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Indian Institute of Science Education and Research
Thiruvananthapuram

Dr Shabnam Iyyani
Assistant Professor Grade I (Physics)
  +91 (0)471 - 2778304
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Publications

  • Refereed Publications
  1. Bordoloi, P. P., Mittal, S., & Iyyani, S.*, From Empirical to Physical Model: Direct Fits of Optically Thin Inverse Compton Scattering to Prompt GRB Spectra, The Astrophysical Journal, 1003, 58 (2026). 
  2. John, A. A., Shete, G. K., Iyyani, S.*, & Bej, S., Multivariate time series classification of Fermi-detected gamma-ray transients using convolutional-recurrent neural networks, Machine Learning: Science and Technology, 7, 025046 (2026). 
  3. Gupta, R., Sonawane, R., Iyyani, S.*, et al., Episode-wise spectro-polarimetry of GRB 220107A: Testing the hypothesis of evolving radiation mechanisms, Astronomy & Astrophysics, 709, 16 (2026). 
  4. Bala, S., Veres, P., Goldstein, A.,.., Iyyani, S., Fastest or Significant: A Systematic Framework for Validating Global Minimum Variability Timescale Measurements of Gamma-Ray Bursts, The Astrophysical Journal, 999, 51 (2026). 
  5. Gupta, R., Racusin, J.,…, Iyyani, S., et al., Extremely luminous optical afterglow of a distant and energetic gamma-ray burst GRB 230204B, The Astrophysical Journal, 997, 246 (2026). 
  6. Bordoloi, P. P., & Iyyani, S.*, Identification and modelling of optically thin inverse Compton scattering in the prompt emission of GRB 131014A, The Astrophysical Journal, 994, 10 (2025). 
  7. Sonawane, R., Iyyani, S.*, Gupta, S., et al., Spectropolarimetry of GRB 180427A: Evidence for Distinct Emission Sites with Varying Polarization, The Astrophysical Journal, 990, 215 (2025). 
  8. Bhalerao, V., Misra, K., Gadiyara, A., Iyyani, S., et al., Transients and time domain astrophysics, Journal of Astrophysics and Astronomy, 46, 40 (2025). 
  9. Sarogi, D., Bala, S., Joshi, J., Iyyani, S., et al., Investigating polarization characteristics of GRB 200503A and GRB 201009A, Journal of Astrophysics and Astronomy, 46, 38 (2025). 
  10. Vyas, K. M., Pe'er, A., & Iyyani, S., Unified theory of negative and positive spectral lags in the gamma-ray burst prompt phase due to shear Comptonization from a structured jet, The Astrophysical Journal Letters, 975, L29 (2024). 
  11. Gupta, R., Pandey, S. B., et al., Iyyani, S., et al., A detailed time-resolved and energy-resolved spectro-polarimetric study of bright GRBs detected by AstroSat CZTI in its first year of operation, The Astrophysical Journal, 972, 166 (2024). 
  12. Mehta, N., & Iyyani, S.*, Exploring Gamma-Ray Burst Diversity: Clustering analysis of emission characteristics of Fermi and BATSE detected GRBs, The Astrophysical Journal, 88, 69 (2024). 
  13. Bhalerao, V., Sawant, D., et al., Iyyani, S., et al., Science with Daksha high energy transients mission, Experimental Astronomy, 23, 57 (2024). 
  14. Saji, J., Iyyani, S.*, & Mazde, K., Statistical Analysis of Long GRBs’ Prompt Emission and X-Ray Flares: Multivariate Clustering and Correlations, The Astrophysical Journal Supplement Series, 269, 2 (2023). 
  15. Chattopadhyay, T., Gupta, S., Iyyani, S., et al., Hard X-Ray Polarization Catalog for a Five-year Sample of Gamma-Ray Bursts Using AstroSat CZT Imager, The Astrophysical Journal, 936, 12 (2022). 
  16. Ryde, F., Iyyani, S.*, et al., Onset of Particle Acceleration during the Prompt Phase in Gamma-Ray Bursts as Revealed by Synchrotron Emission in GRB 160821A, The Astrophysical Journal Letters, 932, L15 (2022). 
  17. Gupta, R., Gupta, S., et al., Iyyani, S., et al., Probing into emission mechanisms of GRB 190530A using time-resolved spectra and polarization studies: synchrotron origin?, Monthly Notices of the Royal Astronomical Society, 511, 1694 (2022). 
  18. Chattopadhyay, T., Gupta, S., Sharma, V., Iyyani, S., et al., Sub-MeV spectroscopy with AstroSat-CZT imager for gamma ray bursts, Journal of Astrophysics and Astronomy, 42, 82 (2021). 
