Exploring The Time The Universe Lit Up… With A Space Telescope!

Colombian astronomer Sofía Rojas Ruiz will be using the James Webb Space Telescope (JWST) to study the first-born bright galaxies and quasars that contributed to the process of illuminating the universe from complete darkness about 13 billion years ago.

Rojas, who is a IMPRS Fellow at the Max Planck Institute for Astronomy in Heidelberg, Germany, says these galaxies, from the Epoch of Reionization, are the fore-runners of our Milky Way but were able to grow a powerful bubble around them, breaking the clouds of neutral hydrogen that were submerging the universe into darkness.

“You can think of the universe as a sponge made out of neutral hydrogen that is growing and evolving… with time, the stars conglomerate into galaxies that start growing powerful enough to make bubbles that eventually will break, allowing us to see light from neighboring galaxies, just as we can now see Andromeda in a clear night,” she says.

Rojas says that as an undergraduate student, she led a project finding some of these bright galaxies by analyzing images from the Hubble Space Telescope (HST).

“The HST findings point to a set of galaxy candidates, however, we cannot learn more about their star composition and ability to make ionizing bubbles in the Epoch of Reionization,” she says, “Fortunately, the JWST offers the perfect and only opportunity to obtain spectra from these galaxies emitting light from special elements that can help us confirm the nature of the galaxy and characterize their ionizing power in a record time.”

Rojas will be leading this project with collaborator Dr. Micaela Bagley, obtaining about 19 hours of JWST spectra of 11 galaxies preselected from HST imaging.

“JWST is going to revolutionize my field of study, and I am over the moon to be able to contribute results to the community from the very beginning,” she says.

From “Cosmos” To The Cosmos

Rojas grew up in Bogota, Colombia and began to love astronomy at a very early age, watching Carl Sagan’s Cosmos series and stargazing with her telescope on the rare occasion of clear skies in the Colombian capital city.

“It was not until 9th grade when I met Dr. Adriana Ocampo, a Colombian-American geologist working at NASA, that I realized my dreams of becoming an astronomer could come true,” she says, “I had a very short but impactful conversation with Dr. Ocampo where she motivated me to follow my dreams of working at NASA and the many career paths I could take, not only through astronomy but also nanotechnology, engineering and even geology… she really opened my eyes to more possibilities.”

Rojas would go on to do her undergraduate studies at the University of Texas at Austin, surviving economically via scholarships and her job doing research with Dr. Steven Finkelstein and the Hubble project, looking for some of the first galaxies born in the universe. She is now based in Germany for her PhD.

“I have been able to contribute to the Colombian community with the many projects we offer at The Network of Colombian Astronomy Students (RECA for its initials in Spanish),” she says adding that they were able to create the first internship program in the country where undergrads had the experience of leading astronomy research projects with national and international supervisors.

“RECA wants to expand its horizons to more Global South communities and we are wanting to work closer with Alpha-Cen, a similar initiative for astronomy development in Central America and the Caribbean,” Rojas says, “My heart is still very close to Colombia and I will continue to support new generations of scientists.”

Another Colombian astronomer María Claudia Ramírez-Tannus will be part of a team using the JWST to unlock the mysteries of protoplanetary disks: disks of dust and gas where planets are going to form.

Ramírez-Tannus explains that stars and their protoplanetary disks form in much denser regions and in the presence of strong radiation and thanks to the JWST astronomers will, for the first time be able to observe these extreme regions to observe the effect of massive stars on protoplanetary disks, and therefore in the formation of other planetary systems.