We have observed the dark cloud Barnard 68 with SCUBA at 850 mu m and with SIMBA at 1.2 mm. The submillimetre and millimetre dust emission correlate well with the extinction map of Alves et al. (\cite{AlvesNature2001}). The AV/850 mu m correlation is clearly not linear and suggests lower temperatures for the dust in the inner core of the cloud. Assuming a model for the temperature gradient, we derive the cloud-averaged dust emissivities (normalised to the V-band extinction efficiency) at 850 mu m and 1.2 mm. We find kappa850 mum/ kappaV =4.0+/- 1.0x 10-5 and kappa1.2 mm/ kappaV = 9.0+/- 3.0x 10-6. These values are compared with other determinations in this wavelength regime and with expectations for models of diffuse dust and grain growth in dense clouds.
Dust emissivity in the submm/mm. SCUBA and SIMBA observations of Barnard 68
2003
Abstract
We have observed the dark cloud Barnard 68 with SCUBA at 850 mu m and with SIMBA at 1.2 mm. The submillimetre and millimetre dust emission correlate well with the extinction map of Alves et al. (\cite{AlvesNature2001}). The AV/850 mu m correlation is clearly not linear and suggests lower temperatures for the dust in the inner core of the cloud. Assuming a model for the temperature gradient, we derive the cloud-averaged dust emissivities (normalised to the V-band extinction efficiency) at 850 mu m and 1.2 mm. We find kappa850 mum/ kappaV =4.0+/- 1.0x 10-5 and kappa1.2 mm/ kappaV = 9.0+/- 3.0x 10-6. These values are compared with other determinations in this wavelength regime and with expectations for models of diffuse dust and grain growth in dense clouds.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
