Mexican astrophysicist studies sidereal relics to understand the universe

Madrid. At 31 years old, José Eduardo Méndez-Delgado is one of the most dazzling astrophysicists in the international scientific community. His family origin, within a humble family – his father, a worker, and his mother, a housewife – from Morelia, Michoacán, did not prevent him from dedicating himself to researching nebulae, stars, and the harmonious movement of the universe. And thanks largely to the public education system and its alma mater fundamental, the National Autonomous University of Mexico (UNAM).

For his research, this young Mexican astrophysicist was recognized with the Princess of Girona International Research Award, one of the most prestigious awards for young talents under 35 years of age. After studying a master’s degree and a doctorate in La Laguna, in the Canary Islands, where one of the most powerful telescopes in the world is installed, and doing research for the German University of Heildelberg, Méndez-Delgado decided to return to the UNAM, in whose Institute of Astronomy he works.

Chemical composition of the universe

In interview with The Daythe Mexican scientist explained some of the most important findings of his research, which delve into the origin of life through the chemical composition of stars.

–What does this award mean for your career?

–It is an honor to receive it, but above all it is an impulse because it motivates me a lot to know the importance that basic science has in society. That is to say, people are interested and are not oblivious to what we do.

–What does your research on the chemical properties of the galaxy consist of?

–We are seeking to understand the chemical composition of the universe in order to understand its formation and evolution. One of the most important questions that we have asked ourselves is what the past of the universe and its evolution has been like and for this we use chemistry for the simple reason that during the big bang only the lightest elements were formed; hydrogen, nitrogen and a little bit of lithium. All other elements were formed later through the life and death of stars.

“So, when we measure an amount of oxygen or nitrogen in a galactic environment we know that there was at least one generation of stars that was born and died there. Through this understanding of the chemical composition we reconstruct the past. And to understand that past we must do well those reconstructions of the evolution and of the galaxies from their chemical fingerprint. Based on that we published an article on the discrepancy of abundances in the journal Naturein which we show observational evidence that could explain a more than 80-year-old enigma that essentially consists of two measurements of the abundance of heavy materials that should coincide do not coincide. And that this is problematic because it raises questions about how part of the universe evolved and we want to know which one is correct.”

–What information have these chemical properties of the galaxy given you so far to understand the history of the universe?

–When one studies oxygen, one knows how many very massive stars have been born and died in that place in the universe because this element is produced precisely after the death of this type of celestial bodies. While other elements, such as nitrogen, have different production mechanisms, one of them in the lower mass stars that live longer. So, when we measure the ratio of the abundance of nitrogen over oxygen we know the generation ratio of low mass stars over higher mass stars that have lived and died in a specific place in the universe.

“In summary, chemical abundance is directly related to the formation of stars, which is essentially what galaxies are doing for most of their lives; stars are born, then they die, they project their interstellar chemical composition and from that gas a new generation is born again with a new chemical composition that after its death returns to contaminate the interstellar medium with more chemical elements. These chemical abundances are like archaeological relics that are connected and allow us to understand what the past was like.”

–In the vastness of the universe and with so many galaxies, is there concrete research on our Milky Way?

–Yes, in fact one of the most important projects in which I participate is the study of our Milky Way, which we are doing through a consortium of researchers from the most important universities. And that we are attacking through a telescope that gives us three-dimensional information about the Milky Way and that gives us information about the different components and their development on a larger scale to obtain data and scientific results that allow us to solve some of the enigmas that are present in science. We have found very interesting things, such as that the abundance of heavy elements in the center of our galaxy is much greater than that in its peripheral areas. This tells us that the formation of our own Milky Way Galaxy was from the inside out.

–Based on that, have you managed to understand the movement of the universe, its apparent harmony?

–Yes, because the galaxy is rotating and with it all the components that are there: gas, stars, etc. In fact, one of the objectives we have is to refine this kinematic map to understand the interaction that exists in our own galaxy with the dark matter that surrounds it. And we have seen that everything is harmoniously linked with the laws of physics, but also that there are phenomena that we still do not understand.

–And in metaphysical terms, how far can we hope to go to know the history of the universe, of our own origin?

–Of course all this has important philosophical meanings. After all, the calcium in our bones, the oxygen we breathe or the carbon in our body were chemical elements that were formed at some point in the death or life of one of the stars that existed in our galaxy. We are tracing the origin of our own origin because there is no barrier that separates the universe from us as humanity. Understanding chemistry in its different contexts allows us to understand many phenomena, including the search for life.

–What importance has UNAM and the Mexican public education system had in your scientific career?

–I trained in public schools and it is at UNAM where I found the passion for astronomy, when I discovered that I could study nebulae, which are beautiful objects, with their colors, their different gas components and their dust clouds. And from there I received magnificent training in astronomy, in particular from Dr. Manuel Peimbert, who taught me much of what he knows about the universe. And after researching and working in Spain and Germany, I decided to return to Mexico because of a commitment that I believe Mexicans should have with the society that formed us and try to ensure that our learning and knowledge have an impact on society.