IIA Institutional Repository

Browsing IIAP Publications by Title

Browsing IIAP Publications by Title

Sort by: Order: Results:

  • Paliya, Vaidehi S; Stalin, C. S; Ajello, M; Kaur, A (IOP Publishing, 2017-08)
    We report the first results obtained from our campaign to characterize the intra-night-optical variability (INOV) properties of Fermi detected blazars, using the observations from the recently commissioned 1.3 m J. ...
  • Goyal, A; Gopal-Krishna; Wiita, P. J; Anupama, G. C; Sahu, D. K; Sagar, R; Joshi, S (EDP Sciences, 2012-08)
    Context. Rapid variations in optical flux are seen in many quasars and all blazars. The amount of variability in different classes of active galactic nuclei has been studied extensively but many questions remain unanswered. ...
  • Bhattacharya, Debbijoy; Gulati, S; Stalin, C. S (Oxford University Press on behalf of the Royal Astronomical Society, 2019-03)
    The majority of the γ-ray sources detected by the Fermi Gamma-ray Space Telescope belong to the blazar class of active galactic nuclei (AGNs). In addition to blazars, a minority of non-blazar AGNs is also found to be γ-ray ...
  • Bhattacharya, Debbijoy; Gulati, S; Stalin, C. S (Oxford University Press on behalf of the Royal Astronomical Society, 2019-03)
    The majority of the γ-ray sources detected by the Fermi Gamma-ray Space Telescope belong to the blazar class of active galactic nuclei (AGNs). In addition to blazars, a minority of non-blazar AGNs is also found to be γ-ray ...
  • Sagar, R; Gopal-Krishna; Wiita, P. J (Royal Astronomical Society, 1996-08)
    As part of an ongoing programme to search for intranight optical variations, we report results for six radio-quiet and one radio-moderate, but all optically bright and luminous, quasi-stellar objects (QSOs), using the ...
  • Gopal-Krishna; Sagar, R; Wiita, J. Paul (Blackwell Publishing, 1995-06)
    We report results from a continuing programme to search for intranight optical variability in one radio-moderate and six radio-quiet (but all optically bright and luminous) quasi-stellar objects, using the 2.34-m Vainu ...
  • Negi, Vibhore; Gopal-Krishna; Joshi, Ravi; Chand, Hum; Wiita, Paul J; Navaneeth, P. K; Singh, Ravi S (Oxford University Press on behalf of Royal Astronomical Society, 2023-07)
    We explore the potential of the ongoing Zwicky Transient Facility (ZTF) survey for studying intranight optical variability (INOV) of active galactic nuclei (AGNs), in particular for picking rare events of large INOV ...
  • Paliya, Vaidehi S; Stalin, C. S; Kumar, Brijesh; Kumar, Brajesh; Bhatt, V. K; Pandey, S. B; Yadav, K. S (Oxford University Press on behalf of the Royal Astronomical Society, 2013-01-21)
    The Large Area Telescope (LAT) on-board the Fermi Gamma-ray Space Telescope has detected γ-ray emission in about half a dozen narrow-line Seyfert 1 (NLSy1) galaxies. This indicates the presence of relativistic jets in these ...
  • Kharb, P; Lena, D; Paragi, Z; Subramanian, S; Vaddi, S; Das, M; Khatun, R (IOP Publishing, 2020-02-10)
    We report the detection of an intriguing parsec-scale radio source in the "offset AGN" candidate, KISSR 102. The elliptical host galaxy includes two optical nuclei at a projected separation of 1.54 kpc, N1 and N2, to the ...
  • Nataraj, H. S; Sahoo, B. K; Das, B. P; Mukherjee, D (The American Physical Society., 2008-07)
    The electric dipole moment (EDM) of paramagnetic atoms is sensitive to the intrinsic EDM contribution from that of its constituent electrons and a scalar--pseudo-scalar (S-PS) electron-nucleus interactions. The electron ...
  • Bell, Cameron P. M; Cioni, Maria-Rosa L.; Wright, A. H; Rubele, Stefano; Nidever, David L.; Tatton, Ben L; van Loon, Jacco Th.; Ivanov, Valentin D.; Subramanian, S; Oliveira, Joana M; Grijs, Richard de; Pennock, Clara M.; Choi, Yumi; Olsen, Knut; Niederhofer, Florian; Choudhury, Samyaday; Delgado, David Mart ́ınez; Munoz, Ricardo R. (Oxford University Press on behalf of the Royal Astronomical Society, 2019-12)
