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Browsing IIAP Publications by Title

Browsing IIAP Publications by Title

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  • The metal-poor end of the Spite plateau I. Stellar parameters, metallicities, and lithium abundances 
    Sbordone, L; Bonifacio, P; Caffau, E; Ludwig, H. -G; Behara, N. T; González Hernández, J. I; Steffen, M; Cayrel, R; Freytag, B; Van’t Veer, C; Molaro, P; Plez, B; Sivarani, T; Spite, M; Spite, F; Beers, T. C; Christlieb, N; François, P; Hill, V (EDP Sciences, 2010-11)
    Context. The primordial nature of the Spite plateau is at odds with the WMAP satellite measurements, implying a primordial Li production at least three times higher than observed. It has also been suggested that A(Li) might ...
  • The metal-poor end of the Spite plateau. II. Chemical and dynamical investigation 
    Pinto, A. M. Matas; Spite, M; Caffau, E; Bonifacio, P; Sbordone, L; Sivarani, T; Steffen, M; François, P; Di Matteo, P (EDP Sciences, 2021-10)
    Context. The study of old, metal-poor stars deepens our knowledge on the early stages of the universe. In particular, the study of these stars gives us a valuable insight into the masses of the first massive stars and their ...
  • Metallicity of Sun-like G-stars that have exoplanets 
    Gurumath, S. R; Hiremath, K. M; Ramasubramanian, V (Indian Academy of Sciences, 2017-07)
    By considering the physical and orbital characteristics of G type stars and their exoplanets, we examine the association between stellar mass and its metallicity that follows a power law. Similar relationship is also ...
  • The metal–poor end of the Spite plateau 
    Sbordone, L; Bonifacio, P; Caffau, E; Ludwig, H. -G; Behara, N; Gonzalez-Hernandez, J. I; Steffen, M; Cayrel, R; Freytag, B; Van't Veer, C; Molaro, P; Plez, B; Sivarani, T; Spite, M; Spite, F; Beers, T. C; Christlieb, N; François, P; Hill, V (Cambridge University Press, 2010-03)
    We present the largest sample available to date of lithium abundances in extremely metal poor (EMP) Halo dwarfs. Four Teff estimators are used, including IRFM and Hα wings fitting against 3D hydrodynamical synthetic ...
  • The metal–poor end of the Spite plateau: gravity sensitivity of the Hα wings fitting. 
    Sbordone, L; Bonifacio, P; Caffau, E; Ludwig, H. -G; Behara, N; Gonzalez-Hernandez, J. I; Steffen, M; Cayrel, R; Freytag, B; Van't Veer, C; Molaro, P; Plez, B; Sivarani, T; Spite, M; Spite, F; Beers, T. C; Christlieb, N; François, P; Hill, V (Cambridge University Press, 2010-04)
    We recently presented (Sbordone et al., 2009a) the largest sample to date of lithium abundances in extremely metal-poor (EMP) Halo dwarf and Turn-Off (TO) stars. One of the most crucial aspects in estimating Li abundances ...
  • Method for tilt correction of calibration lines in high-resolution spectra 
    Das, Tanya; Banyal, R. K (Optical Society of America, 2021-11-01)
    Technological advancement has led to improvement in the design capabilities of astronomical spectrographs, allowing for high-precision spectroscopy, thereby expanding the realms of observational astronomy. High-resolution ...
  • A method to determine distances to molecular clouds using near-IR photometry 
    Maheswar, G; Lee, C. W; Bhatt, H. C; Mallik, S. G. V; Dib, S (EDP Sciences, 2010-01)
    We aim to develop a method to determine distances to molecular clouds using JHK near-infrared photometry. Methods: The method is based on a technique that aids spectral classification of stars lying towards the fields ...
  • Metric observations of transient, quasi-periodic radio emission from the solar corona in association with a ``halo'' CME and an ``EIT wave'' event 
    Ramesh, R; Kathiravan, C; Satya Narayanan, A; Ebenezer, E (The European Southern Observatory, 2003-03)
    We present metric radio observations of quasi-periodic emission from the solar corona in close association with a ``halo'' CME and an ``EIT wave'' phenomenon. The radio event lasted for about 60 s. Its mean periodicity was ...
  • Metric Radio Observations and Ray-tracing Analysis of the Onset Phase of a Solar Eruptive Event 
    Kathiravan, C; Ramesh, R; Subramanian, K. R (University of Chicago Press, 2002-03)
