IIA Institutional Repository: Recent submissions

  • Dependence of the meridional motions of sunspot groups on life spans and age of the groups, and on the phase of the solar cycle 
    Javaraiah, J (Kluwer Academic Publishers, 1999-10)
    We have analyzed data on sunspot groups compiled during 1874-1981 and investigated the following: (i) dependence of the `initial' meridional motion (v_ini(τ)) of sunspot groups on the life span (τ) of the groups in the ...
  • TeV and Superheavy Particles from Supersymmetric Topological Defects, the Extragalactic γ-ray Background, and the Highest Energy Cosmic Rays 
    Bhattacharjee, P; Shafi, Qaisar; Stecker, F. W (The American Physical Society, 1998-04)
    Cosmic topological defects in a wide class of supersymmetric theories can simultaneously be sources of Higgs bosons of mass~supersymmetry breaking scale~TeV, as well as superheavy gauge bosons of mass~η>>1 TeV, η being the ...
  • Spectral line radiation from solar small-scale flux tubes. II 
    Hasan, S. S; Kneer, F; Kalkofen, W (European Southern Observatory, 1998-04)
    We examine spectral line radiation from small-scale magnetic flux tubes in the solar atmosphere. This is a continuation of work by Kneer et al. (1996). The main difference with the previous investigation is in the choice ...
  • Abundance similarities between the RCrB star V854Cen and the born-again Sakurai's object 
    Asplund, M; Gustafsson, B; Kameswara Rao, N; Lambert, D. L (European Southern Observatory, 1998-04)
    The elemental abundances of the mildly hydrogen-deficient R Coronae Borealis (RCrB) star V854Cen have been estimated. The RCrB stars have been divided into majority and minority classes judging by their abundance patterns. ...
  • An operator perturbation method for polarized line transfer. III. Applications to the Hanle effect in 1D media 
    Nagendra, K. N; Frisch, H; Faurobert-Scholl, M (European Southern Observatory, 1998-04)
    In this paper we present an Approximate Lambda Iteration method to treat the Hanle effect (resonance scattering in the presence of a weak magnetic field) for lines formed with complete frequency redistribution. The Hanle ...
  • Black Holes and Rotation 
    Vishveshwara, C. V (Indian Academy of Sciences, 1999-12)
    In this article, we first consider briefly the basic properties of the non –rotating schwarzschild black hole and the rotating Kerr Black hole rotational effects are then described in static and stationary spacetimes with ...
  • DP 2 electric field fluctuations in the dusk-time dip equatorial ionosphere 
    Abdu, M. A; Sastri, J. H; Luhr, H; Tachihara, H; Kitamura, T; Trivedi, N. B; Sobral, J. H. A (American Geophysical Union, 1998-05)
    We have studied the geomagnetic and ionospheric manifestations of the DP 2 activity that occurred on April 7, 1995 using high time resolution magnetometer data of IMAGE network in Scandinavia and of Alcantara (dip 1.2° N), ...
  • Radial modes of rotating neutron stars in the Chandrasekhar-Friedman formalism 
    Datta, B; Hasan, S. S; Sahu, P. K; Prasanna, A. R (World Scientific Publishing Company, 1998-02)
    Eigenfrequencies of radial pulsations of "slowly" rotating neutron stars are calculated in a general relativistic formalism given by Chandrasekhar and Friedman (1972). It is found that the square of the frequencies are ...
  • Cosmic ether 
    Tomaschitz, R (Springer, 1998-03)
    A prerelativistic approach to particle dynamics is explored in an expanding Robertson-Walker cosmology. The receding galactic background provides a distinguished frame of reference and a unique cosmic time. In this context ...
  • Polarization measurements of Vega-like stars 
    Bhatt, H. C; Manoj, P (European Southern Observatory, 2000-10)
    Optical linear polarization measurements are presented for about 30 Vega-like stars. These are then compared with the polarization observed for normal field stars. A significant fraction of the Vega-like stars are found ...
  • Interstellar shocked region chemistry - certain reactions between interstellar molecules and O and N atoms 
    Ghosh, K. K; Saleem, S. S; Kutty, K. N (International Astronomical Union, 1987)
    The reactions between O and N atoms and certain interstellar molecules (H/sub2S, NH/sub3, H/sub2CO, CH/sub3OH, C/sub2H/sub5OH) are studied using the dynamical flowing after glow method. It is found that NH and OH radicals ...
  • Density-matrix approach to a strongly coupled two-component Bose-Einstein condensate 
    Narayanan, A; Ramachandran, H (The American Physical Society, 2000-11)
    The time evolution equations for average values of population and relative phase of a strongly coupled two-component Bose-Einstein condensate (BEC) are derived analytically. The two components are two hyperfine states, ...
  • Modeling Dust Jets And Shells From Comet Hale-Bopp 
    Vasundhara, R; Chakraborty, P; Hänel, A; Heiser, E (Kluwer Academic Publishers, 1997-07)
    Persistent jet and shell structures from comet Hale-Bopp showing gradual changes in the shapes and orientations with aspect angle and solar illumination geometry indicate long lived active sources. A model to simulate the ...
  • High Angular Resolution Radio Observations of the Outer Solar Corona 
    Ramesh, R; Subramanian, K. R; Sastry, Ch. V (Elsevier, 2000)
    We report high angular resolution observations of the outer solar corona carried out at 75 MHz from the Gauribidanur Radio Observatory (Long: 77°26'12" E, Lat: 13°36'12" N) about 100 km north of Bangalore, India, during ...
  • On latitudinal profile of Storm Sudden Commencement in H, Y and Z at Indian Geomagnetic Observatory chain 
    Rastogi, R. G; Pathan, B. M; Rao, D. R. K; Sastry, T. S; Sastri, J. H (Terra Scientific Publishing Company, 2001)
    The unique network of geomagnetic observatories along 145° E geomagnetic longitude extending from the magnetic equator to the north pole has enabled to study the latitudinal profiles of Storm Sudden Commencement (SSC) ...
  • An improved gnomon 
    Ratna, V (Astronomical Society of India, 1998)
    During a project work done by a group of students at senior secondary stage with the guidance of the author, the vertical pillar kind of gnomon has been improved upon. Whereas the traditional gnomon can measure altitude ...
  • Some thoughts on Bhadra Chowkan and Ankapasha in Indian Mathematics 
    Ghanekar, B (Astronomical Society of India, 1998)
    It is shown how the Indian concepts about bhadra Chowkon (Magic Sqares) can be utilized for developing new computer algorithms and how Indian Ankapasha (series) technique can be used for computing trignometric functions
  • The calendric astronomy of the vedas 
    Sidharth, B. G (Astronomical Society of India, 1998)
    The Rig Veda described both a solar and a luni-solar calendrical scheme. Once the precision of Rig Vedic astronomy is recognized, the Great Cosmis Cycles of ancient India can be interpreted meaningfully.
  • Vedic astronomers 
    Holay, P. V (Astronomical Society of India, 1998)
    The aim of this paper is to show that natural origin of Hindu astronomy in remote antiquity is the Indian environment of six seasons of monsoon climate. The deities and demons described in the Rigveda are either astronomical ...
  • The 1999 Outburst of the Recurrent Nova U Scorpii 
    Anupama, G. C; Dewangan, G. C (The American Astronomical Society, 2000-03)
    The optical spectra of the recurrent nova U Sco obtained in five epochs 0.45-42.35 days after the 1999 outburst maximum are presented here. For the first time, an outburst spectrum of U Sco has been obtained as early as ...

Search DSpace

Browse

My Account