, A85, and A clusters. Properties of the cluster potential which binds the gas are calculated for a range of model : Mark J. Henriksen, Richard F. Mushotzky. HEAO 1-A2 spectra of clusters of galaxies are used to determine the temperature profile which characterizes the X-ray emitting gas.

Strong evidence of non-isothermality is found for the Coma, A85, and A clusters. Properties of the cluster potential which binds the gas are calculated for a range of model parameters. The typical binding mass, if the gas Author: Mark J. Henriksen, Richard F. Mushotzky. Spectral Constraints on Models of Gas in Clusters of Galaxies - NASA/ADS HEAO 1-A2 spectra of clusters of galaxies are used to determine the temperature profile which characterizes the X-ray emitting gas.

Strong evidence of non-isothermality is found for the Coma, A85, and A : Mark J. Henriksen, Richard F. Mushotzky. Get this from a library. Spectral constraints on models of gas in clusters of galaxies.

[Mark Jeffrey Henriksen; R F Mushotzky; United States. National Aeronautics and Space Administration. Scientific and Technical Information Branch.]. The HEAO 1A2 spectra of clusters of galaxies are used to determine the temperature profile which characterizes the X-ray emitting gas.

Strong evidence of nonisothermality is found for the Coma, A85, and A clusters. Properties of the cluster potential which binds the gas are calculated for a range of model : M.

Henriksen and R. Mushotzky. Clusters of galaxies are large assemblies of galaxies, hot gas and dark matter bound together by gravity. Galaxy clusters are now one of the most important cosmological probes to test the standard cosmological models.

Constraints on the Dark Energy equation of state from the cluster number density measurements, deviations from the Gaussian. In this Letter we report precise measurements of the X-ray gas mass fraction for a sample of luminous, relatively relaxed clusters spanning the redshift range models have recently been determined from Chandra X-ray data and independent gravitational lensing constraints (Allen, Ettori & Fabian a.

The mean intracluster gas fraction of X-ray clusters within their hydrostatic regions is derived from recent observational compilations of David, Jones & Forman and White & Fabian.

At radii encompassing a mean density times the critical value, the individual sample bi-weight means are moderately (sigma) discrepant; revising binding masses with a virial relation calibrated. plasma spectrum is a book keeping exercise.

The collision rates are in general a function of temperature)and the outcome is directly proportional to the electron density 16 Abundances • Clusters of galaxies deep gravitational potential wells keep all the metals produced by the stellar populations of the member galaxies within the cluster.

ray cluster catalog. §3 introduces our analytic ICM model, while §4 describes our statistical analysis methodology. In §5 we describe the results of our statistical analysis, listing the constraints on gas fraction, concentration parameter, and point source contamination of our clusters.

clusters of OB stars, and that, in this case, the ionizing EUV spectra and H II region emission line spectra predicted by the PEGASE and STARBURST99 codes are essentially identical.

For starburst galaxies, in which the starburst has a luminosity comparable to the luminosity of the host galaxy, the situation is rather different.

We focus on an 86% complete magnitude-limited sample (R__ cluster galaxies. The cluster galaxies with emission lines in their spectra have a. An X-ray spectral analysis of 12 distant clusters of galaxies observed on-axis with the Einstein Observatory imaging proportional counter is presented.

clusters of galaxies has typically ˇ50 velocity measurements per cluster, making this method unusable except in the case of the well-studied rich cluster Coma which has ˇ measured radial velocities, but still, there is the problem of substructures.

X-ray emission The X-ray emission from clusters of galaxies is mainly due to hot and di use. CiteSeerX - Document Details (Isaac Councill, Lee Giles, Pradeep Teregowda): We have searched the far-UV spectra of five clusters of galaxies observed with the Hopkins Ultraviolet Telescope (HUT) for emission in the resonance lines of O VI λλ, and C IV λλ, We do not detect significant emission from either species in any of the spectra.

The gas is not usually associated with individual galaxies, unless a dominant one is at the center of the cluster potential: from Fig 1 of Forman and Jones (taken from the ADS), one can see the range in X-ray morphologies, from the dispersed and irregular morphology of the clusters on the left to the increasingly concentrated forms on the right.

Clusters of Galaxies • Clusters of galaxies are the largest gravitationally bound systems in the Universe.

• At optical wavelengths they appear as over-densities of galaxies with respect to the field average density: hundreds to thousands of galaxies moving in a common gravitational potential well (a smaller assembly is defined a galaxy group). We obtained a deep ?ks Chandra observation of the optically selected cluster of galaxies, RCS +, to investigate the gas mass fraction in this system.

Combining our deep Chandra observation with an archival 50?ks observation, we derive gas mass fractions of f gas =. and. within r and rgas mass fraction in. Galaxies. This guide covers the following topics: Our own Galaxy - the Milky Way, Spiral and elliptical galaxies, Galaxy clusters and large-scale structure, The dark matter of the Universe and origin of large-scale structure.

Author(s): Department of Applied Mathematics and Theoretical Physics, University of Cambridge. Chemical Abundances in Clusters: Other Evidence Another avenue of current research is to use the X-ray spectra to determine what kinds of elements the gas in between the galaxies contains.

These observations can then be used as a further test of models of clusters and their evolution. The luminous matter in a cluster is not all the same. Clusters of galaxies typically contain from about fifty to thousands of galaxies, along with dark matter and diffuse, hot (about 10 7 –10 8 kelvin) gas .Structure formation models predict that clusters of galaxies contain numerous massive subhalos.

The gravity of a subhalo in a cluster compresses the surrounding intracluster gas and enhances its X-ray emission. We present a simple model, which treats subhalos as slow moving and gasless, for computing this effect.The spectral energy distribution of galaxies is a complex function of the star formation history and geometrical arrangement of stars and gas in galaxies.

The computation of the radiative transfer of stellar radiation through the dust distribution is time-consuming.