Research

Detection of Intermediate Mass Black Hole Binaries

Recently, I focussed on exploring the scope of Deep Learning in Gravitational Waves detection to potentially support the conventional matched-filtering techniques for their discovery and generating triggers. I developed a Deep Transfer Learning model to detect vanilla Intermediate-Mass Black Hole (IMBH) binaries with astrophysically-motivated SNR distribution. Here, I proved the optimality of PyCBC searches in real LIGO data for nearly symmetric binaries. Next, I developed a deep learning-based algorithm, THAMES, to extract distinctive features owing to characteristic waveform modulations due to higher-order modes content in the spectrograms of asymmetric binaries and attributes of short-duration noisy glitches. I implemented an image segmentation-based algorithm to look for time coincident triggers in two detectors setting and developed a novel detection statistic to rank these coincident events. This THAMES algorithm outperforms the optimized template-based PyCBC search for signals with higher-order modes.

Observations of Minor Planets with GIT

I led the automation of non-sidereal observations data acquisition and operation for the 70 cm fully robotic GROWTH-India Telescope. I also automated the non-sidereal data reduction for GROWTH-India Telescope, where we developed, tested, and validated our robust and modular data reduction pipeline - Astreaks. I have also been involved in the discovery of Near-Earth Asteroids (NEAs) using data from the Zwicky Transient Facility and follow-up of NEAs and outbursting comets using the GROWTH-India Telescope. I co-discovered the then-known closest asteroid fly-by without impact, 2020 QG. I've also studied the episodically active asteroid (6478) Gault, active asteroid 2005 XR132, the first-ever known inter-Venusian asteroid 2020 AV2, and main belt active asteroid 2005 QN173 with GROWTH Collaboration.

Observatories

I have worked on data from five observatories:

  1. GROWTH India Telescope, 0.7 square degrees field of view mounted on the 0.70-m f/6.5 Corrected Dall-Kirkham telescope, Indian Astronomical Observatory

  2. Zwicky Transient Facility, 47 square degrees field of view mounted on the Samuel Oschin 48-inch Schmidt telescope, Palomar Observatory

  3. LIGO Hanford Gravitational Waves Observatory

  4. LIGO Livingston Gravitational Waves Observatory

  5. Virgo Interferometer, European Gravitational Observatory

Gallery

Gault_final.gif

The episodically active asteroid (6478) Gault in GROWTH-India Telescope data, September'2020.

The confirmation images of Near-Earth Object 2020 UA1 by GROWTH India Telescope, October'2020. Encircled point source is the NEO, amongst the moving stellar streaks.

Acknowledgements

I extend my heartiest thanks to my guides Prof. V. Bhalerao and Prof. A. Pai, who gave me the golden opportunity to work on wonderful research projects. I want to thank them for their consistent support and valuable guidance. I would like to take the opportunity to thank my mentor, Dr B. T. Bolin, for his role in making me understand the various astrometry concepts. I also want to thank Dr M. S. P. Kelley for guiding me in the follow-up of cometary outbursts. I want to thank H. Kumar, who helped me understand various principles and different judgment variables for data processing. I would like to thank Koustav Chandra for his role in making me understand the various concepts needed for gravitational wave data processing. I am exceedingly obliged to the Department of Physics, IIT Bombay, for providing such opportunities to undergraduate students so that we can explore a variety of topics and get some experience in research.


My work includes observations obtained with the 0.7 m GIT, which has a 0.7-degree field of view and was set up by IIA and IITB with funding from DST-SERB and IUSSTF. It is located at the Indian Astronomical Observatory, operated by IIA. We acknowledge funding by the IITB alumni batch of 1994, which partially supports operations of the telescope. I thank P. Dorje, U. Stanzin, J. Stanzin, and the IAO technical staff for their assistance in my observations.


This research has made use of data, software, and web tools obtained from the Gravitational Wave Open Science Center (https://www.gw-openscience.org/), a service of LIGO Laboratory, the LIGO Scientific Collaboration, and the Virgo Collaboration. LIGO Laboratory and Advanced LIGO are funded by the United States National Science Foundation (NSF) as well as the Science and Technology Facilities Council (STFC) of the United Kingdom, the Max-Planck-Society (MPS), and the State of Niedersachsen/Germany for support of the construction of Advanced LIGO and construction and operation of the GEO600 detector. Additional support for Advanced LIGO was provided by the Australian Research Council. Virgo is funded, through the European Gravitational Observatory (EGO), by the French Centre National de Recherche Scientifique (CNRS), the Italian Istituto Nazionale di Fisica Nucleare (INFN), and the Dutch Nikhef, with contributions by institutions from Belgium, Germany, Greece, Hungary, Ireland, Japan, Monaco, Poland, Portugal, Spain.


Last but not least, I want to thank my parents, my grandparents, my brother, and my friend for their consistent support :)