American Journal of Astronomy and Astrophysics

Volume 3, Issue 3, May 2015

  • The Relative Expansion of the Universe

    Lee Qing Jong

    Issue: Volume 3, Issue 3, May 2015
    Pages: 37-39
    Received: Mar. 03, 2015
    Accepted: Apr. 12, 2015
    Published: Apr. 27, 2015
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    Abstract: This is an alternate explanation to the redshift effect and increasing distance between galaxies. Everything in the universe excluding empty space is shrinking, including elementary particles. In contrast to everything else, the empty space would appear to be expanding. This idea is compatible with most of established science, such as the theory of... Show More
  • On Jet Opening Angle and Dynamical Evolution of Some Powerful Extragalactic Radio Sources

    Ezeugo Jeremiah Chukwuemerie

    Issue: Volume 3, Issue 3, May 2015
    Pages: 40-43
    Received: Mar. 26, 2015
    Accepted: Apr. 15, 2015
    Published: Apr. 30, 2015
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    Abstract: We used both analytical and statistical methods of analyses to find out if there is possible connection between jet opening solid angle and linear size evolution of some powerful extragalactic radio sources in our sample. Based on simple linear regression analyses of D-Ω data (where D is observed linear size and Ω is estimated jet opening solid ang... Show More
  • An Analytical Estimate of the Hubble Constant

    Naser Mostaghel

    Issue: Volume 3, Issue 3, May 2015
    Pages: 44-49
    Received: Mar. 19, 2015
    Accepted: Mar. 31, 2015
    Published: Apr. 27, 2015
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    Abstract: Currently the present-time value of the Hubble constant is estimated through finding the optimum fit to the observationally measured data. Here, assuming a flat universe with zero cosmological constant, based on the conservation of total mass-energy and a correction for the effect of time dilation, the total present-time value of the energy density... Show More
  • Stability of Charged Shell Supported by a Phantom Energy

    Ali Eid

    Issue: Volume 3, Issue 3, May 2015
    Pages: 50-55
    Received: Apr. 23, 2015
    Accepted: May 06, 2015
    Published: May 15, 2015
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    Abstract: This paper discusses the evolution of a thin spherically symmetric self gravitating phantom shell around the charged shell. The general equations describing the motion of shell with a general form of equation of state are derived. The different types of space-time R± and T± regions and shell motion are classified depending on the parameters of the ... Show More
  • Fluctuations of Solar Wind Parameters During Polar Reversal

    Iren Sobia, Bidhu S. S., Dickson Benjamin

    Issue: Volume 3, Issue 3, May 2015
    Pages: 56-62
    Received: Apr. 09, 2015
    Accepted: May 01, 2015
    Published: May 19, 2015
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    Abstract: Around the time of polarity reversal in 2000 – 2001, the solar wind plasma parameters and interplanetary magnetic field fluctuations are studied for an interval of time that corresponds to Ulysses in-situ measurements of high-latitude heliospheric magnetic field. This study has been done by investigating solar wind speed, density, temperature and s... Show More
  • A Method to Estimate the Cooling Time of Ultra-Relativistic Electrons in Pulsar Wind Nebulae

    K. L. I. Gunawardhana, K. P. S. C. Jayaratne, J. Adassuriya

    Issue: Volume 3, Issue 3, May 2015
    Pages: 63-69
    Received: Feb. 24, 2015
    Accepted: May 01, 2015
    Published: May 27, 2015
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    Abstract: Pulsar is a highly magnetized rotating neutron star. It continuously emits a wind of relativistic electrons and positrons. This wind creates an electron-positron-cloud around the pulsar. This cloud, which is full of relativistic electrons and positrons, is called a Pulsar Wind Nebula (PWN). As of 2014, 33 Pulsar Wind Nebulae (PWNe) have been detect... Show More