  19. Iyyani, S. & Sharma, V., Study of the Prompt Emission of Short Gamma-Ray Bursts Using a Multicolor Blackbody: A Clue to the Viewing Angle, The Astrophysical Journal Supplement Series, 255, 25 (2021). 
  20. Ahumada, T., Singer, L. P., et al., Iyyani, S., et al., Discovery and confirmation of the shortest gamma-ray burst from a collapsar, Nature Astronomy, 5, 917 (2021). 
  21. Abraham, S., et al., Iyyani, S., et al., A machine learning approach for GRB detection in AstroSat CZTI data, Monthly Notices of the Royal Astronomical Society, 504, 3084 (2021). 
  22. Sharma, V., Iyyani, S.*, & Bhattacharya, D., Identifying Black Hole Central Engines in Gamma-Ray Bursts, The Astrophysical Journal Letters, 908, L2 (2021). 
  23. Sharma, V., Iyyani, S.*, et al., Spectropolarimetric analysis of prompt emission of GRB 160325A: jet with evolving environment of internal shocks, Monthly Notices of the Royal Astronomical Society, 493, 5218 (2020). 
  24. Sharma, V., Iyyani, S.*, et al., Time-varying Polarized Gamma-Rays from GRB 160821A: Evidence for Ordered Magnetic Fields, The Astrophysical Journal Letters, 882, L10 (2019). 
  25. Chand, V., Chattopadhyay, T., Iyyani, S., et al., Violation of Synchrotron Line of Death by the Highly Polarized GRB 160802A, The Astrophysical Journal, 862, 154 (2018). 
  26. Basak, R., Iyyani, S.*, et al., Surprise in simplicity: an unusual spectral evolution of a single pulse GRB 151006A, Monthly Notices of the Royal Astronomical Society, 472, 891 (2017). 
  27. Rao, A. R.,.., Iyyani, S., et al., AstroSat CZT Imager Observations of GRB 151006A: Timing, Spectroscopy, and Polarization Study, The Astrophysical Journal, 833, 86 (2016).
  28. Iyyani, S., Ryde, F., et al., Synchrotron emission in GRBs observed by Fermi: its limitations and the role of the photosphere, Monthly Notices of the Royal Astronomical Society, 456, 2157 (2016). 
  29. Iyyani, S., Ryde, F., et al., Extremely narrow spectrum of GRB 110920A: further evidence for localized, subphotospheric dissipation, Monthly Notices of the Royal Astronomical Society, 450, 1651 (2015). 
  30. Begue, D. & Iyyani, S., Transparency Parameters from Relativistically Expanding Outflows, The Astrophysical Journal, 792, 42 (2014). 
  31. Burgess, J. M., Preece, R. D., et al., Iyyani, S., et al., An Observed Correlation between Thermal and Non-thermal Emission in Gamma-Ray Bursts, The Astrophysical Journal Letters, 784, L43 (2014). 
  32. Burgess, J. M., Preece, R. D.,…. Iyyani, S.*, et al., Time-resolved Analysis of Fermi Gamma-Ray Bursts with Fast- and Slow-cooled Synchrotron Photon Models, The Astrophysical Journal, 784, 17 (2014). 
  33. Preece, R., Burgess, J. M., et al., Iyyani, S., et al., The First Pulse of the Extremely Bright GRB 130427A: A Test Lab for Synchrotron Shocks, Science, 343, 51 (2014). 
  34. Iyyani, S., Ryde, F., et al., Variable jet properties in GRB 110721A: time resolved observations of the jet photosphere, Monthly Notices of the Royal Astronomical Society, 433, 2739 (2013).
  35. Axelsson, M., Baldini, L., et al., Iyyani, S., et al., GRB 110721A: An Extreme Peak Energy and Signatures of the Photosphere, The Astrophysical Journal Letters, 757, L31 (2012).

*Corresponding Author/ Supervisor of the project

Invited Reviews (Refereed Publications)

  1. Iyyani, S., Recent advances in the study of the prompt emission of gamma-ray bursts, Journal of Astrophysics and Astronomy, 43, 37 (2022). 
  2. Iyyani, S., Observations and physics of prompt emission of gamma ray bursts, Journal of Astrophysics and Astronomy, 39, 75 (2018). 
  3. Chandra, P., Anupama, G. C., Arun, K. G., Iyyani, S., et al., Explosive and Radio-Selected Transients: Transient Astronomy with Square Kilometre Array and its Precursors, Journal of Astrophysics and Astronomy, 37, 30 (2016). 
  • PhD Thesis: ‘Photospheric emission in gamma ray bursts: analysis and interpretations of the observations by Fermi gamma ray space telescope.’, PhD Thesis, University of Stockholm, Sweden; Erasmus Mundus Joint Doctorate Fellowship (2015).