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  • Investigations of Statistical Properties of Galactic Foreground Components and the CMB 
    Fazlu, Rahman (Indian Institute of Astrophysics, 2023-08)
    Accurate component separation of full-sky maps in the radio and microwave frequencies, such as the cosmic microwave background (CMB), relies on a thorough understanding of the statistical properties of the Galactic foreground ...
  • Investigations of the Morphology of Dust Shells of Comet C/2001 Q4 (NEAT) 
    Vasundhara, R; Chakraborty, P; Muneer, S; Masi, G; Rondi, S (The American Astronomical Society, 2007-02)
    The morphology of the dust fans and shells in the images of comet C/2001 Q4 (NEAT) showed significant changes between 2004 April and June due to rapid changes in the Earth viewing and solar illumination geometry. We model ...
  • Investigations of the pre-deep impact morphology of the dust coma of comet tempel 1 
    Vasundhara, R (Elsevier, 2009-11)
    The pre-Deep Impact images of Comet Tempel-1 obtained at the Indian Astronomical Observatory are used to investigate the morphology of the dust coma of the comet. We show that the trajectory of a cometary grain under the ...
  • Investigations of the Rotation Pole from the Morphology of Dust Fans of Comet 81P/Wild 2 
    Vasundhara, R; Chakraborty, P (The American Astronomical Society, 2004-12)
    Investigations of the dust morphology of comet 81P/Wild 2 in the I- and R-band images obtained on 1997 May 15 from the Vainu Bappu Observatory, Kavalur, India, are presented. We model the trajectories of dust grains ejected ...
  • Ion-sound turbulence due to shock gradients in collisionless plasmas 
    Gopalswamy, N; Thejappa, G (Indian Academy of Sciences, 1985-11)
    The dispersion relation for ion sound waves generated in a perpendicular shock is derived and the energy density of ion-sound turbulence is obtained using quasilinear theory. The result is compared with the lower hybrid ...
  • Ionization in Ps-H scattering 
    Ray, H (Elsevier, 2002-06)
    Coulomb–Born approximation has been used to study three different types of ionization in positronium (Ps) and hydrogen scattering. The present Ps–H system contains four centers; we have considered all the Coulomb interactions ...
  • Ionization of the Interstellar Medium 
    Mallik, D. C. V (Astronomical Society of India, 1976-09)
  • Ionization potential and excitation energy calculations for Ba+ using the relativistic coupled-cluster method 
    Gopakumar, G; Merlitz, H; Majumder, S; Chaudhuri, R. K; Das, B. P; Mahapatra, U. S; Mukherjee, D (The American Physical Society, 2001-09)
    We report the results of our relativistic coupled cluster singles, doubles, and partial triples calculations of the ionization potentials (IP) and excitation energies (EE) for different low-lying levels of Ba+. The accuracies ...
  • Ionization potentials of beryllium-like ions from the relativistic coupled-cluster-based linear response theory 
    Chaudhuri, R. K; Panda, P. K; Merlitz, H; Das, B. P; Mahapatra, U. S; Mukherjee, D (Institute of Physics, 2000-11)
    We first test our recently developed relativistic coupled-cluster-based linear response theory (RCCLRT) by computing the principal and the shake-up ionization potentials (IP) of highly stripped atoms. Comparison is made ...
  • Ionizations in Ps-atom scattering 
    Ray, H (Elsevier, 2002-05)
    Ionizations in Ps-atom scattering are studied using three different types of target: H, He and Li. Three different types of ionization cross-sections are compared, considering a large number of excitation channels of both ...
  • Ionized Gas in Elliptical Galaxies 
    Singh, K. P; Prabhu, T. P; Kembhavi, A. K; Bhat, P. N (Indian Academy of Sciences, 1995-06)
    We report observations of H alpha nebulosities in the X-ray bright elliptical galaxies which are members of nearby groups of galaxies or clusters. Our sample includes NGC 1399, NGC 1600, NGC 2563, NGC 3607, NGC 4203, ...
  • Ionized molecules in facula models 
    Tripathi, B. M; Gaur, V. P; Pande, M. C (Astronomical Society of India, 1981-09)
    Equivalent widths for the lines of ionized molecules AlH+, CH+, CN+ CO+, N2+, NH+, OH+ and SiH+ have been calculated in five facular and two photospheric models. The calculations suggest that CH+ should show up in facular ...
  • Ionosphere scintillations associated with features of equatorial ionosphere 
    Chandra, H; Vats, H. O; Sethia, G; Deshpande, M. R; Rastogi, R. G; Sastri, J. H; Murthy, B. S (European Geophysical Society, 1979-09)
    Amplitude scintillations of radio beacons aboard the ATS-6 satellite on 40 MHz, 140 MHz and 360 MHz recorded during the ATS-6 phase II at an equatorial station Ootacamund (dip 4 deg N) and the ionograms at a nearby station ...
  • Ionospheric Currents Associated with Solar Flares: A Short Review 
    Roy, M (Astronomical Society of India, 1980-03)
    The enhanced radiation of the X-rays and the ultra-violets during a chromospheric flare can induce a qualitative change in the ionospheric current system. The observational results of this effect, popularly known as ...
  • Ionospheric disturbances associated with magnetic storms at Kodaikanal 
    Bhargava, B. N; Gopala Rao, U. V (Manager of Publications Civil Lines Delhi, 1959-04)
    F2 layer disturbance at Kodaikanal have been analysed for a study of the behaviour of the, critical frequency and the virtual height during geomagnetic storms. The disturbances have been classified for this purpose into ...
  • Ionospheric Effects During February 1980 Solar Eclipse 
    Chandra, H; Deshpande, M. R; Vyas, G. D; Sethia, G; Vats, H. O; Iyer, K. N (Astronomical Society of India, 1980-12)
    Highlights of the ionospheric effects of the total solar eclipse of February 16, 1980 detected by ground-based experiments in India are summarised. Decrease in electron density at various height in ionosphere upto the F2 ...
  • Ionospheric effects of the total solar eclipse of 24 October, 1995 over Ahmedabad 
    Chandra, H; Vyas, G. D; Sharma, S (Astronomical Society of India, 1998)
  • Ionospheric electron content and equivalent slab thickness in the equatorial region 
    Das Gupta, A; Basu, S; Bhar, J. N; Bhattacharyya, J. C (American Geophysical Union, 1975-02)
    The ionospheric total electron content and equivalent slab thickness in the equatorial region around 75° E have been studied. It is found that the slab thickness exhibits a strong latitudinal dependence with a maximum at ...
  • Ionospheric Indication of Short-time Solar Activity Variations 
    Bhattacharyya, J. C; Sunder, R. S (PID [Publications and Information Directorate], 1970)
    A series of Lyot filtergrams have been photometrically analysed and the variations in the plage intensity determined on a number of days. From simultaneous ionosonde records, correlation has been sought between the electron ...
  • Ionospheric storm of 4 - 6 December 1958 in the Indian equatorial region. 
    Sastri, J. H (The Council of Scientific and Industrial Research, 1980-06)
    The characteristics of the ionospheric storm of 4-6 Dec. 1958 in the Indian sector (60-85°B) are studied using published data from ten ionospheric stations distributed from high mid latitudes to dip equator. It is shown ...

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