• Volume 16, Issue 1

      March 1995,   pages  1-67

    • The radio structure of 45 quasars atz < 1.5

      V. K. Kapahi

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      Radio maps at 5 GHz with an angular resolution of 1 to 2 arcsec and a dynamic range ≳ 200:1 are presented for a sample of 45 radio quasars at redshifts between 0.2 and 1.5. The sources were imaged from observations made with the Very Large Array with the aim of investigating the epoch dependence of misalignments and asymmetries in their extended radio structure. Maps of some of the larger radio sources are presented also at a frequency of 1.5 GHz with a typical angular resolution of ≈ 4 arcsec. The radio structure of most of the quasars reported here has been delineated in considerably greater detail than available in the literature.

    • The orbit of the double-line spectroscopic binary system HR 7112

      P. N. Appleton J. J. Eitter C. Uecker

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      We present velocity observations, obtained with the E. W. Fick Observatory 0.6 m telescope, of the 7th magnitudeK1 star HR 7112. Our observations show that HR 7112 is a double-line spectroscopic binary system composed of almost equal mass stars with a period of 215.6 days. The orbit has an eccentricitye = 0.142 and the stars orbit each other with a mean semi-major axis distance of approximately 0.4sin(i) AU. The masses of the stars are consistent with the classification as giant stars. Tidal effects are known to circularise the orbits of giant stars and this process is apparently underway in this system.

    • Statistical response of randomly excited nonlinear radial oscillations in polytropes

      Anunay K. Chaudhary V. B. Bhatia M. K. Das R. K. Tavakol

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      The effect of internal noise on the response characteristics of nonlinear radial pulsation in polytropic model has been investigated using the equivalent linearization technique. The model of the noise is taken to be δ-correlated with zero mean. Both non-stationary and stationary response characteristics have been computed for various nonlinearity parameters in different polytropes.

    • Are many pulsars processed in binary systems?

      A. A. Deshpande R. Ramachandran G. Srinivasan

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      A detailed statistical analysis of pulsarcurrent is presented. The conclusions reached are the following: (1) The birthrate of pulsars is about one in 75 ± 15 years. (2) There is evidence forinjection of pulsars into the population of solitary pulsars. Such an injection is particularly pronounced in the magnetic field range 12 < logB < 12.6. (3) This is interpreted as due torecycled pulsars being released into the population. (4) We tentatively conclude that as much as 10 – 15% of all pulsars may have been born and processed in binary systems.

  • Journal of Astrophysics and Astronomy | News

    • Continuous Article Publication

      Posted on January 27, 2016

      Since January 2016, the Journal of Astrophysics and Astronomy has moved to Continuous Article Publishing (CAP) mode. This means that each accepted article is being published immediately online with DOI and article citation ID with starting page number 1. Articles are also visible in Web of Science immediately. All these have helped shorten the publication time and have improved the visibility of the articles.

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