IIA Institutional Repository

Browsing IIAP Publications by Title

Browsing IIAP Publications by Title

Sort by: Order: Results:

  • Do the Line Widths of Coronal Emission Lines Increase with Height above the Limb? 
    Singh, J; Sakurai, T; Ichimoto, K (University of Chicago Press, 2006-03)
    In our earlier studies we obtained off-the-limb spectroscopic observations in a number of forbidden emission lines ([Fe X–XIV]) to study the physical properties and their temporal variations in steady coronal structures. ...
  • Does a prestellar core always become Tracing? protostellar the evolution of cores from the prestellar to protostellar phase 
    Anathpindika, S; Di Francesco, J (Oxford University Press on behalf of the Royal Astronomical Society, 2013-04-11)
    Recently, a subset of starless cores whose thermal Jeans mass is apparently overwhelmed by the mass of the core has been identified, e.g. the core L183. In the literature, massive cores such as this one are often referred ...
  • Does black hole spin play a key role in the FSRQ/BL Lac dichotomy? 
    Bhattacharya, D; Sreekumar, P; Mukhopadhyay, B; Tomar, I (IOP Publishing, 2016-04)
    Blazars are characterized by large intensity and spectral v ariations across the electromagnetic spectrum It is believed that jets emerging from them are almo st aligned with the line-of-sight. The major- ity of ...
  • Does sunspot activity originate in slow global oscillations of the sun? 
    Gokhale, M. H (Indian Academy of Sciences, 1986-12)
    A Fourier analysis of sunspot activity during the 1933-1954 period using data entending over the first 10 degrees and all azimuthal orders of the spherical harmonics is presented, and results suggest that the sunspot ...
  • Does the Poleward Migration Rate of the Magnetic Fields Depend on the Strength of the Solar Cycle? 
    Makarov, V. I; Tlatov, A. G; Sivaraman, K. R (Springer, 2001)
    We present the pattern of the polar magnetic reversal for cycle 23 derived from Hα synoptic charts and have also included the reversals of the earlier cycles 18-22 for comparison. At the beginning of a new cycle (i.e., ...
  • A Doppler Comparator for Solar Spectra 
    Kubicela, Aleksandar; Sivaraman, K. R (Kodaikanal Observatory, 1969-08)
  • Doppler frequency fluctuations of lower thermospheric reflections in the equatorial electrojet region 
    Sastri, J. H; Ramesh, K. B; Rao, J. V. S. V (Elsevier, 1991-07)
    The origin of short-period fluctuations from Doppler frequency-shift (P) data is investigated by examining their quantitative relationships with ambient electrojet strength and associated ionospheric conditions. The wave ...
  • The double dust envelopes of R coronae borealis stars 
    Montiel, Edward J; Clayton, G. C; Sugerman, B. E. K; Evans, A; Garcia-Hernandez, D. A; Kameswara Rao, N; Matsuura, M; Tisserand, P (IOP Publishing, 2018-10)
    The study of extended, cold dust envelopes surrounding R Coronae Borealis (RCB) stars began with their discovery by the Infrared Astronomical Satellite. RCB stars are carbon-rich supergiants characterized by their extreme ...
  • Double Peaks of the Solar Cycle: An Explanation from a Dynamo Model 
    Karak, B. B; Mandal, Sudip; Banerjee, D (IOP Publishing, 2018-10-10)
    One peculiar feature of the solar cycle that is yet to be understood properly is the frequent occurrence of double peaks (also known as the Gnevyshev peaks). The double peaks, and also multiple peaks and spikes, are often ...
  • Double radio peak and non-thermal collimated ejecta in RS Ophiuchi following the 2006 outburst 
    Eyres, S. P. S; O'Brien, T. J; Beswick, R; Muxlow, T. W. B; Anupama, G. C; Kantharia, N. G; Bode, M. F; Gawroński, M. P; Feiler, R; Evans, A; Rushton, M. T; Davis, R. J; Prabhu, T; Porcas, R; Hassall, B. J. M (Blackwell Publishing, 2009-05)
