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Browsing by Author "Stalin, C. S"

Browsing by Author "Stalin, C. S"

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  • Temporal correlation between the optical and γ-ray flux variations in the blazar 3C 454.3 
    Rajput, Bhoomika; Stalin, C. S; Sahayanathan, S; Rakshit, S; Amit Kumar Mandal (Oxford University Press on behalf of the Royal Astronomical Society, 2019-06)
    Blazars show optical and γ-ray flux variations that are generally correlated, although there are exceptions. Here we present anomalous behaviour seen in the blazar 3C 454.3 based on an analysis of quasi-simultaneous data ...
  • Tests and calibration on ultra violet imaging telescope (UVIT) 
    Amit Kumar; Ghosh, S. K; Kamath, P. U; Postma, Joe; Kathiravan, S; Mahesh, P. K; Nagbhushana, S; Navalgund, K. H; Rajkumar, N; Rao, M. N; Sarma, K. S; Sriram, S; Stalin, C. S; Tandon, S. N (SPIE--The International Society for Optical Engineering, 2012-09)
    Ultra Violet Imaging Telescope on ASTROSAT Satellite mission is a suite of Far Ultra Violet (FUV; 130 – 180 nm), Near Ultra Violet (NUV; 200 – 300 nm) and Visible band (VIS; 320–550nm) imagers. ASTROSAT is a first ...
  • Tracking galaxy evolution through low-frequency radio continuum observations using SKA and citizen-science research using multi-wavelength data 
    Hota, A; Konar, C; Stalin, C. S; Vaddi, Sravani; Mohanty, Pradeepta K; Dabhade, Pratik; Arun, Sai; Bhoga, Dharmik; Rajoria, Megha; Sethi, Sagar (Indian Academy of Sciences, 2016-12)
    We present a brief review of progress in the understanding of general spiral and elliptical galaxies, through merger, star formation and AGN activities. With reference to case studies performed with the GMRT, we highlight ...
  • 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 ...
  • TXS 1433+205: The most distant gamma-ray emitting FR II radio galaxy 
    Paliya, Vaidehi S; Saikia, D. J; Stalin, C. S (Oxford University Press on behalf of Royal Astronomical Society, 2023-03)
    The orientation of the jet axis to the line of sight of the observer plays a major role in explaining the phenomena observed from blazars and radio galaxies. In the γ -ray band, only a handful of radio galaxies have been ...
  • Ultraviolet Imaging Telescope on AstroSat 
    Tandon, S. N; Ghosh, S. K; Hutchings, J; Stalin, C. S; Subramaniam, A (Current Science Association, 2017-08)
    The AstroSat satellite is designed for multiwavelength astronomy for observations covering a spectral range from soft and hard X-rays to the ultraviolet. The Ultraviolet Imaging Telescope (UVIT) is the only non-X-ray ...
  • Ultraviolet Imaging Telescope on AstroSat 
    Tandon, S. N; Ghosh, S. K; Hutchings, J; Stalin, C. S; Subramaniam, A (Current Science Association, 2017-04)
    Solar coronagraph mimics total solar eclipse by blocking the solar disk and enabling the observation of extended coronal atmosphere of the Sun. Visible Emission Line Coronagraph (VELC), on-board Aditya-L1 space mission, ...
  • Unravelling the unusually curved X-ray spectrum of RGB J0710 + 591 using AstroSat observations 
    Goswami, Pranjupriya; Sinha, Atreyee; Chandra, Sunil; Misra, Ranjeev; Chitnis, Varsha; Gogoi, Rupjyoti; Sahayanathan, Sunder; Stalin, C. S; Singh, K. P; Yada, J. S (Oxford University Press on behalf of the Royal Astronomical Society, 2020-02)
    We report the analysis of simultaneous multiwavelength data of the high-energy-peaked blazar RGB J0710 + 591 from the Large Area X-ray Proportional Counters, Soft X-ray focusing Telescope, and Ultraviolet Imaging ...
  • Unusual long-term low-activity states of EGRET blazars in the Fermi era 
    Bhattacharya, Debbijoy; Mohana A, K; Gulati, S; Bhattacharyya, Subir; Bhatt, N; Sreekumar, P; Stalin, C. S (Oxford University Press on behalf of the Royal Astronomical Society, 2017-11)
    We examine the long-term (∼10 years) γ-ray variability of blazars observed by the Energetic Gamma Ray Experiment Telescope (EGRET) and Fermi and find that 10 EGRET-detected flat-spectrum radio quasars (FSRQs) were not ...
  • UVIT Observations of the Small Magellanic Cloud: Point-source Catalog 
    Devaraj, A; Joseph, P; Stalin, C. S; Tandon, S. N; Ghosh, S. K (American Astronomical Society, 2023-04-01)
    Three fields in the outskirts of the Small Magellanic Cloud were observed by the UltraViolet Imaging Telescope (UVIT) on board AstroSat, between 2017 December 31 and 2018 January 1. The observations were carried out on a ...
