IIA Institutional Repository: Recent submissions

  • Radial velocity comparison of Gaia DR2 and RAVE DR5 survey: A systematic offset in radial velocities among a group of highly accurate radial velocity stars 
    Deepak; Reddy, B. E (IOP Publishing, 2018-10)
    Here, we report a comparative study of radial velocity (RV) data of two major surveys: Gaia Data Release 2 and RAVE Data Release 5. We restricted the sample to stars with relatively accurate RVs. The difference between ...
  • 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 ...
  • Polarimetric and spectroscopic study of radio quiet weak emission line quasars 
    Kumar, P; Chand, H; Srianand, R; Stalin, C. S; Petitjean, P; Gopal-Krishna (Oxford University Press on behalf of the Royal Astronomical Society, 2018-10)
    A small subset of optically selected radio-quiet quasars showing weak or no emission lines may turn out to be the elusive radio-quiet BL Lac objects, or simply be radio-quiet QSOs with a still-forming/shielded broad line ...
  • SN 2013ab: a normal type IIP supernova in NGC 5669 
    Bose, S; Valenti, S; Misra, K; Pumo, M. L; Zampieri, L; Sand, D; Kumar, B; Pastorello, A; Sutaria, F. K; Maccarone, T. J; Kumar, B; Graham, M. L; Howell, D. A; Ochner, P; Chandola, H. C; Pandey, S. B (Oxford University Press on behalf of the Royal Astronomical Society, 2015-07-01)
    We present densely sampled ultraviolet/optical photometric and low-resolution optical spectroscopic observations of the Type IIP supernova 2013ab in the nearby (∼24 Mpc) galaxy NGC 5669, from 2 to 190 d after explosion. ...
  • Installation of solar chromospheric telescope at the Indian Astronomical Observatory, Merak 
    Ravindra, B; Prabhu, K; Thulasidharen, K. C; Rajalingam, M; Sagayanathan, K; Kamath, P. U; Dorjey, N; Angchuk, D; Kemkar, P. M. M; Dorjai, T; Banyal, R. K (Indian Academy of Sciences, 2018-10)
    We report the observations of the solar chromosphere from a newly commissioned solar telescope at the incursion site near Pangong Tso lake in Merak (Leh/Ladakh). This new Hα telescope at the Merak site is identical to the ...
  • 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 ...
  • Polarization and QPOs from jets in black hole systems 
    Mangalam, A (Indian Academy of Sciences, 2018-12)
    The historical observations of polarized jet emission for Blazars are reviewed and previous models are discussed. Motivated by this, a model for polarization of both steady and transient behavior using a helical magnetic ...
  • Profiling the binding motif between Be and Mg in the ground state via a single-reference coupled cluster method 
    Mahapatra, U. S; Banerjee, Debi; Chaudhuri, R. K; Chattopadhyay, S (Taylor & Francis, 2015-06)
    We present a study on the performance of our iterative triples correction for the coupled cluster singles and doubles excitations (CCSDT-1a+d) method for computation of potential energy surface (PES), spectroscopic constants, ...
  • Angular momentum of stars and their planets 
    Gurumath, S. R; Hiremath, K. M; Ramasubramanian, V (IOP Publishing, 2019-01)
    To understand the distribution of angular momenta between host stars and their planets, we estimate the spin angular momentum (J spin ) of host stars that follow a power law ${10}^{(42.33\pm 5.40)}{\left(\tfrac{{M}_{\star ...
  • Properties and Occurrence Rates for Kepler Exoplanet Candidates as a Function of Host Star Metallicity from the DR25 Catalog 
    Narang, Mayank; Manoj, P; Furlan, E; Mordasini, C; Henning, Thomas; Mathew, Blesson; Banyal, R. K; Sivarani, T (IOP Publishing, 2018-11)
    Correlations between the occurrence rate of exoplanets and their host star properties provide important clues about the planet formation process. We studied the dependence of the observed properties of exoplanets (radius, ...
  • Membrane-based deformable mirror: intrinsic aberrations and alignment issues 
    Bayanna, A. R; Louis, R. E; Chatterjee, S; Mathew, S. K; Venkatakrishnan, P (Optical Society of America, 2015-03-01)
    A deformable mirror (DM) is an important component of an adaptive optics system. It is known that an on-axis spherical/parabolic optical component, placed at an angle to the incident beam introduces defocus as well as ...
