Fire in the Heart: A Characterization of the High Kinetic Temperatures and Heating Sources in the Nucleus of NGC 253

摘要: The nuclear starburst within the central similar to 15 '' (similar 250 pc; 1 or equal 17 pc) of NGC 253 has been extensively studied as a prototype for phase in galactic evolution. Atacama Large Millimeter/submillimeter Array (ALMA) imaging receiver Bands 6 and 7 used investigate dense gas structure, kinetic temperature, heating processes that drive starburst. A total 29 transitions from molecular species/isotopologues have identified imaged at 1.'' 5-0.'' 4 resolution, allowing identification five previously giant clouds zone (CMZ) 253. Ten formaldehyde (H2CO) molecule derive temperature 0.'' 5-5 structures imaged. On 5 scales we measure T-K greater than 50 K, while on size less 300 K. These measurements further delineate association between potential sources heating. We investigated by comparing our models predict physical conditions associated with possess variety mechanisms. This comparison supplemented tracers recently formed massive stars (Br gamma) shocks ([Fe II]). Derived column densities point radially decreasing abundance molecules sensitivity cosmic-ray mechanical CMZ. are consistent radio spectral index calculations suggest higher concentration cosmic-ray-producing supernova remnants 10 pc