IIA Institutional Repository: Recent submissions

  • Recent advances in RV Tauri stars 
    Giridhar, S (Indian Academy of Sciences, 2020-12)
    The availability of multi-wavelength observations and parallaxes from the space missions and very comprehensive models of AGB evolution that include the accretion of matter from the circumbinary disc have strongly impacted ...
  • Investigation of the helium enhancement in a super lithium-rich giant HD 77361 
    Hema, B. P; Pandey, G (Indian Academy of Sciences, 2020-12)
    In this work, the helium-enhancement (He-enhancement) in the lithium-rich (Li-rich) K-giant HD 77361 is investigated using the strengths of the MgH band and the Mg I lines. The detailed abundance analysis and also the ...
  • A Search for Polarized Thermal Emission from Directly Imaged Exoplanets and Brown Dwarf Companions to Nearby Stars 
    Jensen-Clem, R; Millar-Blanchaer, M. A; van Holstein, R. G; Mawet, Dimitri; Graham, J; Sengupta, S; Marley, M. S; Snik, Frans; Vigan, A; Hinkley, S; de Boer, Jos; Girard, J. H; De Rosa, R. J; Bowler, B. P; Wiktorowicz, S. J; Perrin, M. D; Crepp, J. R; Macintosh, B (IOP Publishing, 2020-12)
    Aerosols in the atmospheres of cloudy gas giant exoplanets and brown dwarfs scatter and polarize these objects' thermal emission. If such an object has an oblate shape or nonuniform cloud distribution, the net degree of ...
  • Star Formation and Evolution of Blister-type H II Region Sh2-112 
    Panwar, N; Sharma, S; Ojha, D. K; Baug, T; Dewangan, L. K; Bhatt, B. C; Pandey, R (IOP Publishing, 2020-12-10)
    We report the observational findings of the Sh2-112 H ii region by using the multiwavelength data analysis ranging from optical to radio wavelengths. This region is powered by the massive O8V-type star BD +45 3216. The ...
  • Abundances of neutron-capture elements in CH and carbon-enhanced metal-poor (CEMP) stars 
    Meenakshi, P; Goswami, A (Indian Academy of Sciences, 2020-12)
    All the elements heavier than Fe are produced either by the slow (-s) or rapid (-r) neutron-capture process. The neutron density prevailing in the stellar sites is one of the major factors that determines the type of ...
  • The horizontal branch morphology of the globular cluster NGC 1261 using AstroSat 
    Sharmila Rani; Pandey, G; Subramaniam, A; Sahu, S; Kameswara Rao, N (Indian Academy of Sciences, 2020-12)
    We present the results obtained from the UV photometry of the globular cluster NGC 1261 using far-UV (FUV) and near-UV (NUV) images acquired with the Ultraviolet Imaging Telescope (UVIT) on-board the AstroSat satellite. ...
  • Galactic chemical evolution and chemical tagging with open clusters 
    Reddy, A. B. S; Giridhar, S; Lambert, D. L (Indian Academy of Sciences, 2020-12)
    The article presents the consolidated results drawn from the chemical composition studies of Reddy et al. (2012, 2013, 2015, 2016) and Reddy & Lambert (2019), who through the high-dispersion echelle spectra (R=60000) of ...
  • Observations with the 3.6-meter Devasthal optical telescope 
    Sagar, R; Kumar, B; Sharma, S (Indian Academy of Sciences, 2020-12)
    The 3.6-meter Indo–Belgian Devasthal optical telescope (DOT) has been used for optical and near-infrared (NIR) observations of celestial objects. The telescope has detected stars of B=24.5±0.2,R=24.6±0.12 and g=25.2±0.2 ...
  • [Rb/Zr] ratio in Ba stars as a diagnostic of the companion AGB stellar mass 
    Shejeelammal, J; Goswami, A (Indian Academy of Sciences, 2020-12)
    Understanding nucleosynthesis in and evolution of asymptotic giant branch (AGB) stars is of primary importance as these stars are the main producers of some of the key elements in the Universe. They are the predominant ...
  • Peculiarities in the Horizontal Branch Stars of Globular Cluster NGC 1851: Discovery of a Blue Straggler Companion to an EHB Star 
    Singh, G; Sahu, S; Subramaniam, A; Yadav, R. K. S (IOP Publishing, 2020-12-10)
    We present a study of far-UV (FUV) bright horizontal branch (HB) stars to understand the peculiarities seen in the HB sequence of the globular cluster NGC 1851, using ground- and space-based multiwavelength data. Optical ...
  • Gaia DR2 data and the evolutionary status of eight high-velocity hot post-AGB candidates 
    Parthasarathy, M; Matsuno, T; Aoki, W (Oxford University Press on behalf of the Astronomical Society of Japan, 2020-12)
    From Gaia DR2 data of eight high-velocity hot post-AGB candidates, LS 3593, LSE 148, LS 5107, HD 172324, HD 214539, LS IV −12 111, LS III +52 24, and LS 3099, we found that six of them have accurate parallaxes which made ...
