Astronomy and Astrophysics Letters dedicated to ISO

SWS H2 observations in the BD+404124 group


We report the detection of pure rotational lines of H2 observed in the direction of three young stellar objects in the BD+404124 group, with the short-wavelength spectrometer (SWS) on board ISO. The rotational population distributions of all three stars are consistent with a thermal distribution. The derived kinetic temperatures are 500 K for BD+404124 and LkHalpha 224 and 800 K for LkHalpha 225. The amounts of molecular hydrogen detected are 0.01 to 0.04 Msolar. The relative abundances of ortho- and para-hydrogen are consistent with a high temperature equilibrium distribution. We conclude that the molecular hydrogen emission in all three regions appears to lie behind approximately 10-25m of visual extinction and is probably not directly associated with any of the optical sources.

Circumstellar matter - Stars: Formation - Stars: Pre-main sequence - Infrared: Stars

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