Time‐Resolved AU‐Scale Jets Traced by Masers in the IRAS 4A/B Regions of NGC 1333

Marvel, Kevin B.; Wilking, B. A.; Claussen, M. J.; Wootten, Alwyn

doi:10.1086/590465

Cited by 25 publications

(52 citation statements)

References 50 publications

(77 reference statements)

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“…The other protostars (IRAS 4A1+4A2 and IRAS 4B) presented water emission in two of the four epochs observed. This confirms the high variability of the H 2 O spots associated with low-mass young stellar objects (Wilking et al 1994;Claussen et al 1996;Marvel et al 2008), with an active phase shorter than four weeks. Table 2 summarises the position, radial velocity, and flux of the observed H 2 O spots.…”

Section: Resultssupporting

confidence: 82%

“…For the Serpens Class 0 objects, Moscadelli et al (2006) found high-velocity spots located perpendicular to the jet axis: the authors suggest that such maser emission originates at the base of the jet, tracing the interaction between the jet itself and the accretion disk. For RNO 15-FIR, water masers are distributed along a line, suggesting their association with a collimated flow, in agreement with the results obtained by Marvel et al (2008) for the NGC 1333-IRAS 4B region. Thus, the origin of H 2 O masers in low-mass protostars is far from being fully understood, calling for further observations at AU-scales.…”

Section: Introductionsupporting

confidence: 89%

“…Interestingly, Marvel et al (2008) predicted that further VLBA observations would reveal new masers south (north) of the NW (SE) maser groups. The comparison of our data with those of Marvel et al (2008) Finally, it is tempting to give an estimate of the width of the H 2 O jet by using the angle defined by the positions of IRAS 4B and spots "e" and "f" (16…”

Section: Ngc 1333-iras 4bmentioning

confidence: 98%

“…Since the A2 maser group shows velocities close to the systemic velocity, Park & Choi (2007) interpreted such H 2 O spots as a tracer of a circumstellar disk. On the other hand, Marvel et al (2008) reported VLBA observations of H 2 O masers towards NGC 1333-IRAS 4B, finding two groups of maser spots expanding away from each other at velocities of ∼78 km s −1 along a direction different from that of the large scale outflow, already traced with fews H 2 O spots by Park & Choi (2007). The disagreement found by Marvel et al (2008) calls for further analysis in order to clarify which are the driving sources and whether NGC 1333-IRAS 4B has a companion as has been proposed by Marvel et al (2008).…”

Section: Ngc 1333-irasmentioning

confidence: 99%

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

Desmurs

Codella

Santiago-García

et al. 2009

A&A

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Context. We have performed observations of water maser emission towards a sample of low-mass protostars, in order to investigate the properties of jets associated with the earliest stages of star formation and their interaction with the surrounding medium. Aims. The main aim is to measure the absolute positions and proper motions of the H 2 O spots in order to investigate the kinematics of the region from where the jet is launched. Methods. We imaged the protostars in the nearby region NGC 1333-IRAS 4 in the water maser line at 22.2 GHz by using the VLBA in phase-reference mode at the milliarcsecond scale over four epochs, spaced by one month to measure proper motions. Results. Two protostars (A2 and B) were detected in a highly variable H 2 O maser emission, with an active phase shorter than four weeks. The H 2 O maps allow us to trace the fast jet driven by the B protostar: we observed both the red-and blue-shifted lobes very close to the protostar, ≤35 AU, moving away with projected velocities of ∼10-50 km s −1 . The comparison with the molecular outflow observed at larger scale suggests a jet precession with a 18 yr −1 rate. By measuring the positional spread of the H 2 O spots we estimate a jet width of ∼2 AU at a distance of ∼12 AU from the driving protostar.

