SIMBAD references

2010A&A...521L..26L - Astronomy and Astrophysics, volume 521, L26-26 (2010/10-1)

Herschel/HIFI measurements of the ortho/para ratio in water towards Sagittarius B2(M) and W31C.

LIS D.C., PHILLIPS T.G., GOLDSMITH P.F., NEUFELD D.A., HERBST E., COMITO C., SCHILKE P., MUELLER H.S.P., BERGIN E.A., GERIN M., BELL T.A., EMPRECHTINGER M., BLACK J.H., BLAKE G.A., BOULANGER F., CAUX E., CECCARELLI C., CERNICHARO J., COUTENS A., CROCKETT N.R., DANIEL F., DARTOIS E., DE LUCA M., DUBERNET M.-L., ENCRENAZ P., FALGARONE E., GEBALLE T.R., GODARD B., GIESEN T.F., GOICOECHEA J.R., GRY C., GUPTA H., HENNEBELLE P., HILY-BLANT P., KOLOS R., KRELOWSKI J., JOBLIN C., JOHNSTONE D., KAZMIERCZAK M., LORD S.D., MARET S., MARTIN P.G., MARTIN-PINTADO J., MELNICK G.J., MENTEN K.M., MONJE R., MOOKERJEA B., MORRIS P., MURPHY J.A., OSSENKOPF V., PEARSON J.C., PERAULT M., PERSSON C., PLUME R., QIN S.-L., SALEZ M., SCHLEMMER S., SCHMIDT M., SONNENTRUCKER P., STUTZKI J., TEYSSIER D., TRAPPE N., VAN DER TAK F.F.S., VASTEL C., WANG S., YORKE H.W., YU S., ZMUIDZINAS J., BOOGERT A., ERICKSON N., KARPOV A., KOOI J., MAIWALD F.W., SCHIEDER R. and ZAAL P.

Abstract (from CDS):

We present Herschel/HIFI observations of the fundamental rotational transitions of ortho- and para-H216O and H218O in absorption towards Sagittarius B2(M) and W31C. The ortho/para ratio in water in the foreground clouds on the line of sight towards these bright continuum sources is generally consistent with the statistical high-temperature ratio of 3, within the observational uncertainties. However, somewhat unexpectedly, we derive a low ortho/para ratio of 2.35±0.35, corresponding to a spin temperature of ∼27K, towards Sagittarius B2(M) at velocities of the expanding molecular ring. Water molecules in this region appear to have formed with, or relaxed to, an ortho/para ratio close to the value corresponding to the local temperature of the gas and dust.

Abstract Copyright: ∼

Journal keyword(s): astrochemistry - ISM: abundances - ISM: molecules - molecular processes - submillimeter: ISM

Simbad objects: 8

goto Full paper

goto View the references in ADS

To bookmark this query, right click on this link: simbad:2010A&A...521L..26L and select 'bookmark this link' or equivalent in the popup menu