The extremely collimated bipolar H$_{\sf 2}$O jet from the NGC 1333–IRAS 4B protostar

Desmurs, J. F.; Codella, C.; Santiago-García, J.; Tafalla, M.; Bachiller, R.

doi:10.1051/0004-6361/200811365

Cited by 13 publications

(19 citation statements)

References 29 publications

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“…The high resolution millimeter interferometer data of Jørgensen et al (2007) as well as our data, however, do not show any overlap between the IRAS 4B blue and red outflow lobes, which would imply that they are not completely, but close to face-on with an inclination close to the line of sight of ∼15-30 • . This range is consistent with that of 10−35 • suggested for IRAS 4B based on VLBI H 2 O water maser observations (Desmurs et al 2009 Under the assumption that the intrinsic lengths of the flows are similar, Fig. 7 presents the various options for the relative orientation of the two outflows viewed from different angles, all three of which can lead to the observed projected situation seen in Fig.…”

Section: Morphologysupporting

confidence: 86%

APEX-CHAMP⁺high-JCO observations of low-mass young stellar objects

Yıldız

Kristensen

Dishoeck

et al. 2012

A&A

109

243

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Context. The NGC 1333 IRAS 4A and IRAS 4B sources are among the most well-studied Stage 0 low-mass protostars, which drive prominent bipolar outflows. Spectrally resolved molecular emission lines provide crucial information about the physical and chemical structure of the circumstellar material as well as the dynamics of the different components. Most studies have so far concentrated on the colder parts (T ≤ 30 K) of these regions. Aims. The aim is to characterize the warmer parts of the protostellar envelope using the new generation of submillimeter instruments. This will allow us to quantify the feedback of the protostars on their surroundings in terms of shocks, ultraviolet (UV) heating, photodissociation, and outflow dispersal. Methods. The dual frequency 2 × 7 pixel 650/850 GHz array receiver CHAMP + mounted on APEX was used to obtain a fully sampled, large-scale ∼4 × 4 map at 9 resolution of the IRAS 4A/4B region in the 12 CO J = 6-5 line. Smaller maps were observed in the 13 CO 6-5 and [C i] J = 2-1 lines. In addition, a fully sampled 12 CO J = 3-2 map made with HARP-B on the JCMT is presented and deep isotopolog observations are obtained at selected outflow positions to constrain the optical depth. Complementary Herschel-HIFI and ground-based lines of CO and its isotopologs, from J = 1-0 up to 10-9 (E u /k ≈ 300 K), are collected at the source positions and used to construct velocity-resolved CO ladders and rotational diagrams. Radiative-transfer models of the dust and lines are used to determine the temperatures and masses of the outflowing and photon-heated gas and infer the CO abundance structure. Results. Broad CO emission-line profiles trace entrained shocked gas along the outflow walls, which have an average temperature of ∼100 K. At other positions surrounding the outflow and the protostar, the 6-5 line profiles are narrow indicating UV excitation. The narrow 13 CO 6-5 data directly reveal the UV heated gas distribution for the first time. The amount of UV-photon-heated gas and outflowing gas are quantified from the combined 12 CO and 13 CO 6-5 maps and found to be comparable within a 20 radius around IRAS 4A, which implies that UV photons can affect the gas as much as the outflows. Weak [C I] emission throughout the region indicates that there is a lack of CO dissociating photons. Our modeling of the C 18 O lines demonstrates the necessity of a "drop" abundance profile throughout the envelopes where the CO freezes out and is reloaded back into the gas phase through grain heating, thus providing quantitative evidence of the CO ice evaporation zone around the protostars. The inner abundances are less than the canonical value of CO/H 2 = 2.7 × 10 −4 , however, implying that there is some processing of CO into other species on the grains. The implications of our results for the analysis of spectrally unresolved Herschel data are discussed.

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Section: Morphologysupporting

confidence: 86%

APEX-CHAMP⁺high-JCO observations of low-mass young stellar objects

Yıldız

Kristensen

Dishoeck

et al. 2012

A&A

109

243

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“…This suggests that the origin of the emission is the same in each of the individual sources and therefore that H 18 2 O emission is dominated by the thermal component and at most weakly masing. Finally, previously detected H 2 O water masers at 22 GHz in IRAS4B are clearly offset from the systemic velocity (Marvel et al 2008;Desmurs et al 2009) and their motions in the outflow propagation direction are perpendicular to the tentative velocity gradient observed in the H 18 2 O transition. Thus, the H 18 2 O line is at least not masing in the gas where the 22 GHz H 2 O maser has its origin.…”

