A Survey of Optical and Near-Infrared Jets in Taurus Embedded Sources

GOMEZ, M., WHITNEY, B. A., KENYON, S. J.

IOP PUBLISHING LTD

Lugar: Londres; Año: 1997 p. 1138 - 1138

e describe optical ([S II], 6732 Å) and near-infrared (H_2<, 2.122 μm) imaging observations of 22 embedded protostars in the Taurus-Auriga molecular cloud. Our survey identifies 4 new [S II] emission sources and 4 new H_2 sources. We detect three emission knots in both [S II] and H_2; one object with H_2< emission has no [S II] emission. These results increase the number of class I sources with optical or near-IR outflows to 13. We also detect [S II] emission in two additional class II sources, ZZ Tau IRS and IC 2087 IRS. When combined with previous results, the frequency of optical outflows among class H sources, ?10%, is much smaller than the frequency among class I sources, 60%. The large difference in the frequency of optical and molecular outflows indicates that outflow activity decreases with age among pre-main-sequence stars. The jets in the Taurus-Auriga protostars are poorly collimated, with multiple knots indicative of large opening angles, ?10°-40°