IIA Institutional Repository: Recent submissions

  • Cosmic Evolution of Black Holes and the M.—σ relation 
    Bhattacharyya, Dipanweeta (Indian Institute of Astrophysics, 2020-01)
    The connection of the SMBHs to their host galaxies is evidenced by the strong correlation between the mass of SMBH and velocity dispersion, σ, of the stars in rest of the galaxy. This is somewhat surprising because the ...
  • Black holes are in sight - Nobel in physics 2020 
    Anupama, G. C (Indian Physics Association, 2020-10)
    The Nobel Prize in Physics 2020 has been awarded to three scientists. One half of the prize was awarded to Roger Penrose and the other half was jointly awarded to Reinhard Genzel and Andrea Ghez. Penrose’s discovery of ...
  • Silver linings in the dark clouds of COVID-19: Improvement of air quality over India and Delhi metropolitan area from measurements and WRF-CHIMERE model simulations 
    Dumka, U. C; Kaskaoutis, D. G; Verma, Shubha; Shantikumar, N. S; Sarvan Kumar; Ghosh, Sanhita (Elsevier B.V., 2021-02)
    The current study examines the impact of the COVID-19 lockdown (25th March until May 17, 2020) period in particulate matter (PM) concentrations and air pollutants (NOx, SO2, CO, NH3, and O3) at 63 stations located at Delhi, ...
  • Atmospheric opacity using 220 GHz (1.36 mm) radiometer data and water vapor trends over Indian Astronomical Observatory (IAO), Hanle 
    Shantikumar, N. S; Sethulakshmy, E. S; Sridevi, Jade; Shrungeshwara, T. S; Vivek, C. G; Angchuk, Dorje; Prabhu, T. P; Tshering Mahay, Tashi (Elsevier B. V., 2020-10-15)
    The present work reports atmospheric opacity at 220 GHz over Indian Astronomical Observatory (IAO)-Hanle during 2006 to 2018. The opacity data were derived from the radiometric measurement of sky-brightness temperature as ...
  • Aerosol optical properties retrieved using Skyradiometer at Hanle in western Himalayas 
    Neeharika, V; Bagare, S. P; Shantikumar, N. S; Rajendra, B. S (Elsevier B. V., 2010-01)
    A Skyradiometer was installed at Hanle in Ladakh, in October 2007 as a part of the site characterization program for the proposed National Large Solar Telescope project. Aerosol optical depth (AOD), single scattering albedo ...
  • An overview of and issues with sky radiometer technology and SKYNET 
    Nakajima, T; Campanelli, M; Che, Huizheng; Estelles, V; Irie, Hitoshi; Kim, Sang-Woo; Kim, Jhoon; Liu, Dong; Nishizawa, T; Pandithurai, Govindan; Soni, Vijay Kumar; Thana, Boossarasiri; Tugjsurn, Nas-Urt; Aoki, Kazuma; Sujung Go; Hashimoto, Makiko; Higurashi, Akiko; Kazadzis, Stelios; Khatri, Pradeep; Kouremeti, Natalia; Kudo, Rei; Marenco, Franco; Momoi, Masahiro; Shantikumar, N. S; Ryder, Claire L; Uchiyama, Akihiro; Yamazaki, Akihiro (European Geosciences Union, 2020-08)
    This paper is an overview of the progress in sky radiometer technology and the development of the network called SKYNET. It is found that the technology has produced useful on-site calibration methods, retrieval algorithms, ...
  • Measurements of solar differential rotation using the century long kodaikanal sunspot data 
    Jha, Bibhuti K; Priyadarshi, Aditya; Mandal, Sudip; Chatterjee, Subhamoy; Banerjee, D (Springer, 2021-01)
    The rotational profile of the Sun is considered to be one of the key inputs in a solar dynamo model. Hence, precise and long-term measurements of this quantity is important for our understanding of solar magnetism and its ...
  • The completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: large-scale structure catalogues and measurement of the isotropic BAO between redshift 0.6 and 1.1 for the Emission Line Galaxy Sample 
    Raichoor, A; de Mattia, A; Ross, A. J; Zaho, Chang; Alam, S; Avila, S; Bautista, J; Brinkmann, J; Brownstein, J. R; Burtin, E; Chapman, M. J; Chuang, C-H; Comparat, J; Dawson, K. S; Arjun Dey; des Bourboux, Helion du Mas; Elvin-Poole, Jack; Gonzalez-Perez, V; Gorgoni, C; Kneib, Jean-Paul; Kong, Hui; Lang, Dustin; Moustakas, John; Myers, Adam D; Muller, Eva-Maria; Nadathur, Seshadri; Newman, J. A; Percival, W. J; Rezaie, M; Rossi, G; Ruhlmann-Kleider, Vanina; Schlegel, David J; Schneider, D. P; Seo, Hee-Jong; Tamon, Amelie; Tinker, Jeremy L; Tojeiro, Rita; Vivek, M; Yeche, Christophe; Gong-Bo, Zhao (Oxford University Press on behalf of the Royal Astronomical Society, 2021-01)
    We present the Emission Line Galaxy (ELG) sample of the extended Baryon Oscillation Spectroscopic Survey from the Sloan Digital Sky Survey IV Data Release 16. We describe the observations and redshift measurement for the ...
