IIA Institutional Repository: Recent submissions

  • Performance evaluation of high-speed camera system for adaptive optics 
    Chinnappan, V; Saxena, A. K; Sreenivasan, A (Astronomical Society of India, 2002-09)
    Atmospheric turbulence distorts the incoming wavefront from the star light, thus severely limiting the resolution of the groundbased optical telescopes (Fried 1966). Adaptive optics is being implemented in all big ...
  • A remote-controlled fast infrared photometer for simultaneous lunar occultation observations in K and L bands - successful observations of two M3 giants 
    Mondal, S; Chandrasekhar, T; Kikani, P. K (Astronomical Society of India, 2002-09)
    Details of successful use of a new high speed infrared photometer for recording lunar occultation light curves simultaneously in K (2.2 /..Lm) and L (3.6 fJ.m) bands are presented, The photometer has also a provision to ...
  • Science from Astrosat 
    Singh, K. P (Astronomical Society of India, 2002-09)
    ASTROSAT is an X-ray and UV observatory that is planned to be launched in 2006 A.D. It will cover the entire X-ray spectral hand from 0.3 to 150 keY in one mission, with simultaneous UV observations in the 1350 - 3000 ...
  • Convective Intensification of Magnetic Flux Tubes in Stellar Photospheres 
    Rajaguru, S. P; Kurucz, R. L; Hasan, S. S (The American Astronomical Society, 2002-02)
    The convective collapse of thin magnetic flux tubes in the photospheres of Sun-like stars is investigated using realistic models of the superadiabatic upper convection zone layers of these stars. The strengths of convectively ...
  • Enhanced He{I} Absorption at the Feet of Solar X-Ray Loops 
    Venkatakrishnan, P; Sakurai, T; Suematsu, Y; Ichimoto, K (Astronomical Society of Japan, 1996)
    A comparison of He{I} spectroheliograms and Yohkoh soft X-ray images of active regions indicates that He{I} absorption is enhanced at the feet of hot X-ray loops. It is suggested that the conduction of heat from the loops ...
  • Embedded Clusters in Giant Extragalactic HII Regions.III.Extinction and Star Formation 
    Mayya, Y. D; Prabhu, T. P (American Astronomical Society, 1996-03)
    A study of star formation is carried out on 35 giant extragalactic H II regions (GEHRs) in seven galaxies using optical photometric data in BVR broad bands and in the emission line of Hα. Interstellar extinction, metallicity ...
  • Influence of Rotation on Pulsar Radiation Characteristics 
    Ahmadi, P; Gangadhara, R. T (The American Astronomical Society, 2002-02)
    We present a relativistic model for pulsar radio emission by including the effect of rotation on coherent curvature radiation by bunches. We find that rotation broadens the width of the leading component compared to the ...
  • Morphologies in megaparsec-size powerful radio galaxies 
    Subrahmanyan, R; Saripalli, L; Hunstead, R. W (Royal Astronomical Society, 1996-03)
    We present radio images with the Australia Telescope of a sample of powerful radio galaxies. The observations were designed to be sensitive to the largest-scale structures in the radio sources. The morphologies are ...
  • CCD observations of the H-alpha line in late G and K supergiants and their interpretation 
    Mallik, S. G. V (American Astronomical Society, 1993-01-01)
    CCD echelle spectra of the H-alpha line at 6563 A have been obtained for a sample of 30 G and K supergiants with a spectral resolution of about 0.24 A. The data clearly indicate that the observed H-alpha profile is a deep ...
  • On the evaluation of magnetic shear from H-alpha pictures 
    Venkatakrishnan, P (Kluwer Academic Publishers, 1993-01-10)
    It is shown that pre-flare activity in H-alpha filaments is unrelated to changes in magnetic shear. Changes in the shear angle are found to be related to either redeployment of the sources of magnetic flux relative to the ...
