IIA Institutional Repository: Recent submissions

  • Simultaneous near-sun observations of a moving type IV radio burst and the associated white-light coronal mass ejection 
    Hariharan, K; Ramesh, R; Kathiravan, C; Wang, T. J (Springer, 2016-05)
    We present rare contemporaneous low-frequency (< 100 MHz) imaging, spectral, and polarimetric observations of a moving type IV radio burst that had close spatio-temporal association with a white-light coronal mass ejection ...
  • A generic FPGA-based detector readout and real-time image processing board 
    Mayuresh, Sarpotdar; Mathew, J; Safonova, M; Murthy, J (SPIE--The International Society for Optical Engineering, 2016-08)
    For space-based astronomical observations, it is important to have a mechanism to capture the digital output from the standard detector for further on-board analysis and storage. We have developed a generic (application- ...
  • Long-term study of Mkn 421 with the HAGAR array of telescopes 
    Sinha, A; Shukla, A; Saha, L; Acharya, B. S; Anupama, G. C; Bhattacharjee, P; Britto, R. J; Chitnis, V. R; Prabhu, T. P; Singh, B. B; Vishwanath, P. R (EDP Sciences, 2016-07)
    Context. The HAGAR Telescope Array at Hanle, Ladakh has been regularly monitoring the nearby blazar Mkn 421 for the past seven years. Aims. Blazars show flux variability in all timescales across the electromagnetic ...
  • Accuracy measurement for image retrieval system 
    Thabasu Kannan, S; Kumaravel, P (Vandana Publications, 2015-08)
    During the past decades we have been observing a permanent increase in image data, leading to huge repositories. Content-based image retrieval (CBIR) methods have tried to improve the access to image data. To date, numerous ...
  • Small scale clustering of late forming dark matter 
    Agarwal, S; Corasaniti, P.-S; Das, Subinoy; Rasera, Y (The American Physical Society, 2015-09-15)
    We perform a study of the nonlinear clustering of matter in the late-forming dark matter (LFDM) scenario in which dark matter results from the transition of a nonminimally coupled scalar field from radiation to collisionless ...
  • Unravelling the Components of a Multi-Thermal Coronal Loop Using Magnetohydrodynamic Seismology 
    Prasad, S. K; Jess, D. B; Klimchuk, J. A; Banerjee, D (IOP Publishing, 2017-01-10)
    Coronal loops, constituting the basic building blocks of the active Sun, serve as primary targets to help understand the mechanisms responsible for maintaining multi-million Kelvin temperatures in the solar and stellar ...
  • Role of primordial black holes in the direct collapse scenario of supermassive black hole formation at high redshifts 
    Pandey, Kanhaiya L; Mangalam, A (Indian Academy of Sciences, 2018-02)
    In this paper, we explore the possibility of accreting primordial black holes as the source of heating for the collapsing gas in the context of the direct collapse black hole scenario for the formation of super-massive black ...
  • Solar Active Longitudes from Kodaikanal White-Light Digitized Data 
    Mandal, Sudip; Chatterjee, Subhamoy; Banerjee, D (IOP Publishing, 2017-01-20)
    The study of solar active longitudes has generated great interest in recent years. In this work we have used a unique, continuous sunspot data series obtained from the Kodaikanal observatory and revisited the problem. An ...
  • CCD time-series photometry of variable stars in globular clusters and the metallicity dependence of the horizontal branch luminosity 
    Arellano Ferro, A; Bramich, D. M; Giridhar, S (Institute de Astronomia, 2017-04)
    We describe and summarize the findings from our CCD time-seri es photom- etry of globular clusters (GCs) program and the use of differe nce image analysis (DIA) in the extraction of precise light curves down to V ≈ 19 ...
  • The role of radiation pressure in the narrow line regions of Seyfert host galaxies 
    Davies, R. L; Dopita, M. A; Kewley, L; Groves, B; Sutherland, R; Hampton, E. J; Shastri, P; Kharb, P; Bhatt, H. C; Scharwachter, J; Jin, C; Banfield, J; Zaw, I; James, B; Juneau, S; Srivastava, S (IOP Publishing, 2016-06-10)
    We investigate the relative significance of radiation pressure and gas pressure in the extended narrow line regions (ENLRs) of four Seyfert galaxies from the integral field Siding Spring Southern Seyfert Spectroscopic ...
