Document Type
Article
Abstract
Hydrogen gas is useful when trying to understand galaxies because it helps make stars. In space, hydrogen gas is in many cases in a form called neutral hydrogen (HI). This gas emits a faint type of light called the 21 cm line, which is a type of radio wave. This light is useful because it can go through dust in space, unlike optical light. This means we can use it to look inside galaxies and study the gas even if there is dust that is in front of stars in the galaxy.
In my research I was given data from a telescope called the Very Large Array (VLA), which produces data cubes containing information about the intensity of emission as a function of position and velocity. The Very Large Array (VLA) uses advanced interferometry and a large collecting area to gather high-sensitivity data more quickly, making observations faster and with better resolution, and it can observe 21cm emission. These clear radio images show where the hydrogen gas is, how it moves, and how much of it there is in a galaxy. This gives us information about how stars are forming and how galaxies change.
In this project, I studied a galaxy called Markarian 54 (MRK54). MRK54 is interesting to study because it is a galaxy merger. When this happens, the gas gets pulled into elongated structures, like tidal tails, and stars can start forming in new places. By looking at where the gas is and how it is moving, we can learn how galaxy collisions change the shape of a galaxy and what happens to the gas during and after the galaxies have merged. I looked at the 21 cm radio waves from the hydrogen gas in MRK54 and I created moment maps to show where the gas is, how it moves, and how turbulent it is. These maps are tools that help us learn more about the hydrogen makeup in the galaxy.
To make these maps, some challenges I faced in analyzing this data included cleaning up the data by removing noisy parts and adjusting errors in the measurements. I also used the galaxy’s redshift (z =0.0449), which is a number that tells us how far away the galaxy is. This redshift was found in a study by Leitet and others in 2013. I used the equations for the moment maps from another study by Walter and others in 2008.
Recommended Citation
Terry, Amaya
(2025)
"Using Moment Maps to Observe Hydrogen Gas in Markarian 54,"
Scholarly Horizons: University of Minnesota, Morris Undergraduate Journal: Vol. 12:
Iss.
2, Article 8.
DOI: https://doi.org/10.61366/2576-2176.1165
Available at:
https://digitalcommons.morris.umn.edu/horizons/vol12/iss2/8
Primo Type
Article