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Browsing IIAP Publications by Title

Browsing IIAP Publications by Title

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  • Sankarasubramanian, K; Sudhakar, M; Sudhakar, M; Nandi, Anuj; Ramadevi, M. C; Adoni, A. A; Kushwaha, A; Agarwal, Anil; Dey, A; Joshi, B; Singh, Brajpal||Girish, V; Tomar, I; Majhi, K. K; Kumar; Olekar, Manjunath; Bug, M; Pala, Manohar; Thakur, Mukund Kumar; Badagandi, Rajeev R; Ravishankar, B. T; Garg, Sarthak; Sitaramamurthy, N; Sridhara, N; Umapathy, C. N; Gupta, Vinod Kumar; Agrawal, Vivek Kumar; Yougandar, B (Current Science Association, 2017-04)
    Aditya-L1 mission will carry two high-spectral resolution X-ray spectrometers to study solar flares. The soft X-ray spectrometer will cover the energy range from 1 to 30 keV, while the hard X-ray spectrometer will cover ...
  • Sankarasubramanian, K; Sudhakar, M||Nandi, Anuj; Ramadevi, M. C; Adoni, A. A; Kushwaha, A; Agarwal, Anil; Dey, A; Joshi, B; Singh, Brajpal; Girish, V; Tomar, I; Majhi, K. K; Kumar; Olekar, Manjunath; Bug, M; Pala, Manohar; Thakur, Mukund Kumar; Badagandi, Rajeev R; Ravishankar, B. T; Garg, Sarthak|; Sitaramamurthy, N; Sridhara, N; Umapathy, C. N; Gupta, Vinod Kumar; Agrawal, Vivek Kumar; Yougandar, B (Current Science Association, 2017-08)
    Aditya-L1 mission will carry two high-spectral resolution X-ray spectrometers to study solar flares. The soft X-ray spectrometer will cover the energy range from 1 to 30 keV, while the hard X-ray spectrometer will cover ...
  • Soundararajaperumal, S (Indian Institute of Astrophysics, Bangalore, 1999)
  • Stalin, C. S; Srianand, R; Petitjean, P (Wiley-Blackwell, 2011-05)
    We study the X-ray and optical properties of 16 broad absorption line (BAL) quasars detected in a ≈3 deg2 region common to the wide synoptic (W-1) component of the Canada–France–Hawaii Telescope Legacy Survey (CFHTLS) and ...
  • Yao, Yuhan; Ho, Anna Y. Q; Medvedev, Pavel; Nayana, A. J; Perley, Daniel A; Kulkarni, S. R; Chandra, Poonam; Sazonov, Sergey; Gilfanov, Marat; Khorunzhev, Georgii; Khatami, David K; Sunyaev, Rashid (American Astronomical Society, 2022-08-01)
    We present AT2020mrf (SRGe J154754.2+443907), an extra-galactic (z = 0.1353) fast blue optical transient (FBOT) with a rise time of tg,rise = 3.7 days and a peak luminosity of Mg,peak = −20.0. Its optical spectrum ...
  • Kuznetsov, A. A; Karakotov, R. R; Chandrashekhar, K; Banerjee, D (IOP Publishing, 2023-01)
    We present observations of the active M-dwarf binary AT Mic (dM4.5e+dM4.5e) obtained with the orbital observatory AstroSat. During 20 ks of observations, in the far-ultraviolet (130–180 nm) and soft X-ray (0.3–7 keV) spectral ...
  • Haghighi, R. R; Chatterjee, S; Vyas, A; Pratik Kumar; Thulkar, S (American Association of Physicists in Medicine, 2011-10)
    The attenuation coefficient, μ(E) of substances, at any energy (E) of the x-ray photon, is known to depend on the electron density (ρe) and the effective atomic number (Zeff) of the material. While the dependence on ρe is ...
  • Joshi, A; Wang, W; Pandey, J. C; Singh, K. P; Naik, S; Raj, A; Anupama, G. C; Rawat, N (EDP Sciences, 2022-01)
    Using X-ray observations from the NuSTAR and Swift satellites, we present temporal and spectral properties of an intermediate polar (IP) IGR J16547-1916. A persistent X-ray period at ∼546 s confirming the optical spin ...
  • Ghosh, K. K; Soundararajaperumal, S (University of Chicago Press, 1992-04)
    Results of the spectral analysis of the X-ray (0.1-10 keV) spectrum of the radio-quiet quasar, PHL 909, are presented. A spectrum of this quasar, which was observed on 1984/349, was obtained from the Exosat archives. ...
