Methanol At The Edge Of The Galaxy: New Observations To Constrain The Galactic Habitable Zone

Abstract

Searches have been conducted for various J=2-1 transitions of methanol at 3 mm in a sample of molecular clouds located 13-23.5 kpc from the Galactic Center, using the 12m telescope of the Arizona Radio Observatory (ARO). The sources are in the Cygnus arms, and typically are cold with T$_{K}$ approximately 20 K. Multiple transitions of this organic molecule were detected in 19 clouds, including ones at distances of approximately 23.5 kpc. Typical abundances found for methanol are 1x10$^{9}$. The results suggest that the Galactic Habitable Zone (GHZ) may exist much further from the Galactic Center than previously thought.