12CO(J=3?2) detections in bulges of low surface brightness galaxies with APEX

Galaz G.; Cortes P.; Bronfman, L.; Rubio M.


Using the APEX sub-millimeter telescope we have detected for the first time the CO rotational transition 12CO(J=32) in two of five low surface brightness galaxies. For galaxies with positive detection, the emission is detected in their bulges, with measured gas velocity dispersion of about 80 km/s and observed main-beam brightness temperature TM B ~ 10 mK. Using a standard CO to H2 conversion factor, we are able to estimate molecular gas masses for LSBs with positive detections, and upper limits for those LSBs with negative detections. Assuming a higher gas temperature for the generation of the 12CO(J=32) line compared to that for the 12CO(J=10) one, results suggest that a warm molecular gas component is present in bulges, indicating a radiation field preventing the formation of large cooler amounts of molecular gas, compared to high surface brightness galaxies with higher metallicity and likely more dust. © 2008 Copyright International Astronomical Union 2008.

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Título de la Revista: Proceedings of the International Astronomical Union
Volumen: 3
Número: S245
Editorial: Cambridge University Press
Fecha de publicación: 2007
Página de inicio: 191
Página final: 192
URL: http://www.scopus.com/inward/record.url?eid=2-s2.0-46749096839&partnerID=q2rCbXpz