[O I] 63 μm Jets in Class 0 Sources Detected By Herschel
Journal
Date Issued
2015
Author(s)
•
Santangelo, G.
•
•
•
Cabrit, S.
•
•
Davis, C. J.
•
Eislöffel, J.
•
Kristensen, L.
•
Herczeg, G.
•
Neufeld, D.
•
van Dishoeck, E. F.
Description
Financial support from INAF, under PRIN2013 program “Disks, jets and the dawn of planets” is acknowledged.
Abstract
We present Herschel PACS mapping observations of the [O i] 63 μm line toward protostellar outflows in the L1448, NGC 1333-IRAS4, HH 46, BHR 71, and VLA 1623 star-forming regions. We detect emission spatially resolved along the outflow direction, which can be associated with a low-excitation atomic jet. In the L1448-C, HH 46 IRS, and BHR 71 IRS1 outflows this emission is kinematically resolved into blue- and redshifted jet lobes, having radial velocities up to 200 km s-1. In the L1448-C atomic jet the velocity increases with the distance from the protostar, similarly to what is observed in the SiO jet associated with this source. This suggests that [O i] and molecular gas are kinematically connected and that the latter could represent the colder cocoon of a jet at higher excitation. Mass flux rates ({{\dot{M}}jet}(O i)) have been measured from the [O i] 63 μm luminosity adopting two independent methods. We find values in the range (1-4) × 10-7 {{M}☉ } yr-1 for all sources except HH 46, for which an order of magnitude higher value is estimated. {{\dot{M}}jet}(O i) are compared with mass accretion rates (\dot{M}acc) onto the protostar and with {{\dot{M}}jet} derived from ground-based CO observations. {{\dot{M}}jet}(O i)/\dot{M}acc ratios are in the range 0.05-0.5, similar to the values for more evolved sources. {{\dot{M}}jet}(O i) in HH 46 IRS and IRAS4A are comparable to {{\dot{M}}jet}(CO), while those of the remaining sources are significantly lower than the corresponding {{\dot{M}}jet}(CO). We speculate that for these three sources most of the mass flux is carried out by a molecular jet, while the warm atomic gas does not significantly contribute to the dynamics of the system.
Volume
801
Issue
2
Start page
121
Issn Identifier
0004-637X
Ads BibCode
2015ApJ...801..121N
Rights
open.access
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