  • UVIT observations of the star-forming ring in NGC 7252: Evidence of possible AGN feedback suppressing central star formation 
    George, K; Joseph, P; Mondal, Chayan; Devaraj, A; Subramaniam, A; Stalin, C. S; Cote, P; Ghosh, S. K; Hutchings, J. B; Mohan, Rekhesh; Postma, J; Sankarasubramanian, K; Sreekumar, P; Tandon, S. N (EDP Sciences, 2018-05)
    Context. Some post-merger galaxies are known to undergo a starburst phase that quickly depletes the gas reservoir and turns it into a red-sequence galaxy, though the details are still unclear. Aims. Here we explore the ...
  • UVIT view of Centaurus A: a detailed study on positive AGN feedback 
    Joseph, P; Sreekumar, P; Stalin, C. S; Paul, K. T; Mondal, Chayan; George, Koshy; Mathew, Blesson (Oxford University Press on behalf of Royal Astronomical Society, 2022-10)
    Supermassive black holes at the centre of active galactic nuclei (AGNs) produce relativistic jets that can affect the star formation characteristics of the AGN hosts. Observations in the ultraviolet (UV) band can provide ...
  • UVIT view of ram-pressure stripping in action: Star formation in the stripped gas of the GASP jellyfish galaxy JO201 in Abell 85 
    George, K; Poggianti, B. M; Gullieuszik, M; Fasano, G; Bellhouse, C; Postma, J; Moretti, A; Jaffe, Y; Vulcani, B; Bettoni, D; Fritz, J; Cote, P; Ghosh, S. K; Hutchings, J. B; Mohan, Rekhesh; Sreekumar, P; Stalin, C. S; Subramaniam, A; Tandon, S. N (Oxford University Press on behalf of the Royal Astronomical Society, 2018-09)
    Jellyfish are cluster galaxies that experience strong ram-pressure effects that strip their gas. Their Hα images reveal ionized gas tails up to 100 kpc, which could be hosting ongoing star formation. Here, we report the ...
  • Variable mass accretion and failed wind explain changing-look phenomena in NGC 1365 
    Mondal, Santanu; Adhikari, T. P; Hryniewicz, K; Stalin, C. S; Pandey, Ashwani (EDP Sciences, 2022-06)
    Changing-look active galactic nuclei (CLAGNs) show a complex nature in their X-ray spectral shape and line-of-sight column-density variation. The physical mechanisms responsible for these variations are unclear. Here, we ...
  • Variables in Globular Cluster NGC 5024 
    Safonova, M; Stalin, C. S (IOP Publishing, 2011-12)
    We present the results of a commissioning campaign to observe Galactic globular clusters for the search of microlensing events. The central 10' × 10' region of the globular cluster NGC 5024 was monitored using the 2 m ...
  • The violent hard X-ray variability of MRK 421 observed by Nustar in 2013 April 
    Paliya, Vaidehi S; Bottcher, M; Diltz, C; Stalin, C. S; Sahayanathan, S; Ravikumar, C. D (IOP Publishing, 2015-10-01)
    The well-studied blazar Markarian 421 (Mrk 421, z = 0.031) was the subject of an intensive multi-wavelength campaign when it flared in 2013 April. The recorded X-ray and very high-energy (E > 100 GeV) γ-ray fluxes are the ...
  • The WIRCAM Deep Infrared Cluster Survey I. Groups and clusters at z  ≳  1.1 
    Bielby, R. M; Finoguenov, A; Tanaka, M; McCracken, H. J; Daddi, E; Hudelot, P; Ilbert, O; Kneib, J. P; Le Fèvr, O; Mellier, Y; Nandra, K; Petitjean, P; Srianand, R; Stalin, C. S; Willott, C. J (EDP Sciences, 2010-12)
    We use a combination of CFHTLS deep optical data, WIRcam Deep Survey (WIRDS) near-infrared data and XMM-Newton survey data to identify z ≳ 1.1 clusters in the CFHTLS D1 and D4 fields. Counterparts to such clusters can not ...
  • WISE view of narrow-line Seyfert 1 galaxies: mid-infrared colour and variability 
    Rakshit, S; Johnson, A; Stalin, C. S; Gandhi, Poshak; Hoenig, Sebastian (Oxford University Press on behalf of the Royal Astronomical Society, 2019-02)
    We present the colour and flux variability analysis at 3.4 μm (W1 band) and 4.6 μm (W2 band) of 492 narrow-line Seyfert 1 (NLSy1) galaxies using archival data from the Wide-field Infrared Survey Explorer (WISE). In the ...
  • WISE view of narrow-line Seyfert 1 galaxies: mid-infrared colour and variability 
    Rakshit, S; Johnson, A; Stalin, C. S; Gandhi, Poshak; Hoenig, Sebastian (Oxford University Press on behalf of the Royal Astronomical Society, 2019-02)
    We present the colour and flux variability analysis at 3.4 μm (W1 band) and 4.6 μm (W2 band) of 492 narrow-line Seyfert 1 (NLSy1) galaxies using archival data from the Wide-field Infrared Survey Explorer (WISE). In the ...
  • X-ray and optical properties of broad absorption line quasars in the Canada–France–Hawaii Telescope Legacy Survey 
    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 ...

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