First results from the CALYPSO IRAM-PdBI survey

Codella, C.; Maury, A.; Gueth, F.; Maret, S.; Беллоче, А.; Cabrit, S.; André, Ph.

doi:10.1051/0004-6361/201323024

Cited by 58 publications

(95 citation statements)

References 39 publications

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“…Compact continuum emission along protostellar jets has already been observed in other sources (e.g. Gueth et al 2003;Maury et al 2010;Codella et al 2014); envelope emission or shock-heated dust along the jet have been suggested as possible explanations for the origin of these features. However, a larger statistically suitable sample is crucial in order to assess this issue.…”

Section: Continuum Emission: Source Multiplicity and Propertiesmentioning

confidence: 68%

“…Finally, jet variability, in particular episodic ejection (see e.g. Codella et al 2014), may also play a role.…”

Section: Discussionmentioning

confidence: 99%

“…An extended structure with A2 at the vertex is seen in SO emission at the systemic velocity, possibly probing the hot corino and outflow cavity walls (see also Sect. 3.1.1 and Codella et al 2014, for NGC 1333-IRAS2A).…”

Section: Line Emission: Jet Kinematicsmentioning

confidence: 98%

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Jet multiplicity in the proto-binary system NGC 1333-IRAS4A

Santangelo

Codella

Cabrit

et al. 2015

A&A

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Context. Owing to the paucity of sub-arcsecond (sub)mm observations required to probe the innermost regions of newly forming protostars, several fundamental questions are still being debated, such as the existence and coevality of close multiple systems. Aims. We study the physical and chemical properties of the jets and protostellar sources in the NGC 1333-IRAS4A proto-binary system using continuum emission and molecular tracers of shocked gas. Methods. We observed NGC 1333-IRAS4A in the SiO(6−5), SO(6 5 −5 4 ), and CO(2−1) lines and the continuum emission at 1.3, 1.4, and 3 mm using the IRAM Plateau de Bure Interferometer in the framework of the CALYPSO large program. Results. We clearly disentangle for the first time the outflow emission from the two sources A1 and A2. The two protostellar jets have very different properties: the A1 jet is faster, has a short dynamical timescale ( 10 3 yr), and is associated with H 2 shocked emission, whereas the A2 jet, which dominates the large-scale emission, is associated with diffuse emission, bends, and emits at slower velocities. The observed bending of the A2 jet is consistent with the change of propagation direction observed at large scale and suggests jet precession on very short timescales (∼200−600 yr). In addition, a chemically rich spectrum with emission from several complex organic molecules (e.g. HCOOH, CH 3 OCHO, CH 3 OCH 3 ) is only detected towards A2. Finally, very high-velocity shocked emission (∼50 km s −1 ) is observed along the A1 jet. An LTE analysis shows that SiO, SO, and H 2 CO abundances in the gas phase are enhanced up to (3−4) × 10 −7 , (1.4−1.7) × 10 −6 , and (3−7.9) × 10 −7 , respectively. Conclusions. The intrinsic different properties of the jets and driving sources in NGC 1333-IRAS4A suggest different evolutionary stages for the two protostars, with A1 being younger than A2, in a very early stage of star formation previous to the hot-corino phase.

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Section: Continuum Emission: Source Multiplicity and Propertiesmentioning

confidence: 68%

“…Finally, jet variability, in particular episodic ejection (see e.g. Codella et al 2014), may also play a role.…”

Section: Discussionmentioning

confidence: 99%

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Jet multiplicity in the proto-binary system NGC 1333-IRAS4A

Santangelo

Codella

Cabrit

et al. 2015

A&A

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“…The observations of IRAS 4B are dynamic range limited, causing convolution artifacts to appear around the compact continuum peak; these artifacts are not real (see text). Toward IRAS 2A, Codella et al (2014) reported two secondary continuum sources that are 2 and 2.4 away, one along the blueshifted outflow and one southwest of the main component. Tobin et al (2015a) show that IRAS 2A is a binary on 0 .…”

Section: Sample and Observationsmentioning

confidence: 99%

Constraining the physical structure of the inner few 100 AU scales of deeply embedded low-mass protostars