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Section: Resultssupporting

confidence: 82%

Section: Introductionsupporting

confidence: 89%

Section: Ngc 1333-iras 4bmentioning

confidence: 98%

Section: Ngc 1333-irasmentioning

confidence: 99%

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

Desmurs

Codella

Santiago-García

et al. 2009

A&A

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“…Marvel et al (2008) conclude that in IRAS4A-NW, the maser emission cannot be directly associated with the large scale outflow. For IRAS4B the masers have been associated with the outflow (Marvel et al 2008;Desmurs et al 2009), but the position angle of the "maser outflow" still differs from that of the CO outflow by some 20-30 • . 2 O line is drawn with a vertical dotted line at v lsr = 7 km s −1 , and the gray outline in the background is the on-source spectrum averaged in a region of the same size as the other spectra.…”

Section: Watsonmentioning

confidence: 74%

Subarcsecond resolution observations of warm water toward three deeply embedded low-mass protostars

Persson

Jørgensen

Dishoeck

2012

A&A

122

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Context. Water is present during all stages of star formation: as ice in the cold outer parts of protostellar envelopes and dense inner regions of circumstellar disks, and as gas in the envelopes close to the protostars, in the upper layers of circumstellar disks and in regions of powerful outflows and shocks. Because of its key importance in the understanding of its origin in our own solar system, following the evolution of water all the way to the planet-forming disk is a fundamental task in research in star formation and astrochemistry. Aims. In this paper we probe the mechanism regulating the warm gas-phase water abundance in the innermost hundred AU of deeply embedded (Class 0) low-mass protostars, and investigate its chemical relationship to other molecular species during these stages. Methods. Millimeter wavelength thermal emission from the para-H 18 2 O 3 1,3 −2 2,0 (E u = 203.7 K) line was imaged at high angular resolution (0. 75; 190 AU) with the IRAM Plateau de Bure Interferometer toward the deeply embedded low-mass protostars NGC 1333-IRAS2A and NGC 1333-IRAS4A. Results. Compact H 182 O emission is detected toward IRAS2A and one of the components in the IRAS4A binary; in addition CH 3 OCH 3 , C 2 H 5 CN, and SO 2 are detected. Extended water emission is seen toward IRAS2A, possibly associated with the outflow. Conclusions. The results complement a previous detection of the same transition toward NGC 1333-IRAS4B. The detections in all systems suggests that the presence of water on 100 AU scales is a common phenomenon in embedded protostars and that the nondetections of hot water with Spitzer toward the two systems studied in this paper are likely due to geometry and high extinction at mid-infrared wavelengths. We present a scenario in which the origin of the emission from warm water is in a flattened disk-like structure dominated by inward motions rather than rotation. The gas-phase water abundance varies between the sources, but is generally much lower than a canonical abundance of 10 −4 , suggesting that most water (>96%) is frozen out on dust grains at these scales. The derived abundances of CH 3 OCH 3 and SO 2 relative to H 18 2 O are comparable for all sources pointing toward similar chemical processes at work. In contrast, the C 2 H 5 CN abundance relative to H 18 2 O is significantly lower in IRAS2A, which could be due to different chemistry in the sources.

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Heavy water around the L1448-mm protostar

Codella

Ceccarelli

Nisini

et al. 2010

A&A

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Context. L1448-mm is the prototype of a low-mass Class 0 protostar driving a high-velocity jet. Given its bright H 2 O spectra observed with ISO, L1448-mm is an ideal laboratory to observe heavy water (HDO) emission. Aims. Our aim is to image the HDO emission in the protostar surroundings, the possible occurrence of HDO emission also investigating off L1448-mm, towards the molecular outflow. Methods. We carried out observations of L1448-mm in the HDO(1 10 -1 11 ) line at 80.6 GHz, an excellent tracer of HDO column density, with the IRAM Plateau de Bure Interferometer. Results. We image for the first time HDO emission around L1448-mm. The HDO structure reveals a main clump at velocities close to the ambient one towards the the continuum peak that is caused by the dust heated by the protostar. In addition, the HDO map shows tentative weaker emission at 2000 AU from the protostar towards the south, which is possibly associated with the walls of the outflow cavity opened by the protostellar wind. Conclusions. Using an LVG code, modelling the density and temperature profile of the hot-corino, and adopting a gas temperature of 100 K and a density of 1.5 × 10 8 cm −3 , we derive a beam diluted HDO column density of ∼7 × 10 13 cm −2 , corresponding to a HDO abundance of ∼4 × 10 −7 . In addition, the present map supports the scenario where HDO can be efficiently produced in shocked regions and not uniquely in hot corinos heated by the newly born star.

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Time‐Resolved AU‐Scale Jets Traced by Masers in the IRAS 4A/B Regions of NGC 1333

Cited by 25 publications

References 50 publications

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

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

Subarcsecond resolution observations of warm water toward three deeply embedded low-mass protostars

Heavy water around the L1448-mm protostar

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