Faculty Details

Areas of Interest

• 21-cm Cosmology
• Cosmic Dawn and Epoch of Reionization
• Low-Frequency Radio Astronomy
• Diffuse Synchrotron Emission

Current Research

The Universe changes its phase from the completely neutral stage to ionization state by the radiation of the first source and galaxies. This is one of the important milestone in evolution history named as the Epoch of Reionization (EoR). The 21-cm line emission from the neutral hydrogen (HI) is an important tool to study this epoch. A lot of astrophysical and cosmological information such as timing, duration of the epoch, the properties, and the evolution of the first stars and galaxies can be revealed using this 21-cm line.The two next-generation telescopes, the

Hydrogen Epoch of Reionization Array (HERA) and the Square Kilometre Array (SKA), are expected to detect it for the very first time, and this will open up an entirely new observational window to probe the first stars and galaxies. We are working on simulation, develop statistical algorithms, and also analyze the real data to unveil the evolution history of the Universe using 21-cm radiation.

Students

Current PhD Students

• PH22D020    Shouvik Sarkar

Recent Publications

• Calibration requirements for Epoch of Reionization 21-cm signal observations -- II. Analytical estimation of the bias and variance with time-correlated residual gains. J. Kumar, P. Dutta, S. Choudhuri. Monthly Notices of the Royal Astronomical Society. 512. 186 . 2022.
• Patterns of primary beam non-redundancy in close-packed 21 cm array observations. S. Choudhuri, P Bull, H Garsden. Monthly Notices of the Royal Astronomical Society. 506. 2066. 2021.
• The auto and cross angular power spectrum of the Cas A supernova remnant in radio and X-ray . P Saha, S Bharadwaj, S Chakravorty, N Roy, S. Choudhuri, HM Günther, Smith, R. K.. Monthly Notices of the Royal Astronomical Society. 502. 5313. 2021.
• Stringent constraint on the radio signal from dark matter annihilation in dwarf spheroidal galaxies using the TGSS. A Basu, N Roy, S. Choudhuri, KK Datta, D Sarkar. Monthly Notices of the Royal Astronomical Society. 502. 1605. 2021.
• Demonstrating the Tapered Gridded Estimator (TGE) for the Cosmological HI 21-cm Power Spectrum using 150MHz GMRT observations. S Pal, S Bharadwaj, A Ghosh, S. Choudhuri. Monthly Notices of the Royal Astronomical Society. 501. 3378. 2021.
• First multi-redshift limits on post-Epoch of Reionization (post-EoR) 21 cm signal from z = 1.96 - 3.58 using uGMRT. A. Chakraborty, A. Datta, N. Roy, S. Bharadwaj, T. R. Choudhury, K. K. Datta, S. Pal, M. Choudhury, S. Choudhuri, P. Dutta, D. Sarkar. The Astrophysical Journal Letters. 907. 7. 2021.
• Angular power spectrum of supernova remnants: effects of structure, geometry and diffuse foreground. S. Choudhuri, P Saha, N Roy, S Bharadwaj, J Dey. Monthly Notices of the Royal Astronomical Society. 501. 3364. 2021.
• Characterizing EoR foregrounds: A study of the Lockman Hole Region at 325 MHz. A Mazumder, A Chakraborty, A Datta, S. Choudhuri, N Roy, Y Wadadekar, Ishwara-Chandra, C. H.. Monthly Notices of the Royal Astronomical Society. 495. 4071. 2020.
• All sky angular power spectrum: I. Estimating brightness temperature fluctuations using TGSS 150 MHz survey. S. Choudhuri, A Ghosh, N Roy, S Bharadwaj, HT Intema, S. S. Ali. Monthly Notices of the Royal Astronomical Society. 494. 1936. 2020.
• A study of Kepler supernova remnant: angular power spectrum estimation from radio frequency data. P Saha, S Bharadwaj, N Roy, S. Choudhuri, D Chattopadhyay. Monthly Notices of the Royal Astronomical Society. 489. 5866. 2019.
• Detailed study of ELAIS N1 field with the uGMRT -- II. Source Properties and Spectral Variation Of Foreground Power Spectrum from 300-500 MHz Observations. A Chakraborty, N Roy, A Datta, S. Choudhuri, KK Datta, P Dutta, Bharadwaj, S., Intema, H., Choudhury, M,. Pal, S., Choudhury, T. R.. Monthly Notices of the Royal Astronomical Society. 490. 243. 2019.
• Detailed study of the ELAIS N1 field with the uGMRT - I. Characterizing the 325 MHz foreground for redshifted 21 cm observations. A Chakraborty, A Datta, S. Choudhuri, N Roy, H Intema, M Choudhury, Datta, K. K. Pal, S, Bharadwaj, S., Dutta, P., Choudhury, T. R.. Monthly Notices of the Royal Astronomical Society. 487. 4102. 2019.
• A Tapered Gridded Estimator (TGE) for the Multi-Frequency Angular Power Spectrum (MAPS) and the Cosmological HI 21-cm Power Spectrum. S Bharadwaj, S Pal, S. Choudhuri, P Dutta. Monthly Notices of the Royal Astronomical Society. 483. 5694. 2019.
• An Image-based Tapered Gridded Estimator (ITGE) for the angular power spectrum. S. Choudhuri, P Dutta, S Bharadwaj. Monthly Notices of the Royal Astronomical Society. 483. 3910 . 2019.
• Turbulent power spectrum in warm and cold neutral medium using the Galactic HI 21 cm emission. S. Choudhuri, N Roy. Monthly Notices of the Royal Astronomical Society. 483. 3437. 2019.
• Validating a novel angular power spectrum estimator using simulated low frequency radio-interferometric data. S. Choudhuri, N Roy, S Bharadwaj, SS Ali, A Ghosh, P Dutta. New Astronomy. 57 . 94. 2017.
• The angular power spectrum measurement of the Galactic synchrotron emission in two fields of the TGSS survey. S. Choudhuri, S Bharadwaj, SS Ali, N Roy, HT Intema, A Ghosh. Monthly Notices of the Royal Astronomical Society. 470. L11 . 2017.
• Imaging the redshifted 21 cm pattern around the first sources during the cosmic dawn using the SKA. R Ghara, TR Choudhury, KK Datta, S. Choudhuri. Monthly Notices of the Royal Astronomical Society. 464. 2234. 2017.
• Prospects of Measuring the Angular Power Spectrum of the Diffuse Galactic Synchrotron Emission with SKA1 Low. SS Ali, S Bharadwaj, S. Choudhuri, A Ghosh, N Roy. Journal of Astrophysics and Astronomy. 37. 11. 2016.
• The visibility-based tapered gridded estimator (TGE) for the redshifted 21-cm power spectrum. S. Choudhuri, S Bharadwaj, S Chatterjee, SS Ali, N Roy, A Ghosh. Monthly Notices of the Royal Astronomical Society. 463. 4093 . 2016.
• Tapering the sky response for angular power spectrum estimation from low-frequency radio-interferometric data. S. Choudhuri, S Bharadwaj, N Roy, A Ghosh, SS Ali. Monthly Notices of the Royal Astronomical Society. 459. 151 . 2016.
• Visibility-based angular power spectrum estimation in low-frequency radio interferometric observations. S. Choudhuri, S. Bharadwaj, A. Ghosh, Sk. S. Ali. Monthly Notices of the Royal Astronomical Society. 445. 4351. 2014.

Teaching

• 2022 : (Jul - Nov) :  PH5060 Physics Lab I (PG)
• 2023 : (March - June) :  PH1020 Physics II
• 2023 : (July - Nov) :  PH1010 Physics I