  • Additional calibration of the ultraviolet imaging telescope on board AstroSat 
    Tandon, S. N; Postma, J; Joseph, P; Devaraj, A; Subramaniam, A; Subramaniam, I. V; George, K; Ghosh, S. K; Girish, V; Hutchings, J. B; Kamath, P. U; Kathiravan, S; Kumar, A; Lancelo, J. P; Leahy, D; Mahesh, P. K; Mohan, R; Nagabhushana, S; Pati, A. K; Kameswara Rao, N; Sankarasubramanian, K; Sriram, S; Stalin, C. S (IOP Publishing, 2020-04)
    Results of the initial calibration of the Ultra-Violet Imaging Telescope (UVIT) were reported earlier by Tandon et al. The results reported earlier were based on the ground calibration as well as the first observations in ...
  • Variability and the Size–Luminosity Relation of the Intermediate-mass AGN in NGC 4395 
    Cho, Hojin; Woo, Jong-Hak; Hodges-Kluck, E; Son, Donghoon; Shin, Jaejin; Gallo, Elena; Bae, Hyun-Jin; Brink, T. G; Cho, Wanjin; Filippenko, A. V; Horst, J. C; Ilic, Dragana; Joner, M. D; Kang, Daeun; Kang, Wonseok; Kaspi, Shai; Kim, Taewoo; Kovacevic, A. B; Kumar, S; Le, Huynh Anh N; Nadzhip, A. E; Nunez, F. P; Metlov, V. G; Oknyansky, V. L; Park, Songyoun; Popovic, L. C; Rakshit, S; Schramm, M; Shatsky, N. I; Spencer, M; Sung, E.-H; Sung, H.-i; Tatarnikov, A. M; Vince, O (IOP Publishing, 2020-04-01)
    We present a variability study of the lowest-luminosity Seyfert 1 nucleus of the galaxy NGC 4395 based on photometric monitoring campaigns in 2017 and 2018. Using 22 ground-based and space telescopes, we monitored NGC ...
  • SALT revisits DY Cen: a rapidly evolving strontium-rich single helium star 
    Jeffery, C. S; Kameswara Rao, N; Lambert, D. L (Oxford University Press on behalf of the Royal Astronomical Society, 2020-04)
    The hydrogen-deficient star DY Cen has been reported as an R CrB-type variable, an extreme helium star (with some hydrogen), and as a single-lined spectroscopic binary. It has been associated with a dramatic change in ...
  • A multiwavelength view of the open cluster NGC 2527: discovery of active stars 
    Shah, N; Singh, K. P; Subramaniam, A (Oxford University Press on behalf of the Royal Astronomical Society, 2020-04)
    Star clusters are ideal platforms for categorizing X-ray emitting stars and to study X-ray emission as a function of stellar age and activity. We present a comprehensive study of an open star cluster, NGC 2527, by combining ...
  • Ensemble Average of Three-dimensional Minkowski Tensors of a Gaussian Random Field in Redshift Space 
    Appleby, S; Joby, P. K; Pravabati, C; Park, C (IOP Publishing, 2019-11-20)
    We present the ensemble expectation values for the translation-invariant, rank-2 Minkowski tensors in three dimensions, for a linearly redshift-space-distorted Gaussian random field. The Minkowski tensors W1 0,2, W2 0,2 ...
  • Toward precision radial velocity measurements using Echelle spectrograph at VainuBappu Telescope 
    Chamarthi, Sireesha; Banyal, R. K; Sriram, S (SPIE-The International Society for Optical Engineering, 2019-04)
    The Echelle spectrograph operating at Vainu Bappu Telescope is a general purpose instrument designed for high-resolution spectroscopy. It is being considered for precision Doppler measurements without altering the existing ...
  • Properties of radio-loud quasars in the Sloan Digital Sky Survey 
    Gaur, H; Gu, M; Ramya, S; Guo, H (EDP Sciences, 2019-11)
    We present a study of a sample of 223 radio-loud quasars (up to redshift < 0.3) in order to investigate their spectral properties. Twenty-six of these radio-loud quasars are identified as flat-spectrum radio quasars (FSRQs), ...
  • Optical and X-ray studies of three polars: RX J0859.1 + 0537, RX J0749.1–0549, and RX J0649.8–0737 
    Joshi, Arti; Pandey, J. C; Singh, K. P; Anupama, G. C; Singh, H. P (Oxford University Press on behalf of the Royal Astronomical Society, 2020-01)
    We present optical photometric and spectroscopic observations, and an analysis of archival X-ray data of three polars: RX J0859.1+0537, RX J0749.1–0549, and RX J0649.8–0737. Optical light curves of these three polars reveal ...
  • Simultaneous longitudinal and transverse oscillations in filament threads after a failed eruption 
    Mazumder, R; Pant, V; Manuel Luna; Banerjee, D (EDP Sciences, 2020-01)
    Context. Longitudinal and transverse oscillations are frequently observed in the solar prominences and/or filaments. These oscillations are excited by a large-scale shock wave, impulsive flares at one leg of the filament ...

Search DSpace

Browse

My Account