  • A SALT spectral study of S0s hosting pseudobulges 
    Vaghmare, K; Barway, Sudhanshu; Vaisanen, Petri; Ramphul, Rajin; Wadadekar, Yogesh; Kembhavi, Ajit K (Oxford University Press on behalf of the Royal Astronomical Society, 2018-11)
    We present a SALT-RSS spectroscopic study of a sample of S0 galaxies established by Vaghmare et al. (2015) as having pseudobulges using a combination of photometric criteria. We extract the spectra of various regions along ...
  • A multiwavelength study of three hybrid blazars 
    Stanley, E. C; Kharb, P; Lister, M. L; Marshall, H. L; O'Dea, C; Baum, S (IOP Publishing, 2015-07-01)
    We present multiwavelength imaging observations of PKS 1045−188, 8C 1849+670, and PKS 2216−038, three radio-loud active galactic nuclei from the MOJAVE-Chandra Sample that straddle the Fanaroff-Riley (FR) boundary between ...
  • Astrophysics with new horizons: making the most of a generational opportunity 
    Zemcov, Michael; Arcavi, Iair; Arendt, Richard; Bachelet, Etienne; Ranga Ram Chary; Cooray, Asantha; Dragomir, Diana; Conn Henry, Richard; Lisse, Carey; Matsuura, Shuji; Murthy, J; Nguyen, Chi; Poppe, Andrew R; Street, Rachel; Werner, Michael (IOP Publishing, 2018-11)
    The outer solar system provides a unique, quiet vantage point from which to observe the universe around us, where measurements could enable several niche astrophysical science cases that are too difficult to perform near ...
  • Dynamics of on-disk plumes as observed with the interface region imaging spectrograph, the atmospheric imaging assembly, and the helioseismic and magnetic imager 
    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 ...
  • Forward modeling of standing slow modes in flaring coronal loops 
    Yuan, D; Van Doorsselaere, T; Banerjee, D; Antolin, P (IOP Publishing, 2015-07-01)
    Standing slow-mode waves in hot flaring loops are exclusively observed in spectrometers and are used to diagnose the magnetic field strength and temperature of the loop structure. Owing to the lack of spatial information, ...
  • Abnormal rotation rates of sunspots and durations of associated flares 
    Suryanarayana, G. S; Hiremath, K. M; Bagare, S. P; Hegde, M (EDP Sciences, 2015-08)
    Context. Short-duration and long-duration flares are important in terms of their association with coronal heating and coronal mass ejections, respectively. Sunspot motions in the photosphere have been known to be associated ...
  • Frequency-dependent core shifts and parameter estimation for the blazar 3C 454.3 
    Mohan, Prashanth; Agarwal, A; Mangalam, A; Gupta, A. C; Wiita, P. J; Volvach, A. E; Aller, M. F; Aller, H. D; Gu, M. F; Lahteenmaki, A; Tornikoski, M; Volvach, L. N (Oxford University Press on behalf of the Royal Astronomical Society, 2015-09-11)
    We study the core shift effect in the parsec-scale jet of the blazar 3C 454.3 using the 4.8– 36.8 GHz radio light curves obtained from three decades of continuous monitoring. From a piecewise Gaussian fit to each flare, ...
  • Ultraviolet stellar population of the old open cluster M67 (NGC 2682) 
    Sindhu, N; Subramaniam, A; Anu Radha, C (Oxford University Press on behalf of the Royal Astronomical Society, 2018-11)
    We present the results of ultraviolet (UV) photometry of the old open cluster M67 obtained using Galaxy Evolution Explorer in far-ultraviolet (FUV) and near-ultraviolet (NUV) bands. UV detections of 18 blue straggler stars ...
  • Non-gaussianity of diffuse galactic synchrotron emission at 408 MHz 
    Rana, S; Ghosh, T; Bagla, Jasjeet S; Pravabati, C (Oxford University Press on behalf of the Royal Astronomical Society, 2018-11)
    Diffuse Galactic emission at low frequencies is a major contaminant for studies of redshifted 21 cm line studies. Removal of these foregrounds is essential for exploiting the signal from neutral hydrogen at high redshifts. ...

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