• Farooq Ahmed

      Articles written in Journal of Astrophysics and Astronomy

    • Changes in sizes and shapes of spherical galaxies in head-on collisions

      Farooq Ahmed Saleh Mohammed Alladin

      More Details Abstract Fulltext PDF

      Head-on collisions of two identical spherical galaxies are studied for two initial velocities (1) nearly equal to and (2) greater than the capture velocity. Orbits of about 500 representative stars are computed taking into account the effects of dynamical friction in the motion of the galaxies. From the computer studies the changes in the structure of the galaxies are deduced. The galaxies contract at closest approach and expand as they recede from each other. When the initial velocity is nearly equal to the capture velocity, the mean radius expands to almost double its size and the galaxies have a prolate structure until the closest approach with the longer axis in the direction of motion. The prolate structure is destroyed as the galaxies recede. For larger collision velocity (V ∼ 1.5 Vcap), the mean radius expands by 50 per cent and the galaxies are prolate until the closest approach and distinctly oblate after the collision. The fractional increase in the binding energy is 0.46 in the first case and 0.30 in the second case.

  • 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.

    • Editorial Note on Continuous Article Publication

      Posted on July 25, 2019

      Click here for Editorial Note on CAP Mode

© 2023-2024 Indian Academy of Sciences, Bengaluru.