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

• Aims. 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. Methods. 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. Results. We detect molecular emission in 19 galaxies in two 8 GHz-wide bands centred at 88 and 112 GHz. The main detected molecules are CO, (CO)-C-13, 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 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 (

Ämnesord

NATURVETENSKAP  -- Fysik -- Astronomi, astrofysik och kosmologi (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Astronomy, Astrophysics and Cosmology (hsv//eng)

Nyckelord

nearby galaxies

galaxies: evolution

galaxies: active

ISM: molecules

seyfert-galaxies

star-formation

interstellar-medium

dense gas

luminous infrared galaxies

arp 220

vibrationally excited hc3n

hnc line emission

massive

abundances

evolution

galaxies: ISM

Publikations- och innehållstyp

art (ämneskategori)

ref (ämneskategori)