Herbig-Haro flows near compact reflection nebulae

Abstract

We have performed an optical CCD imaging survey of star-forming regions identified through compact reflection nebulae and/or embedded IRAS sources in order to search for new Herbig–Haro (HH) flows. Here we present the discovery of hitherto unknown HH objects in seven of these regions. A bright bow shock, HH 461, is found along the axis defined by the previously known HH 164 jet from the luminous young A star LkHα 198. The little-known cometary nebula PP 11, illuminated by the partly embedded IRAS source 03507+3801 in the Perseus clouds, contains an HH object HH 462, found along the symmetry axis of the nebula. A small jet, HH 463, emanates from the recently identified FU Orionis candidate PP 13S, while another HH flow, HH 464/HH 465, appears to originate from the nearby T Tauri star PP 13N. A group of HH objects, HH 466–468, are located around the nebulous young T Tauri binary GK Tau. A well-collimated HH jet and an associated bow shock, HH 470, are found extending from the young nebulous T Tauri star Haro 4-255 in Orion, and a tiny reflection nebula and associated HH object, HH 469, are located close by the deeply embedded Class I source Haro 4-255 FIR. In light of these new HH flows in Haro 4-255, we re-interpret existing 12CO data on this source in terms of two overlapping molecular outflows. The young star LkHα 316 and the nearby IRAS source 05451+0037 in Orion are found to be associated with a cluster of HH objects, HH 471–474. It is likely that a nearby and previously identified HH object, HH 71, also originates in this region. Finally, a chain of HH objects, HH 475, is found near the little-studied compact bipolar reflection nebula PP 95 in the Cygnus clouds. The origin of this HH chain remains unclear, and HH 475 may equally well be driven by one of several luminous massive young stars in the region.