IIAP Publications: Recent submissions

  • THE VARIABLE STAR POPULATION IN THE GLOBULAR CLUSTER NGC 6934 
    Yepez, M. A; Ferro, A. A; Muneer, S; Giridhar, S (Instituto de Astronomia, 2018-04)
    We report an analysis of new V and I CCD time-series photometry of the globular cluster NGC 6934. Through the Fourier decomposition of the RR Lyrae light curves the mean values of [Fe/H] and the distance of the cluster ...
  • NIR properties of Be stars in star clusters in the Magellanic Clouds 
    Paul, K. T; Subramaniam, A; Mathew, B; Shruthi, S. B (Elsevier B.V, 2017-10)
    Magellanic Clouds are the nearby galaxies which are ideal to study the properties of metal poor stellar population. In this study, we explore the near-IR properties of optically identified classical Be stars in 19 star ...
  • Coronal Proerties of the Seyfert 1 Galaxy 3C 120 with NuSTAR 
    Priyanka Rani; Stalin, C. S (IOP Publishing, 2018-04-01)
    We present a measurement of the cut-off energy, a proxy for the temperature of the corona in the nuclear continuum of the Seyfert 1 galaxy 3C 120 using ~120 ks of observation from NuSTAR. The quality broadband spectrum ...
  • CME productivity associated with Solar Flare peak X-ray emission flux 
    Suryanarayana, G. S; Balakrishna, K. M (Elsevier B.V, 2018-05-01)
    It is often noticed that the occurrence rate of Coronal Mass Ejections (CMEs) increases with increase in flare duration where peak flux too increase. However, there is no complete association between the duration and peak ...
  • Variation of supergranule parameters with solar cycles: results from century-long Kodaikanal digitized Ca II K data 
    Chatterjee, Subhamoy; Mandal, Sudip; Banerjee, D (IOP Publishing, 2017-05)
    The Ca ii K spectroheliograms spanning over a century (1907–2007) from Kodaikanal Solar Observatory, India, have recently been digitized and calibrated. Applying a fully automated algorithm (which includes contrast enhancement ...
  • Once in a blue moon: detection of bluing' during debris transits in the white dwarf WD 1145+017 
    Hallakoun, N; Xu, S; Maoz, D; Marsh, T. R; Ivanov, V. D; Dhillon, V. S; Bours, M. C. P; Parsons, S. G; Kerry, P; Sharma, S; Su, K; Sridharan, R|; Pravec, P; Kusnirak, P; Kucakova, H; Armstrong, J. D; Arnold, C (Oxford University Press on behalf of the Royal Astronomical Society, 2017-08)
    The first transiting planetesimal orbiting a white dwarf was recently detected in K2 data of WD 1145+017 and has been followed up intensively. The multiple, long and variable transits suggest the transiting objects are ...
  • V2676 Oph: Estimating Physical Parameters of a Moderately Fast Nova 
    Raj, A; Pavana, M; Kamath, U. S; Anupama, G. C; Walter, F. M (Copernicus Foundation for Polish Astronomy, 2018-03)
    Using our previously reported observations, we derive some physical parameters of the moderately fast nova V2676 Oph 2012 #1. The best-fit CLOUDY model of the nebular spectrum obtained on 2015 May 8 shows a hot white dwarf ...
  • Hanle-Zeeman Scattering Matrix for Magnetic Dipole Transitions 
    Megha, A; Sampoorna, M; Nagendra, K. N; Sankarasubramanian, K (IOP Publishing, 2017-07)
    The polarization of the light that is scattered by the coronal ions is influenced by the anisotropic illumination from the photosphere and the magnetic field structuring in the solar corona. The properties of the coronal ...
  • Theoretical analysis of effective electric fields in mercury monohalides 
    Srinivasa Prasannaa, V; Abe, M; Bannur, V. M; Das, B. P (The American Physical Society, 2017-04)
    Mercury monohalides are promising candidates for electron electric dipole moment searches. This is due to their extremely large values of effective electric fields, besides other attractive experimental features. We have ...
  • On Minkowski Functionals of CMB polarization 
    Pravabati, C; Vidhya, G; Yogendran, K. P; Park, C (Elsevier B.V, 2017-08)
    CMB polarization data is usually analyzed using Eand Bmodes because they are scalar quantities under rotations along the lines of sight and have distinct physical origins. We explore the possibility of using the Stokes ...