Persson

Harsono

Tobin

et al. 2016

A&A

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Context. The physical structure of deeply embedded low-mass protostars (Class 0) on scales of less than 300 AU is still poorly constrained. While molecular line observations demonstrate the presence of disks with Keplerian rotation toward a handful of sources, others show no hint of rotation. Determining the structure on small scales (a few 100 AU) is crucial for understanding the physical and chemical evolution from cores to disks. Aims. We determine the presence and characteristics of compact, disk-like structures in deeply embedded low-mass protostars. A related goal is investigating how the derived structure affects the determination of gas-phase molecular abundances on hot-core scales. Methods. Two models of the emission, a Gaussian disk intensity distribution and a parametrized power-law disk model, are fitted to subarcsecond resolution interferometric continuum observations of five Class 0 sources, including one source with a confirmed Keplerian disk. Prior to fitting the models to the de-projected real visibilities, the estimated envelope from an independent model and any companion sources are subtracted. For reference, a spherically symmetric single power-law envelope is fitted to the larger scale emission (∼1000 AU) and investigated further for one of the sources on smaller scales. Results. The radii of the fitted disk-like structures range from ∼90−170 AU, and the derived masses depend on the method. Using the Gaussian disk model results in masses of 54−556 × 10 −3 M , and using the power-law disk model gives 9−140 × 10 −3 M . While the disk radii agree with previous estimates the masses are different for some of the sources studied. Assuming a typical temperature distribution (r −0.5 ), the fractional amount of mass in the disk above 100 K varies from 7% to 30%. Conclusions. A thin disk model can approximate the emission and physical structure in the inner few 100 AU scales of the studied deeply embedded low-mass protostars and paves the way for analysis of a larger sample with ALMA. Kinematic data are needed to determine the presence of any Keplerian disk. Using previous observations of p-H 18 2 O, we estimate the relative gas phase water abundances relative to total warm H 2 to be 6.2 × 10 −5 (IRAS 2A), 0.33 × 10 −5 (IRAS 4A-NW), 1.8 × 10 −7 (IRAS 4B), and <2 × 10 −7 (IRAS 4A-SE), roughly an order of magnitude higher than previously inferred when both warm and cold H 2 were used as reference. A spherically symmetric single power-law envelope model fails to simultaneously reproduce both the small-and large-scale emission.

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“…Recent observations show that SO can be used to image high-velocity protostellar jets, similar to a standard tracer such as SiO (Lee et al 2010;Tafalla et al 2010;Codella et al 2014b). However, only two protostellar jets have so far been clearly mapped in SO lines: HH 211 and NGC 1333-IRAS 2A, and estimates of the SO abundance have only been derived for HH 211.…”

Section: Introductionmentioning

confidence: 99%

The jet and the disk of the HH 212 low-mass protostar imaged by ALMA: SO and SO₂emission

Podio

Codella

Gueth

et al. 2015

A&A

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Context. The investigation of the disk formation and jet launching mechanism in protostars is crucial to understanding the earliest stages of star and planet formation. Aims. We aim to constrain the physical and dynamical properties of the molecular jet and disk of the HH 212 protostellar system at unprecedented angular scales, exploiting the capabilities of the Atacama Large Millimeter Array (ALMA). Methods. The ALMA observations of HH 212 in emission lines from sulfur-bearing molecules, SO 9 8 −8 7 , SO 10 11 −10 10 , SO 2 8 2,6 −7 1,7 , are compared with simultaneous CO 3−2, SiO 8−7 data. The molecules column density and abundance are estimated using simple radiative transfer models. Results. SO 9 8 −8 7 and SO 2 8 2,6 −7 1,7 show broad velocity profiles. At systemic velocity, they probe the circumstellar gas and the cavity walls. Going from low to high blue-and red-shifted velocities the emission traces the wide-angle outflow and the fast (∼100−200 km s −1 ), collimated (∼90 AU) molecular jet revealing the inner knots with timescales ≤50 yr. The jet transports a massloss rate ≥0.2−2×10 −6 M yr −1 , implying high ejection efficiency (≥0.03−0.3). The SO and SO 2 abundances in the jet are ∼10 −7 −10 −6 . SO 10 11 −10 10 emission is compact and shows small-scale velocity gradients, indicating that it originates partly from the rotating disk previously seen in HCO + and C 17 O, and partly from the base of the jet. The disk mass is ≥0.002−0.013 M and the SO abundance in the disk is ∼10 −8 −10 −7 . Conclusions. SO and SO 2 are effective tracers of the molecular jet in the inner few hundreds AU from the protostar. Their abundances indicate that 1−40% of sulfur is in SO and SO 2 due to shocks in the jet/outflow and/or to ambipolar diffusion at the wind base. The SO abundance in the disk is 3−4 orders of magnitude larger than in evolved protoplanetary disks. This may be due to an SO enhancement in the accretion shock at the envelope-disk interface or in spiral shocks if the disk is partly gravitationally unstable.

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First results from the CALYPSO IRAM-PdBI survey

Cited by 58 publications

References 39 publications

Jet multiplicity in the proto-binary system NGC 1333-IRAS4A

Jet multiplicity in the proto-binary system NGC 1333-IRAS4A

Constraining the physical structure of the inner few 100 AU scales of deeply embedded low-mass protostars

The jet and the disk of the HH 212 low-mass protostar imaged by ALMA: SO and SO₂emission

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First results from the CALYPSO IRAM-PdBI survey

Cited by 58 publications

References 39 publications

Jet multiplicity in the proto-binary system NGC 1333-IRAS4A

Jet multiplicity in the proto-binary system NGC 1333-IRAS4A

Constraining the physical structure of the inner few 100 AU scales of deeply embedded low-mass protostars

The jet and the disk of the HH 212 low-mass protostar imaged by ALMA: SO and SO2emission

Contact Info

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The jet and the disk of the HH 212 low-mass protostar imaged by ALMA: SO and SO₂emission