Monday 11 September at 2:30pm

Randolph Klein - AIU Jena

"An intermediate-mass Class 0 Object - ISO Observations of CB3"

ABSTRACT: "The massive core of the molecular cloud CB3 is associated with a molecular outflow and water maser emission as signs of active star formation. We present observations of this star-forming region obtained with the Infrared Space Telescope (ISO). We used the photo-spectrometer ISOPHOT and the infrared camera ISOCAM to investigate the cloud core of CB3. A bright IR object is found very near to the centre of the core, but we argue that it is not the object responsible for the high luminosity. The ISOCAM observations revealed a cloud of PAH emission next to the dense core. Two Herbig-Haro objects are detected along the ``blue'' outflow axis by their H2 emission. They appear also in the ISOCAM observations. Far infrared (FIR) and ground-based sub-millimetre observations yielded the complete spectral energy distribution (SED) of the CB3 cloud core. The lack of an NIR source associated with the cloud core and the strongly rising SED with a maximum at about 120um implies that CB3 hosts a Class 0 protostar still accreting and producing the outflow. Fitting a modified blackbody curve to the SED returned a temperature of 34K, a luminosity of 725 Lo and a dust emissivity proportional to nu**1.6. Assuming that the luminosity is due to accretion and deuterium burning, we conclude that the protostar has a mass between 5 and 10 Mo and accretes at a rate between 5 and 2x10e-5 Modot/yr."