"The wind being blown out of NGC 253 by the central starburst is thought to be approximately conical in structure with a temperature-stratified nature. The centre is filled with fast-moving and hot (a temperature of about 106 K) X-ray-emitting gas, and is surrounded by layers of cooler (10,000 K) Hα-emitting gas and cold (100 K) molecular CO-emitting gas. Bolatto and colleagues’ results clearly show this cold CO layer at the edges of the warmer phases. The hot phase is also thought to contain clouds of cold material swept up by the wind.” Via.

"The wind being blown out of NGC 253 by the central starburst is thought to be approximately conical in structure with a temperature-stratified nature. The centre is filled with fast-moving and hot (a temperature of about 106 K) X-ray-emitting gas, and is surrounded by layers of cooler (10,000 K) Hα-emitting gas and cold (100 K) molecular CO-emitting gas. Bolatto and colleagues’ results clearly show this cold CO layer at the edges of the warmer phases. The hot phase is also thought to contain clouds of cold material swept up by the wind.” Via.