Parsec-Scale CO Outflow and H[TINF]2[/TINF] Jets in Barnard 5

Yu, Ka Chun; Billawala, Youssef; Bally, John

doi:10.1086/301123

Cited by 60 publications

(90 citation statements)

References 80 publications

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“…When the ambient cloud is subtracted, however, the mass spectra break up into two components, with the low-velocity gas slopes becoming much shallower. As in the case of B5 IRS 1 discussed in YBB99, the break in the spectra may be indicative of two di †erent types of entrainment mechanisms (one at the head of the jet, and the second along the sides of the jet) as discussed by Smith et al (1997) and Zhang & Zheng (1997). A comparison of published data shows that for lowmass stars, there do not appear to be any di †erences in c between young and more evolved sources.…”

Section: Discussionmentioning

confidence: 74%

“…The clear break in the mass spectra may be indicative of the dual entrainment mechanisms modeled by Smith, Suttner, & Yorke (1987) and Zhang & Zheng (1997), where the high-velocity gas has been directly accelerated by a jet, and the low-velocity gas has been entrained by the bow shock wings further upstream. Note that the velocity extent of the MMS 9 H outÑow is not very great (with no detected gas clump with velocities greater than 15 km s~1 from the ambient cloud velocity).…”

Section: Mass Spectra Slopesmentioning

confidence: 82%

“…DOES OUTFLOW ENTRAINMENT CHANGE OVER TIME? Smith et al (1987) and Zhang & Zheng (1997) modeled the entrainment of ambient gas by bow shocks at the head of a jet and predicted mass spectra that could be Ðtted by broken power laws. A number of possible ways in which the mass spectrum could change or evolve over time was discussed in YBB99.…”

Section: Mass Spectra Slopesmentioning

confidence: 99%

“…According to the interpretations of Smith et al (1987) and Zhang & Zheng (1997), steep slopes in mass spectra are an indication of gas directly accelerated by the tip of the jet, while gas accelerated along the far wings of the bow and the jet wall would fall under a shallow slope in the mass spectra. Thus, it appears that the amount of low-and high-velocity gas swept up via these two methods remains proportionally the same over time.…”

Section: Mass Spectra Slopesmentioning

confidence: 99%

“…NRAO is a facility of the National Science Foundation, operated under a cooperative agreement by Associated Universities, Inc. bow shockÈlike features or knots that outline a cavity, suggest that the narrow jet is driving the less collimated CO Ñows (e.g., L1448, Bachiller et al 1995 ;L1157, Umemoto et al 1992, Gueth, Guilloteau, & Bachiller 1996, Yu, Billawala, & Bally 1999.…”

Section: Introductionmentioning

confidence: 99%

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A Multiwavelength Study of Outflows in OMC-2/3

Billawala

Smith

et al. 2000

The Astronomical Journal

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We present new v \ 1È0 S(1) 12CO J \ 2 ] 1, and 12CO J \ 3 ] 2 observations of the star-H 2 , forming clouds OMC-2 and OMC-3, one of the densest known groupings of outÑows from low-mass young stellar objects (YSOs) in the sky. High-velocity 12CO J \ 2 ] 1 gas in this region suggests that previously discoveredÑows are driving and entraining molecular outÑows. However, the large H 2 number of sources and Ñows within the narrow molecular Ðlament means it is difficult to make a Ðrm association of molecular outÑow gas with Ñows, except for in the case of the bipolar east-west H H 2 Ñow. A number of Herbig-Haro (HH) objects, including ones far to the west and east of the main ridge, are identiÐed with knots. High-resolution spectroscopy in the v \ 1È0 S(1) line of 10 knots shows H 2 H 2 line proÐles consistent with dual forward and reverse shocks. C-shock modeling suggest that asymmetries seen in suspected bow shocks could be evidence of varying magnetic Ðeld orientations throughout the cloud. One of the bow shocks in the H Ñow, YBD-5, can be successfully modeled by a 100 km s~1 C-shock propagating into a magnetized, 106 cm~3 medium, although the observations and limitations within the computer code itself do not entirely rule out J-shocks. Mass spectra of the H Ñow are broken power laws, which might be evidence for a jet that has two entrainment mechanisms for accelerating ambient molecular gas into the outÑow. The luminosity in this Ñow is many times smaller than H 2 the CO mechanical luminosity, but this fact cannot rule out the possibility that a narrow highly collimated jet drives the molecular outÑow, owing to uncertainties in extinction, outÑow dynamic times, cooling contributions from other lines, and the wind model used. OutÑows from OMC-2/3 are likely to contribute to the turbulent pumping of gas within the molecular ridge north of the Orion Nebula. Highvelocity gas clumps north of the sources investigated here may represent evidence of additional undiscovered outÑows from young stars.

