IIA Institutional Repository: Recent submissions

  • Mid-infrared variability of γ-ray emitting blazars 
    Anjum, A; Stalin, C. S; Rakshit, S; Gudennavar, S. B; Durgapal, A (Oxford University Press on behalf of the Royal Astronomical Society, 2020-05)
    Using data from the Wide-field Infrared Survey Explorer, we studied the mid-infrared (mid-IR) 3.4 μm (W1-band) and 4.6 μm (W2-band) flux variability of γ-ray emitting blazars. Our sample consists of 460 flat spectrum radio ...
  • Effects of dark matter on the upper bound mass of neutron stars 
    Kumar, S. S; Kenath, A; Sivaram, C (Elsevier B.V, 2020-05)
    Observations have indicated that we do not see neutron stars (NS) of mass near the theoretical upper limit as predicted. Here we invoke the role of dark matter (DM) particles in star formation, and their role in lowering ...
  • Detection of Polarization due to Cloud Bands in the Nearby Luhman 16 Brown Dwarf Binary 
    Millar-Blanchaer, M. A; Girard, J. H; Karalidi, T; Marley, M. S; van Holstein, R. G; Sengupta, S; Mawet, Dimitri; Kataria, Tiffany; Jos de Boer, F. S (IOP Publishing, 2020-05-01)
    Brown dwarfs exhibit patchy or spatially varying banded cloud structures that are inferred through photometric and spectroscopic variability modeling techniques. However, these methods are insensitive to rotationally ...
  • Spectroscopic and geometrical evolution of the ejecta of the classical nova ASASSN-18fv 
    Pavana, M; Raj, A; Bohlsen, T; Anupama, G. C; Gupta, R; Selvakumar, G (Oxford University Press on behalf of the Royal Astronomical Society, 2020-05)
    The optical spectroscopic observations of ASASSN-18fv observed from 2018 March 24 to 2019 January 26 are presented. The optical spectra are obtained from Mirranook, Vainu Bappu, and South African Astronomical observatories. ...
  • Cosmic Spin and Mass Evolution of Black Holes and Its Impact 
    Bhattacharyya, Dipanweeta; Mangalam, A (IOP Publishing, 2020-06-01)
    We build an evolution model of the central black hole that depends on the processes of gas accretion, the capture of stars, mergers, and electromagnetic torque. In the case of gas accretion in the presence of cooling ...
  • Spectroscopic and geometrical evolution of the ejecta of the classical nova ASASSN-18fv 
    Pavana, M; Raj, A; Bohlsen, T; Anupama, G. C; Gupta, R; Selvakumar, G (Oxford University Press on behalf of the Royal Astronomical Society, 2020-06)
    The optical spectroscopic observations of ASASSN-18fv observed from 2018 March 24 to 2019 January 26 are presented. The optical spectra are obtained from Mirranook, Vainu Bappu, and South African Astronomical observatories. ...
  • Omega centauri: weak MgH band in red giants directly traces the helium content 
    Reddy, A. B. S (Oxford University Press on behalf of the Royal Astronomical Society, 2020-06)
    High spectral resolution and high signal-to-noise ratio optical spectra of red giants in the globular cluster Omega Centauri are analysed for stellar parameters and chemical abundances of 15 elements including helium by ...
  • A census of young stellar population associated with the Herbig Be star HD 200775 
    Saha, Piyali; Maheswar, G; Kamath, U. S; Lee, C. W; Puravankara, Manoj; Mathew, B; Sharma, Ekta (Oxford University Press on behalf of the Royal Astronomical Society, 2020-06)
    The region surrounding the well-known reflection nebula, NGC 7023, illuminated by a Herbig Be star, HD 200775, located in the dark cloud L1174 is studied in this work. Based on the distances and proper motion values from ...
  • Bar rejuvenation in S0 galaxies? 
    Barway, Sudhanshu; Saha, Kanak (Oxford University Press on behalf of the Royal Astronomical Society, 2020-07)
    Based on the colour measurements from a multiband, multicomponent 2D decompositions of S0 and spiral galaxies using SDSS images, we found that bars are bluer in S0 galaxies compared to the spiral galaxies. Most of the S0s ...
  • Discovery of a near-infrared bar and a pseudobulge in the collisional ring galaxy Cartwheel 
    Barway, Sudhanshu; Mayya, Y. D; Robleto-Orus, Aitor (Oxford University Press on behalf of the Royal Astronomical Society, 2020-09)
    We report the discovery of a bar, a pseudo-bulge, and unresolved point source in the archetype collisional ring galaxy Cartwheel using careful morphological analysis of a near-infrared (NIR) Ks-band image of excellent ...
  • Optical studies of two stripped envelope supernovae − SN 2015ap (Type Ib) and SN 2016P (Type Ic) 
    Gangopadhyay, A; Misra, K; Sahu, D. K; Wang, Shan-Qin; Kumar, Brajesh; Li, Long; Anupama, G. C; Dastidar, R; Elias-Rosa, N; Kumar, Brijesh; Singh, Mridweeka; Pandey, S. B; Sanwal, Pankaj; Singh, A; Srivastav, S; Tartaglia, L; Tomasella, L (Oxford University Press on behalf of the Royal Astronomical Society, 2020-09)
    We present the photometric and spectroscopic studies of a Type Ib SN 2015ap and a Type Ic SN 2016P. SN 2015ap is one of the bright (MV = −18.04 mag) Type Ib while SN 2016P lies at an average value among the Type Ic SNe (MV ...