    We present a method to map the total intrinsic reddening of a foreground extinguish- ing medium via the analysis of spectral energy distributions (SEDs) of background galaxies. In this pilot study, we implement ...
  • Bell, C. P. M.; Cioni, Maria-Rosa L; Wright, A. H; Rubele, Stefano; Nidever, David L; Tatton, Ben L; van Loon, Jacco Th; Ivanov, Valentin D; Subramanian, S; Oliveira, J. M; Grijs, Richard de; Pennock, Clara M; Choi, Yumi; Zaritsky, Dennis; Olsen, Knut; Niederhofer, Florian; Choudhury, S; Martinez-Delgado, David; Munoz, R. R (Oxford University Press on behalf of the Royal Astronomical Society, 2019-11)
    We present a method to map the total intrinsic reddening of a foreground extinguishing medium via the analysis of spectral energy distributions (SEDs) of background galaxies. In this pilot study, we implement this technique ...
  • Bell, C. P. M; Cioni, Maria-Rosa L; Wright, A. H; Rubele, Stefano; Nidever, David L; Tatton, Ben L; van Loon, Jacco Th; Zaritsky, Dennis; Choi, Yumi; Choudhury, Samyaday; Clementini, Gisella; de Grijs, Richard; Ivanov, Valentin D; Majewski, Steven R; Marconi, Marcella; Martinez-Delgado, David; Massana, Pol; Munoz, Ricardo R; Niederhofer, Florian; Noel, Noelia E D; Oliveira, Joana M; Olsen, Knut; Pennock, Clara M; Ripepi, V; Subramanian, S; Katherina Vivas, A (Oxford University Press on behalf of the Royal Astronomical Society, 2020-11)
    We present a map of the total intrinsic reddening across ≃34 deg2 of the Small Magellanic Cloud (SMC) derived using optical (ugriz) and near-infrared (IR; YJKs) spectral energy distributions (SEDs) of background galaxies. ...
  • Sowmya, K; Nagendra, K. N; Sampoorna, M (Astronomical Society of the Pacific, 2014-10)
    The Second Solar Spectrum formed by coherent scattering processes in the Sun, is highly structured. It is characterized by numerous blend lines, both intrinsically polarizing and depolarizing, superposed on the background ...
  • Krishan, V (Indian Institute of Astrophysics, 1988)
  • Krishan, V (International Astronomical Union, 1990)
    Self-organization i.e the formation of large ordered structures in a turbulent medium is a consequence of inverse cascade where energy preferentially transfers towards large spatial scales. It is envisaged that this may ...
  • Gaur, V. K (Indian academy of Sciences, 1999-02)
    Inverse modelling forced itself on the attention of scientists in the 1960s with the advent of satellites and other revelatory technologies, despite their putative ill-posedness, when it became clear that estimation of ...
  • Subramanian, S; Ramya, S; Das, M; George, K; Sivarani, T; Prabhu, T. P (Oxford University Press on behalf of the Royal Astronomical Society, 2016-01)
    We present an analysis of the optical nuclear spectra from the active galactic nuclei (AGN) in a sample of low surface brightness (LSB) galaxies. Using data from the Sloan Digital Sky Survey (SDSS), we derived the virial ...
  • Thakur, P; Mannaday, V. K; Jiang, I; Sahu, D. K; Chand, S (Societe Royale des Sciences de Liege, 2018-04)
    We report the results of the transit timing variation (TTV) analysis of the extra-solar planet Qatar1b using thirty eight light curves. Our analysis combines thirty five previously available transit light curves with three ...
  • Rangwal, Geeta; Yadav, R. K. S; Bisht, D; Durgapal, Alok; Sariya, Devesh P (Oxford University Press on behalf of Royal Astronomical Society, 2023-08)
    We present the intracluster kinematics and dynamics of three open clusters: NGC 1193, NGC 2355, and King 12 by incorporating kinematical and photometric data from Gaia DR3, as well as a ground-based telescope. After ...

Search DSpace


Browse

My Account