HNCO ABUNDANCES IN GALAXIES: TRACING THE EVOLUTIONARY STATE OF STARBURSTS

作者：Martin Sergio^*; Martin Pintado J; Mauer**erger R

来源：Astrophysical Journal, 2009, 694(1): 610-617.

DOI：10.1088/0004-637X/694/1/610

• galaxies: abundances
• galaxies: ISM
• galaxies: starburst
• galaxies: Seyfert
• ISM: molecules
• radio lines: galaxies

The chemistry in the central regions of galaxies is expected to be strongly influenced by their nuclear activity. To find the best tracers of nuclear activity is of key importance to understand the processes taking place in the most obscured regions of galactic nuclei. In this work, we present multiline observations of CS, C(34)S, HNCO, and C(18)O in a sample of 11 bright galaxies prototypical for different types of activity. The (32)S/(34)S isotopic ratio is similar to 10, supporting the idea of an isotopical (34)S enrichment due to massive star formation in the nuclear regions of galaxies. Although C(32)S and C(34)S do not seem to be significantly affected by the activity type, the HNCO abundance appears highly contrasted among starbursts (SBs). We observed HNCO abundance variations of nearly 2 orders of magnitude. The HNCO molecule is shown to be a good tracer of the amount of molecular material fueling the SB and therefore can be used as a diagnostics of the evolutionary state of a nuclear SB.

• 出版日期2009-3-20