Dark matter for the win in state-wide science competition
May 17, 2019
Catharina Hock (14), a student at Lessing High School in Mannheim, has won the physics category of the state-wide science competition "Schüler experimentieren" ("pupils experiment"), which took place May 16-17 in Balingen, Wurttemberg, with a project in collaboration with Haus der Astronomie, with HdA managing scientist Markus Pössel as one of her advisors.
Using the Python programming language, including Astropy, Hock had analyzed the rotation curve and brightness distribution of the galaxy NGC 3198. Starting from the brightness distribution, she had then simulated the rotation curve one would expect if all the mass of NGC 3198 was in the form of stars, atomic or molecular gas. The discrepancy between the simulated and the actual rotation curve points to the existence of non-stellar matter. Modelling that contribution, Hock was able to estimate the amount of Dark Matter present in NGC 3198.
The analysis relied on public data. Atomic hydrogen data was taken from the THINGs survey, which was led by Fabian Walter of the Max Planck Institute for Astronomy. Walter also contributed to Catharina's project with helpful advice. Data about the galaxy's stars was taken from the SINGS survey with NASA's Spitzer space telescope, and about molecular hydrogen (by proxy, using carbon monoxide as a marker) from the HERACLES survey at the IRAM 30 m radio telescope.