• GULAB C. DEWANGAN

      Articles written in Journal of Astrophysics and Astronomy

    • Science with the AstroSat Soft X-ray telescope: An overview

      SUDIP BHATTACHARYYA KULINDER PAL SINGH GORDON STEWART SUNIL CHANDRA GULAB C. DEWANGAN NILIMA S. KAMBLE SANDEEP VISHWAKARMA JAYPRAKASH G. KOYANDE VARSHA CHITNIS

      More Details Abstract Fulltext PDF

      The Soft X-ray Telescope (SXT) aboard the AstroSat satellite is the first Indian X-ray telescope in space. It is a modest size X-ray telescope with a charge coupled device (CCD) camera in the focal plane, which provides X-ray images in the $\sim$0.3–8.0 keV band. A forte of SXT is in providing undistorted spectraof relatively bright X-ray sources, in which it excels over some current large CCD-based X-ray telescopes. Here, we highlight some of the published spectral and timing results obtained using the SXT data to demonstrate the capabilities and overall performance of this telescope.

    • AstroSat view of the NLS1 galaxy Mrk 335

      SAVITHRI H. EZHIKODE GULAB C. DEWANGAN RANJEEV MISRA

      More Details Abstract Fulltext PDF

      We present the results from the multi-wavelength monitoring observations of the Narrow-Line Seyfert 1 galaxy Mrk 335 with AstroSat. We analysed both the X-ray (SXT and LAXPC) and UV (UVIT) data of the source at two epochs, separated by $\sim$18 days. The source was in a low flux state during theobservations, and the X-ray spectra were found to be harder than usual. The presence of soft X-ray excess was identified in the observations, and the broadband X-ray continuum was modelled with power-law and black body (modified by intrinsic absorption) and a distant neutral reflection component. We did not find any variability in the X-ray spectral shape or the flux over this period. However, the UV flux is found to be variable between the observations. The obtained results from the X-ray analysis point to a scenario where theprimary emission is suppressed and the component due to distant reflection dominates the observed spectrum.

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    • Continuous Article Publication

      Posted on January 27, 2016

      Since January 2016, the Journal of Astrophysics and Astronomy has moved to Continuous Article Publishing (CAP) mode. This means that each accepted article is being published immediately online with DOI and article citation ID with starting page number 1. Articles are also visible in Web of Science immediately. All these have helped shorten the publication time and have improved the visibility of the articles.

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      Posted on July 25, 2019

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