    We report Multi-Element Radio-Linked Interferometer Network, Very Large Array, One-Centimetre Radio Array, Very Long Baseline Array (VLBA), Effelsberg and Giant Metrewave Radio Telescope observations beginning 4.5 days ...
  • Double-peaked Emission Lines Due to a Radio Outflow in KISSR 1219 
    Kharb, P; Subramanian, S; Vaddi, Sravani; Mousumi Das; Paragi, Z (IOP Publishing, 2017-09)
    We present the results from 1.5 and 5 GHz phase-referenced VLBA and 1.5 GHz Karl G. Jansky Very Large Array (VLA) observations of the Seyfert 2 galaxy KISSR 1219, which exhibits double-peaked emission lines in its optical ...
  • DP 2 electric field fluctuations in the dusk-time dip equatorial ionosphere 
    Abdu, M. A; Sastri, J. H; Luhr, H; Tachihara, H; Kitamura, T; Trivedi, N. B; Sobral, J. H. A (American Geophysical Union, 1998-05)
    We have studied the geomagnetic and ionospheric manifestations of the DP 2 activity that occurred on April 7, 1995 using high time resolution magnetometer data of IMAGE network in Scandinavia and of Alcantara (dip 1.2° N), ...
  • Dramatic Changes in the Polarization of AR Pup 
    Raveendran, A. V; Deshpande, M. R; Kameswara Rao, N; Joshi, U. C; Kuleshrestha, A. K (Konkoly Observatory, 1985-04-25)
  • Dual Active Galactic Nuclei in Nearby Galaxies 
    Mousumi Das; Rubinur, K; Preethi, K; Varghese, A; Novakkuni, N; James, A (Societe Royale des Sciences de Liege, 2018-04)
    Galaxy mergers play a crucial role in the formation of massive galaxies and the buildup of their bulges. An important aspect of the merging process is the in-spiral of the supermassive black-holes (SMBHs) to the centre ...
  • A dual cavity Fabry-Perot device for high precision doppler measurements in astronomy 
    Banyal, R. K; Reiners, A (World Scientific Publishing Co., 2017-03)
    We propose a dual cavity Fabry–Perot interferometer as a wavelength calibrator and a stability tracking device for astronomical spectrograph. The FPI consists of two adjoining cavities engraved on a low expansion monoblock ...
  • A dual Fabry-Perot based narrow band imager for the National Large Solar Telescope 
    Ravindra, B; Banyal, R. K (Astronomical Society of India, 2011)
    A large solar telescope is usually equipped with several postfocus instruments deployed to study the dynamics of the solar features at di erent wavelengths. Indian Institute of Astrophysics (IIA) has proposed to build ...
  • Dual frequency observations of solar microwave bursts using the VLA 
    Shevgaonkar, R. K; Kundu, M. R (The American Astronomical Society, 1985-05)
    Simultaneous VLA observations of microwave bursts at 6 and 2 cm in a solar active region are presented and discussed. Using the full-day synthesis, I and V maps of the active region are produced. The radiation mechanisms ...
  • Dual input null networks utilizing RC ladders 
    Sen Roy, N (PID [Publications and Information Directorate], 1968)
    Two RC ladder networks are presented each of which, with an auxiliary input channel, shows transmission zero at a frequency that can be varied simply and widely by varying the ratio of the two inputs
  • Duration of equatorial spread-F 
    Sastri, J. H (Copernicus Publications, 1984-06)
    From an analysis of ionogram data of Kodaikanal (dip 3.5 deg N) for a 3-yr period of high sunspot activity, it is shown that the duration of equatorial spread-F (ESF), on the average, bears a direct relationship to the ...
  • Duration of Polar Activity Cycles and Their Relation to Sunspot Activity 
    Makarov, V. I; Tlatov, A. G; Sivaraman, K. R (Springer, 2003-05)
    We have defined the duration of polar magnetic activity as the time interval between two successive polar reversals. The epochs of the polarity reversals of the magnetic field at the poles of the Sun have been determined ...

Search DSpace


Browse

My Account