Research
For all your days, prepare,
And meet them ever alike.
When you are the anvil - Bear,
When you are the hammer - Strike.
What do I do?
I work on the time-series analysis of radio frequency pulsar data.
Pulsars: These are spinning neutron stars whose magnetic pole passes through our line of sight every once in a while. Pulsars are formed when a star, much heavier(8-20 times) than our sun explodes. With impeccable periodicity, these are often called astronomical clocks. BUT we don't know how they emit!
With the data I get at radio frequencies, I study the emission of pulsar and try to deduce new science.
A pulsar rotating along it's rotation axis with light beams emanating from either of its magnetic poles.
Credits: M. KramerIn more technical terms ...
I study single pulse emission from a variety of pulsars using numerous pulsar emission models. Recently I've got some wonderful pulsar data from uGMRT (upgraded-Giant Meterwave Radio Telescope, Pune, India) and MWA (Murchison Widefield Array, Western Australia).
I'll be writing about it in more details after I publish my research.
Publications
Revisiting the sub-pulse drifting phenomenon in PSR J1822-2256: Drift Modes, Sparks, and Emission Heights
In this work, we studied the subpulse drifting phenomenon in the pulsar J1822-2256. In this phenomenon, systematic shifts are observed in the pulse phases of substructures within the main pulse, which shows as slanted drift bands when the pulses are stacked together. With our analysis, we found multiple drifting modes in this pulsar and calculated the emission heights for each of the modes. Click here to read the full publication.
Single -pulse analysis and average emission characteristics of PSR J1820-0427 from observations made with the MWA and uGMRT
This paper explores the pulse-to-pulse variability in the pulsar J1820-0427. Pulsars are extremely precise clocks from which we observe radiation at equal intervals. This radiation is an (approximately) direct measure of the plasma activity in the pulsar magnetosphere. Therefore, studying single pulses provides an instantaneous window into the dynamic pulsar magnetosphere. However, given that pulsars are not bright sources, it is difficult to observe every single pulse. In this work, we observed the pulsar J1820-0427 with an impeccable signal-to-noise ratio of ~100. To find out what pulsar emission physics we unravelled from the seemingly random data, click here to read the full publication.
PSR J0026-1955: A curious case of evolutionary subpulse drifting and nulling
Subpulse drifting is a well-known phenomenon in long-period pulsars; however, the physics behind it is debated. In this paper, we have studied the newly discovered pulsar J0026-1955 with the uGMRT for the first time and found the extremely rare phenomenon of evolutionary subpulse drifting. The figure shows how the drift rate globally evolves over time in a drift sequence while also exhibiting local variabilities. In addition to this, the pulsar also shows drift memory across nulls, another rare phenomenon with great implications. To read the full publication, click here.
Observing Proposals
18 hours of pulsar observing time at Band-3 (300-500 MHz) and Band-4 (550-750 MHz) for studying a newly discovered pulsar. (Co-I, upgraded-Giant Metrewave Radio Telescope, Cycle 44)
uGMRT follow-up of a new sub-pulse drifting pulsar J0024-1931. (Co-I, upgraded-Giant Metrewave Radio Telescope, Cycle 41)
Investigation of sub-pulse drifting properties for five pulsars. (PI, upgraded-Giant Metrewave Radio Telescope, Cycle 38)
Investigation of sub-pulse drifting properties for three pulsars. (PI, Murchison Widefield Array, 2020-A)
UVIT Observations on Radio Deep Field of ELAIS-N1 (Co-I, A09 Observing Cycle of Astrosat (2020)
Conferences and Workshops
The curious case of subpulse drifting and nulling in PSR J0026-1955, National Conference on REcent Trends in the study of Compact Objects (RETCO-V) 2023
A curious case of subpulse drifting and nulling in pulsar J0026-1955, Astronomical Society of India 2023
Single-pulse and average emission characteristics of PSR J1820-0427, International Radio Science Union - Regional Conference on Radio Science 2022
Investigation of subpulse drifting and nulling properties of PSR J0026–1955, Orange Conference 2022
Understanding the pulsar emission physics through investigations of pulse-to-pulse variability characteristics, Monash University, Nov. 2022, invited
Understanding the single pulse variability in PSR J1820–0427 using multi-frequency observations, SKA Pathfinder Radio Continuum Survey 2022
Revisiting the subpulse drifting phenomenon in PSR J1822-2256, National Astronomical Meeting 2022
Wide-band Studies of PSR J1822-2256 using uGMRT, Astronomical Society of India 2022
Phased Arrays and Pulsar Observations in Radio Astronomy, IIT Indore, Apr. 2022, invited
Sub-pulse drifting in PSR J1822-2256: Drift Modes, Sparks & Emission Heights, Science At Low-Frequencies - VII 2021
Space, Time, and Gravity, IEEE NCU - SB 2021, invited
Search for Fast Transients using Machine Learning, Recent Advances in Space Science 2019
International Pulsar Timing Array Conference, 2021
SKA Science Meeting: A Precursor View of the SKA Sky, 2021
Compact Stars In The QCD Phase Diagram VIII: The Era Of Multi-Messenger Astronomy, 2020
GROWTH Astronomy School, 2020
Radio Astronomy School (NCRA-TIFR), 2019
Multi-wavelength Sky Observations - AstroSat and Beyond, 2019
Talks
Keep checking this website to know more about my ongoing/published work.