Tell me some things about yourself. Where are you from? Why did you choose to study science? What do you like/dislike about working as a scientist?

I was born and raised in New Delhi, India. I completed my B.Sc. (Hons) Physics (2010-13) and M.Sc. Physics (2013- 15) from University of Delhi.
Since a young age I have enjoyed solving mathematics and science problems. However, I particularly became a devotee of physics in high-school (I was 17 years old). While learning the fundamental concepts of electricity and magnetism, and being amazed by the sophistication of theorems, laws and differential equations, I had an epiphany that – nature hosts a wide variety of complex phenomena, and many of these physical processes (both at micro- and macro-scale) can be completely described by simple physical laws and mathematical equations. This is something we take for granted as we become mature scientists, but back then, I was really awestruck by this realisation. My curiosity and interest in physics was also supported by my brilliant school teacher. Before finishing high-school, I was confident to pursue physics as my career.
Being an astronomer is surely one of the best jobs in the world, and also one of the “coolest” (I am sure many of my colleagues will agree!!). To me, astronomy has a tinge of romantic and philosophical aspect to it – the study of the twinkling stars, the analysis of the galaxies billions of light years away, demystifying the expansion of the limitless Universe, unravelling the concept of space and time (the Genesis), the giant telecopes (or the new-age cathedrals) giving access to deep dark night skies – all of this makes this field very interesting and satiating. Another exciting aspect of this job is the freedom to solve new problems. It also gives me a sense of pleasure to be able to contribute to the cutting-edge field of research.
I dont particularly dislike anything about working as a scientist, except one thing that often causes debilitating stress and anxiety in young researchers - the lack of long-term/permanent positions in this field.

What is your field of research and/or what project are you involved in at the OKC?

I work in the field of Milky Way formation and dynamics. Essentially, I use stellar dynamics to understand the formation and dynamics of our Galaxy, and also to examine the nature of the mysterious dark matter. To tackle these problems, I work at the interface of data analysis, simulations and theory. In this regard, I have made significant contributions particularly towards the development of new ideas and techniques to detect and analyse “stellar streams” of the Milky Way. Through these endeavours, I have analysed various datasets, both large-scale (e.g., SDSS, Pan-STARRS1) and spectroscopic (e.g.,LAMOST, APOGEE, SEGUE). In particular among these datasets, I have produced several scientic results based on the prodiguous ESA/Gaia catalogue.

In this image, a linear group of colored points shows stars that move on very similar orbits.
Our home galaxy, the Milky Way, comprises about a hundred billion stars, and all the stars typically move on very different orbits. In this image, a linear group of colored points highlights those stars that move on very similar orbits. These structures are called “stellar streams”, and stars in a given stream originate from the same “star cluster” as they get torn off by the gravitational force of the Milky Way. The color indicates distance from Earth, with “red” denoting very distant systems (~ 100,000 light years), and “blue” denoting relatively nearby systems (~10,000 light years). These streams were detected by analysing observations of the ESA/Gaia satellite using the STREAMFINDER algorithm. These streams are currently helping us to address two fundamental puzzles of astronomy – the formation of the Milky Way and the nature of the mysterious dark matter.


Which of your skills are you most proud of?

I think it was either Sigmund Freud or Carl Jung who once said that [paraphrasing] “if you start to climb the ladder of success with the feeling of pride, watch out for a dog that immediately starts to follow you, as it can bite you. The name of this deadly dog is ego.” Please don’t mind, but I am not very much in the favour of the word “proud”.
As a scientist, I have picked up the skills of self-learning, self-motivation, being persistent and dedicated to a particular problem for a very, very long time. In terms of hard skills, I have the knowledge of astronomical software and tools, and experience in investigating catalogues produced from observations and large-scale cosmological simulations.

What new skills would you like to learn in the next year?

As a researcher, I would like to hone my skill of scientific writing, and also become competent to explore some of the datasets scheduled in the coming 1-3 years (e.g., Gaia DR3+, WEAVE, 4MOST). Also, I am keen to work with more young researchers (graduate and Ph.D. students) and gain experience in supervision. As an academic person, I am also interested to pick up teaching skills.

What advances or new results are you excited about or looking forward to?

I am particularly interested in the long-standing puzzle of how galaxies form in a Universe dominated by dark matter, and also of the nature of dark matter. To address these questions, the community has long focussed on the Milky Way to study it as a reference galaxy. While the current generation of deep photometric surveys (e.g., SDSS, Pan-STARRS1, DES) have helped us to unveil the spatial structure of the Galactic halo, the advent of the Gaia mission has now provided detailed astrometric measurements that are helping us to also deduce the kinematical structure of our Galaxy. This kinematic information, in combination with the spatial information, gives access to the 5D phase-space information of the Milky Way stars. What we are now missing is the information on radial velocities and chemistry of the stars. In this regard, the upcoming spectroscopic surveys (WEAVE, 4MOST) will yield excellent radial velocity and chemical abundance information for millions of halo stars. I look forward to the studies that will unlock the true potential of these surveys by combining their measurements to construct detailed 6D phase-space distribution maps of our Galaxy. This will be very helpful to address fundamental questions of Galaxy formation and dark matter.

What's your favorite food?

I am damn foodie and have a sweet tooth. I have several favourites – chicken tikka masala with naan, lamb biryani, Flammekueche, moussaka, chocolate ice cream, rum cake...

What do you hope to see accomplished scientifically in the next 50 years?

In the next 50 years, I am sure that interstellar travel will become much cheaper, and thus a common endeavour. If so, this will be great accomplishment in itself. This may eventually also provide a much more powerful eye to observe and understand the Universe. Along side, I am also sure that the images of the first human stepping on the planet Mars are not very far. Also, I hope that soon we are able to unravel the existence and the nature of the mysterious dark matter. Also, I completely agree with my colleagues Dr. Pablo Fernández de Salas and Dr. Luca Visinelli who stated in previous interviews that it will be extremely beneficial to the socity if we could soon find working cures for diseases such as cancer and dementia, and clean environment solutions for our energy needs.