IIAP Publications: Recent submissions

  • Observations of the Interaction of Acoustic Waves and Small-scale Magnetic Fields in a Quiet Sun 
    Pradeep Chitta, L; Jain, R; Kariyappa, R; Jefferies, S. M (IOP Publishing, 2012-01-10)
    The effect of the magnetic field on photospheric intensity and velocity oscillations at the sites of small-scale magnetic fields (SMFs) in a quiet Sun near the solar disk center is studied. We use observations made by the ...
  • Data analysis method for the search of point sources of gamma rays with the HAGAR telescope array 
    Britto, R. J; Acharya, B. S; Anupama, G. C; Bhattacharjee, P; Chitnis, V. R; Cowsik, R; Dorji, N; Duhan, S. K; Gothe, K. S; Kamath, P. U; Mahesh, P. K; Manoharan, J; Nagesh, B. K; Parmar, N. K; Prabhu, T. P; Rao, S. K; Saha, L; Saleem, F; Saxena, A. K; Sharma, S. K; Shukla, A; Singh, B. B; Srinivasan, R; Srinivasulu, G; Sudersanan, P. V; Tsewang, D; Upadhya, S. S; Vishwanath, P. R (French Society of Astronomy and Astrophysics, 2011-12)
    The High Altitude GAmma-Ray (HAGAR) experiment is the highest altitude atmospheric Cherenkov sampling array, set up at 4300 m amsl in the Himalayas (Northern India). It constitutes 7 telescopes, each one with seven 90 ...
  • Status of the Himalayan Gamma-Ray Observatory (HIGRO) and observation with HAGAR at very high energies 
    Britto, R. J; Acharya, B. S; Anupama, G. C; Bhatt, N; Bhattacharjee, P; Bhattacharya, S; Chitnis, V. R; Cowsik, R; Dorji, N; Duhan, S. K; Gothe, K. S; Kamath, P. U; Koul, R; Mahesh, P. K; Manoharan, J; Mitra, A; Nagesh, B. K; Parmar, N. K; Prabhu, T. P; Rannot, R. C; Rao, S. K; Saha, L; Saleem, F; Saxena, A. K; Sharma, S. K; Shukla, A; Singh, B. B; Srinivasan, R; Srinivasulu, G; Sudersanan, P. V; Tickoo, A. K; Tsewang, D; Upadhya, S. S; Vishwanath, P. R; Yadav, K. K (French Society of Astronomy and Astrophysics, 2011-12)
    High Altitude GAmma Ray (HAGAR) telescope array, which is the first stage of HImalayan Gamma Ray Observatory (HIGRO), has been successfully installed at Hanle in Himalayas and has been collecting science data since September, ...
  • Influence Function Measurement of Continuous Membrane Deformable Mirror Actuators Using Shack Hartmann Sensor 
    Roopashree, M. B; Vyas, A; Prasad, B. R (American Institute of Physics, 2011-10)
    The characterization of a continuous membrane deformable mirror (CDM) involves the measurement of influence function, which quantifies the response of individual actuators to application of different voltages. In this ...
  • Experimental evaluation of centroiding algorithms at different light intensity and noise levels 
    Roopashree, M. B; Vyas, A; Prasad, B. R (American Institute of Physics, 2011-10)
    In this paper, we present results from an experimental evaluation of centroiding algorithms, simple center of gravity (CoG) and weighted center of gravity (WCoG) in a Shack Hartmann wavefront sensor at different light ...
  • Intensity Weighted Noise Reduction in MEMS Based Deformable Mirror Images 
    Roopashree, M. B; Vyas, A; Prasad, B. R (American Institute of Physics, 2011-10)
    The frames captured with a compact, high-resolution, monochrome progressive scan CCD camera, of a continuous facesheet microelectromechanical systems (MEMS) deformable mirror (DM), include unwanted diffractive, background ...
  • Suzaku X-ray spectral study of the Compton-thick Seyfert galaxy NGC 5135 
    Singh, V; Risaliti, G; Braito, V; Shastri, P (Wiley-Blackwell, 2012-01)
    We present the 0.5–50 keV Suzaku broad-band X-ray spectral study of the Compton-thick active galactic nucleus (AGN) in NGC 5135. The Suzaku observation provides the first detection of NGC 5135 above 10 keV that allowed us, ...
  • Comprehensive abundance analysis of red giants in the open clusters NGC 752, 1817, 2360 and 2506 
    Reddy, A. B. S; Giridhar, S; Lambert, D. L (Wiley-Blackwell, 2012-01)
    We have analysed high-dispersion echelle spectra (R ≳ 50 000) of red giant members for four open clusters to derive abundances for many elements. The spread in temperatures and gravities being very small among the red ...
  • Solar cycle variations in the growth and decay of sunspot groups 
    Javaraiah, J (Springer, 2012-04)
    We analysed the combined Greenwich (1874–1976) and Solar Optical Observatories Network (1977–2011) data on sunspot groups. The daily rate of change of the area of a spot group is computed using the differences between the ...
  • The astronomical significance of ‘Nilurallu’, the megalithic stone alignment at Murardoddi In Aandhra Pradesh, India 
