Abstract by Rochelle Steele
Physics and Astronomy
J. Ward Moody
Ramping it up: a new method of finding distances to galaxies
To understand the universe, we need to know how far away galaxies are. But measuring the distances to galaxies is difficult. The most common method to do this uses cosmological redshift. Due to the expansion of the universe, light from distant galaxies is redshifted proportional to distance, making redshift a good indicator for distance. The most accurate way to find redshift is spectroscopy, observing the light split into its component wavelengths (i.e. a spectrum). This method is very accurate but is difficult to use on survey work since it requires a lot of light and can only be done a few objects at a time. Another method, photometry, is much quicker and requires less light. But most other photometric methods, like Beck et al. (2016), have a high standard error of about 6150 km/s. I will present a photometric redshift method that is currently being developed at BYU called the ramp filter method. Using a pair of one-of-a-kind filters, with ramped bandpasses instead of flat ones, we can calculate a redshift from photometric observations with an accuracy of 573 km/s (Lesser et al. 2019). I will continue to verify and improve this method with further observations and research.