Module 6 – Doppler Mapping

Matthew Toman, Abe Javier Rodriguez

We have graphed two galaxies, Andromeda M31 and the Cigar galaxy M82, respectively by their velocities, signal average, and quick look spectrum.

Andromeda:

M82:

We first put observations in for Andromeda in the radio by mapping it rather than using the on/off type map for M82, since it was big enough. We then split it up both into three colors on afterglow by luminosity. Once we had a distinct shape and each part was colored we took the angular size of Andromeda. We simply used an optical image of M82 to find its angular size. For both we imported their respective spectral txt files to excel. We then just did the small angle formula for each galaxy then calculated their velocities and mass in that order. We took the data from the first sheet of the Andromeda spreadsheet and used it for M82. We found that the M82 was 32 billion solar masses and that Andromeda has a mass of 141 billion solar masses.

Our M82 measurement is closer to the real estimated mass with an error of less than 40% but our Andromeda measurement was way off.