Extended warm CO gas in three nearby galaxies
نویسندگان
چکیده
We report the detection of distributed CO(3–2) line emission in nearby normal galaxies. The CO gas is a well-known tracer of physical conditions in the emitting regions. The line transitions from higher energy levels (the J=3 level is 33 K above ground) are indicators of the presence of warm and dense gas. Until now this warm gas has been studied only in the nuclei of starburst galaxies. Using the Heinrich Hertz Telescope on Mt. Graham we were able to detect extended CO(3–2) line emission in more than ten normal galaxies. In this paper we present the results for the three galaxies M51, NGC 278 and NGC 4631. In particular, we compare our results with observations of the lower CO line transitions made with radio telescopes of similar angular resolution.
منابع مشابه
Warm molecular gas in nearby galaxies . Mapping of the CO ( 3 – 2 ) emission
Using the Heinrich-Hertz-Telescope on Mt. Graham, Arizona, we have observed several nearby galaxies in the CO(3–2) line. The CO(3–2) emission traces – in contrast to lower rotational transitions – a warmer and denser component of the molecular gas. We find that this emission is spatially extended in the target galaxies. The excitation conditions seem to vary with the location of the gas within ...
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