Characterizing the Youngest Herschel-detected Protostars. II. Molecular Outflows from the Millimeter and the Far-infrared

Tobin, John J. and Stutz, Amelia M. and Manoj, P. and Megeath, S. Thomas and Karska, Agata and Nagy, Zsófia (2016) Characterizing the Youngest Herschel-detected Protostars. II. Molecular Outflows from the Millimeter and the Far-infrared. ASTROPHYSICAL JOURNAL, 831. ISSN 1538-4357

Preview

Text 1607.00787.pdf Available under License Creative Commons Attribution. Download (3MB) | Preview

Abstract

We present CARMA CO (J = 1 → 0) observations and Herschel PACS spectroscopy, characterizing the outflow properties toward extremely young and deeply embedded protostars in the Orion molecular clouds. The sample comprises a subset of the Orion protostars known as the PACS Bright Red Sources (PBRS) (Stutz et al.). We observed 14 PBRS with CARMA and 8 of these 14 with Her- schel, acquiring full spectral scans from 55 μm to 200 μm. Outflows are detected in CO (J = 1 → 0) from 8 of 14 PBRS, with two additional tentative detections; outflows are also detected from the outbursting protostar HOPS 223 (V2775 Ori) and the Class I protostar HOPS 68. The outflows have a range of morphologies, some are spatially compact, <10000 AU in extent, while others extend beyond the primary beam. The outflow velocities and morphologies are consistent with being dominated by intermediate inclination angles (80◦ ≥ i ≥20◦). This con- firms the interpretation of the very red 24 μm to 70 μm colors of the PBRS as a signpost of high envelope densities, with only one (possibly two) cases of the red colors resulting from edge-on inclinations. We detect high-J (Jup > 13) CO lines and/or H2O lines from 5 of 8 PBRS and only for those with detected CO outflows. The far-infrared CO rotation temperatures of the detected PBRS are marginally colder (∼230 K) than those observed for most protostars (∼300 K), and only one of these 5 PBRS has detected [OI] 63 μm emission. The high envelope densities could be obscuring some [OI] emission and cause a ∼20 K reduction to the CO rotation temperatures.

Actions (login required)

Edit Item