  • A theoretical study of the Build-Up of the Sun's Polar Magnetic Field by using a 3D Kinematic Dynamo Model 
    Hazra, G; Choudhuri, A. R; Miesch, Mark S (IOP Publishing, 2017-01-20)
    We develop a three-dimensional kinematic self-sustaining model of the solar dynamo in which the poloidal field generation is from tilted bipolar sunspot pairs placed on the solar surface above regions of strong toroidal ...
  • The violent hard X-ray variability of MRK 421 observed by Nustar in 2013 April 
    Paliya, Vaidehi S; Bottcher, M; Diltz, C; Stalin, C. S; Sahayanathan, S; Ravikumar, C. D (IOP Publishing, 2015-10-01)
    The well-studied blazar Markarian 421 (Mrk 421, z = 0.031) was the subject of an intensive multi-wavelength campaign when it flared in 2013 April. The recorded X-ray and very high-energy (E > 100 GeV) γ-ray fluxes are the ...
  • Expected performances of a Laue lens made with bent crystals 
    Virgilli, Enrico; Valsan, V; Frontera, Filippo; Caroli, Ezio; Liccardo, Vincenzo; Stephen, John Buchan (SPIE-The International Society for Optical Engineering, 2017-10)
    In the context of the Laue project devoted to build a Laue lens prototype for focusing celestial hard x-/soft gamma-rays, a Laue lens made of bent crystal tiles, with 20-m focal length, is simulated. The focusing energy ...
  • Tracing the outer disk of NGC 300: an ultraviolet view 
    Mondal, Chayan; Subramaniam, A; George, K (Indian Academy of Sciences, 2019-07-11)
    We present an ultra-violet (UV) study of the galaxy NGC 300 using GALEX far-UV (FUV) and near-UV (NUV) observations. We studied the nature of UV emission in the galaxy and correlated it with optical, H I and mid-infrared ...
  • Temporal variations of the solar EUV network properties 
    Varghese, B.S; Raju, K. P; Kurian, P. J (Indian Academy of Sciences, 2019-07-11)
    The chromospheric network extended to the transition region as the solar EUV network disperses at the coronal level. The EUV emission lines from the transition region give information about different atmospheric heights. ...
  • Dark matter (energy) may be indistinguishable from modified gravity (MOND) 
    Sivaram, C (World Scientific Publishing Co Pte Ltd, 2017-10)
    For Newtonian dynamics to hold over galactic scales, large amounts of dark matter (DM) are required which would dominate cosmic structures. Accounting for the strong obser- vational evidence that the universe is accelerating ...
  • Planet nine, dark matter and MOND 
    Sivaram, C; Arun, K; Kiren, O. V (Springer, 2016-07)
    Here we propose the possibility that the recently postulated Neptune-sized planet with an orbital period of 15,000 years could be a gravitationally condensed dark matter (DM) object. The observed mass of Planet Nine fits ...
  • Combined complete active space configuration interaction and perturbation theory applied to conformational energy prototypes: Rotation and inversion barriers 
    Sinha Ray, Suvonil; Mahapatra, U. S; Chaudhuri, R. K; Chattopadhyay, S (Elsevier B.V, 2017-11)
    A second-order multireference perturbation theory, termed as IVO-SSMRPT which allows the use of CASCI reference wave functions with improved virtual orbitals (IVO) for capturing static correlation and state-specific ...
  • Broadband observations of high redshift blazars 
    Paliya, Vaidehi S; Parker, M. L; Fabian, A. C; Stalin, C. S (IOP Publishing, 2016-07-01)
    We present a multi-wavelength study of four high redshift blazars, S5 0014+81 (z = 3.37), CGRaBS J0225+1846 (z = 2.69), BZQ J1430+4205 (z = 4.72), and 3FGL J1656.2−3303 (z = 2.40) using quasi-simultaneous data from the ...
  • Diffuse radiation from the Aquila Rift 
    Jyothy, S. N; Murthy, J; Karuppath, N; Sujatha, N. V (Oxford University Press on behalf of the Royal Astronomical Society, 2015-12-01)
    We present an analysis of the diffuse ultraviolet (UV) background in a low latitude region near the Aquila Rift based on observations made by the Galaxy Evolution Explorer (GALEX). The UV background is at a level of about ...

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