\section{DATA}

This study is done using new-millimetre-wave observations from the Atacama Large Millimeter/submillimeter Array (ALMA) interferometer in Chile. Although similar research has been done on other galaxies, ALMA provides a particularly well resolved data set, allowing us to resolve the centre and width of spectral lines, and thus measure the clouds' radial velocities and magnitudes of internal motions.

Although molecular gas is comprised mainly of molecular hydrogen ($H_2$), at GMCs' typically low temperatures of 10K, $H_2$ does not emit radiation. Instead, we obtained our spectral data from the next most abundant gas: carbon monoxide molecules's J=1-0 emission. 

The ALMA observations provided us with data cubes that form a map of the galaxy where each position is associated with a frequency spectrum. Using the Doppler shift and distance to the galaxy, we transformed the data cubes into position-position-velocity (PPV) cubes, which we then used to identify molecular clouds and their properties. Fig. \ref{xypos} displays the maximum temperature map of M100 in sky coordinates, where each point is the brightest value in the spectrum at that position in the data cube. The bright carbon monoxide (CO) regions make the nucleus and spiral arms clearly visible and allow us to identify the GMAs.