Interview with Mr. Sushilkumar, University of Texas, San Antonio

Interview with Mr. Sushilkumar
University Of Texas, San Antonio

"Resolution of current sheets are essential to understand non-ideal effects in pulsar magnetosphere"

"In my opinion astronomy courses must be introduced during bachelor degree"

Our team member, Aditya Togi, had an opportunity to meet Mr. Sushilkumar to know his current research focus and kind of solutions being  considered.  Mr. Sushilkumar is pursuing his PhD at university of Texas, San Antonio. He is currently working on to understand the dynamics of a pulsar in magnetosphere. His work has a potential application to understand the structure of the neutron star which has been a kind of mystery for a long time.

Commonly accepted geometry of a pulsar as an inclined rotator
Image credit: Imagine the Universe at NASA/GSFC

We sincerely thank Mr. Sushilkumar for accepting our request for this interview and sparing sometime for the same.



Q1. Please describe your background giving the following details

  • Name Sushilkumar Sreekumar
  • School name and place St. Francis High School, Borivali West Mumbai
  • Graduated college/place Mumbai University, Kalina campus
  • Your expertise Computational Astrophysics
  • Your hobbies/interest Swimming, biking

Q2.  Please describe your current occupation and doctoral research area giving the following details

  • Adviser name Dr. Eric Schlegel
  • Research group Astronomy
  • Institute where you are pursuing the research University of Texas, San Antonio

Q3.  Please describe your research problem

The main goal of our project titled “Time evolution of pulsar magnetosphere- An implicit approach” is to understand the field dynamics of a pulsar in a region called the magnetosphere, which is a source of high energy emission from these extreme source. This is done by developing a time evolution simulation code under the pretext of finite difference time domain.

Gamma radiation(violet) far above the surface of the compact remains of the star, for example, while radio waves(green) are emitted over the magnetic pole in the form of a cone. The rotation  moves the emission regions across the terrestrail line of sight, making the pulsar light up periodically in the sky.
Image credit: NASA/Fermi/Cruz de Wile

Q4.  Any unique approach taken or unique selling point of your solution?

Above mentioned time evolution code is done by using implicit finite difference time domain approach which has the benefit of better resolution. Better resolution will imply better understanding of the current distribution in pulsar magnetosphere which currently is not well known. As a result the source for the spin down or energy loss can be identified, which is the primary motivation for a pulsar magnetosphere research.

Composite x-ray(blue) and optical(red) image of crab nebula in constellation taurus. Crab pulsar(seen distinctly at the center) is called the space laboratory among astrophysicist.
Image credit: X-ray: NASA/CXC/ASU/J.Hester et al; Optical:NASA/HST/ASU/J.Hester et al

Q5. How good is your solution (or going to be if not proven yet) compared to others?

Previous researchers in pulsar magnetosphere had used explicit form of finite difference but has the limitation on grid and temporal resolution and as a result current sheets are unresolved in these simulations. Resolution of current sheets are essential to understand non-ideal effects in pulsar magnetosphere and as a result our code is better in understanding the non-ideal effects like current sheets, reconnection effects.

Q6. Please describe the possible applications of your research to space domain.

Understanding pulsars which are termed as the most exotic astrophysical source in the universe is critical as it would help us better our understanding of the stellar evolution and draw a distinction with black hole. Understanding the energy loss in a pulsar is also a long standing problem as energy loss is dominated by non-thermal gamma-ray emission. Recent studies have shown that these high energy emission is coming from magnetosphere and hence understanding these dynamic structure is critical. We believe that our code can capture non-ideal effects which will help to understand these energy losses and magnetosphere structure which eventually will help us understand the structure of the neutron star which has elucidated astrophysicist for the past 80 years.

Colorful map above shows an LAT eye view of pulsars at gamma-ray energies. Brighter color indicate brighter gamma-ray sources.
Image credit: NASA


Q7. What do you think about the quality of research happening in India related to astronomy field and what changes are required to promote better research here?

The fact that astronomy courses in India (especially in Mumbai University) are taught only during Master’s degree speaks volume. In my opinion astronomy courses must be introduced during bachelor degree. Bachelor degree is foundation ground on which your master degree and research life can be built and I think many students (me including) fail to understand this. Introducing astronomy from undergraduate degree will give an opportunity for students to understand the nuances of the field and appreciate the fact astronomy is one of the best science to understand nature. Astronomy experiments during undergraduate can be a good stepping stone for students to see one of the oldest science in action.

Lab experiments during Master’s degree must be replaced by project work where students get to work with researchers. This hands on experience can do wonders to confidence and motivation. And I think this is legitimate as number of students for astronomy is less. Understanding computer coding, data analysis and instrumentation is very critical to succeed in astronomy and master’s degree is perfect scenario for the same. Having a mentor will help the student to learn more and become more curious than cautious. In addition, such attempt will not only make the course interesting but only inflict the interest of doing independent research and make them better thinkers. Conversational interaction with their mentor will enable them to resolve all their inhibition about course and future prospects.

Q8. What is the right method to encourage the students to get motivated towards basic science and astronomy in India? What is your personal experience? What are the missing links in India for the students to get involved in the above area?

 In my opinion there is no “right method” to encourage the students. Each student is different and hence their motivational factor will be different. However attempts can be made to encourage them towards basic science and astronomy. Motivation that astronomy being a natural science will help to understand our nature and the very source of our existence. Attempt is to infuse astronomy courses in high school or bachelor degree can be helpful. One of the key ingredient in doing basic science research is mentorship. Collaboration with institutions, universities and attending conferences can play a key role to motivate students and make them realize that there is nothing like basic science. Patience is the key to succeed in astronomy and students must be made aware of it. Sometimes it is long laborious work for/with little outcome.

A proper mentor-ship during my bachelor and master degree would have helped me to pursue my lifelong dream of doing research with more vigor and zeal.


Aditay Togi (PhD)

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