Colombian astrophysicist Luz Angela Garcia’s journey in astronomy started out with encyclopedias and a telescope as a child, now she is a researcher looking into a range of mysteries including what the young universe was like and why the expansion of the universe is speeding up.
Garcia, currently a researcher at Universidad ECCI in Bogota, Colombia, says one of her main projects is the study of the Epoch of Reionization.
“This is the era when the free hydrogen of the intergalactic medium became ionized due to the intensive radiation released by the first stars and galaxies that formed in the Universe,” she says.
Garcia says this is a complex process, and physicists don’t have many direct observations of this slice of time.
“So I use numerical simulations that mimic the processes that occurred when the Universe was very young,” Garcia says, “This project started with my PhD work and now I’m using very high-resolution numerical simulations to explore the conclusion of Reionization.”
Garcia is also involved in a project seeking some hints on the nature of dark energy and the unsolved mystery as to why the universe’s expansion is speeding up, not slowing down.
“We have observational evidence that indicates that the Universe is subject to an accelerated expansion today, but astronomers don’t know why,” she says, “The standard model postulates the existence of the cosmological constant as the cause of such rapid expansion, though it is not the only explanation.”
Garcia says that along with researchers from Colombia’s Observatorio Astronómico Nacional, she and her team are proposing alternative models for this dark energy component, and constrain such models with the most “exquisite” set of cosmological observations to date.
“We do so through the implementation of numerical codes that allow us to quantify how likely a model is according to the observations,” she says.
Garcia is also involved in the Dark Energy Spectroscopic Instrument (DESI) collaboration, which will obtain optical signals from tens of millions of galaxies and quasars, constructing a 3D map of objects up to 11 billion light years away.
“My contribution focuses on spotting and managing particular features of the synthetic spectra of quasars, the most brilliant objects in the Universe,” she says.
Garcia says the main challenge for most of these projects is having access to the computing facilities, due to their costs and the lack of infrastructure in developing countries, adding that scientists from the Global South learn to be very resourceful in order to get the resources to get the results they need.
“The silver lining is that the community is today much more open in terms of data availability and exchange, public source code, and sharing their cosmological simulations and the pipelines if one presents an idea that it’s worth exploring,” Garcia says, “I think this is a unique opportunity for researchers in developing countries to show how their expertise is very relevant to overcome different problems and to listen to the lessons they have learned during their research path.”
From Little Telescope To Big Physics
Garcia grew up in Bogota, Colombia and according to her parents, since an early age she was interested in mathematics and science.
“I started exploring astronomy through encyclopedias, a little telescope I was given at age 8, and small experiments I designed for my younger brothers,” she says, “Since then, I was always interested in science, but the area that really caught my attention was physics.”
Garcia says that for her, there was not a specific “eureka moment,” it was more that astronomy grew on her over time.
“I had the support of my family and teachers, so, at the point that I had to choose my undergraduate studies I was more than sure that I wanted to do astronomy, and the natural path was through physics,” she says, “I was enchanted by the fact that one can capture the essence of a phenomenon and understand at some level how the Universe works through models,” she says.
She now has a bachelor’s degree in physics and a master’s in Astronomy from Colombia’s National University. She also did her doctoral studies from Swinburne University of Technology, in Melbourne, Australia.
Another Colombian researcher looking to the stars is Lauren Flor-Torres who is using robotic telescopes to study distant stars with planets detected around them.
Flor-Torres is also helping women and girls, see a path for themselves in STEM in general and astronomy in particular.