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Browsing IIAP Publications by Title

Browsing IIAP Publications by Title

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  • Krishan, V; Berger, M; Priest, E. R (National Solar Observatory, 1988-07)
    The coronal loop plasma is represented by a superposition of the three lowest order Chandrasekhar-Kendall modes. The temporal evolution of the velocity and magnetic field in each of these mode is determined using ideal MHD ...
  • van Ballegooijen, A. A; Nisenson, P; Noyes, R. W; Löfdahl, M. G; Stein, R. F; Nordlund, Å; Krishnakumar, V (The American Astronomical Society, 1998-12)
    The interaction of magnetic fields and convection is investigated in the context of the coronal heating problem. We study the motions of photospheric magnetic elements using a time series of high-resolution G-band and ...
  • Pant, V; Dolla, L; Mazumder, R; Banerjee, D; Krishna Prasad, S; Vemareddy, P (IOP Publishing, 2015-07-01)
    We examine the role of small-scale transients in the formation and evolution of solar coronal plumes. We study the dynamics of plume footpoints seen in the vicinity of a coronal hole using the Atmospheric Imaging Assembly ...
  • Sen, Anisha; Rajaguru, S. P (American Astronomical Society, 2023-10-20)
    The distribution and evolution of photospheric magnetic fields in sunspots, plages, and network, and variations in their relative flux content, play key roles in radial velocity (RV) fluctuations observed in Sun-as-a-star ...
  • Samanta, T; Tian, H; Banerjee, D; Schanche, N (IOP Publishing, 2017-02-01)
    Plages are the magnetically active chromospheric structures prominently visible in the Ca ii K line (3933.67 Å). A plage may or may not be associated with a sunspot, which is a magnetic structure visible in the solar ...
  • Kalkofen, W; Hasan, S. S; Ulmschneider, P (Cambridge University Press, 2003)
    Wave propagation in the nonmagnetic chromosphere is described for plane and spherical waves, and excitation by means of impulses in small source regions in the photosphere; excitation for flux tube waves in the magnetic ...
  • Pradeep Chitta, L; van Ballegooijen, A. A; Rouppe van der Voort, L; DeLuca, E. E; Kariyappa, R (IOP Publishing, 2012-06-10)
    The subarcsecond bright points (BPs) associated with the small-scale magnetic fields in the lower solar atmosphere are advected by the evolution of the photospheric granules. We measure various quantities related to the ...
  • Hasan, S. S; van Ballegooijen, A. A (The American Astronomical Society, 2008-06-20)
    We consider recent observations of the chromospheric network and argue that the bright network grains observed in the Ca ii H and K lines are heated by an as-yet-unidentified quasi-steady process. We propose that the heating ...
  • Hasan, S. S; van Ballegooijen, A. A; Kalkofen, W; Steiner, O (The American Astronomical Society, 2005-10)
    The aim of this work is to identify the physical processes that occur in the network and contribute to its dynamics and heating. We model the network as consisting of individual flux tubes, each with a nonpotential field ...
  • Ray, H (Kluwer Academic Publishers, 2003-02)
    Accurate theoretical data for the transition probabilities are highly demanding in astrophysics and in the study of plasma in astrophysical objects and fusion devices. Na-like highly stripped ions of iron group, specially ...
  • Brown, E. T; Bendick, R; Bourles, D. L; Gaur, V. K; Molnar, P; Raisbeck, G. M (Elsevier Science BV, 2003-10)
    Cosmic ray exposure ages for formation of perched alluvial terraces and for abundant of an alluvial/debrisflow fan on opposite slides of the Tangtse Valley (The out flow at the northwest end of lake panggong, which is in ...
  • Gogoi, Antareep; Sharma, Ravi Kumar; Chanda, Prolay; Das, Subinoy (IOP Publishing, 2021-07-10)
    We present a novel scenario in which light (~few eV) dark fermions (sterile neutrinos) interact with a scalar field as in mass-varying neutrino dark energy theories. As the eV sterile states naturally become nonrelativistic ...
  • Prabhu, T. P (Indian Institue of Astrophysics, Bangalore, 1977)
    The emission line profiles of the spectrum of the spectrum of the envelope of Nova V 1500 Cyg, 1975 are studied. The spectral region covers LamdaLamda 3700-8800. The velocity structure of the profiles and the time variation ...
  • Bhargavi, S. G; Cowsik, R (The American Astronomical Society, 2000-12)
    We report multiband observations of the optical transient associated with GRB 000301c carried out 2000 March 2-4 using the 2.34 m Vainu Bappu Telescope at Kavalur, India. When combined with other reported data, the initial ...
  • Pandey, S. B; Sagar, R; Anupama, G. C; Bhattacharya, D; Sahu, D. K; Castro-Tirado, A. J; Bremer, M (EDP Sciences, 2004-04)
    The CCD magnitudes in Johnson UBV and Cousins RI photometric passbands for the afterglow of the long duration GRB 030226 are presented. Upper limits of a few mJy to millimeter wave emission at the location of optical are ...
  • Kameswara Rao, N; Vagiswari, A; Birdie, C (Indian Academy of Sciences, 2011-05-25)
    G.V.Juggarow was one of the early pioneers of observational astronomy in India who built his own observatory in 1840 at Vizagapatam (Vizagapatnam). His legacy was continued by his son-in-law A.V.Nursing Row till 1892, his ...
  • Anupama, G. C; Sivarani, T; Pandey, G (EDP Sciences, 2001-02)
    We present medium-resolution optical spectra of the type II supernova SN 1998S obtained during the pre-maximum, maximum and early decline phases. The early decline spectra show complex Balmer line profiles: a narrow P-Cygni ...
  • Sastri, J. H (D. Reidel Publishing Company, 1986-05)
    Evidence is presented to show that during epochs of high sunspot activity, the duration of manifestation of equatorial spread-F (ESF) irregularities in the Earth's equatorial ionosphere undergoes a systematic modulation ...
  • Bilham, R; Gaur, V. K; Molnar, P (American Association for the Advancement of Science, 2001-08)
    The devastating earthquake in Bhuj on 26 January 2001 highlighted the high earthquake risk in the Indian region of Gujarat. In their Perspective, Bilham et al. warn that major earthquakes may be expected in another part ...
  • Kameswara Rao, N; Ashoka, B. N; Lloyd, C; Pike, C. D; Stickland, D. J (Indian Academy of Sciences, 1990-12)
    A new radial velocity study has been made of the highly eccentric, early-type binary BD - 1 deg 1004 using spectra from the Kavalur Observatory. All available archival material has also been reexamined. An attempt has been ...

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