• J. TIWARI

      Articles written in Journal of Astrophysics and Astronomy

    • Observations of AR Sco with Chandra and AstroSat soft X-ray telescope

      K. P. SINGH V. GIRISH J. TIWARI P. E. BARRETT D. A. H. BUCKLEY S. B. POTTER E. SCHLEGEL V. RANA G. STEWART

      More Details Abstract Fulltext PDF

      We present our AstroSat soft X-ray observations of a compact binary system, AR Sco, and analysis of its X-ray observations with Chandra that were taken only about a week before the AstroSat observations. An analysis of the soft X-ray (0.3–2.0 keV) data limits the modulation of the spin, orbital, or beat periods to less than 0.03 counts s$^{-1}$ or <10% of the average count rate. The X-ray flux obtainedfrom both observatories is found to be almost identical (within a few percent) in flux, and about 30% lower than reported from the nine months older observations with XMM-Newton. A two-temperature thermal plasma model with the same spectral parameters fit Chandra and AstroSat data very well, and requires very little absorption in the line of sight to the source. The low-temperature component has thesame temperature ($\sim$1 keV) as reported earlier, but the high-temperature component has a lower temperature of $5.0^{+0.8}_{-0.7}$ keV as compared to 8.0 keV measured earlier, however, the difference is not statistically significant.

  • 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

© 2022-2023 Indian Academy of Sciences, Bengaluru.