    We report metric radio observations and the results obtained using two-dimensional ray-tracing analysis of the solar corona close to the onset phase of the exceptionally bright prominence eruption and the associated massive ...
  • Metric Radio Observations of the Evolution of a ``Halo'' Coronal Mass Ejection Close to the Sun 
    Ramesh, R; Kathiravan, C; Sastry, Ch. V (The American Astronomical Society, 2003-07-10)
    We report direct imaging observations of the propagation of a diffuse thermal radio enhancement in close temporal and spatial association with a ``halo'' coronal mass ejection from the solar atmosphere, in the metric ...
  • Metric-affine effects in crystallization processes of white dwarfs 
    Kalita, Surajit; Sarmah, Lupamudra; Wojnar, Aneta (2023-02-15)
    We analyze the effects of modified gravity on specific heats of electrons and ions, Debye temperature, crystallization process, and cooling mechanism in white dwarfs. We derive the Lane-Emden-Chandrasekhar equation and ...
  • MG II emission of Pop. 2 long-period Cepheids 
    Parthasarathy, M; Parsons, S. B (1984-12)
    The Population II Cepheid pulsational variables AL Vir (P = 10.3 days) and W Vir (P = 17.3 days) were observed with IUE at two phases each. Only low-dispersion mid-UV exposures were feasible, but were sufficient to show a ...
  • MHD Seismology of a loop-like filament tube by observed kink waves 
    Pant, V; Srivastava, A. K; Banerjee, D; Goossens, M; Chen, P.-F; Joshi, N. C; Zhou, Y.-H (IOP Publishing, 2015-10)
    We report and analyze observational evidence of global kink oscillations in a solar filament as observed in Hα by instruments administered by National Solar Observatory (NSO)/Global Oscillation Network Group (GONG). An ...
  • MHD waves at a tangential discontinuity with inclined magnetic fields and flows 
    Satya Narayanan, A; Pandey, V; Venkatakrishnan, P (European Solar Physics, 2008-09)
    Propagation of magnetohydrodynamic (MHD) waves in inhomo- geneous magnetic plasmas is interesting from space and astrophysical point of view. In this study, the combined effect of non-parallel propagation, steady flow and ...
  • MHD Waves in Coronal Holes 
    Banerjee, D; Krishna Prasad, S (John Wiley & Sons, Inc., 2015-05)
    Coronal holes are the dark patches in the solar corona associated with relatively cool, less dense plasma and unipolar fields. The fast component of the solar wind emanates from these regions. Several observations ...
  • MHD waves on the Sun 
    Hasan, S. S (Indian Association for the Cultivation of Science, 1992)
    Theoretical aspects of wave propagation in an atmosphere with a vertical magnetic field are reviewed. Starting from the ideal magneto hydrodynamic equations. The differential equations governing linear oscillations presented ...
  • Micro-fluctuations of fried's parameter (ro) 
    Saha, S. K; Yeswanth, L (Anita Publications, 2004)
    The atmospheric coherence is a highly variable parameter depending upon the high velocity wind. The size of the atmospheric coherence length widely known as, Fried's parameter, ro, has been computed during night at the ...
  • Microflares in accretion disks 
    Krishan, V; Ramadurai, S; Wiita, P. J (The European Southern Observatory, 2003-02)
    We have investigated the phenomenon of explosive chromospheric evaporation from an accretion disk as a mechanism for fast variability in accreting sources such as low mass X-ray binaries and active galactic nuclei. This ...
  • Microwave emission from late-type dwarf stars UV Ceti and YZ Canis Minoris 
    Kundu, M. R; Shevgaonkar, R. K (The University of Chicago Press, 1985-10-15)
    Simultaneous high-resolution observations of two late-type dwarf stars, UV Cet and YZ CMi, at 6 and 20 cm are presented. These observations put sufficient constraints on existing interpretations to conclude that the quiescent ...
  • Microwave Propagation and Troposphere: Eclipse Time Observation 
    Mishra, U; Sen, S; Sharma, S; Barbara, A. K; Devi, M (Indian Institute of Astrophysics, Bangalore, 1997)
    The effect of 24th October 1995 solar eclipse were studied on the reception of Latikor-Shillong and Nongpiur-Shillong links both operating at a frequency of 11GHz. The surface temperature, pressure and humidity were ...

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