Section: Discussion: An Upper Limit On the Ratio Of The Hdo/h 2 O Abumentioning

confidence: 65%

THE HDO/H ₂ O RATIO IN GAS IN THE INNER REGIONS OF A LOW-MASS PROTOSTAR

Jørgensen

Dishoeck

2010

ApJ

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The HDO/H 2 O abundance ratio is thought to be a key diagnostic for the evolution of water during the star and planet formation process and thus for its origin on Earth. We here present millimeter-wavelength high angular resolution observations of the deeply embedded protostar NGC 1333-IRAS4B from the Submillimeter Array targeting the 3 12 -2 21 transition of HDO at 225.6 GHz (E u = 170 K). We do not (or only very tentatively) detect the HDO line toward the central protostar, contrasting the previous prominent detection of a line from another water isotopologue, H 18 2 O, with similar excitation properties using the IRAM Plateau de Bure Interferometer. The non-detection of the HDO line provides a direct, model-independent, upper limit to the HDO/H 2 O abundance ratio of 6 × 10 −4 (3σ ) in the warm gas associated with the central protostar. This upper limit suggests that the HDO/H 2 O abundance ratio is not significantly enhanced in the inner ≈50 AU around the protostar relative to what is seen in comets and Earth's oceans and does not support previous suggestions of a generally enhanced HDO/H 2 O ratio in these systems.

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“…• for IRAS4B, whereas proper motions 10-40 km s −1 and radial velocities ±8 km s −1 of H 2 O masers (Desmurs et al 2009) indicate i = 50…”

Section: Inclination Anglesmentioning

confidence: 96%

“…References. for independent inclination estimates i obs (measured with respect to the line of sight): (1) Girart & Acord (2001); (2) Desmurs et al (2009); (3) Gueth et al (1996); (4) Cabrit et al (1988); (5) This work (footnote 3); (6) Tobin et al (2008); (7) Hartigan et al (2005); (8) NoriegaCrespo & Garnavich (2001); (9) Chrysostomou et al (1996); (10) Hartigan et al (2000); (11) Brinch et al (2007a); (12) Lee et al (2000).…”

Section: The 557 Ghz Broad Component Profilementioning

confidence: 99%

Molecule survival in magnetized protostellar disk winds

Yvart

Cabrit

Forêts

et al. 2015

A&A

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Context. The origin of molecular protostellar jets and their role in extracting angular momentum from the accreting system are important open questions in star formation research. In the first paper of this series we showed that a dusty magneto-hydrodynamic (MHD) disk wind appeared promising to explain the pattern of H 2 temperature and collimation in the youngest jets. Aims. We wish to see whether the high-quality H 2 O emission profiles of low-mass protostars, observed for the first time by the HIFI spectrograph on board the Herschel satellite, remain consistent with the MHD disk wind hypothesis, and which constraints they would set on the underlying disk properties. Methods. We present synthetic H 2 O line profiles predictions for a typical MHD disk wind solution with various values of disk accretion rate, stellar mass, extension of the launching area, and view angle. We compare them in terms of line shapes and intensities with the HIFI profiles observed by the WISH key program towards a sample of 29 low-mass Class 0 and Class 1 protostars. Results. A dusty MHD disk wind launched from 0.2-0.6 AU AU to 3-25 AU can reproduce to a remarkable degree the observed shapes and intensities of the broad H 2 O component observed in low-mass protostars, both in the fundamental 557 GHz line and in more excited lines. Such a model also readily reproduces the observed correlation of 557 GHz line luminosity with envelope density, if the infall rate at 1000 AU is 1-3 times the disk accretion rate in the wind ejection region. It is also compatible with the typical disk size and bolometric luminosity in the observed targets. However, the narrower line profiles in Class 1 sources suggest that MHD disk winds in these sources, if present, would have to be slower and/or less water rich than in Class 0 sources. Conclusions. MHD disk winds appear as a valid (though not unique) option to consider for the origin of the broad H 2 O component in low-mass protostars. ALMA appears ideally suited to further test this model by searching for resolved signatures of the warm and slow wide-angle molecular wind that would be predicted.

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The extremely collimated bipolar H$_{\sf 2}$O jet from the NGC 1333–IRAS 4B protostar

Cited by 13 publications

References 29 publications

APEX-CHAMP⁺high-JCO observations of low-mass young stellar objects

APEX-CHAMP⁺high-JCO observations of low-mass young stellar objects

THE HDO/H ₂ O RATIO IN GAS IN THE INNER REGIONS OF A LOW-MASS PROTOSTAR

Molecule survival in magnetized protostellar disk winds

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The extremely collimated bipolar H$_{\sf 2}$O jet from the NGC 1333–IRAS 4B protostar

Cited by 13 publications

References 29 publications

APEX-CHAMP+high-JCO observations of low-mass young stellar objects

APEX-CHAMP+high-JCO observations of low-mass young stellar objects

THE HDO/H 2 O RATIO IN GAS IN THE INNER REGIONS OF A LOW-MASS PROTOSTAR

Molecule survival in magnetized protostellar disk winds

Contact Info

Product

Resources

About

APEX-CHAMP⁺high-JCO observations of low-mass young stellar objects

APEX-CHAMP⁺high-JCO observations of low-mass young stellar objects

THE HDO/H ₂ O RATIO IN GAS IN THE INNER REGIONS OF A LOW-MASS PROTOSTAR