Molecules as tracers of galaxy evolution: an EMIR survey. I. Presentation of the data and first results

Details Molecules as tracers of galaxy evolution: an EMIR survey. I. Presentation of the data and first results Molecules as tracers of galaxy evolution: an EMIR survey. I. Presentation of the data and first results

2011-01-11

arxiv.org/abs/1101.2122v1

Astronomy and Astrophysics

Astrophysics

Cosmology and Extragalactic Astrophysics

Scientific paper

We investigate the molecular gas properties of a sample of 23 galaxies in order to find and test chemical signatures of galaxy evolution and to compare them to IR evolutionary tracers. Observation at 3 mm wavelengths were obtained with the EMIR broadband receiver, mounted on the IRAM 30 m telescope on Pico Veleta, Spain. We compare the emission of the main molecular species with existing models of chemical evolution by means of line intensity ratios diagrams and principal component analysis. We detect molecular emission in 19 galaxies in two 8 GHz-wide bands centred at 88 and 112 GHz. The main detected transitions are the J=1-0 lines of CO, 13CO, HCN, HNC, HCO+, CN, and C2H. We also detect HC3N J=10-9 in the galaxies IRAS 17208, IC 860, NGC 4418, NGC 7771, and NGC 1068. The only HC3N detections are in objects with HCO+/HCN<1 and warm IRAS colours. Galaxies with the highest HC3N/HCN ratios have warm IRAS colours (60/100 {\mu}m>0.8). The brightest HC3N emission is found in IC 860, where we also detect the molecule in its vibrationally excited state.We find low HNC/HCN line ratios (<0.5), that cannot be explained by existing PDR or XDR chemical models. Bright HC3N emission in HCO+-faint objects may imply that these are not dominated by X-ray chemistry. Thus the HCN/HCO+ line ratio is not, by itself, a reliable tracer of XDRs. Bright HC3N and faint HCO+ could be signatures of embedded starformation, instead of AGN activity.

Affiliated with

Also associated with

No associations

Rating

Molecules as tracers of galaxy evolution: an EMIR survey. I. Presentation of the data and first results does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Molecules as tracers of galaxy evolution: an EMIR survey. I. Presentation of the data and first results, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Molecules as tracers of galaxy evolution: an EMIR survey. I. Presentation of the data and first results will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-160590