Anell Cornejo Cárdenas and Danielle de Brito Silva obtained the scholarship from the National Research and Development Agency (ANID in Spanish), an institution responsible for the management and execution of research programs and instruments in all fields that promote, encourage and develop knowledge, technology and innovate in science based on policies by the Ministry of Science, Technology, Knowledge and Innovation. Learn more about ANID here.
What is your relationship with ERIS?
Anell: At the beginning of this semester I joined ERIS due to an invitation made by Professor Paula Jofré to participate in a trip to Concepción where the Gen Universal project was presented to several girls and boys from this region. Thanks to this trip, I noticed that there is a great interest in astronomy from many students, which motivated me even more to join ERIS in order to boost their desire to learn about this beautiful discipline. So, in this moment my objective and relationship with ERIS is to support and guide these children so that they can learn more about what scientific research is, particularly in the astronomical area.
Danielle: One of the current projects of ERIS is “When galactic history is known”, where we aim to use simulated galaxies to build phylogenetic trees and compare our results with real data. The exciting thing about this project is that when we use simulated galaxies, we have access to the entire history of stellar particles, therefore we can know how accreted stars can be identified in phylogenetic trees, which is very useful when trying to unveil the Galactic halo, since it is a very diverse environment with stars from different progenitor galaxies. I am actively working on this ERIS project, since one of the aims of my research about old stars is to create a phylogenetic tree of ancient stars in order to rebuild the ancient assembly history of the Galaxy.
What is the thesis you are working on about?
Anell: The light that we perceive from galaxies gives us a lot of information about their past and their current state, which allows us to know their history and get clues about their evolution in the future. In astronomy, this light is known as the electromagnetic spectrum and it is essential to study the characteristics of various astronomical bodies, such as galaxies. However, to obtain the spectrum of a galaxy is often not an easy task, because its light could come from very far away, which makes it difficult to observe it with our instruments. This is why it is sometimes useful to simulate, or generate on computers, models of these galaxies and their spectra. My thesis project is based on this, where we seek to generate spectra of galaxies that are similar to what we would obtain if we observed these galaxies through an astronomical instrument. Then having these spectre, we will be able to study some properties of the groups of stars that make up these galaxies, which we can then use to build phylogenetic trees and thus trace back the history of these galaxies.
Danielle: The title of my thesis is “Unveiling the Milky Way before redshift 1 through its stellar population content”. Understanding the assembly history of the Milky Way is of the utmost importance to understanding the formation and evolution of galaxies in general because we can study resolved stellar populations and from this, recover information on how galaxies evolve throughout time. In this scenario, stellar abundances play a central role in galactic archaeology and by studying chemical abundances of stars, we can retrieve information of the star formation history of our galaxy, as well as information on accreted events that happened in the past and contributed to the Galaxy as we know it today. In my Ph.D. thesis, I am studying old stars in terms of their chemical abundances, dynamics and ages in order to unveil the past of the Milky Way and also its accretion history. I am also looking forward to building the first phylogenetic tree of ancient stars using simulations, data from large telescopes and from space missions.
Why did you choose the current institution and supervision?
Anell: I am currently studying at the Pontificia Universidad Católica de Chile and I decided to study at this institution because it offers a pleasant educational and working environment, in which I can interact with people from different cultures and prepares me well for the demands that I could have in the future. In addition, this institution has an excellent teaching team and a very good infrastructure. My current supervisor is Professor Patricia Tissera and I wanted to work with her because I have always been interested in computer simulations of galaxies, since many new and interesting things can be discovered that we are not able to observe using instruments such as telescopes or satellites. Thanks to her I learned about the ERIS project, which motivated me a lot and I wanted to join from the first moment I heard about it.
Danielle: I am Brazilian, from São Paulo and have a Bachelor’s Degree in Physics from University of São Paulo (USP). Working in different research teams and institutions is very important to acquire scientific maturity, therefore I also wanted to have professional experience outside of Brazil in other research groups.
When I was finishing my undergraduate studies, my previous supervisor (Dr. Paula Coelho) received from my current supervisor (Dr. Paula Jofré) information about the new Ph.D. program from Universidad Diego Portales. I thought the Ph.D. program from UDP was very exciting because it was very flexible. Since I like to create new things, I liked the idea of being part of a new Ph.D. program, because I felt I could contribute to its development. Also, Chile has lots of interesting opportunities for astronomers: both in terms of telescopes (which would allow me to gain observational experience and work with excellent data) and also in terms of a big community (which would allow me to create a professional network).
I really love studying the past of the Universe using old stellar populations. As an undergraduate student I worked with extragalactic stellar populations to understand the history of galaxies, but I felt it was time to study our Galaxy: the Milky Way. When we study the Milky Way we have the advantage of studying individual stars. Also, this is a great period to study our Galaxy due to the advent of big surveys. Dr. Paula Jofré is a leader in the field of Galactic Archaeology, therefore I thought it would be good to start my Ph.D. under her supervision. After the first months of my Ph.D. I saw that we worked really well together and I still work under her supervision until this day in very exciting projects.