IIA Institutional Repository: Recent submissions

  • Optical identification and BVRI photometry of a few 'unidentified' IRAS sources of a late type stellar nature 
    Iyengar, K. V. K (Astronomical Society of India, 1993)
    A search for the optical counterparts of 21 'unidentified' IRAS sources was carried out using the Palomar Observatory Sky Survey (POSS), European Space Observatory (ESO) and Space Engineering Research Center (SERC) Sky ...
  • Infrared colors of RS CVn binaries 
    Rengarajan, T. N; Verma, R. P; Iyengar, K. V. K (Astronomical Society of India, 1993)
    IRAS 1D COADD data for 82 RS CVn systems have been analysed to obtain their magnitudes at 12 and 25 micrometers. Their colors V - (12) and (12) - (25) have been computed and discussed. For 62 stars, the excess at 12 ...
  • Dust around Herbig Ae/Be stars: IRAS low resolution spectra 
    Bhatt, H. C; Gorti, U (Astronomical Society of India, 1993)
    IRAS low resolution spectra are presented for 17 Herbig Ae/Be stars. The observed spectral characteristics are correlated with reddening E(B-V) and the spectral type of the star. The silicate emission feature at 9.7 ...
  • Disruption of forced current sheets in astrophysical plasmas 
    Lakhina, G. S (Astronomical Society of India, 1993)
    Ion tearing mode instability of the forced current sheets is studied. The trapped electrons have a strong stabilizing effect on the excitation of the instability. The presence of background turbulence can effectively lead ...
  • Faraday rotation versus stimulated Raman scattering in intense sources 
    Gangadhara, R. T; Krishan, V (Astronomical Society of India, 1993)
    A coherent plasma process such as the stimulated Raman scattering plays significant role in bringing about the changes in polarization characteristics of radiation. It is found that some of the observed polarization ...
  • Optical testing of a gamma-ray telescope mirror 
    Udupa, D. V; Shukla, R. P; Saksena, G. D (Astronomical Society of India, 1993)
    A large size concave mirror for use in the gamma-ray telescope TACTIC was tested. Focal length of the concave spherical mirror of diameter 600 mm was measured to be 401.2 cm using the Ronchi test. The surface accuracy of ...
  • Mobile domes for TACTIC telescope 
    Karkera, B. N; Puri, I. K; Bhat, C. L; Koul, R; Murthy, G. S. K; Suthar, R. L; Kmble, S. H (Astronomical Society of India, 1993)
    A system of mobile domes which have a minimal shadowing effect, is proposed for the TACTIC telescope being set up at Gurushikar, Mt. Abu. The important design considerations and the salient features of the proposed concept ...
  • Design philosophy of TACTIC -- a high sensitivity VHE gamma-ray telescope 
    Bhat, C. L; Razdan, H; Koul, R; Sapru, M. L; Tickoo, A. K; Rannot, R. C; Kaul, R. K; Kaul, C. L (Astronomical Society of India, 1993)
    TACTIC is a high-sensitivity gound-based very high energy (VHE) telescope designed for undertaking comprehensive temporal and spectral studies of galactic and extragalactic gamma-ray sources. Its main design specifications, ...
  • Site-selection studies at Gurushikar, Mt. Abu for project 'GRACE' 
    Sapru, M. L; Bhat, C. L; Kaul, M. K; Kaul, S. K; Kaul, S. R; Dhar, V. K; Kaul, R. K; Rannot, R. C; Tickoo, A. K (Astronomical Society of India, 1993)
    Holding the promise of yielding up to 1150 hrs of good-quality atmospheric Cerenkov data per calendar year, Gurushikar in Mt. Abu, Rajasthan, offers itself as a good observatory site for our proposed new gamma-ray astrophysics ...
  • Some representative Cerenkov light images recorded by 144-pixel SHALON gamma-ray telescope 
    Nikolsky, S. I; Sinitsyna, V. G; Acobian, A. M; Matizov, B; Vorobiov, S. P; Bhat, C. L; Tickoo, A. K; Rannot, R. C; Sapru, M. L; Razdan, H (Astronomical Society of India, 1993)
    The 144-pixel SHALON imaging telescope was deployed on the nights of 1993 January 20 and 21 to record Cerenkov images of sample cosmic-ray events coming from the direction of zenith. Here, in this preliminary work, we ...