  • Helium Enhancement in the Metal-rich Red Giants of ω Centauri 
    Hema, B. P; Pandey, G; Kurucz, R. L; Prieto, C. A (IOP Publishing, 2020-07-01)
    The helium-enriched (He-enriched) metal-rich red giants of ω Centauri, discovered by Hema & Pandey using the low-resolution spectra from the Vainu Bappu Telescope, and confirmed by the analyses of the high-resolution spectra ...
  • Creating a large aspheric primary mirror using spherical segments 
    Jacob, A; Parihar, P; James, Melvin.K (Springer, 2020-08)
    The use of aspheric mirrors is a common practice to design astronomical telescopes with a few optical elements. In the most preferred optical design Ritchey Chretien (RC), both primary and secondary mirrors are hyperboloid. ...
  • An attempt of identification of barium hydride molecular lines in sunspot umbral spectra 
    Karthikeyan, B; Shanmugapriya, G; Rajamanickam, N; Bagare, S. P (Elsevier B.V, 2020-07)
    A high-resolution sunspot umbra spectrum recorded in National Solar Observatory, Kitt Peak in the visible and infrared wave number range 13, 600 – 25, 000cm−1 was taken in the present study for identifying the rotational ...
  • Discovery of ubiquitous lithium production in low-mass stars 
    Bharat Kumar, Y; Reddy, B. E; Campbell, S. W; Maben, Sunayana; Zhao, G; Ting, Yuan-Sen (Springer Nature, 2020-11)
    The vast majority of stars with mass similar to that of the Sun are expected to destroy lithium (Li) gradually over the course of their lives, via low-temperature nuclear burning. This has now been supported by observations ...
  • Probing Transit Timing Variation and Its Possible Origin with 12 New Transits of TrES-3b 
    Mannaday, V. K; Thakur, P; Jiang, I; Sahu, D. K; Joshi, Y. C; Pandey, A. K; Joshi, S; Yadav, R. K; Su, Li-Hsin; Sariya, D. P; Yeh, Li-Chin; Griv, Evgeny; Mkrtichian, D; Shlyapnikov, A; Moskvin, V; Ignatov, V; Vanko, M; Puskullu, C (IOP Publishing, 2020-07)
    We present 12 new transit light curves of the hot-Jupiter TrES-3b observed during 2012−2018 to probe the transit timing variation (TTV). By combining the midtransit times determined from these 12 transit data with ...
  • Detection of CH+, CH and H2 Molecules in the Young Planetary Nebula IC 4997 
    Kameswara Rao, N; Lambert, D. L; Reddy, A. B. S; Manchado, A; Diaz-Luis, J. J; Garcia-Hernandez, D. A (IOP Publishing, 2020-07-01)
    We have detected CH+ and CH molecular absorption lines from the youngcompact planetary nebula IC 4997 from high resolution optical spectra. A high-resolution infra-red (H and K bands) spectrum provides detection of H2 ...
  • Modeling the Survival of Population III Stars to the Present Day 
    Dutta, Jayanta; Sur, Sharanya; Stacy, Athena; Bagla, Jasjeet Singh (IOP Publishing, 2020-09-20)
    Recent numerical simulations have suggested the probability of a fraction of the primordial stars being ejected from the cluster of their origin. We explore the possibility that some of these can remain on the main sequence ...
  • The Sloan Digital Sky Survey Quasar Catalog: Sixteenth Data Release 
    Lyke, Brad W; Higley, Alexandra N; McLane, J. N; Schurhammer, D. P; Myers, A. D; Ross, A. J; Dawson, K; Chabanier, S; Martini, P; Busca, N. G; Mas des Bourboux, Helion du; Salvato, Mara; Streblyanska, A; Zarrouk, P; Burtin, E; Anderson, S. F; Bautista, J; Bizyaev, D; Brandt, W. N; Brinkmann, J; Brownstein, J. R; Comparat, J; Green, Paul; de la Macorra, Axel; Munoz Gutierrez, Andrea; Hou, Jiamin; Newman, J. A; Palanque-Delabrouille, N; Paris, I; Percival, W. J; Petitjean, P; Rich, J; Rossi, G; Schneider, D. P; Smith, Alexander; Vivek, M; Weaver, Benjamin A (IOP Publishing, 2020-09)
    We present the final Sloan Digital Sky Survey IV (SDSS-IV) quasar catalog from Data Release 16 of the extended Baryon Oscillation Spectroscopic Survey (eBOSS). This catalog comprises the largest selection of spectroscopically ...
  • Effects of dark matter in red giants 
    Clea, Sunny; Sivaram, C; Gudennavar, S. B (Elsevier B. V., 2020-12)
    Dark matter (DM) which constitutes five-sixths of all matter is hypothesized to be a weakly interacting non-baryonic particle, created in the early stages of cosmic evolution. It can affect various cosmic structures in the ...

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