IIA Institutional Repository: Recent submissions

  • Tracing the evolution of ultraluminous infrared galaxies into radio galaxies with low frequency radio observations 
    Nandi, S; Mousumi Das; Dwarakanath, K. S (Oxford University Press on behalf of the Royal Astronomical Society, 2021-06)
    We present radio observations of ultraluminous infrared galaxies (ULIRGs) using the Giant Metrewave Radio Telescope (GMRT) and combine them with archival multifrequency observations to understand whether ULIRGs are the ...
  • Correlation between optical and γ-ray flux variations in BL Lacs 
    Rajput, Bhoomika; Shah, Zahir; Stalin, C. S; Sahayanathan, S; Rakshit, S (Oxford University Press on behalf of the Royal Astronomical Society, 2021-06)
    We report here results of the analysis of correlated flux variations between the optical and GeV γ-ray bands in three bright BL Lac objects, namely AO 0235+164, OJ 287, and PKS 2155−304. This was based on the analysis of ...
  • TXS 1206 + 549: a new γ -ray-detected narrow-line Seyfert 1 galaxy at redshift 1.34? 
    Rakshit, S; Schramm, Malte; Stalin, C. S; Tanaka, I; Paliya, Vaidehi S; Pal, Indrani; Kotilainen, Jari; Shin, Jaejin (Oxford University Press on behalf of the Royal Astronomical Society, 2021-06)
    Radio and γ-ray loud narrow-line Seyfert 1 galaxies (NLS1s) are unique objects to study the formation and evolution of relativistic jets, as they are believed to have high accretion rates and powered by low mass black holes ...
  • The VMC Survey – XL. three-dimensional structure of the small magellanic cloud as derived from red clump stars 
    Tatton, B. L; van Loon, J. Th; Cioni, M.-R. L; Bekki, K; Bell, C. P. M; Choudhury, S; de Grijs, R; Groenewegen, M. A. T; Ivanov, V. D; Marconi, M; Oliveira, J. M; Ripepi, V; Rubele, S; Subramanian, S; Sun, N.-C (Oxford University Press on behalf of the Royal Astronomical Society, 2021-06)
    Galaxy interactions distort the distribution of baryonic matter and can affect star formation. The nearby Magellanic Clouds are a prime example of an ongoing galaxy interaction process. Here, we use the intermediate-age ...
  • Comparing the inner and outer star-forming complexes in the nearby spiral galaxies NGC 628, NGC 5457, and NGC 6946 using UVIT observations 
    Yadav, Jyoti; Mousumi Das; Patra, Narendra Nath; Dwarakanath, K. S; Rahna, P. T; McGaugh, S. S; Schomber, James; Murthy, J (IOP Publishing, 2021-06-10)
    We present a far-UV (FUV) study of the star-forming complexes (SFCs) in three nearby galaxies using the Ultraviolet Imaging Telescope. The galaxies are close to face-on and show significant outer disk star formation. Two ...
  • Solar soft X-ray irradiance variability, I: segmentation of Hinode/XRT full-disk images and comparison with GOES (1 - 8 Å) X-ray flux 
    Adithya, H. N; Kariyappa, R; Shinsuke, Imada; Kanya, Kusano; Zender, Joe; Dame, Luc; Gabriel, Giono; DeLuca, Edward; Weber, Mark (Springer, 2021-04)
    It is of great interest and importance to study the variabilities of solar EUV, UV and X-ray irradiance in heliophysics, in Earth’s climate, and space weather applications. A careful study is required to identify, track, ...
  • Seeing measurements with the Merak Hα Telescope 
    Vishnu, Unni. C; Sridharan, R; Ravindra, B; Prabhu, K (Springer, 2021-04)
    The parameter-search method (PSM) established by Rengaswamy, Ravindra, and Prabhu (Solar Phys.294, 5, 2019) for measuring the terrestrial atmospheric seeing from long-exposure solar Hα images is further validated - through ...
  • Imaging and spectral observations of a type-II radio burst revealing the section of the CME-Driven shock that accelerates electrons 
    Majumdar, Satabdwa; Tadepalli, Srikar Paavan; Maity, Samriddhi Sankar; Deshpande, Ketaki; Anshu Kumari; Ritesh Patel; Gopalswamy, Nat (Springer, 2021-04)
    We report on a multi-wavelength analysis of the 26 January 2014 solar eruption involving a coronal mass ejection (CME) and a Type-II radio burst, performed by combining data from various space and ground-based instruments. ...
  • Broad-band study of OQ 334 during its flaring state 
    Prince, Raj; Khatoon, Rukaiya; Stalin, C. S (Oxford University Press on behalf of the Royal Astronomical Society, 2021-04)
    The blazar OQ 334 displayed a γ-ray flare in 2018, after being in the long quiescent γ-ray state since 2008. Subsequent to the flare, the source was in a higher γ-ray flux state and again flared in 2020. We present here ...
  • Activity of the first interstellar comet 2I/Borisov around perihelion: results from Indian observatories 
    Aravind, K; Ganesh, Shashikiran; Venkataramani, Kumar; Sahu, D. K; Angchuk, D; Sivarani, T; Unni, Athira (Oxford University Press on behalf of the Royal Astronomical Society, 2021-04)
    Comet 2I/Borisov is the first true interstellar comet discovered. Here, we present results from observational programs at two Indian observatories, 2 m Himalayan Chandra Telescope at the Indian Astronomical Observatory, ...
