Dense gas in the Galactic central molecular zone is warm and heated by turbulence

Understand

The Galactic center is the closest region in which we can study star formation under extreme physical conditions like those in high-redshift galaxies.

• We measure the temperature of the dense gas in the central molecular zone (CMZ) and examine what drives it.
• We mapped the inner 300 pc of the CMZ in the temperature-sensitive J = 3-2 para-formaldehyde (p-H$_2$CO) transitions.
• We used the $3_{2,1} - 2_{2,0} / 3_{0,3} - 2_{0,2}$ line ratio to determine the gas temperature in $n \sim 10^4 - 10^5 $cm$^{-3}$ gas.