  • Static structure of chameleon dark matter as an explanation of dwarf spheroidal galaxy cores 
    Das, Subinoy; Prolay Krishna Chanda (The American Physical Society, 2017-04)
    We propose a novel mechanism that explains the cored dark matter density profile in recently observed dark matter rich dwarf spheroidal galaxies. In our scenario, dark matter particle mass decreases gradually as a function ...
  • High-resolution spectroscopy of the extremely iron-poor post-AGB star CCâLyr 
    Aoki, W; Matsuno, Tadafumi; Honda, S; Parthasarathy, M (Astronomical Society of Japan, 2017-04)
    High-resolution optical spectroscopy was conducted for the metal-poor post-AGB star CC Lyr to determine its chemical abundances and spectral line profiles. Our standard abundance analysis confirms its extremely low ...
  • Optical variability of narrow-line and broad-line Seyfert 1 galaxies 
    Rakshit, S; Stalin, C. S (IOP Publishing, 2017-05)
    We studied the optical variability ( OV ) of a large sample of narrow-line Seyfert 1 ( NLSy1 ) and broad-line Seyfert 1 ( BLSy1 ) galaxies with z  <  0.8 to investigate any differences in their OV ...
  • Tensor Minkowski Functionals: first application to the CMB 
    Vidhya, G; Pravabati, C (IOP Publishing, 2017-05)
    ensor Minkowski Functionals (TMFs) are tensor generalizations of the usual Minkowski Functionals which are scalar quantities. We introduce them here for use in cos- mological analysis, in particular to analyze ...
  • Structure and variability in the corona of the ultrafast rotator LO Pegasi 
    Lalitha, S; Schmitt, J. H. M. M; Singh, K. P (EDP Sciences, 2017-07)
    Context. Low-mass ultrafast rotators show the typical signatures of magnetic activity and are known to produce flares, probably as a result of magnetic reconnection. As a consequence, the coronae of these stars exhibit ...
  • Coronal magnetic field lines and electrons associated with type IIIV radio bursts in a solar flare 
    Kishore, P; Kathiravan, C; Ramesh, R; Ebenezer, E (Indian Academy of Sciences, 2017-05)
    We recently investigated some of the hitherto unreported observational characteristics of the low frequency (85–35 MHz) type III–V bursts from the Sun using radio spectropolarimeter observations. The quantitative ...
  • Hundred Years of Einstein's Cosmological Constant 
    Sivaram, C; Arun, K; Kiren, O. V; Sivaram, C (Isaac Scientific Publishing, 2018-06)
    It was little over a hundred years ago that Einstein introduced the ‘cosmological constant’ in his General Theory of Relativity in order to obtain a static universe, to conform to the philosophical view of the universe ...
  • In-orbit performance of UVIT and first results 
    Tandon, S. N; Hutchings, J. B; Ghosh, S. K; Subramaniam, A; George, K|; Girish, V; Kamath, P. U; Kathiravan, S; Kumar, A; Lancelot, J.P; Mahesh, P. K; Mohan, Rekhesh; Murthy, J; Nagabhushana, S; Pati, A. K; Postma, J; Kameswara Rao, N; Sankarasubramanian, K; Sreekumar, P; Sriram, S; Stalin, C. S; Sutaria, F. K; Sreedhar, Yuvraj Harsha; Barve, Indrajit V; Mondal, Chayan; Snehalata Sahu (Indian Academy of Sciences, 2017-06)
    The performance of the ultraviolet telescope (UVIT) on-board AstroSat is reported. The performance in orbit is also compared with estimates made from the calibrations done on the ground. The sensitivity is found to be ...
  • Long-term variations in the intensity of plages and networks as observed in Kodaikanal Ca-K digitized data 
    Priyal, M; Singh, J; Ravindra, B; Kameshwaran Rathina, Somasundaram (Springer, 2017-07)
    In our previous article (Priyal et al. in Solar Phys. 289, 127, 2014) we have discussed the details of observations and methodology adopted to analyze the Ca-K spectroheliograms obtained at the Kodaikanal Observatory (KO) ...
  • Accretion and wind dynamics in tidal disruption events 
    Mageshwaran, T; Mangalam, A (International Astronomical Union, 2017-06)
    We have constructed self similar models of time dependent and non relativistic ac- cretion disks in both sub and super-Eddington phase of TDEs with wind outflows for a general viscosity prescription which is a function ...

Search DSpace


Browse

My Account