Detection of Multiple Bipolar Flows in NGC 7027 With Submillimeter Array

Huang, Zhen-Yuan; Hasegawa, T.; Dinh-V-Trung,; Kwok, Sun; Müller, S.; Hirano, Naomi; Lim, Jeremy; Mariappan, C. Muthu; Lyo, A-Ran

doi:10.1088/0004-637x/722/1/273

Cited by 9 publications

(15 citation statements)

References 22 publications

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“…i Mass-loss rate, and expansion velocity of NGC 7027 obtained from Zhang et al (2008). j LSR velocity of NGC 7027 adopted from Huang et al (2010).…”

Section: Discussionmentioning

confidence: 99%

The spectra of evolved stars at 20--25\,GHz: tracing circumstellar chemistry during the asymptotic giant branch to planetary nebula transition

Zhang,

Chau,

Nakashima

et al. 2020

Preprint

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We report an unbiased radio line survey towards the circumstellar envelopes of evolved stars at the frequency range from 20 to 25 GHz, aiming to obtain a more complete unbiased picture of the chemical evolution in the final stages of stellar evolution. The observation sample includes the asymptotic giant branch (AGB) star IRC+10216, the proto-planetary nebulae (PPNs) CRL 2688 and CRL 618, and the young planetary nebula (PN) NGC 7027, representing an evolutionary sequence spanning about 10,000 years. Rotational transitions from cyanopolyyne chains and inversion lines from ammonia are detected in the AGB star and PPNs, while the PN displays several recombination lines. The different spectral behaviors of these evolved stars clearly reflect the evolution of circumstellar chemistry during the AGB-PPN-PN transitions.

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“…i Mass-loss rate, and expansion velocity of NGC 7027 obtained from Zhang et al (2008). j LSR velocity of NGC 7027 adopted from Huang et al (2010).…”

Section: Discussionmentioning

confidence: 99%

The spectra of evolved stars at 20--25\,GHz: tracing circumstellar chemistry during the asymptotic giant branch to planetary nebula transition

Zhang,

Chau,

Nakashima

et al. 2020

Preprint

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“…A significant amount of molecular gas is indeed found even in well-developed, ~few×10 3 yr old PNe with hot ( T eff ≈10 5 K) central stars, e.g. NGC 7027 or NGC 6302 (Huang et al 2010; Santander-García et al 2017).…”

Section: Discussionmentioning

confidence: 99%

A rotating fast bipolar wind and disk system around the B[e]-type star MWC 922

Contreras

Báez-Rubio

Alcolea

et al. 2019

A&A

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We present interferometric observations with the Atacama Large Millimeter Array (ALMA) of the free-free continuum and recombination line emission at 1 and 3 mm of the "Red Square Nebula" surrounding the B[e]-type star MWC922. The unknown distance to the source is usually taken to be d=1.7-3 kpc. The unprecedented angular resolution (upto∼0.″02) and exquisite sensitivity of these data unveil, for the first time, the structure and kinematics of the emerging, compact ionized region at its center. We imaged the line emission of H30α and H39α, previously detected with single-dish observations, as well as of H51ϵ, H55γ, and H63δ, detected for the first time in this work. The line emission is seen over a full velocity range of ~180 km s−1 arising in a region of diameter <0.″14 (less than a few hundred au) in the maser line H30α, which is the most intense transition reported here. We resolve the spatio-kinematic structure of a nearly edge-on disk rotating around a central mass of ~10 M⊙ (d=1.7 kpc) or ~18 M⊙ (d=3 kpc), assuming Keplerian rotation. Our data also unveil a fast (~100 km s−1) bipolar ejection (a jet?) orthogonal to the disk. In addition, a slow (<15 km s−1) wind may be lifting off the disk. Both, the slow and the fast winds are found to be rotating in a similar manner to the ionized layers of the disk. This represents the first empirical proof of rotation in a bipolar wind expanding at high velocity (~100 km s−1). The launching radius of the fast wind is found to be <30-51 au i.e., smaller than the inner rim of the ionized disk probed by our observations. We believe that the fast wind is actively being launched, probably by a disk-mediated mechanism in a (accretion?) disk around a possible compact companion. We have modelled our observations using the radiative transfer code MORELI. This has enabled us to describe with unparalleled detail the physical conditions and kinematics in the inner layers of MWC 922, which has revealed itself as an ideal laboratory for studying the interplay of disk rotation and jet-launching. Although the nature of MWC 922 remains unclear, we believe it could be a ~15 M⊙ post-main sequence star in a mass-exchanging binary system. If this is the case, a more realistic value of the distance may be d~3 kpc.

