Research

My first observing experience in La Palma when the Cumbre Vieja volcano was erupting. Three months later, I carried out more observations, and that went smoothly.

The fascinating field of galactic archaeology is what keeps me awake. In this field, we explore the history, formation, and evolution of our very own galaxy, the Milky Way, and its neighbours such as the Large and Small Magellanic Clouds and a few more galaxies in the Nearby Universe.

It is like being a cosmic detective, examining the ancient remnants of stars to reconstruct the story of our galactic origins.

The stars I am interested in are metal-poor stars, often referred to as living fossils of our galaxy. These stars are relics from the early universe, formed when the Milky Way was still in its infancy. They also take us into the realms of the smallest, tiniest, and earliest galaxies that merged with our own. These ancient galactic entities, long since absorbed by the Milky Way, hold precious clues about the intricate dance of cosmic collisions over billions of years. By studying them, we can piece together the puzzle of how the Milky Way came into existence.

Unlike distant galaxies that are beyond our reach, studying our own cosmic backyard allows us to directly observe and analyze the remnants of the individual stars in these tiny galaxies that became part of our galactic family, complementing high-redshift analysis. It provides a level of spatial resolution on a star-by-star basis and encompasses a mass range that is currently beyond the reach of direct high-redshift investigations. For this, we need chemical composition, kinematics, and distribution of these ancient galactic interlopers.

To unravel the kinematics of ancient stars, I harness the capabilities of the Gaia satellite, which provides precise measurements of stellar positions, distances, and motions for about 2 billion stars. To efficiently identify these intriguing stars amidst the vast stellar population, I use the Pristine survey, streamlining a remarkable photometric shortcut. I also use other public spectroscopic surveys and catalogues. I supplement my analysis with my own spectroscopic follow-up at observatories in La Palma, analyzing the chemical composition and abundance patterns of these stars. This gives us a glimpse of the conditions in which these stars were born 10-13 billion years ago.

Understanding the evolution of our galaxy has profound implications for our broader understanding of the universe. We piece together the narrative of how small galaxies merged and merged again in fast and secular processes, eventually helping us refine our understanding of the universe. Some of the elements we see in these stars are what life on Earth is made of: we are made of star stuff.