Large scale grain mantle disruption in the Galactic Center

J. Martin-Pintado(1), J. R. Rizzo(1), P. de Vicente(1), N. J. Rodriguez-Fernández(1) and A. Fuente(1)

Observatorio Astronómico Nacional, Apartado 1143, E-28800 Alcalá de Henares, Spain

Paper: ApjL 2001, in press

Weblink: http://www.oan.es/preprints/oan00-23.pdf

EPrint Server: astro-ph/0011512


Abstract:

We present observations of C2H5OH toward molecular clouds in Sgr A, Sgr B2 and associated with thermal and non-thermal features in the Galactic center. C2H5OH emission in Sgr A and Sgr B2 is widespread, but not uniform. C2H5OH emission is much weaker or it is not detected in some molecular clouds in both complexes, in particular those with radial velocities between 70 and 120 km/s. While most of the clouds associated with the thermal features do not show C2H5OH emission, that associated with the Non-Thermal Radio Arc shows emission. and The fractional abundance of C2H5OH in most of the clouds with radial velocities between 0 and 70 km/s in Sgr A and Sgr B2 is relatively high, of few 10-8. The C2H5OH abundance decreases by more than one order of magnitude (\lsim 10-9) in the clouds associated with the thermal features. The large abundance of C2H5OH in the gas-phase indicates that C2H5OH has formed in grains and released to gas-phase by shocks in the last 105 years. in The implications of this finding in the origin of the shocks in the GC is briefly discussed.


Preprints available from the authors at vicente@oan.es , or the raw TeX (no figures) if you click here.

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