Understanding the star formation process in the filamentary dark cloud GF 9: Near-infrared observations

We have performed a near-infrared JHK survey of a dense core and a diffuse filament region within the filamentary dark cloud GF 9 (LDN 1082). The core region is associated with the IRAS point source PSC 20503+6006 and is suspected of being a site of star formation. The diffuse filament region has no associated IRAS point sources and is likely quiescent. We find that neither the core nor the filament region appears to contain a Class I or Class II young stellar object. As traced by the dust extinction, the core and filament regions contain 26 and 22 M_⊙, respectively, with an average H₂ volume density for both regions of ∼2500 cm^-3. The core region contains a centrally condensed extinction maximum with a peak extinction of A_V ≳ 10 mag that appears to be associated with the IRAS point source. The average H₂ volume density of the extinction core is ∼8000 cm^-3. The dust within the filament, however, shows no sign of a central condensation and is consistent with a uniform-density cylindrical distribution.