Publication of young CATA astronomer highlighted for breakthrough in the study of primordial black holes

This research seeks to determine the incidence of primordial black holes in the formation of dark matter and whether it is feasible for stars to form.

La joven astrónoma Catalina Casanueva, integrante del Centro de Astrofísica y Tecnologías Afines (CATA), llevó a cabo un interesante estudio sobre agujeros negros primordiales y su vinculación con la materia oscura que será publicado en la revista Astronomy & Astrophysics.

She is a PhD candidate in astrophysics and is part of the team of Patricia Tissera, Principal Investigator of the Cosmology and Galaxy Formation area of CATA.

This study makes it possible to explore primordial black holes, whose existence has not yet been confirmed, and their possible influence on the evolution of the universe. These objects are theoretical candidates for dark matter, and their study deepens our understanding of both dark matter and cosmic formation and evolution.

These can only form a very small fraction of the dark matter. If they were a significant part, they would drastically alter the formation of stars and galaxies.

“Primordial black holes are not formed by the death of a star, but originate in the early universe, due to the extremely dense and energetic conditions at that time. During the first moments after the Big Bang, density fluctuations in the universe were so intense that some regions were able to collapse under their own gravity, forming these black holes. They are relevant because they are candidates for dark matter, which constitutes approximately 85% of the matter in the universe, and determining the nature of dark matter is one of the greatest mysteries in astrophysics today,” explains Catalina Casanueva.

Their paper states that they were able to place a constraint on the amount of dark matter that could be composed of primordial black holes of a specific mass and created a model to simulate how the presence of these would affect the gas in the galaxy. Through that determine whether it is feasible for stars to form or not, according to the model used.

They assumed that very massive holes could generate too much energy, heat up too much gas and inhibit star formation. Ahora, al considerar agujeros muy pequeños, 10-12 masas solares, se tenía la idea de que no afectaría tanto, lo que justamente terminó resultando, pero a nivel intermedio no había mayores antecedentes.

Since the candidate they studied was a black hole of 33 solar masses, which coincides with an observation of a Merger of black holes observable through gravitational waves, they wanted to see if it was feasible for galaxies to exist and thus establish the limits.

“There are astronomers who impose limits on the existence of primordial black holes through observations, such as through the gravitational lensing effect. However, we focus on studying the early universe using simulations. These allow us to recreate the extreme conditions of the early universe and study how primordial black holes might have affected gas and galaxy formation at those stages. This type of analysis cannot be done with observational methods because of the enormous distances and times involved. Through simulations, we can explore theoretical scenarios and better understand the potential influence of primordial black holes on the evolution of the universe, providing a more complete view of their impact on the formation and development of cosmic structures,” adds Catalina Casanueva, breaking down the study to be published in Astronomy & Astrophysics.

In conclusion, in developing this model, they tested and determined for different masses of black holes what would be the maximum fraction of dark matter they could compose. Those of 1 solar mass cannot constitute more than 1% of dark matter. Those of 33 and 100 solar masses cannot constitute more than 0.1%.

New steps

They will now implement this model in GADGET and generate simulations to open study options for other researchers. They are also looking at issues related to primordial black holes, such as the background radiation they emit.

Catalina Casanueva also emphasized the importance of participating in the Cosmology and Galaxy Formation team at CATA, together with Patricia Tissera.

“It is very gratifying to work with great researchers, to participate in workshops where we can present and exchange views with other astronomers, which allows us to advance in studies such as this one on primordial black holes,” Catalina concludes.