IIA Institutional Repository

Browsing by Author "Stalin, C. S"

Browsing by Author "Stalin, C. S"

Sort by: Order: Results:

  • Spectral properties of quasars from sloan digital sky survey data release 14: the catalog 
    Rakshit, S; Stalin, C. S; Kotilainen, J (IOP Publishing, 2020-07)
    We present measurements of the spectral properties for a total of 526,265 quasars, out of which 63% have a continuum signal-to-noise ratio > 3 pixel−1, selected from the fourteenth data release of the Sloan Digital Sky ...
  • Spectroscopic reverberation mapping of Quasar PKS 0736 + 017: broad-line region and black-hole mass 
    Pandey, Shivangi; Rakshit, Suvendu; Woo, Jong-Hak; Stalin, C. S (Oxford University Press on behalf of Royal Astronomical Society, 2022-10)
    To understand the mass distribution and co-evolution of supermassive black holes with their host galaxy, it is crucial to measure the black hole mass of AGN. Reverberation mapping is a unique tool to estimate the black ...
  • Star Formation in the Dwarf Seyfert Galaxy NGC 4395: Evidence for Both AGN and SN Feedback? 
    Nandi, Payel; Stalin, C. S; Saikia, D. J; Muneer, S; Mountrichas, George; Wylezalek, D; Sagar, R; Patig, M. K (American Astronomical Society, 2023-06-20)
    We present a detailed multiwavelength study of star formation in the dwarf galaxy NGC 4395, which hosts an active galactic nucleus (AGN). From our observations with the Ultra-Violet Imaging Telescope, we have compiled a ...
  • Strong lens time delay challenge. II. results of TDC1 
    Liao, K; Treu, T; Marshall, P; Fassnacht, C. D; Rumbaugh, N; Dobler, G; Aghamousa, A; Bonvin, V; Courbin, F; Hojjati, A; Jackson, N; Kashyap, V; Rathna Kumar, S; Linder, Eric; Mandel, Kaisey; Meng, Xiao-Li; Meylan, G; Moustakas, L. A; Prabhu, T. P; Romero-Wolf, A; Shafieloo, A; Siemiginowska, A; Stalin, C. S; Tak, H; Tewes, M; van Dyk, D (IOP Publishing, 2015-02-20)
    We present the results of the first strong lens time delay challenge. The motivation, experimental design, and entry level challenge are described in a companion paper. This paper presents the main challenge, TDC1, which ...
  • Study of correlation between optical flux and polarization variations in BL Lac objects 
    Rajput, Bhoomika; Pandey, Ashwani; Stalin, C. S; Mathew, Blesson (Oxford University Press on behalf of Royal Astronomical Society, 2022-12)
    Polarized radiation from blazars is one key piece of evidence for synchrotron radiation at low energy, which also shows variations. We present here our results on the correlation analysis between optical flux and polarization ...
  • Study of X-ray variability and coronae of Seyfert galaxies using NuSTAR 
    Priyanka Rani; Stalin, C. S; Goswami, K. D (Oxford University Press on behalf of the Royal Astronomical Society, 2019-04)
    The primary X-ray emission in active galactic nuclei (AGNs) originates in a compact region called the corona located very close to the supermassive black hole and the accretion disc. The knowledge of the cut-off energy ...
  • Surface photometry of three Wolf-Rayet galaxies 
    Singh, M; Sanwal, B. B; Stalin, C. S (Astronomical Society of India, 2001)
    CCD photometric observations of the Wolf-Rayet galaxies NGC 1741, IIZw40 and IRAS 01003-2238 were taken with 104 cm telescope of the U.P. State Observatory NainiTal using 1024 x 1024 CCD camera in B V R I and H? filters. ...
  • 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 ...

Search DSpace

Browse

My Account