  • Singh, V; Shastri, P (American Institute of Physics, 2008-08)
    We study the systematics of the X-ray emission from Seyfert nuclei in the frame work of unification. In order to do this rigorously a sample with types 1 and 2 matched in orientation-independent parameters is studied. The ...
  • Priyanka Rani; Stalin, C. S; Rakshit, S (Oxford University Press on behalf of the Royal Astronomical Society, 2017-04)
    We present results of a systematic study of flux variability on hourly time-scales in a large sample of active galactic nuclei (AGN) in the 3−79 keV band using data from Nuclear Spectroscopic Telescope Array. Our sample ...
  • Ghosh, K. K; Soundararajaperumal, S (University of Chicago Press, 1992-10)
    Results of the detailed X-ray (0.1-10 keV) spectral analysis of the Seyfert 1 galaxy, MGC 2-58-22, are presented based on the Exosat observations on 1984 November 16-26. X-ray spectra of this source were obtained from the ...
  • Pal, Indrani; Stalin, C. S; Chatterjee, Rwitika; Agrawal, Vivek K (Indian Academy of Sciences, 2023-12)
    X-ray polarimetry is a powerful tool to probe the geometry of the hot X-ray corona in active galactic nuclei (AGN). Here, we present our results on the characterisation of the X-ray polarization of the radio-quiet Seyfert-type ...
  • Ghosh, K. K; Soundararajaperumal, S (Blackwell Publishing, 1992-11)
    A spectra analysis of eight Seyfert galaxies shows that while seven have soft excesses in their spectra, with no low-energy absorption, ESO 140-G43 exhibits low energy absorption, and may have weak soft excess that is ...
  • Pal, Indrani; Stalin, C. S; Parker, M. L; Agrawal, Vivek K; Marchesi, S (Oxford University Press on behalf of Royal Astronomical Society, 2022-12)
    We present the timing and spectral analysis of the Compton Thick Seyfert 2 active galactic nuclei NGC 1068 observed using NuSTAR and XMM–Newton. In this work for the first time we calculated the coronal temperature (⁠kTekTe⁠) ...
  • Singh, V; Shastri, P; Risaliti, G (EDP Sciences, 2011-08)
    Context. The unification scheme of Seyfert galaxies predicts that the observed differences between types 1 and 2 Seyfert galaxies are solely due to the differing orientations of the toroidal-shaped obscuring material around ...
  • Ghosh, K. K; Soundararajaperumal, S (European Southern Observatory, 1993-06)
    X-ray (0.1-10 keV) spectra of NGC 4593 were obtained with EXOSAT on seven epochs between 1984 and 1986 using the low and medium energy detectors. Detailed results of the spectral analysis of the seven spectra (obtained ...
  • Ghosh, K. K; Sondararajaperumal, S (The American Astronomical Society, 1991-10)
    Results are presented of observations of the broad-line radio galaxy, 3C 390.3 that were made with Exosat on several occasions between 1984 and 1986 using low- (LE) and medium-energy (ME) detectors. Detailed findings of ...
  • Ghosh, K. K; Soundararajaperumal, S; Kalai Selvi, M; Sivarani, T (EDP Sciences, 1992-02)
    Results of the X-ray (0.1-10 keV) spectral analysis of the Seyfert I galaxy, NGC 3783, which was observed with EXOSAT on three epochs between 1983 and 1985, are presented here. No low energy absorption, intrinsic to the ...
  • Ghosh, K. K; Soundararajaperumal, S (EDP Sciences, 1991-12)
    A study of the X-ray (0.1-10 keV) spectrum from the radio-loud quasar, PKS 1217 + 023 is presented. This quasar was observed with Exosat on two epochs in January 29 and May 14, 1984. The data were obtained from the Exosat ...

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