Infrared monitoring of OH/IR stars near the Galactic Center

Wetensch. publicatieFaculteit der Wiskunde en Natuurwetenschappe

A new sample of OH/IR stars in the Galactic center

Wetensch. publicatieFaculteit der Wiskunde en Natuurwetenschappe

Age determinations of main-sequence stars: combining different methods

Wetensch. publicatieFaculteit der Wiskunde en Natuurwetenschappe

The nature of OH/IR stars in the galactic centre

Wetensch. publicatieFaculteit der Wiskunde en Natuurwetenschappe

AGB stars in the Magellanic Clouds. II. The rate of star formation across the LMC

Wetensch. publicatieFaculteit der Wiskunde en Natuurwetenschappe

The ATCA/VLA OH 1612 MHz survey. II. Observations of the galactic Disk region

Wetensch. publicatieFaculteit der Wiskunde en Natuurwetenschappe

A Vega--like disk associated with the planetary system of rho (1) CNC

Wetensch. publicatieFaculteit der Wiskunde en Natuurwetenschappe

Chemical telemetry of OH observed to measure interstellar magnetic fields

We present models for the chemistry in gas moving towards the ionization front of an HII region. When it is far from the ionization front, the gas is highly depleted of elements more massive than helium. However, as it approaches the ionization front, ices are destroyed and species formed on the grain surfaces are injected into the gas phase. Photodissociation removes gas phase molecular species as the gas flows towards the ionization front. We identify models for which the OH column densities are comparable to those measured in observations undertaken to study the magnetic fields in star forming regions and give results for the column densities of other species that should be abundant if the observed OH arises through a combination of the liberation of H2O from surfaces and photodissociation. They include CH3OH, H2CO, and H2S. Observations of these other species may help establish the nature of the OH spatial distribution in the clouds, which is important for the interpretation of the magnetic field results.Comment: 11 pages, 2 figures, accepted by Astrophysics and Space Scienc