  • Mechanical design and deflection analysis of TACTIC gamma-ray telescope 
    Ramesh Kumar; Suthar, R. L; Murthy, G. S. K; Koul, R; Bhat, C. L; Karkera, B. N (Astronomical Society of India, 1993)
    The high sensitivity gamma-ray telescope TACTIC to be set up at Gurushikar is presently being manufactured at the Central Workshop, Bhabha Atomic Research Centre (BARC). Deflection analysis of the mirror basket assembly, ...
  • Detector instrumentation and drive system for TACTIC gamma-ray telescope 
    Koul, R; Bhat, C. L; Tickoo, A. K; Kaul, I. K; Kaul, S. K; Kaul, S. R; Sapru, M. L; Rannot, R. C (Astronomical Society of India, 1993)
    TACTIC, a high sensitivity gamma-ray telescope is being set up at Gurushikar, Mt. Abu, to undertake comprehensive temporal and spectral studies of cosmic gamma-ray sources in the TeV energy range. The salient features of ...
  • Near infrared high angular resolution observations of stars and circumstellar regions by the technique of lunar occultations 
    Chandrasekhar, T; Ashok, N. M; Sam Ragland (Astronomical Society of India, 1993)
    A program of high angular resolution observations of stars and their circumstellar regions using the technique of lunar occultations has been initiated at the Physical Research Laboratory, Ahmedabad. A liquid nitrogen ...
  • Gamma ray analysis in planetary mapping 
    Yadav, J. S; Arnold, J. R (Astronomical Society of India, 1993)
    n this work, we present ways to improve the analysis procedure for high resolution gamma ray planetary mapping. This study is aimed at providing better analysis procedures for the Gamma Ray Spectrometer (GRS) experiment ...
  • An assessment of far-infrared measurements and their processing 
    Ghosh, S. K; Das, B; Rengarajan, T. N; Verma, R. P (Astronomical Society of India, 1993)
    Three image processing schemes, used for generating far-infrared (FIR) astronomical maps have been compared for their relative merits. Two of these schemes based on the maximum entropy method (MEM) have been developed at ...
  • A two band far-infrared photometer with bolometer arrays 
    Verma, R. P; Rengarajan, T. N; Ghosh, S. K (Astronomical Society of India, 1993)
    A new two band photometer for the Tata Institute of Fundamental Research (TIFR) 1m balloon-borne telescope is described. The detector system consists of two arrays (of six detectors each) of liquid He-3 cooled bolometers. ...
  • A data acquisition system for the TIFR near-infrared camera 
    Ghosh, S. K; Naik, M. B (Astronomical Society of India, 1993)
    A near infrared array camera based on a SBRC 58 x 62 InSb detector (TIRCAM-1) is being developed at Tata Institue of Fundamental Research (TIFR) for astronomical imaging applications. The data acquisition system for this ...
  • Programme for the restoration of the masonry instruments at Delhi Jantar Mantar 
    Babu, G. S. D; Venugopal, V. R (Astronomical Society of India, 1993)
    In 1724 AD, Maharaja Sawai Jai Singh II of Jaipur built a large observatory at Delhi comprising of huge masonry instruments, with which he made careful observations of the celestial objects. He then built four other similar ...
  • Astronomical significance to two Mohenjodaro seals 
    Abhyankar, K. D (Astronomical Society of India, 1993)
    It is shown that the Mohenjodaro Seal No. 420 is a representation of the four constellations corresponding to the four cardinal points of vernal equinox, summer solstice, autumnal equinox and winter solstice at the epoch ...
  • Astronomical observatories for schools, school systems and colleges 
    Ratna, Ved (Astronomical Society of India, 1993)
    n ancient times, India's leadership inatories aimed at schools and school systems in Delhi, Bhopal, Bhubaneshwar, Mysore and Ajmer. In spite of all the seriousness on the part of the then Head of the Department of Science ...

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