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“…Recent studies have shown that this object is a multipolar PN in the making (see Huang et al 2010). High-velocity jets exhibit a multipolar shape in H 2 extending over roughly 20 (Sabin et al 2007).…”

Section: Source Samplementioning

confidence: 94%

“…NGC7027 is a young PN (kinematical age of 600 years, Masson 1989), with a high degree of axial symmetry. Recent studies have shown that this object is a multipolar PN in the making (see Huang et al 2010). High-velocity jets exhibit a multipolar shape in H 2 extending over roughly 20 (Sabin et al 2007).…”

Section: Source Samplementioning

confidence: 94%

“…While the inner part of the torus has been ionized, the ancient AGB molecular content has been completely reprocessed in the envelope (Herpin et al 2002). The HCN emission extends over 20 (Huang et al 2010). We had access to an estimate of the CN distribution from Plateau de Bure observations (Josselin et al, private communication,), showing CN at a a distance of 10000 AU from the central object.…”

Section: Source Samplementioning

confidence: 99%

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Magnetic field in IRC+10216 and other C-rich evolved stars

Duthu

Herpin

Wiesemeyer

et al. 2017

A&A

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Context. During the transition from the asymptotic giant branch (AGB) to planetary nebulae (PN), the circumstellar geometry and morphology change dramatically. Another characteristic of this transition is the high mass-loss rate, that can be partially explained by radiation pressure and a combination of various factors, such as the stellar pulsation, the dust grain condensation, and opacity in the upper atmosphere. The magnetic field can also be one of the main ingredients that shapes the stellar upper atmosphere and envelope. Aims. Our main goal is to investigate for the first time the spatial distribution of the magnetic field in the envelope of IRC+10216. More generally we intend to determine the magnetic field strength in the circumstellar envelope (CSE) of C-rich evolved stars, compare this field with previous studies for O-rich stars, and constrain the variation of the magnetic field with r the distance to the star's centre. Methods. We use spectropolarimetric observations of the Stokes V parameter, collected with Xpol on the IRAM-30 m radiotelescope, observing the Zeeman effect in seven hyperfine components of the CN J = 1-0 line. We use the Crutcher et al. (1996, ApJ, 456, 217) method to estimate the magnetic field. For the first time, the instrumental contamination is investigated, through dedicated studies of the power patterns in Stokes V and I in detail.Results. For C-rich evolved stars, we derive a magnetic field strength (B) between 1.6 and 14.2 mG while B is estimated to be 6 mG for the proto-PN (PPN) AFGL618, and an upper value of 8 mG is found for the PN NGC 7027. These results are consistent with a decrease of B as 1/r in the environment of AGB objects, that is, with the presence of a toroidal field. But this is not the case for PPN and PN stars. Our map of IRC+10216 suggests that the magnetic field is not homogeneously strong throughout or aligned with the envelope and that the morphology of the CN emission might have changed with time.

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Detection of Multiple Bipolar Flows in NGC 7027 With Submillimeter Array

Cited by 9 publications

References 22 publications

The spectra of evolved stars at 20--25\,GHz: tracing circumstellar chemistry during the asymptotic giant branch to planetary nebula transition

The spectra of evolved stars at 20--25\,GHz: tracing circumstellar chemistry during the asymptotic giant branch to planetary nebula transition

A rotating fast bipolar wind and disk system around the B[e]-type star MWC 922

Magnetic field in IRC+10216 and other C-rich evolved stars

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