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Section: Discussionmentioning

confidence: 74%

Section: Mass Spectra Slopesmentioning

confidence: 82%

Section: Mass Spectra Slopesmentioning

confidence: 99%

Section: Mass Spectra Slopesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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A Multiwavelength Study of Outflows in OMC-2/3

Billawala

Smith

et al. 2000

The Astronomical Journal

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Observational Constraints on the Conservation of Momentum and Energy in Jet-Driven Molecular Outflows

Dionatos

2019

Astrophysics and Space Science Proceedings

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Observations of a curving molecular outflow from V380 Ori-NE: further support for prompt entrainment in protostellar outflows

Davis

Dent

Matthews

et al. 2000

Monthly Notices of the Royal Astronomical Society

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CO J=3–2 and 4–3 observations of V380 Ori‐NE reveal a highly collimated bipolar molecular outflow associated with a jet traced here in H2 1–0 S(1) line emission. The source of the flow is also detected at 450 and 850 μm with SCUBA. The combined CO and near‐IR observations offer compelling support for the prompt entrainment model of jet‐driven molecular outflows. Not only are the H2 shock fronts spatially coincident with peaks in the CO outflow lobes, but the slope of the mass–velocity distribution in the flow, measured here at intervals along both flow lobes, also clearly decreases just behind the advancing shock fronts (and towards the ends of the flow lobes), as one would expect if the high‐to‐low velocity mass fraction was enhanced by the entraining shocks. We also find that both lobes of the CO outflow clearly deviate, by some 20°, from the H2 jet direction near the source. Both lobes may be being deflected at the locations of the observed H2 shock fronts, where they impact dense, ambient material. Alternatively, the almost point‐symmetric CO flow pattern could be caused by precession at the source. The submillimetre (submm) data reveal the source of the outflow, V380 Ori‐NE. The 450‐ and 850‐μm maps show an elongated peak superimposed on to an extensive pedestal of weaker emission. The major axis of the source is oriented parallel with the inner flow axis. Indeed, weak 850‐μm emission is detected along much of the bipolar outflow, particularly in the southern lobe and towards the southernmost CO intensity peak. The submm ‘continuum’ data therefore probably trace warm dust and CO associated with the outflow. These data also confirm the status of V380 Ori‐NE as a Class I protostar. Overall, the orientation, simplicity and symmetry of this outflow, combined with the remarkable strength of the high‐velocity line‐wing emission in comparison to the ambient emission, make this system a perfect laboratory for future detailed studies of bipolar molecular outflows and their association with collimated jets from young, deeply embedded protostars.

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Parsec-Scale CO Outflow and H[TINF]2[/TINF] Jets in Barnard 5

Cited by 60 publications

References 80 publications

A Multiwavelength Study of Outflows in OMC-2/3

A Multiwavelength Study of Outflows in OMC-2/3

Observational Constraints on the Conservation of Momentum and Energy in Jet-Driven Molecular Outflows

Observations of a curving molecular outflow from V380 Ori-NE: further support for prompt entrainment in protostellar outflows

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