  • SAO 244567 - A post-AGB star which has turned into a planetary nebula within the last 40 years 
    Parthasarathy, M; Garcia-Lario, P; Pottasch, S. R; Manchando, A; Clavel, J; de Martino, D; Van de Steene, G. C. M; Sahu, K. C (European Sothern Observatory, 1993-01)
    SAO 244567 (Hen 1357 = CPD -59 deg 6926 = IRAS 17119-5926) is an IRAS source with far infrared colors and flux distribution similar to those of planetary nebulae. The IUE ultraviolet spectra obtained in July 1988 and April ...
  • Soft X-ray Imaging Telescope on ASTROSAT 
    Singh, K. P (Astronomical Society of India, 2002-09)
    A Soft X-ray focusing Telescope (SXT) with an X-ray sensitive CCD camera at the focal plane is being developed for the ASTROSAT. Made from conical foil mirrors with a CeD detector in the focal plane SXT will have a ...
  • Science with IUCAA telescope 
    Srianand, R; Gupta, R; Kembhavi, A; Ramaprakash, A. N; Tandon, S. N (Astronomical Society of India, 2002-09)
    We present a brief overview of the proposed astronomical observations using the first light instrument !FOSC for the WCAA 2 m telescope.
  • Near Infrared PICNIC Imager (NIPI) for IUCAA Telescope 
    Deep, A; Ramaprakash, A. N; Tandon, S. N; Gupta, R; Burse, M. P; Chordia, P. A; Das, H. K; Engineer, S; Kohok, A. A; Mestry, V. B (Astronomical Society of India, 2002-09)
    In this paper we present the current status of development of the Near Infrared PICNIC Imager (NIPI), which will be the first near-ffi instrument on IUCAA telescope. When used at one of the Cassegrain side ports of ...
  • Magnetic fields in cometary globules. I. CG 22 
    Sridharan, T. K; Bhatt, H. C; Rajagopal, J (Royal Astronomical Society, 1996-04)
    We report first results from a program to study magnetic fields in cometary globules (CGs). These are clouds near massive stars showing a head-tail morphology. Linear optical polarization measurements on stars seen projected ...
  • A new investigation of microbursts at meter-decameter wavelengths 
    Subramanian, K. R; Gopalswamy, N; Sastry, Ch. V (Kluwer Academic Publishers, 1993-02)
    The results of a new investigation of microbursts at meter-decameter wavelengths are reported. Several properties of microbursts reported earlier are confirmed, and some new properties, such as time profile characteristics, ...
  • Dispersion Velocity of Galactic Dark Matter Particles 
    Cowsik, R; Ratnam, C; Bhattacharjee, P (The American Physical Society, 1996-05)
    The self-consistent spatial distribution of particles of galactic dark matter is derived including their own gravitational potential, as also of that of the visible matter of the Galaxy. In order to reproduce the observed ...
  • Transient 1/f noise 
    Sinha, S (The American Physical Society, 1996-05)
    We provide examples of transient (nonasymptotic) ``1/f noise,'' occurring over reasonably long time scales, in extended nonlinear systems modeling complex spatiotemporal phenomena. These studies contribute towards establishing ...
  • Near Infrared Observations of Sakurai's Object during 1998-99 
    Kamath, U. S; Ashok, N. M (Springer, 2002-03)
    We present new near-infrared observations of Sakurai's Object obtained during 1998-99 when this final helium shell flash object was in the dust condensation phase. The infrared colours have reddened compared to earlier ...
  • IUCAA 2 meter telescope and its first light instrument IFOSC 
    Gupta, R; Burse, M; Das, H. K; Kohok, A; Ramaprakash, A. N; Engineer, S; Tandon, S. N (Astronomical Society of India, 2002-09)
    The various features of the IUCAA 2-meter telescope, its site parameters and considerations made for preserving the local seeing in terms of ventilation, thermal emissivity of the dome etc are described. The first ...

Search DSpace

Browse

My Account