  • The completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: BAO and RSD measurements from anisotropic clustering analysis of the quasar sample in configuration space between redshift 0.8 and 2.2 
    Hou, Jiamin; Sanchez, Ariel G; Ross, A. J; Smith, A; Neveux, R; Bautista, J; Burtin, E; Zaho, Chang; Scoccimarro, Roman; Dawson, K. S; de Mattia, A; de la Macorra, A; des Bourboux, Helion du Mas; Eisenstein, D. J; Gil-Marin, H; Lyke, Brad W; Mohammad, F. G; Mueller, E.-M; Percival, W. J; Rossi, G; Magana, M. V; Zarrouk, Pauline; Zhao, Gong-Bo; Brinkmann, J; Brownstein, J. R; Chuang, C.-H; Myers, A. D; Newman, J. A; Schneider, D. P; Vivek, M (Oxford University Press on behalf of the Royal Astronomical Society, 2021-01)
    We measure the anisotropic clustering of the quasar sample from Data Release 16 (DR16) of the Sloan Digital Sky Survey IV extended Baryon Oscillation Spectroscopic Survey (eBOSS). A sample of 343 708 spectroscopically ...
  • DarpanX: A python package for modeling X-ray reflectivity of multilayer mirrors 
    Mondal, B; Vadawale, S. V; Mithun, N. P. S; Vaishnava, C. S; Tiwari, N. K; Goyal, S. K; Panini, S. S; Navalkar, V; Karmakar, C; Patel, M. R; Upadhyay, R. B (Elsevier B.V, 2021-01)
    Multilayer X-ray mirrors consist of a coating of a large number of alternate layers of high Z and low Z materials with a typical thickness of 10–100 Å , on a suitable substrate. Such coatings play an important role in ...
  • Multi-band behaviour of the TeV blazar PG 1553+113 in optical range on diverse timescales 
    Agarwal, A; Mihov, B; Andruchow, I; Cellone, S. A; Anupama, G. C; Agrawal, V; Zola, S; Slavcheva, L; Slavcheva-Mihova, L; Ozdonmez, A; Ege, Ergun; Raj, A; Mammana, L; Zibecchi, L; Fernandez-Lajus, E (EDP Sciences, 2021-01)
    Context. The TeV BL Lac object PG 1553+113 is one of the primary candidates for a binary supermassive black hole system. Aims. We study the flux and spectral variability of PG 1553+113 on intra-night to long-term ...
  • Study of UV-bright stellar populations in the globular cluster NGC 1261 using Astrosat 
    Rani, S; Pandey, G; Subramaniam, A; Snehalata Sahu; Kameswara Rao, N (Oxford University Press on behalf of the Royal Astronomical Society, 2021-02)
    We present UV photometry of the globular cluster NGC 1261 using images acquired with the Ultraviolet Imaging Telescope (UVIT) on board Astrosat. We performed point-spread function (PSF) photometry on four near-UV (NUV) and ...
  • Automated Detection of Accelerating Solar Eruptions Using Parabolic Hough Transform 
    Ritesh Patel; Pant, V; Priyanka Iyer; Banerjee, D; Mierla, M; West, M. J (Springer, 2021-02)
    Solar eruptions such as coronal mass ejections (CMEs) observed in the inner solar corona (up to 4 R⊙) show acceleration profiles that appear as parabolic ridges in height–time plots. Inspired by the white-light automated ...
  • A statistical study of solar radio Type III bursts and spaceweather implication 
    Ndacyayisenga, T; Uwamahoro, J; Raja, K. S; Monstein, C (Elsevier B.V, 2021-02-15)
    olar radio bursts (SRBs) are the signatures of various phenomenon that happen in the solar corona and interplanetary medium (IPM). In this article, we have studied occurrence of Type III bursts and their association with ...
  • Dynamics of accretion and winds in tidal disruption events 
    Mageshwaran, T; Mangalam, A (Elsevier B. V, 2021-02)
    We have constructed self-similar models of a time-dependent accretion disk in both sub and super-Eddington phases with wind outflows for tidal disruption events (TDEs). The physical input parameters are the black hole (BH) ...
  • Development of High Resolution System for Stellar Imaging 
    Sreekanth Reddy, V (Indian Institute of Astrophysics, 2021-01)
    Adaptive Optics (AO) technology is a part of ground-based astronomical observatories around the world. It enables the telescopes to attain near diffraction-limited resolution. We have designed, developed and tested a ...
  • Solar photography 
    Smith, C. M (Amateur Photographic Society of Madras, 1896-06)
  • Constraints on the epoch of dark matter formation from Milky Way satellites 
    Das, Subinoy; Nadler, E. O (The American Physical Society, 2021-02-15)
    A small fraction of thermalized dark radiation that transitions into cold dark matter (CDM) between big bang nucleosynthesis and matter-radiation equality can account for the entire dark matter relic density. Because of ...
  • Discovery of an M-type companion to the Herbig Ae Star V1787 Ori 
    Arun, R; Mathew, B; Rengaswamy, S; Manoj, P; Narang, M; Kartha, S. S; Maheshwar, G (Oxford University Press on behalf of the Royal Astronomical Society, 2021-02)
    The intermediate-mass Herbig Ae star V1787 Ori is a member of the L1641 star-forming region in the Orion A molecular cloud. We report the detection of an M-type companion to V1787 Ori at a projected separation of 6.66 arcsec ...
  • The First Extensive Exploration of UV-bright Stars in the Globular Cluster NGC 2808 
    Prabhu, D. S; Subramaniam, A; Snehalata Sahu (IOP Publishing, 2021-02-10)
    In this study, we identified and characterized the hot and luminous UV-bright stars in the globular cluster NGC 2808. We combined data from the Ultra Violet Imaging Telescope (UVIT) on board the Indian space satellite AstroSat ...

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