SIMBAD references

2009AJ....137.3843B - Astron. J., 137, 3843-3858 (2009/April-0)

Outflows and young stars in Orion's large cometary clouds L1622 and L1634.

BALLY J., WALAWENDER J., REIPURTH B. and MEGEATH S.T.

Abstract (from CDS):

New observations of protostellar outflows associated with young stars in two of Orion's outlying cometary clouds, L1622 and L1634, are presented. The Hα surface brightness of the bright rims are used to argue that both clouds are located at a distance of about 400 pc in the interior of the Orion superbubble where they are illuminated by Orion's massive stars. Spitzer IRAC and MIPS images reveal 28 candidate young stellar objects (YSOs). Combined with the 14 spectroscopically confirmed T Tauri stars, there are at least 34 YSOs in L1622. Narrow-band images have led to the identification of about a dozen shock complexes in L1622. At least six belong to a highly collimated externally irradiated, bipolar jet, HH 963, that is powered by a low-luminosity Class II YSO located outside the projected edge of the L1622 dark cloud. However, the sources of most shocks remain unclear. The Spitzer/IRAC images reveal a compact, highly obscured, S-symmetric outflow brightest in the 4.5 µm images. A faint [S II] counter part, HH 962, is associated with the western end of this flow which appears to be powered by an obscured source in the L1622 cloud interior. The currently identified sample of YSOs implies a star formation efficiency of about 4% for L1622. The L1634 cloud contains nine YSOs and three outflows, including the well known HH 240/241 system. A new flow, HH 979, is powered by the embedded YSO IRS7 in L1634 and crosses the eastern lobe of the HH 240 outflow. Spitzer/IRAC images show 4.5 µm emission indicating molecular shocks from the Herbig-Haro objects closest to IRS 7. A YSO embedded in a condensation located 5' north of HH 240/241 is identified in the Spitzer images. This source drives an irradiated outflow, HH 980, whose lobes emerge into the ionized environment of the Orion-Eridanus superbubble interior. The star formation efficiency of L1634 is estimated to be about 3%.

Abstract Copyright:

Journal keyword(s): ISM: Herbig-Haro objects - ISM: individual (Lynds 1662, Lynds 1634) - ISM: jets and outflows - ISM: kinematics and dynamics - stars: formation

Simbad objects: 68

goto Full paper

goto View the references in ADS

To bookmark this query, right click on this link: simbad:2009AJ....137.3843B and select 'bookmark this link' or equivalent in the popup menu