A survey of HC3N in extragalactic sources. Is HC3N a tracer of activity in ULIRGs?
Artikel i vetenskaplig tidskrift, 2011

Context. HC3N is a molecule that is mainly associated with Galactic star-forming regions, but it has also been detected in extragalactic environments. Aims. To present the first extragalactic survey of HC3N, when combining earlier data from the literature with six new single-dish detections, and to compare HC3N with other molecular tracers (HCN, HNC), as well as other properties (silicate absorption strength, IR flux density ratios, C II flux, and megamaser activity). Methods. We present mm IRAM 30 m, OSO 20 m, and SEST observations of HC3N rotational lines (mainly the J = 10-9 transition) and of the J = 1-0 transitions of HCN and HNC. Our combined HC3N data account for 13 galaxies (excluding the upper limits reported for the non-detections), while we have HCN and HNC data for more than 20 galaxies. Results. A preliminary definition "HC3N-luminous galaxy" is made based upon the HC3N/HCN ratio. Most (similar to 80%) HC3N-luminous galaxies seem to be deeply obscured galaxies and (U) LIRGs. A majority (similar to 60% or more) of the HC3N-luminous galaxies in the sample present OH mega- or strong kilomaser activity. A possible explanation is that both HC3N and OH megamasers need warm dust for their excitation. Alternatively, the dust that excites the OH megamaser offers protection against UV destruction of HC3N. A high silicate absorption strength is also found in several of the HC3N-luminous objects, which may help the HC3N to survive. Finally, we find that a high HC3N/HCN ratio is related to a high dust temperature and a low C II flux.

dense molecular gas

radio lines: ISM

nearby galaxies

starburst galaxies

galactic nuclei

galaxies: active

galaxies: starburst


spiral galaxies

radio lines:


galaxies: ISM

ultraluminous infrared galaxies

ISM: molecules



interstellar clouds



Johan Lindberg

Nordic Optical Telescope

Köbenhavns Universitet


Susanne Aalto

Chalmers, Rymd- och geovetenskap, Radioastronomi och astrofysik

Francesco Costagliola

Chalmers, Rymd- och geovetenskap, Radioastronomi och astrofysik

J. P. Perez-Beaupuits

Rijksuniversiteit Groningen

Max Planck-institutet

Raquel Rodriguez-Monje


Sebastien Muller

Chalmers, Rymd- och geovetenskap, Onsala rymdobservatorium

Astronomy and Astrophysics

0004-6361 (ISSN) 1432-0746 (eISSN)

Vol. 527 23 A150


Astronomi, astrofysik och kosmologi



Mer information

Senast uppdaterat