• K. Kasturirangan

      Articles written in Journal of Astrophysics and Astronomy

    • X-ray observation of XTE J2012+381 during the 1998 outburst

      S. Naik P. C. Agrawal B. Paul A. R. Rao S. Seetha K. Kasturirangan

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      The outburst of X-ray transient source XTE J2012+381 was detected by the RXTE All-Sky Monitor on 1998 May 24th. Following the outburst, X-ray observations of the source were made in the 2–18 keV energy band with the Pointed Proportional Counters of the Indian X-ray Astronomy Experiment (IXAE) on-board the Indian satellite IRS-P3 during 1998 June 2nd–10th. The X-ray flux of the source in the main outburst decreased exponentially during the period of observation. No large amplitude short-term variability in the intensity is detected from the source. The power density spectrum obtained from the timing analysis of the data shows no indication of any quasi-periodic oscillations in 0.002–0.5 Hz band. The hardness ratio i.e. the ratio of counts in 6–18 keV to 2–6 keV band, indicates that the X-ray spectrum is soft with spectral index >2. From the similarities of the X-ray properties with those of other black hole transients, we conclude that the X-ray transient XTE J2012+381 is likely to be a black hole.

    • SROSS C-2 detections of gamma ray bursts and the SGR 1627-41

      S. Sinha P. Sreekumar K. Kasturirangan

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      The GRB monitor (GRBM) on board the Indian SROSS C-2 satellite has detected 53 classical gamma ray bursts since its launch in May, 1994 till its re-entry in July, 2001. For a subset of 26 events, locations were obtained from simultaneous observations by other gammaray detectors in space. The sky distribution of these 26 SROSS C-2 bursts is consistent with isotropy. The distribution of event durations shows evidence for bimodality. There is an evidence for a moderate hardness ratio-intensity (HIC) correlation in the data. The SROSS C-2 GRBM has also detected three episodes of emission from the SGR 1627-41.

    • AstroSat: Concept to achievements


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      AstroSat has completed 5 years of successful in-orbit operation on 28 September 2020. AstroSat is ISRO’s first Indian multi-wavelength satellite operating as a space Observatory. It is the only satellite which can simultaneously observe in the Far UV and a wide X-ray band from 0.3 to 80 keV using differentinstruments. This astronomy mission was conceived, following the success of several piggy back astronomy experiments flown earlier on Indian satellites. AstroSat is the result of collaboration between ISRO and several astronomy institutions within India and abroad. There are over 150 refereed publications resulting from data from AstroSat, in addition to Astronomy Telegrams, Circulars and Conference proceedings. This paper provides a brief summary of the evolution of the concept of Astrosat, how it was realized and scientificoutcome from this mission.

  • Journal of Astrophysics and Astronomy | News

    • 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.

    • Editorial Note on Continuous Article Publication

      Posted on July 25, 2019

      Click here for Editorial Note on CAP Mode

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