SWS H-2 observations in the BD+40 degrees 4124 group
Wesselius, PR vandenAncker, ME Young, ET Clark, FO Prusti, T Roelfsema, PR Waelkens, Christoffel Wooden, DH Boxhoorn, DR Heras, AM Huygen, Eric Kester, DJM Lahuis, F
Astronomy and astrophysics vol:315 issue:2 pages:L197-L200
We report the detection of pure rotational lines of H-2 observed in the direction of three young stellar objects in the BD+40 degrees 4124 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 approximate to 500 K for BD+40 degrees 4124 and LkH alpha 224 and approximate to 800 K for LkH alpha 225. The amounts of molecular hydrogen detected are 0.01 to 0.04 M.. 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 10-25(m) of visual extinction and is probably not directly associated with any of the optical sources.