  • The VMC survey – XLI. Stellar proper motions within the small magellanic cloud 
    Niederhofer, Florian; Cioni, Maria-Rosa L; Rubele, Stefano; Schmidt, Thomas; Diaz, Jonathan D; Matijevic, Gal; Bekki, Kenji; Bell, C. P. M; de Grijs, Richard; Youssoufi, Dalal El; Ivanov, Valentin D; Oliveira, Joana M; Ripepi, Vincenzo; Subramanian, S; Sun, Ning-Chen; van Loon, Jacco Th (Oxford University Press on behalf of the Royal Astronomical Society, 2021-04)
    We used data from the near-infrared Visible and Infrared Telescope for Astronomy (VISTA) survey of the Magellanic Cloud system (VMC) to measure proper motions (PMs) of stars within the Small Magellanic Cloud (SMC). The ...
  • Estimation of the size and structure of the broad line region using Bayesian approach 
    Mandal, A. K; Rakshit, S; Stalin, C. S; Petrov, R. G; Mathew, B; Sagar, R (Oxford University Press on behalf of the Royal Astronomical Society, 2021-04)
    Understanding the geometry and kinematics of the broad line region (BLR) of active galactic nuclei (AGN) is important to estimate black hole masses in AGN and study the accretion process. The technique of reverberation ...
  • New results on the direct observations of thermal radio emission from a solar coronal mass ejection 
    Ramesh, R; Anshu Kumari; Kathiravan, C; Ketaki, D; Wang, T. J (American Geophysical Union, 2021-04-28)
    We report observations of thermal emission from the frontal structure of a coronal mass ejection (CME) using data obtained with the Gauribidanur RAdioheliograPH simultaneously at 80 and 53 MHz on May 1, 2016. The CME was ...
  • A near-infrared photometer for the 1-m telescope of Vainu Bappu Observatory 
    Mishra, Anwesh Kumar; Kamath, U. S (Indian Academy of Sciences, 2021-04)
    A near-infrared photometer based on an InGaAs PIN photodiode and the filter set recommended by Infrared Working Group (IRWG) have been designed and built. It is mounted on the 1-m Carl–Zeiss telescope at the Vainu Bappu ...
  • SN 2020ank: a bright and fast-evolving H-deficient superluminous supernova 
    Amit Kumar; Brajesh Kumar; Pandey, S. B; Sahu, D. K; Singh, A; Anupama, G. C; Aryan, Amar; Gupta, Rahul; Anirban Dutta; Misra, K (Oxford University Press on behalf of the Royal Astronomical Society, 2021-04)
    We investigate the observational properties of a hydrogen-deficient superluminous supernova (SLSN) SN 2020ank (at z = 0.2485), with the help of early phase observations carried out between –21 and +52 d since g-band maximum. ...
  • Coherent Curvature Radio Emission and Polarization from Pulsars 
    Gangadhara, R. T; Han, J. L; Wang, P. F (IOP Publishing, 2021-04-20)
    We have developed a collective plasma radio emission model for the radio pulsars based on the implications of the tangent model. The secondary pair (electron–positron) plasma particles get arranged into a phased array like ...
  • Effects of thermal emission on Chandrasekhar's semi-infinite diffuse reflection problem 
    Sengupta, Soumya (IOP Publishing, 2021-04-20)
    The analytical results of Chandrasekhar's semi-infinite diffuse reflection problem is crucial in the context of the stellar or planetary atmosphere. However, the atmospheric emission effect was not taken into account in ...
  • Relation between Quiescence and Outbursting Properties of GX 339-4 
    Bhowmic, Riya; Debnath, Dipak; Chatterjee, Kaushik; Nagarkoti, Shreeram; Chakrabarti, S. K; Sarkar, Ritabrata; Chatterjee, Debjit; Jana, Arghajit (IOP Publishing, 2021-04-01)
    Galactic black hole candidate GX 339-4 underwent several outbursting phases in the past two and a half decades at irregular intervals of 2–3 years. The nature of these outbursts in terms of the duration, number of peaks, ...
  • Gas infalling motions in the envelopes of very low luminosity objects 
    Kim, Mi-Ryang; Lee, Chang Won; Maheswar, G; Myers, Philip C; Kim, Gwanjeong (IOP Publishing, 2021-04-01)
    We present the results of a single-dish survey toward 95 very low luminosity objects (VeLLOs) in optically thick (HCN 1−0) and thin (N2H+ 1−0) lines performed for the purpose of understanding the physical processes ...
  • A Fock space coupled cluster based probing of the single- and double-ionization profiles for the poly-cyclic aromatic hydrocarbons and conjugated polyenes 
    Chaudhuri, R. K; Chattopadhyay, Sudip (American institute of Physics, 2021-03-21)
    Sequential formation of a poly-cyclic aromatic hydrocarbon (PAH) dication in the H I regions of the interstellar medium (ISM) is proposed to be a function of internal energy of the doubly ionized PAHs, which, in turn, is ...

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