February is Black History Month in the United States. For this month and beyond, we wish to continue highlighting the important work and achievements of Black astronomers, physicists, educators, and scientists through our #BlackInAstro series. This is an ongoing, year-round series in collaboration with blackinastro.com (@BlackInAstro on Twitter). For our cornerstone post, see here.
Christian Aganze is a physics PhD student at the University of California, San Diego. He studies brown dwarfs with the intent to better understand the structure of the Milky Way galaxy. His path to academia starts all the way back in Rwanda, where he grew up until he moved to the United States to study in Morehouse College (a historically black college in Atlanta, Georgia) as an undergraduate.
When growing up, Christian was interested in the sciences but his interest and subsequent career in astronomy did not start “from watching the stars at night or being an amateur observer”. In fact, when he first started his undergraduate studies in Morehouse College, his initial major was computer science, and he was also interested in math. It wasn’t until his sophomore year of college, after gaining research experience in a materials science lab at Morehouse (with Prof. T. Searles), that he got into an REU in astronomy. He first became interested in brown dwarfs when his current advisor, Prof. Adam Burgasser, went to Morehouse College to give a talk on his research: “I thought his research was very interesting, so I asked him if I could join his lab.”
A good and long journey
After this REU experience, Christian had already gained interest in astronomy research and published his first paper. Prof. Burgasser had been awarded a UC-HBCU grant (a University of California grant for students of historically black colleges) to have a student join his group, so Christian joined his lab and continued his research on brown dwarfs into graduate school.
Christian’s thesis research is on using the information we know about brown dwarfs, which are cool objects that have masses between that of heavy planets and of stars, to better understand how our galaxy formed and evolved over time. “Most of this work has been done with bright stars, but not with brown dwarfs, because they are very difficult to observe due to being intrinsically faint”. He uses Hubble Space Telescope’s WISPS (WFC3 Infrared Spectroscopic Parallel Survey) and 3D-HST to find distant brown dwarfs in the galaxy. – “we are basically trying to construct a spatial, kinematic and chemical map of the galaxy with brown dwarfs ”. Since brown dwarfs have long lifetimes (>1 trillion years), those that formed when the Galaxy was young are still around, because they are fully convective and not fusing Hydrogen, they preserved the initial abundance they had when they were first formed (unlike stars). Christian is hopeful that with JWST’s launch (and its future survey PASSAGES: Parallel Application of Slitless Spectroscopy to Analyze Galaxy Evolution, led by UCLA professor Matthew Malkan) and the upcoming Nancy Grace Roman Telescope, more surveys sensitive to the detection of brown dwarfs will become available to create an even larger historical composition map of the Milky Way galaxy: “with JWST(hundreds) and Roman (millions!), we will be able to look at brown dwarfs in the halo of our galaxy. I am running simulations to see how far we will be able to see these objects, and predict their observable properties (colors, kinematics etc.).”
Recently, Christian has also become interested in galactic dynamics and stellar streams. He has gained interest in this subject because stellar streams track the potential of the Milky Way and could also get disrupted by interactions with dark matter subhalos. This current work, which is not his primary thesis project, is in collaboration with Dr. Sarah Pearson at NYU: “The interaction creates gaps in the streams, which we can actually see. So I am running simulations to check whether we can actually see these gaps with the Nancy Grace Roman Telescope telescope as well. This would help us better understand the structure of dark matter.”
While in Rwanda and at Morehouse College, two places where the majority of the population is Black, Christian stated that “most of the people looked like me. Most of my experience with other people from other races happened in graduate school.” He recognizes having some hiccups due to general systemic biases throughout his career because of being Black, but no specific events that he could cite at the moment of the interview. According to Christian, it has been a good and long journey to pursue a graduate degree in astronomy at a different place, and he has had good mentors and Black scientists he looks up to: “they are probably where I get my inspiration from.”
A source of pride in Christian’s life is his perseverance. “I know this is not something tangible, but doing things and not giving up on my goals is something that I have done and I am proud of. A big part of grad school is feeling like you’re not good enough.” Indeed, graduate school is a place where oftentimes students face impostor syndrome and fear of failure, so perseverance, along with having good mentors, are key to achieving success.
Engaging with peers
Looking back at his undergraduate years, Christian wishes he had found a set of peers and created a network of young Black people in astronomy earlier in his career. He also would tell his younger self to find mentors from a similar background who have had successful careers in astronomy. Inspired by this advice he wished he had taken earlier, Christian is engaged in organizations and societies for Black physicists and astronomers, such as the National Society of Black Physicists. He would advise “finding these groups of people and keeping in touch with them, and helping each other out with applications, research opportunities or even just homework”. Christian firmly believes these societies can really help a young scientist thrive and communicate their way through academia.
To learn more about Christian Aganze, check out his Twitter!
Astrobite edited by Catherine Manea
Featured image credit: Astrobites collaboration