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Akshatha Gopinath

Hello! I am Akshatha, yet another Homo Sapien hitchhiking my way across the Universe. I am currently trying to do this vicariously from the comfort of my chair - until better technology comes around. Here you can find an overview of my quest so far.

I am a PhD candidate working with Prof. dr. Jason Hessels since Sept 2020. My research focusses on low frequency observations of Fast Radio Bursts, specifically with the LOFAR and NenuFAR telescopes. My general research interests lie in all things producing and receiving radio emission, and I find elusive high energy transients very exciting. I am also keen on contributing to radio observing techniques, especially given my background in signal processing and electronics engineering.

Education

Ph.D in Astronomy (focussing on Fast Radio Bursts)

Advisor : Prof. dr. Jason W. T. Hessels

Anton Pannekoek Institute for Astronomy, University of Amsterdam, Netherlands

M.Sc. in Astronomy (Astronomy and Research track)

Leiden University, Leiden, Netherlands

B.Eng. in Electrical and Electronics

BMS College of Engineering, Bangalore, India

Pre-University

SBM Jain College, Bangalore, India

Physics, Chemistry, Mathematics and Electronics track.

Research Projects

Reconstructing the synchrotron cosmic web

M.Sc. Final thesis
Advisor : Dr. Reinout van Weeren and Martijn Oei, Leiden University

I worked on this project as a part of a larger search for the magnetized signal in radio due to accretion shocks in the warm-hot intergalactic medium. Observing these low frequency emissions from the synchrotron cosmic web could give us a peek into the structure and origin of magnetic fields in the filaments of the cosmic web. I developed a prediction method to construct the synchrotron cosmic web, using Enzo magnetohydrodynamic (MHD) simulations. Using observables such as galaxy luminosities in the SDSS catalogue to trace the web, we want to predict the properties of filaments magnetic field strength, temperature, gas density - from which we can infer the radio emissivity of these filaments. Such a ‘mapping’ function was developed and tested using the simulations. The goal is to apply this prediction to search for filaments of the web in the Lockman Hole field from where we have a very deep LOFAR image. Using galaxies as tracers of this web, I predicted the expected synchrotron emission from the respective filamentary regions in the simulation box.

Matching kernel method for comparing transition disk datasets

Advisors : Prof. Christoph Keller, Dr. Jos de Boer, Dr. Christian Ginsky. Leiden University

The project involved analysis how data of the same object, recorded with different instruments, observing modes or in different wavelengths can be combined while taking the variations of theinstrumental response function into account. A matching kernel to convert one PSF response to another was found, and different conditions under which this matching kernel is efficient and otherwise were explored. The method was applied to the transition disk around RXJ1615.3-3255, while using Reference Differential Imaging.

The matching kernel method does very well in converting one Point Spread Function to another, under different conditions of noise, widths, and shapes of the PSFs. While the division method of deconvolution fails for the case of zero noise level in the narrower PSF, Wiener deconvolution is able to handle this case better. This is now applied while performing RDI on the IFS images of RXJ1615, and is seen to aid in reducing the over-subtraction and under-subtraction in the RDI images. However, it results in the disk around RXJ1615 not being visible in the RDI images. It is found that the reduction in disk signal is affected less by the core of the kernel, while being significantly affected by the halo component of the kernel.

(Backyard) Radio telescope using a Television Dish Antenna

– Jul ’16 - Sep ’16: Built a radio telescope in my backyard using a 60 cm diameter television dish antenna, satellite finder, Arduino microcontroller and RadioSkyPipe software to monitor the Sun. Plotted Sun's drift scan and calculated its brightness temperature at 11.2 GHz using Rayleigh Jeans approximation.

– Dec ’17 - Jan ’18: Advisor - Prof. R. Ramesh, Indian Institute of Astrophysics
I subsequently recorded the sun, moon and galactic background drift scans with better pointing accuracy. I also tried interferometry with two such dishes; and I developed and tested the analog and digital back end receivers for the same, and obtained solar interferometric fringes.

Other Interests

Apart from astronomy, I enjoy teaching science and conducting outreach activities for school students and the general public. I also perform the Indian classical dance form - Bharatanatyam, and enjoy sketching, painting, hiking and burying myself in books.