    Kameswara Rao, N; Thakur, Priya; Mallinathpur, Y (Centre for Astronomy, James Cook University, 2011-11)
    The stone alignment ‘Nilurallu' at Murardoddi is a megalithic monument containing standing stones of 12 to 16 feet high that are arranged somewhat in a squarish pattern. This is one of the stone alignments listed by Allchin ...
  • Hypertelescope Approach: A Novel Method for Imaging of Stellar Objects 
    Saha, S. K (Optical Society of India, 2011)
    The diffraction limited phase retrieval of a degraded image is an important subject that is being implemented in other branches of physics too, for example, electron microscopy, wavefront sensing, and crystallography. A ...
  • Aperture Synthesis at Optical Wavelengths 
    Saha, S. K (Department of Applied Optics and photonics, University of Calcutta, 2011)
    Optical stellar interferometers have demonstrated milli-arcsecond resolution with few apertures spaced tens of meters apart. Results from the area of stellar angular diameters with implications for emergent fluxes, ...
  • The Amplitude of Sunspot Minimum as a Favorable Precursor for the Prediction of the Amplitude of the Next Solar Maximum and the Limit of the Waldmeier Effect 
    Ramesh, K. B; Lakshmi, N. B (Springer, 2012-02)
    The linear relationship between the maximum amplitudes (R max) of sunspot cycles and preceding minima (R min) is one of the precursor methods used to predict the amplitude of the upcoming solar cycle. In the recent past ...
  • Some aspects of rotational and magnetic energies for a hierarchy of celestial objects 
    Sivaram, C; Arun, K (Springer, 2012-02)
    Celestial objects, from earth like planets to clusters of galaxies, possess angular momentum and magnetic fields. Here we compare the rotational and magnetic energies of a whole range of these celestial objects together ...
  • Enigmatic aspects of entropy inside the black hole: what do falling comoving observers see? 
    Sivaram, C; Arun, K (Springer, 2012-01)
    In a recent paper it was suggested that inclusion of mutual gravitational interactions can give a possible scenario for reversing gravitation collapse and averting a singular phase. We extend this idea to the still unsolved ...
  • Evolution of Spinning and Braiding Helicity Fluxes in Solar Active Region NOAA 10930 
    Ravindra, B; Yoshimura, K; Dasso, S (IOP Publishing, 2011-12-10)
    The line-of-sight magnetograms from Solar Optical Telescope Narrowband Filter Imager observations of NOAA Active Region 10930 have been used to study the evolution of spinning and braiding helicities over a period of five ...
  • Gaseous outflows in Seyferts and unification: The case of Mrk 533 
    Shastri, P; Murthy, J; Hutchings, J; Wills, B. J (Cambridge University Press, 2004-11)
    We present our recent results from the observation of the O VI λ λ1032,1038 emission doublet in Seyfert galaxies of type 2 with the FUV spectrograph on the FUSE satellite. These observations are part of our investigation ...
  • Active galactic nucleus activity and black hole masses in low surface brightness galaxies 
    Ramya, S; Prabhu, T. P; Mousumi Das (Wiley-Blackwell, 2011-12)
    We present medium resolution optical spectroscopy of a sample of nine low surface brightness (LSB) galaxies. For those that show clear signatures of active galactic nucleus (AGN) emission, we have disentangled the AGN ...
  • The recent star-formation history of the Large and Small Magellanic Clouds 
    Indu, G; Subramaniam, A (EDP Sciences, 2011-11)
    Aims. Recent interactions between the Large and the Small Magellanic Clouds (LMC and SMC) and the Milky Way can be understood by studying their recent star formation history. This study aims to detect any directional or ...
  • Observations with the High Altitude GAmma-Ray (HAGAR) telescope array in the Indian Himalayas 
    Britto, R. J; Acharya, B. S; Anupama, G. C; Bhatt, N; Bhattacharjee, P; Bhattacharya, S; Chitnis, V. R; Cowsik, R; Dorji, N; Duhan, S. K; Gothe, K. S; Kamath, P. U; Koul, R; Manoharan, J; Mahesh, P. K; Mitra, A; Nagesh, B. K; Parmar, N. K; Prabhu, T. P; Rannot, R. C; Rao, S. K; Saha, L; Saleem, F; Saxena, A. K; Sharma, S. K; Shukla, A; Singh, B. B; Srinivasan, R; Srinivasulu, G; Sudersanan, P. V; Tickoo, A. K; Tsewang, D; Upadhya, S. S; Vishwanath, P. R; Yadav, K. K (Copernicus Publications, 2011-11)
    The High Altitude GAmma-Ray (HAGAR) array is a wavefront sampling array of 7 telescopes, set-up at Hanle, at 4270 m amsl, in the Ladakh region of the Himalayas (Northern India). It constitutes the first phase of the HImalayan ...

Search DSpace


Browse

My Account