Molecular hydrogen knots in Chamaeleon I dark cloud

PERSI, P., GOMEZ, M., TAPIA, M., ROTH, M., MARENZI, A. R.

Volterra, Italia

Conferencia; Low-mass stars and brown dwarfs: IMF, accretion and activity; 2004

Osservatorio Astrofisico di Arcetri, Italia

We have searched for shock-excited molecular hydrogen knots in five selected areas of the Chamaeleon I dark cloud using narrow-band images centered on the H_2 line and neighboring continuum. In the northern part of the cloud (Cha IN), we found seven new H_2 knots, five of which are aligned in the direction of a previously known CO molecular bipolar outflow. The class I low mass stellar object ISO-ChaI 192 that shows the characteristics of an FU Orionis-type star, is the driving source of the molecular flow and is the exciting star of five knots. In the other three searched areas including very low mass young objects, candidate and bona-fide young brown dwarfs, we fail to detect any H_2 emission at our sensitivity limit of about 10^-17 W/m2.