2000/10/25 by Shuro Takano, Naomasa Nakai, Kentarou Kawaguchi +1 · 21 citations
Physics and Astronomy · #Abundance (ecology) #Ammonia #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Cosmochemistry #Galaxies: Formation, Evolution, Phenomena #Galaxy #Order (exchange) #Spiral galaxy #astro-ph
paper · pdf · doi:10.1093/pasj/52.6.l67
published in Publications of the Astronomical Society of Japan 52(6), L67-L71 (Oxford University Press) · 6 pages, 2 fugures
arxiv created 2000/10/25 · openalex publication_date 2000/12/01 · arxiv updated 2015/06/24 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Abstract The ammonia (J,K) = (1,1), (2,2), (3,3), and (4,4) transitions in the 23.7−24.1 GHz region were searched in a nearby galaxy, Maffei 2, to study the relation between the molecular abundances and the physical conditions in galaxies. The (1,1), (2,2), and (3,3) emission lines were clearly detected. The obtained rotational temperatures and ortho-to-para abundance ratios are about 30 K and about 2.6, respectively. The abundance of NH3 relative to H2 in Maffei 2 was found to be the largest among galaxies where NH3 has already been detected, and the abundance in Maffei 2 is more than an order of magnitude larger than the already reported upper limit in M 82. Hence, we further confirmed the systematically peculiar molecular abundance regarding the formation mechanisms of molecules already reported in M 82.